Technical field

Aspects of the present invention relate to a rotor for an electric rotating machine.

Background

In general, an electric rotating machine comprises a stator and a rotor rotatable about an axis of rotation in relation to the stator. In general, at least one of the rotor and stator may be provided with one or more windings, one or more permanent magnets, or one or more other elements interacting with the stator or rotor. Some electric rotating machines are equipped with a fluid system for cooling one or more of the rotor and stator, since during operation of the electric rotating machine one or more of the rotor and stator may be heated to such a degree that cooling is advisable. The fluid system may guide an oil, or any other fluid, in one or more channels or compartments to cool one or more of the rotor and stator.

Summary

The inventors of the present invention have found drawbacks in conventional electric rotating machines. For example, some conventional electric rotating machines are too bulky and take up too much space. A bulky electric rotating machine is problematic when there is limited space for installations and equipment, which may be the case for vehicles. For example, some conventional electric rotating machines equipped with conventional fluid cooling systems are too bulky.

An object of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

The above and further objects are solved by the subject matter of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

According to a first aspect of the invention, the above mentioned and other objects are achieved with a rotor for an electric rotating machine, wherein the rotor is configured to rotate in relation to a stator of the electric rotating machine, wherein the rotor comprises a rotor shaft configured to rotate together with the rotor about an axis or rotation in relation to the stator of the electric rotating machine, wherein the rotor shaft comprises a first end portion and a second end portion, wherein the rotor shaft has a longitudinal extension extending from the first end portion to the second end portion, wherein the longitudinal extension of the rotor shaft extends in a longitudinal direction in parallel to the axis of rotation, wherein the first end portion has an outer surface and forms an annular recess at the outer surface of the first end portion, wherein the annular recess of the first end portion surrounds the axis of rotation, and wherein the annular recess of the first end portion is configured to receive and accommodate at least a portion of one or more members of the electric rotating machine.

An advantage of the rotor according to the first aspect is that an improved electric rotating machine is provided. An advantage of the rotor according to the first aspect is that a less bulky, or a more compact, electric rotating machine in relation to conventional solutions is provided. A less bulky, or a more compact, electric rotating machine is provided by the rotor according to the first aspect since at least a portion of one or more members of the electric rotating machine is accommodated in the annular recess instead of having the member located axially outside the outer ends of the longitudinal extension of the rotor. It is to be understood that by “axially outside” is meant a position outside an outer end of the longitudinal extension of the rotor in a longitudinal direction in parallel to, or in line with, the axis of rotation. An advantage of the rotor according to the first aspect is that the longitudinal extension of the electric rotating machine in a longitudinal direction in parallel to the axis of rotation of the rotor is reduced in relation to conventional solutions.

For some embodiments, the axis of rotation of the rotor shaft may be described to extend through the first and second end portions of the rotor shaft. For some embodiments, the rotor shaft may be rotatable in relation to the one or more members of the electric rotating machine. For some embodiments, the annular recess of the first end portion may be configured to receive and accommodate the one or more members of the electric rotating machine. For some embodiments, the member of the electric rotating machine may comprise a bearing, a spline, a grounding ring, a retaining ring, a spring, a position sensor, a position sensor wheel, or any other device of the electric rotating machine. For some embodiments, it may be defined that the rotor shaft is configured to be supported by one or more bearings.

According to an advantageous embodiment of the rotor according to the first aspect, the rotor shaft is configured to be supported by one or more bearings, and wherein the annular recess of the first end portion is configured to receive and accommodate at least a portion of at least one of the one or more bearings. An advantage of this embodiment is that an improved electric rotating machine is provided. An advantage of this embodiment is that a less bulky, or a more compact, electric rotating machine in relation to conventional solutions is provided. A less bulky, or a more compact, electric rotating machine is provided by the rotor according to the first aspect since at least a portion of at least one of the one or more bearings is accommodated in the annular recess instead of having every bearing located axially outside the outer ends of the longitudinal extension of the rotor. It is to be understood that by “axially outside” is meant a position outside an outer end of the longitudinal extension of the rotor in a longitudinal direction in parallel to, or in line with, the axis of rotation. An advantage of this embodiment is that the longitudinal extension of the electric rotating machine in a longitudinal direction in parallel to the axis of rotation of the rotor is reduced in relation to conventional solutions.

According to an advantageous embodiment of the rotor according to the first aspect, the rotor shaft is configured to be supported by one or more bearings, wherein the annular recess of the first end portion is configured to receive and accommodate at least one of the one or more bearings. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that the bulkiness of the electric rotating machine is further reduced. An advantage of this embodiment is that an even more compact electric rotating machine is provided.

According to a further advantageous embodiment of the rotor according to the first aspect, the second end portion has an outer surface and forms an annular recess at the outer surface of the second end portion, wherein the annular recess of the second end portion surrounds the axis of rotation, and wherein the annular recess of the second end portion is configured to receive and accommodate at least a portion of one or more members of the electric rotating machine.

An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that the bulkiness of the electric rotating machine is further reduced. An advantage of this embodiment is that an even more compact electric rotating machine is provided.

According to an advantageous embodiment of the rotor according to the first aspect, the rotor shaft is configured to be supported by one or more bearings, wherein the annular recess of the second end portion is configured to receive and accommodate at least a portion of at least one of the one or more bearings. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that the bulkiness of the electric rotating machine is further reduced. An advantage of this embodiment is that an even more compact electric rotating machine is provided.

According to another advantageous embodiment of the rotor according to the first aspect, the rotor shaft is configured to be supported by one or more bearings, wherein the annular recess of the second end portion is configured to receive and accommodate at least one of the one or more bearings. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that the bulkiness of the electric rotating machine is further reduced. An advantage of this embodiment is that an even more compact electric rotating machine is provided. According to yet another advantageous embodiment of the rotor according to the first aspect, the rotor shaft is configured to be supported by one or more bearings, wherein the annular recess is configured to receive and accommodate at least a portion of an annular bearing of the one or more bearings. An advantage of this embodiment is that a further improved electric rotating machine is provided, since the annular recess is configured, or formed, for an annular bearing.

According to still another advantageous embodiment of the rotor according to the first aspect, the rotor shaft is configured to be supported by one or more bearings, wherein the annular recess is configured to receive and accommodate an annular bearing of the one or more bearings. An advantage of this embodiment is that a further improved electric rotating machine is provided, since the annular recess is configured, or formed, for an annular bearing.

According to an advantageous embodiment of the rotor according to the first aspect, the annular recess opens in the longitudinal direction. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that the bulkiness of the electric rotating machine is further reduced. An advantage of this embodiment is that an even more compact electric rotating machine is provided. For some embodiments, the annular recess may open in a direction transverse to the longitudinal direction or transverse to the axis of rotation.

According to a further advantageous embodiment of the rotor according to the first aspect, the rotor shaft forms an internal compartment for guiding a cooling fluid. An advantage of this embodiment is that a further improved electric rotating machine is provided. For some embodiments, the cooling fluid may comprise or consist of one or more of the group of: a liquid; a gas; and a gas mixture. The liquid may comprise or consist of an oil or an oil mixture.

According to another advantageous embodiment of the rotor according to the first aspect, the internal compartment extends from the first end portion of the rotor shaft to the second end portion of the rotor shaft. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that an improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided.

According to an advantageous embodiment of the rotor according to the first aspect, the rotor shaft forms the internal compartment in the form of an annular gap surrounding the axis of rotation. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that a further improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided. This embodiment is especially advantageous for an annular gap with a large radius, which results in a large diameter of the rotor shaft, since then there is plenty of room for a bearing with a large diameter in the annular recess between the axis of rotation and windings or permanent magnets of the rotor mounted to the rotor shaft.

According to yet another advantageous embodiment of the rotor according to the first aspect, the rotor shaft comprises a shell and an inner section, wherein the shell houses the inner section, wherein the shell and the inner section are configured to rotate together with the rotor shaft, and wherein the internal compartment is formed between the inner section and the shell.

An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that a further improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided.

According to still another advantageous embodiment of the rotor according to the first aspect, the internal compartment is limited by an inner side of the rotor shaft, wherein the inner side of the rotor shaft faces the internal compartment, wherein the inner side of the rotor shaft has a longitudinal extension extending from the first end portion of the rotor shaft to the second end portion of the rotor shaft, and wherein the inner side of the rotor shaft forms one or more helical grooves surrounding the axis of rotation.

An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that a further improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided by way of the one or more helical grooves. By way of the one or more helical grooves, when the rotor shaft rotates, the guidance of the cooling fluid is assisted, promoted or supported, whereby a reduced pump unit, or no pump unit, for driving the cooling fluid through the internal compartment is needed. The reduced pump unit, or the exclusion of the pump unit, results in that the bulkiness of the electric rotating machine is further reduced.

According to an advantageous embodiment of the rotor according to the first aspect, the inner side of the rotor shaft forming the one or more helical grooves faces the the axis of rotation. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that a further improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided. For alternative embodiments, the inner side forming the one or more helical grooves may face away from the axis of rotation.

According to a further advantageous embodiment of the rotor according to the first aspect, the inner side of the rotor shaft forming the one or more helical grooves is an inner side of the shell. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that a further improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided. For alternative embodiments, the inner side of the rotor shaft forming the one or more helical grooves may be an outer side of the inner section.

According to another advantageous embodiment of the rotor according to the first aspect, the inner side of the rotor shaft forms one or more helical grooves along the entire length of the longitudinal extension of the inner side of the rotor shaft.

According to yet another advantageous embodiment of the rotor according to the first aspect, the shell comprises the first and second end portions of the rotor shaft. According to still another advantageous embodiment of the rotor according to the first aspect, the shell comprises a tubular member positioned between the first and second end portions of the rotor shaft. An advantage of this embodiment is that a further improved electric rotating machine is provided.

According to another advantageous embodiment of the rotor according to the first aspect, the internal compartment is connected to a channel connectable to one or more bearings supporting the rotor shaft so as to guide cooling fluid to the bearing, for example in order to lubricate the bearing. Thus, the cooling fluid may act as a lubricant for the bearing. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that an improved lubrication of the bearing is provided.

According to a second aspect of the invention, the above mentioned and other objects are achieved with a rotor for an electric rotating machine, wherein the rotor is configured to rotate in relation to a stator of the electric rotating machine, wherein the rotor comprises a rotor shaft configured to rotate together with the rotor about an axis or rotation in relation to the stator of the electric rotating machine, wherein the rotor shaft comprises a first end portion and a second end portion, wherein the rotor shaft has a longitudinal extension extending from the first end portion to the second end portion, wherein the longitudinal extension of the rotor shaft extends in a longitudinal direction in parallel to the axis of rotation, wherein the rotor shaft forms an internal compartment for guiding a cooling fluid, wherein the internal compartment is limited by an inner side of the rotor shaft, wherein the inner side of the rotor shaft faces the internal compartment, wherein the inner side of the rotor shaft has a longitudinal extension extending from the first end portion of the rotor shaft to the second end portion of the rotor shaft, and wherein the inner side of the rotor shaft forms one or more helical grooves surrounding the axis of rotation for assisting in the guidance of the cooling fluid.

By way of the one or more helical grooves, when the rotor shaft rotates, the guidance of the cooling fluid is assisted, promoted or supported, whereby a reduced pump unit, or no pump unit, for driving the cooling fluid through the internal compartment is required. The reduced pump unit, or the exclusion of the pump unit, results in that the bulkiness of the electric rotating machine is reduced. Thus, an advantage of the rotor according to the second aspect is that a less bulky, or a more compact, electric rotating machine in relation to conventional solutions is provided. An advantage of the rotor according to the second aspect is that an improved electric rotating machine is provided. An advantage of the rotor according to the second aspect is that an improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided by way of the one or more helical grooves.

According to an advantageous embodiment of the rotor according to the second aspect, the inner side of the rotor shaft forming the one or more helical grooves faces the the axis of rotation. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that a further improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided. For alternative embodiments, the inner side forming the one or more helical grooves may face away from the axis of rotation.

According to a further advantageous embodiment of the rotor according to the second aspect, the inner side of the rotor shaft forming the one or more helical grooves is an inner side of the shell. An advantage of this embodiment is that a further improved electric rotating machine is provided. An advantage of this embodiment is that a further improved cooling of one or more of the rotor and a stator of the electric rotating machine is provided. For alternative embodiments, the inner side of the rotor shaft forming the one or more helical grooves may be an outer side of the inner section. According to another advantageous embodiment of the rotor according to the second aspect, the inner side of the rotor shaft forms one or more helical grooves along the entire length of the longitudinal extension of the inner side of the rotor shaft.

According to a third aspect of the invention, the above mentioned and other objects are achieved with an electric rotating machine comprising a stator, and a rotor according to any one of the embodiments disclosed above or below.

Advantages of the electric rotating machine according to the third aspect and its embodiments correspond to the above- or below-mentioned advantages of the rotor according to the first or second aspect and its embodiments.

According to an advantageous embodiment of the electric rotating machine according to the third aspect, the electric rotating machine comprises one or more bearings.

According to an advantageous embodiment of the electric rotating machine according to the third aspect, the electric rotating machine forms, or comprises, a rotor compartment holding the rotor.

According to a fourth aspect of the invention, the above mentioned and other objects are achieved with a vehicle comprising one or more of the group of:

• a rotor according to any one of the embodiments disclosed above or below; and

• an electric rotating machine according to any one of the embodiments disclosed above or below.

Advantages of the vehicle according to the fourth aspect and its embodiments correspond to the above- or below-mentioned advantages of the rotor according to the first or second aspect and its embodiments.

The vehicle may be a wheeled vehicle, i.e. a vehicle having wheels. The vehicle may for example be a bus, a tractor vehicle, a heavy vehicle, a truck, or a car. The tractor vehicle, and/or the truck, may, or may be configured to, haul, or pull, a trailer. However, other types of vehicles are possible. The vehicle may be referred to as a motor vehicle. The vehicle may be an electric vehicle, EV, for example a hybrid vehicle or a hybrid electric vehicle, HEV, or a battery electric vehicle, BEV. Thus, a hybrid electric vehicle, HEV, and a battery electric vehicle, BEV, are versions, or examples, of an electric vehicle, EV. The EV may comprise one or more electric motors or electrical machines. The vehicle may comprise a combustion engine. For some embodiments, the vehicle may include only a combustion engine for the propulsion of the vehicle.

The vehicle may comprise a powertrain. The powertrain may be configured in accordance with any one of the embodiments disclosed above or below. The powertrain of the vehicle may comprise one or more of the group of: a combustion engine; an electric battery cell unit; an electric battery arrangement; and an electric battery pack.

The above-mentioned features and embodiments of the rotor, the electric rotating machine and the vehicle, respectively, may be combined in various possible ways providing further advantageous embodiments.

Further advantageous embodiments of the rotor, the electric rotating machine and the vehicle according to the present invention and further advantages with the embodiments of the present invention emerge from the detailed description of embodiments.

Brief Description of the Drawings

Embodiments of the invention will now be illustrated, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, where similar references are used for similar parts, in which:

Figure 1 is a schematic side view of an embodiment of the rotor according to the first aspect of the invention;

Figure 2 is a schematic front view of the rotor of figure 1 ;

Figure 3 is a schematic rear view of the rotor of figure 1 ; Figure 4 schematically illustrates a cross-section of the rotor of figures 1 -3 along A- A in figure 2;

Figure 5 is a schematic perspective view of the cross-section of figure 4;

Figure 6 is a schematic front perspective view of an embodiment of the rotor according to the first aspect of the invention provided with an annular outer section having permanent magnets and bearings in the annular recesses;

Figure 7 is a schematic rear perspective view of the rotor of figure 6;

Figure 8 schematically illustrates a cross-section of the rotor of figures 6 and 7 along B-B in figure 6;

Figure 9 is a schematic perspective view of the cross-section of figure 8;

Figure 10 schematically illustrates the guidance of cooling fluid in the rotor of figure 8;

Figures 11 -12 schematically illustrate cross-sections of an embodiment of the rotor according to the second aspect of the invention;

Figure 13 is a schematic perspective view of an embodiment of the annular outer section having permanent magnets of the rotor of figure 6;

Figure 14 illustrates a cross-section of an embodiment of the electric rotating machine according to the third aspect of the invention;

Figure 15 is a schematic diagram illustrating an embodiment of a fluid cooling system for cooling one or more of the rotor and stator of an embodiment of the electric rotating machine according to the third aspect of the invention; and Figure 16 is a schematic side view of an embodiment of the vehicle according to the fourth aspect.

Detailed Description

With reference to figures 1 to 5, an embodiment of the rotor 100 for an electric rotating machine 400 (see figure 14) according to the first aspect of the invention is schematically illustrated. The rotor 100 is configured to rotate in relation to a stator 404 of the electric rotating machine 400 (see figure 14). The rotor 100 includes a rotor shaft 102 configured to rotate together with the rotor 100 about an axis or rotation 104 in relation to the stator 404 of the electric rotating machine 400. For some embodiments, it may be defined that the rotor shaft 102 is configured to be supported, or suspended, by one or more bearings 406 (see figures 8 and 14), more specially one or more bearings 406 of the electric rotating machine 400, for example two or more bearings 406. For some embodiments, the rotor shaft 102 may be configured to be supported, or suspended, by one bearing 406 only. For some embodiments, the rotor shaft 102 may be described to be configured to be rotatably mounted to the one or more bearings 406. The bearing 406 may be referred to as a rotary bearing.

With reference to figures 1 to 5, the rotor shaft 102 includes a first end portion 106 and a second end portion 108. The rotor shaft 102 has a longitudinal extension 1 10 extending from the first end portion 106 to the second end portion 108. The longitudinal extension 1 10 of the rotor shaft 102 extends in a longitudinal direction 1 12 in parallel to, or in line with, the axis of rotation 104. In this context, “in parallel” is to be understood as substantially in parallel. Thus, there may be deviations from strictly parallel. The first end portion 106 has an outer surface 1 14 and forms an annular recess 1 16, or an annular depression or indentation, at the outer surface 1 14 of the first end portion 106. The annular recess 1 16 of the first end portion 106 surrounds the axis of rotation 104. The annular recess 1 16 of the first end portion 106 is configured to receive and accommodate at least a portion of one or more members 405 of the electric rotating machine 400. For some embodiments, the member 405 of the electric rotating machine 400 may comprise a bearing 406, a spline, a grounding ring, a retaining ring, a spring, a position sensor, a position sensor wheel, or any other device of the electric rotating machine 400. For some embodiments, the rotor shaft 102 may be rotatable in relation to the one or more members 405 of the electric rotating machine 400. For some embodiments, the annular recess 1 16 of the first end portion 106 may be configured to receive and accommodate the one or more members 405 of the electric rotating machine 400.

With reference to figures 1 to 5, for some embodiments, the annular recess 1 16 of the first end portion 106 may be configured to receive and accommodate at least a portion of at least one 406 of the one or more bearings 406. Expressed alternatively, the rotor shaft 102 may be configured to receive and accommodate at least a portion of at least one 406 of the one or more bearings 406 in the annular recess 116 of the first end portion 106. With reference to figures 1 to 5, for some embodiments, the first end portion 106 may be referred to as a first axial end portion, and the second end portion 108 may be referred to as a second axial end portion. For some embodiments, the rotor shaft 102 may be described to have a transverse extension 1 17 extending in a direction 1 19 transverse to the the axis of rotation 104, for example from a first point 121 at the periphery 123 of the rotor shaft 102 to a second point 125 at the periphery 123 of the rotor shaft 102, the second point 125 being opposite the first point 121. For some embodiments, it may be defined that the axis of rotation 104 extends through the first and second end portions 106, 108.

With reference to figures 1 to 5, for some embodiments, the annular recess 1 16 of the first end portion 106 may be configured to receive and accommodate at least one 406 of the one or more bearings 406 (see also figure 8). For some embodiments, the second end portion 108 has an outer surface 1 18 and may form an annular recess 120 at the outer surface 1 18 of the second end portion 108. The annular recess 120 of the second end portion 108 surrounds the axis of rotation 104. The annular recess 120 of the second end portion 108 is configured to receive and accommodate at least a portion of one or more members 405 of the electric rotating machine 400. For some embodiments, the annular recess 120 of the second end portion 108 may be configured to receive and accommodate the one or more members 405 of the electric rotating machine 400. For some embodiments, the annular recess 120 of the second end portion 108 may be configured to receive and accommodate at least a portion of at least one 406 of the one or more bearings 406 (see also figure 8). For some embodiments, the annular recess 120 of the second end portion 108 may be configured to receive and accommodate at least one 406 of the one or more bearings 406.

With reference to figures 1 to 5, for some embodiments it may be defined that the annular recess 1 16, 120 opens in the longitudinal direction 1 12. For some embodiments, it may be defined that the annular recess 1 16, 120 is circular, forms a circle, or has the shape of a circle. With reference to figures 1 to 5, for some embodiments, the rotor shaft 102 may form, or may comprise, an internal compartment 122 for guiding a cooling fluid, for example for cooling one or more of the rotor 100 and the stator 404 of the electric rotating machine 400. The internal compartment 122 may extend from the first end portion 106 of the rotor shaft 102 to the second end portion 108 of the rotor shaft 102. For some embodiments, the rotor shaft 102 forms the internal compartment 122 in the form of an annular gap 124 surrounding the axis of rotation 104, i.e. the internal compartment 122 may comprise, or may be formed as, an annular gap 124. For some embodiments, the cooling fluid may comprise or consist of one or more of the group of: a liquid; a gas; and a gas mixture. The liquid may comprise or consist of an oil or an oil mixture.

With reference to figures 1 to 5, for some embodiments, the rotor shaft 102 includes a shell 126 and an inner section 128. The shell 126 may be described as an outer shell. The inner section 128 may be cylindrical or tubular and/or may have a cylindrical surface. For some embodiments, the inner section 128 may be described as an inner element, member, structure or insert. The shell 126 houses the inner section 128. The shell 126 and the inner section 128 are configured to rotate together with the rotor shaft 102. The internal compartment 122 may be formed between the inner section 128 and the shell 126. For some embodiments, the inner section 128 may have an outer surface 130, and the shell 126 may have an inner surface 132, wherein the internal compartment 122 may be formed between the outer surface 130 of the inner section 128 and the inner surface 132 of the shell 126. The inner surface 132 of the shell 126 may be described to face the axis of rotation 104. The outer surface 130 of the inner section 128 may be described to face away from the axis of rotation 104.

With reference to figures 1 to 5, for some embodiments, the shell 126 may comprise the first and second end portions 106, 108 of the rotor shaft 102. For some embodiments, the shell 126 may comprise a tubular member 134 positioned between the first and second end portions 106, 108 of the rotor shaft 102. For some embodiments, the tubular member 134, the first and second end portions 106, 108 and the inner section 128 may be separate parts, which, when assembled together, form the rotor shaft 102, or a major part of the rotor shaft 102. For some embodiments, one or more of the tubular member 134, first and second end portions 106, 108 and inner section 128 may be made of a material comprising or consisting of a metal or a metal alloy, such as aluminium, or any other metal or metal alloy. For some embodiments, one or more of the tubular member 134, first and second end portions 106, 108 and inner section 128 may be made of a material comprising or consisting of a polymer or a polymer composite, such as plastic or a fibre-reinforces polymer, or any other polymer or polymer composite. However, it is to be understood that other materials are possible.

With reference to figures 6 to 9, another embodiment of the rotor 200 for an electric rotating machine 400 (see figure 14) according to the first aspect of the invention is schematically illustrated. Several features of the embodiment of the rotor 200 of figures 6 to 9 may correspond to features of the embodiment of the rotor 100 of figures 1 to 5 and are thus not repeated here to avoid repetition. In figures 6 to 9, in addition to the rotor shaft 102, the rotor 200 includes an annular outer section 250 having one or more permanent magnets. Further, the embodiment of the annular outer section 250 is also schematically illustrated in isolation in figure 13. The annular outer section 250 may be mounted to the rotor shaft 102, for example by way of one or more of the group of: a thread attachment; a friction attachment; a positive locking attachment; and a bayonet attachment. In the illustrated embodiment, the rotor shaft 102, the shell 126 or an outer surface 252 of the shell 126 forms a plurality of longitudinal grooves 254 (see also figure 1 ) configured for engagement with a plurality of longitudinal protrusions of an inner side 256 of the annular outer section 250. However, other attachments are possible, such as welding. For alternative embodiments, instead of permanent magnets, the annular outer section 250, and/or the rotor 200, may include one or more windings, or one or more other elements interacting with the stator 404. As schematically illustrated in figures 6 to 9, the annular recess 1 16 of the first end portion 106 accommodates one 406 of the one or more bearings 406, and the annular recess 120 of the second end portion 108 accommodates at least a portion of one 406 of the one or more bearings 406.

As schematically illustrated in figures 6 to 9, the annular recess 1 16, 120 may be configured to receive and accommodate at least a portion of an annular bearing 407 of the one or more bearings 406. For some embodiments, the annular recess 1 16, 120 may be configured to receive and accommodate an annular bearing 407 of the one or more bearings 406. For some embodiments, the bearing 406 may comprise a ball bearing, or a rolling bearing.

With reference to figure 8, for some embodiments, the internal compartment 122 may be connected, or connectable, to a channel 409, or a conduit, connectable, or connected, to one or more bearings 406 supporting the rotor shaft 102 so as to guide cooling fluid to the bearing 406 in order to lubricate the bearing 406. Thus, the cooling fluid may act as a lubricant for the bearing 406. The channel 409 may be configured to guide only a portion of the cooling fluid guided through the internal compartment 122. For some embodiments, the channel 409 may be formed by the rotor 200. More specifically, the channel 409 may be formed by the rotor shaft 102, and/or by one of the first and second end portions 106, 108 of the rotor shaft 102. For some embodiments, it may be defined that the internal compartment 122 is fluidly connected to the channel 409. For some embodiments, it may be defined that the channel 409 is fluidly connectable to one or more bearings 406.

Figure 10 schematically illustrates the guidance of cooling fluid in the rotor 200 of figure 8 by way of arrows.

With reference to figures 1 1 and 12, an embodiment of the rotor 300 for an electric rotating machine 400 (see figure 14) according to the second aspect of the invention is schematically illustrated. The rotor 300 is configured to rotate in relation to a stator 404 of the electric rotating machine 400. The rotor 300 includes a rotor shaft 102 configured to rotate together with the rotor 300 about an axis or rotation 104 in relation to the stator 404 of the electric rotating machine 400. The rotor shaft 102 has a first end portion 106 and a second end portion 108. The rotor shaft 102 has a longitudinal extension 1 10 extending from the first end portion 106 to the second end portion 108. The longitudinal extension 1 10 of the rotor shaft 102 extends in a longitudinal direction 1 12 in parallel to the axis of rotation 104. The rotor shaft 102 forms an internal compartment 122 for guiding a cooling fluid. The internal compartment 122 is limited, restricted, or defined, by an inner side 136 of the rotor shaft 102. The inner side 136 of the rotor shaft 102 faces the internal compartment 122. The inner side 136 of the rotor shaft 122 has a longitudinal extension 138 extending from the first end portion 106 of the rotor shaft 102 to the second end portion 108 of the rotor shaft 102. The inner side 136 of the rotor shaft 102 forms one or more helical grooves 140, or channels, surrounding the axis of rotation 104 for assisting in, or for promoting or supporting, the guidance of the cooling fluid, more specifically when the rotor 300 rotates about the axis or rotation 104. For some embodiments, the rotor shaft 102 may include one or more internal walls 142, or ribs, separating the one or more helical grooves 140 in the longitudinal direction 1 12.

With reference to figures 1 1 and 12, for some embodiments, the inner side 136 of the rotor shaft 102 forming the one or more helical grooves 140 may face the the axis of rotation 104. For some embodiments, the inner side 136 of the rotor shaft 102 forming the one or more helical grooves 140 may be an inner side 132, or an inner surface 132, of the shell 126 of the rotor shaft 102. For some embodiments, the inner side 136 of the rotor shaft 102 may form one or more helical grooves 140 along the entire length, or longitudinal stretch, of the longitudinal extension 138 of the inner side 136 of the rotor shaft 102.

Features from the different embodiments illustrated above or below may be combined to form further embodiments. For example, one or more of the rotors 100, 200 of figures

I to 9 may be provided with the one or more helical grooves of the rotor 300 of figures

I I and 12.

Figure 14 illustrates a cross-section of an embodiment of the electric rotating machine 400 according to the third aspect of the invention. The electric rotating machine 400 includes a stator 404 and a rotor 100, 200, 300 according to any one of the embodiments disclosed above or below. For some embodiments, it may be defined that the electric rotating machine 400 includes one or more bearings 406, for example two or more bearings 406. For some embodiments, the electric rotating machine 400 may include only one bearing 406. The electric rotating machine 400 may act, or function, as an electric motor 402, for example for propelling a vehicle 500 (for example, see figure 16), such as an EV, and/or as an electric generator 402, for example, for charging one or more electric battery arrangements and/or one or more electric battery packs.

With reference to figure 14, the stator 404 may include one or more stator windings 408, or one or more other elements interacting with the rotor 200. The one or more stator windings 408 may include one or more end windings. The stator 404 may be annular. The stator 404 may surround the rotor 200. It may be defined that the stator 404 is spaced from the rotor 200 to form a gap 410 between the stator 404 and the rotor 200, such as an annular gap 410. The rotor 200 may include one or more permanent magnets. Thus, the electric rotating machine 400 may be a permanent magnet, PM, machine. However, for alternative embodiments, the electric rotating machine 400 be configured for and operate according to other electrical operation schemes for electric rotating machines. For example, for alternative embodiments, the rotor 200 may include one or more rotor windings, or one or more other elements interacting with the stator 404. Various conventional electrical operation schemes for conventional electric rotating machines are known to the skilled person and are thus not discussed herein in further detail.

With reference to figure 14, the electric rotating machine 400 may include a rotor compartment 412 holding the rotor 200. It may be defined that the rotor 200 is located in the rotor compartment 412, and/or that the rotor compartment 412 houses the rotor 200. The electric rotating machine 400 may include a housing 414 which houses the stator 404 and the rotor 200. The housing 414 may define, or form, the rotor compartment 412. For some embodiments, the electric rotating machine 400 may include two gable units 416, 418 immovable in relation to the stator 404. The two gable units 416, 418 may be part of the housing 414. For some embodiments, the gable unit 416, 418 may be referred to as an end unit. The rotor 200 may be located between the two gable units 416, 418. It may be defined that the axis of rotation 104 extends through the gable units 416, 418. For example, the rotor 200 may be connected, or attached, to the gable units 416, 418, for example via the one or more bearings 406.

With reference to figure 15, the electric rotating machine 400 may include a fluid cooling system 420 for cooling one or more of the rotor 200 and stator 404. As mentioned above, the cooling fluid of the fluid cooling system 420 may comprise or consist of one or more of the group of: a liquid; a gas; and a gas mixture. The liquid may comprise or consist of an oil or an oil mixture. Thus, a cooling fluid of the fluid cooling system 420 may be an oil or an oil mixture.

With reference to figures 8 and 15, the fluid cooling system 420 may include one or more internal compartments 122 and/or one or more channels (not illustrated) for guiding a cooling fluid, for example to and from the stator 404 and/or the rotor 200. The housing 414 may include, or form, the one or more channels (not illustrated). With reference to figure 14, the fluid cooling system 420 may include an inlet 422 for the inlet of cooling fluid and an outlet 424 for the outlet of cooling fluid. The inlet 422 and the outlet 424 may be an inlet 422 and outlet 424 of the rotor 200 and/or of the housing 414. The inlet 422 may be an inlet 422 for the inlet of cooling fluid to the one or more internal compartments 122 and/or channels. The outlet 424 may be an outlet 424 for the outlet of cooling fluid from the one or more internal compartments 122 and/or channels.

With reference to figure 15, the fluid cooling system 420 may include one or more conduits 426, or lines, for guiding a cooling fluid, for example to or from the one or more internal compartments 122 and/or channels of the housing 414. The fluid cooling system 420 may include a fluid collector and provider 428, for example a fluid collecting tray or vessel, or a fluid sump. For some embodiments, the fluid collector and provider 428 may be fluidly connected to the one or more internal compartments 122 and/or channels via a heat exchanger 430.

With reference to figure 16, an embodiment of the vehicle 500 according to the third aspect of the invention is schematically illustrated. The vehicle 500 includes one or more of the group of: a rotor 100, 200, 300 according to any one of the embodiments disclosed above or below; and an electric rotating machine 400 according to any one of the embodiments disclosed above or below. The one or more electric rotating machines 400 may comprise one or more electric motors 402 and/or one or more electric generators 402. For example, the one or more electric motors 402 may be configured for propelling the vehicle 500. For example, one or more electric generators 402 may be configured for charging one or more electrical battery arrangements 506 and/or one or more electric battery packs 510 of the vehicle 500.

With reference to figure 16, the vehicle 500 is illustrated as a tractor vehicle. However, in other embodiments, the vehicle 500 may, for example, be a bus, a truck, a heavy truck or a car. Other types of vehicles are also possible. The vehicle 500 may be an electric vehicle, EV, for example a hybrid vehicle or a hybrid electric vehicle, HEV, or a battery electric vehicle, BEV.

With reference to figure 16, the vehicle 500 may be a wheeled vehicle, i.e. a vehicle 500 having wheels 502. Only the wheels 502 on the left-hand side of the vehicle 500 are visible in figure 16. It is to be understood that the vehicle 500 may have fewer or more wheels than what is shown in figure 16. The vehicle 500 may comprise a powertrain 504, for example configured for one of an EV, HEV and BEV. The vehicle 500 may be configured to hold or carry, or may include, one or more electrical battery arrangements 506 including two or more electric battery cells 508. The vehicle 500 may be configured to hold or carry, or may include, one or more electric battery packs 510 including two or more electric battery cells 508 and/or including two or more electrical battery arrangements 506, which may be referred to as modules. The electrical battery arrangement 506 and/or the electric battery pack 510 may, for example, be attachable to a chassis 512 of the vehicle 500. It is to be understood that the vehicle 500 may include further unites, components, such as electrical and/or mechanical components, a combustion engine 514 and other devices required for a vehicle 500, such as for an EV, HEV or BEV.

With reference to figure 16, it may be defined that the powertrain 504 and/or the one or more electric rotating machines 400 is/are configured to propel, or drive, the vehicle 500. It may be defined that the powertrain 504 includes the electrical battery arrangement 506 and/or the electric battery pack 510. The one or more electric rotating machines 400 may be located at locations different from what is illustrated in figure 16, for example in connection with the combustion engine 514, for example acting as an electric generator. With reference to figure 16, the vehicle 500 may include a vehicle electrical system 516. It may be defined that the vehicle electrical system 516 is configured for direct current. It may be defined that vehicle electrical system 516 is a vehicle high voltage system 516. It may be defined that the vehicle high voltage system 516 is configured for a high voltage, such as a voltage above 60 V, for example above 400 V, or above 450 V, such as above 650 V. For example, the vehicle high voltage system 516 may be configured for a voltage up to 1500 V and/or for a voltage above 1500 V. The electric power, or the electric current, for example the direct current, of the vehicle electrical system 516 may be transferred at a high voltage, for example at one or more of the voltages levels mentioned above. The vehicle electrical system 516 may be configured to transfer the electric power, or the electric current, at a high voltage, for example at one or more of the voltages levels mentioned above. The vehicle electrical system 516 may be configured to transfer direct current.

With reference to Figure 16, the vehicle electrical system 516 may be electrically connected, or connectable, to one or more electrical battery arrangements 506 and/or one or more electric battery packs 510. It may be defined that the electrical battery arrangement 506 and/or the electric battery pack 510 is/are configured for high voltage, for example for one or more of the voltages levels mentioned above. The vehicle electrical system 516 may be configured to electrically connect the electrical battery arrangement 506 and/or the electric battery pack 510 to the powertrain 504 of the vehicle 500. The vehicle electrical system 516 may be configured to electrically connect the electrical battery arrangement 506 and/or the electric battery pack 510 to the one or more electric rotating machines 400 of the vehicle 500. It may be defined that the vehicle electrical system 516 is configured to transfer the electric power, or the electric current, for example between the one or more electric rotating machines 400 (and/or the powertrain 504) and the electrical battery arrangement 506 and/or the electric battery pack 510.

It is to be understood that embodiments of the rotor 100, 200, 300 and the electric rotating machine 400 may be applied to configurations, structures, or apparatuses different from a vehicle 500. The present invention is not limited to the above-described embodiments. Instead, the present invention relates to, and encompasses all different embodiments being included within the scope of the independent claims.