OUTBOARD DRIVE DEVICE

TECHNICAL FIELD

The present invention relates to a mounting device for mounting an endless belt in an outboard drive device. The present invention is also related to a method for mounting such a belt in an outboard drive device. This type of belts is used for transferring power to a propeller shaft in an outboard drive device, such as an outboard motor. Outboard motors are self-contained propulsion and steering devices for watercrafts, such as boats, and are arranged to be fastened to the transom of such a watercraft. One type of such watercrafts is boats that are designed to plane during operation, wherein the propeller shaft is arranged below a hull of the watercraft during operation. Outboard motors comprises a power head with a motor, such as a combustion engine or an electric motor, a midsection and a lower unit, wherein the propeller shaft is arranged in a propeller shaft housing of the lower unit.

BACKGROUND

In outboard drive devices, such as outboard motors, numerous systems for transferring power from the motor to the propeller are known. The most common systems for transferring power from the motor to the propeller are belt drives or gear drives. A gear drive comprises gears and vertical shafts and a belt drive comprises a belt arranged on pulleys, the pulleys are in turn arranged on shafts so that power is transmitted from one shaft to another shaft. For example, the belt connects the crankshaft of the motor and the propeller shaft. Alternatively, the belt connects an intermediate shaft, such as a transmission output shaft, and the propeller shaft. Belt drives present several advantages for an outboard drive device, namely that simple and reliable power transmission is assured over long distances requiring few parts. This results in an outboard drive device with simplified maintenance.

Even though a drive belt of an outboard motor can be mounted relatively easy there is a need for a device and a method for mounting the belt in the outboard drive device in a more efficient and reliable manner. SUMMARY

An object of the present invention is to provide a mounting device and a method for mounting an endless loop flexible drive belt in an outboard drive device in a secure and efficient manner.

The present invention is related to a mounting device for mounting an endless loop flexible drive belt in a propeller shaft housing of an outboard drive device. The mounting device comprises:

- an elongated extendable body assembly for tensioning the belt. The extendable body assembly has a longitudinal axis and is axially extendable, a first end and a second end. The first end comprises a first support structure and the second end comprises a second support structure for supporting the belt during tensioning thereof, and

- at least one resilient spring element arranged on the first support structure of the extendable body assembly. The spring element projects from the first support structure of the extendable body assembly and is configured to deform gradually under increased load to provide support for the belt when the belt is tensioned by extending the extendable body assembly.

When the belt is mounted in the propeller housing it is inserted into a top opening of the propeller housing. The top opening connects to a propeller shaft cavity of the propeller housing. The top opening can be relatively narrow. A portion of the belt is inserted into the top opening to be connected to a propeller shaft and the remaining portion of the belts projects from the propeller housing to be connected to another shaft of the outboard drive device, such as a transmission output shaft, a crankshaft or another drive shaft thereof. An advantage of providing the mounting device for mounting the belt is that the belt can be inserted through the top opening of the propeller housing in an efficient and secure manner to be mounted in the outboard drive device. Mounting by means of the mounting device also results in a more reliable outboard drive device.

For example, the belt to be mounted comprises fibers for reinforcement, such as carbon fibers, glass fibers or similar types of fibers. For example, the fibers are arranged in the longitudinal direction of the belt, such as in loops inside the belt. For example, the belt is made of rubber or similar flexible material comprising such reinforcement fibers therein. The fibers provide additional strength to the belt. However, the belt is sometimes damaged. It has surprisingly been found that this may be due to damage to the fibers of the belt during mounting of the belt in the propeller housing and it is believed that the reason is that the belt may be overloaded, particularly during insertion through the top opening of the propeller housing, wherein the fibers of the belt can be damaged. The mounting device of the present invention results in that the belt can be mounted and also dismounted without being damaged. The mounting device results in that the belt will not be overloaded damaged when mounting the belt in the propeller shaft housing of the outboard drive device. Moreover, the mounting device provides a user-friendly tool, that enable the user to stretch the belt in a controlled manner.

By providing the belt around the mounting device and progressively extending the elongated extendable body assembly, so that the belt is arranged on and supported by the first support structure and the second support structure, a realtively uniform and gradual extension of the endless loop flexible belt is believed to be provided.

According to an embodiment, the spring element of the mounting device, at least in an unbiased position, projects from the first support structure at least partially in opposite radial directions. The spring element can be arced or substantially straight before load is provided, wherein the spring element is gradually bent toward the elongated extendable body assembly with increased load. Hence, in a biased position, opposite ends of the spring element can extend substantially in the axial direction.

According to an embodiment, the spring element of the mounting device is releasably connected to the first support structure. Hence, the spring element can be removed from the first support structure and removed through the propeller shaft cavity after the belt has been inserted into the propeller shaft cavity through the top opening of the propeller shaft housing.

According to an embodiment, the spring element of the mounting device comprises one or more resiliently flexible plates having a spring function. The resiliently flexible plates are also called spring plates herein. Spring plates provide gradual support for the belt during tensioning thereof in an efficient manner. For example, the spring plates are made of sheet metal, resiliently flexible plastic materials or similar, wherein the spring plates have inherent resilient flexible properties when bent around an axis running along a plane of the spring plates.

According to an embodiment, the mounting device comprises a plurality of spring plates, superimposed onto one another and fixedly attached to the first support structure of the extendable body assembly. A plurality of spring plates give a favourable support for the belt during tensioning.

According to an embodiment, each of the spring plates has a different size. The spring plates are superimposed by increasing order of size starting from the spring plate arranged closest to the support structure, thereby providing additional support for the belt when the belt is tensioned by the mounting device. Hence, according to one embodiment, the spring element is a laminated spring or a leaf spring, wherein each spring plate is a leaf of the leaf spring.

According to an embodiment, the second support structure of the mounting device is releasably connected to the second end of the extendable body. The second support structure being removable results in further facilitated removal of the mounting device after insertion of the belt into the top opening of the propeller shaft housing.

According to an embodiment, the second support structure of the mounting device has an arced and toothed outer surface for meshing with corresponding teeth of the belt. The arced and toothed surface meshes with a toothed belt and gives proper support during tensioning of the belt. According to an embodiment, the second support structure of the mounting device is a cylindrical body.

According to an embodiment, the extendable body assembly of the mounting device is extendable by means of a mechanical, hydraulic, pneumatic or electric power device. For example, the extendable body assembly is extendable by means of a hydraulic jack arrangement. Hence, the appropriate load can be applied on the belt in an easy an efficient manner.

According to an embodiment, the extendable body assembly of the mounting device is dismountable into a first elongated part and a second elongated part to further facilitate removal of the mounting device after insertion of a portion of the belt into the top opening of the propeller shaft housing. Hence, the first elongated part and the second elongated part of the extendable body assembly are releasably connectable to each other. For example, the first elongated part is configured to receive the second elongated part.

According to an embodiment, the first support structure has an arced outer surface supporting the one or more spring elements. The arced outer surface can thus be adapted to provide the proper support and shape for the tensioned belt to be inserted into the top opening of the propeller shaft housing.

The present invention is also related to a method for mounting an endless loop flexible drive belt in a propeller shaft housing of an outboard drive device. The method comprises the steps of: a) arranging the belt around an extendable mounting device comprising an elongated and axially extendable body assembly having a first end and a second end, wherein the first end comprises a first support structure provided with at least one spring element, and the second end comprises a second support structure; b) bringing the first and second support structures of the mounting device to support the belt; c) extending the mounting device gradually inside the belt thereby tensioning the belt and bending it around the spring element while deforming the spring element gradually with increased load, thereby providing support for the belt; d) partially inserting a portion of the mounting device and the tensioned belt into an opening of the propeller shaft housing adapted to receive the belt and connecting to a propeller shaft cavity of the propeller shaft housing; e) releasing the tension on the belt by the mounting device, and f) removing the mounting device from the belt and from the propeller shaft housing.

The method for mounting the belt in the propeller shaft housing results in an efficient mounting and a more reliable outboard drive device.

By providing the belt around the mounting device and progressively extending the elongated extendable body assembly, so that the belt is arranged on and supported by the first support structure and the second support structure, a uniform and gradual stretching and tensioning of the belt is ensured. The belt is prevented from being overloaded on the inner side by the gradually increased tensioning together with the support from the spring element. For example, the pressure applied by the first support structure and the second support structure is uniform over the width of the endless loop flexible belt.

Once tensioned, the belt is inserted through the top opening and arranged in the propeller shaft housing. Then, the mounting device can easily be collapsed and dismounted. The mounting device is then retracted from the propeller shaft housing leaving a portion of the belt in the propeller shaft housing to be connected with the propeller shaft, e.g. through a pulley.

According to an embodiment, the method further comprises the steps of releasing the spring element from the first support structure after step e) and removing the spring element from the propeller shaft housing through the propeller shaft cavity.

According to an embodiment, the method further comprises the steps of applying grease to the outside of the belt prior to step d).

According to an embodiment, the method further comprising the steps of extending the mounting device surrounded by the belt by means of a hydraulic jack arrangement or other arrangement for extending the mounting device.

Further characteristics and advantages of the present invention will become apparent from the description of the embodiments below, the appended drawings and the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with the aid of exemplary embodiments and with reference to the accompanying drawings, in which:

Fig. l is a schematic and partial section view of an outboard drive device in the form of an outboard motor, wherein the propeller shaft housing is illustrated in section and a cowling and midsection cover have been removed;

Fig. 2 is an exploded perspective view of a portion of the outboard drive device of Fig. 1, illustrating the midsection and the propeller shaft housing; Fig. 3 is an exploded perspective view of a portion of the outboard drive device of Figs. 1 and 2, illustrating the propeller shaft housing, the belt and an intermediate support more in detail;

Fig. 4 is an exploded perspective view of a mounting device for mounting the belt in a propeller shaft housing;

Fig. 5 is a schematic view of the mounting device arranged in the belt;

Fig. 6 is a schematic view of the mounting device arranged in the belt, wherein the belt is stretched by the mounting device; and

Fig. 7 is a flow chart illustrating a method of mounting the endless loop flexible belt in the propeller shaft housing of the outboard drive device.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Referring to Figure 1, an outboard drive device 10 in the form of an outboard motor is illustrated. Hence, in the illustrated embodiment the outboard drive device 10 is a self-contained marine propulsion and steering device, which is arranged for attachment to a transom of a marine vessel, such as a boat (not illustrated). Alternatively, the outboard drive device is a sterndrive, which is also called inboard/outboard motor. In the following, the outboard drive device is described as an outboard motor.

The outboard drive device 10 comprises a power head 13, a midsection 14 and a propeller shaft housing 15. The power head 13 is the uppermost arranged unit and the propeller shaft housing 15 is the lowermost arranged unit. The midsection 14 is arranged between the power head 13 and the propeller shaft housing 15. The power head 13 comprises a motor, such as an engine 11. In the illustrated embodiment, the motor is a combustion engine. Alternatively, the motor is an electric motor. The engine or other type of motor comprises a crankshaft 21 for outputing power in the form of rotational power.

The propeller shaft housing 15 is arranged for receiving a propeller shaft 17 and the propeller shaft 17 is arranged to be connected to a propeller 12. The propeller shaft 17 is partially arranged inside the propeller shaft housing 15 and extends out from the propeller shaft housing 15 for connection to the propeller 12. Hence, the propeller 12 is arranged outside the propeller shaft housing 15. The propeller shaft housing 15 may further include a skeg 18 and other conventional parts, such as a torpedo-shaped part for the propeller shaft 17.

The midsection 14 is formed as a leg connecting the power head 13 and the propeller shaft housing 15. For example, the midsection 14 houses a gearbox. The gearbox is optional. A power coupling system transfers rotational power from the crankshaft 21 of the engine 11 to the propeller 12. By way of example, such a power coupling system is described with reference to Figure 1. The power coupling system of Fig. 1 comprises a power transmission device 22, the gearbox and an endless loop flexible drive belt 24, wherein the power transmission device transfers power from the crankshaft to the gearbox and the belt transfer power from the gearbox to the propeller shaft. In the illustrated embodiment with a gearbox, the midsection 14 houses a transmission drive shaft 30, a forward gear 31, reverse gear 32 and an output drive shaft 28 connected to gear 23 selectively cooperating with the forward gear 31 and the reverse gear 32. For example, the power transmission device 22 is a belt, chain, gears or other suitable arrangement for transferring power from the crankshaft to the gearbox.

The belt 24 connects the output drive shaft 28 in the midsection 14 and the propeller shaft 17 and transfers rotational power from the output drive shaft 28 to the propeller shaft 17. The propeller shaft 17 is arranged below the output drive shaft 28 and substantially in parallel thereto, wherein the belt 24 extends perpendicular to the output drive shaft 28 and the propeller shaft 17. Alternatively, the belt 24 is connected directly to the crankshaft or is connected to the crankshaft through another intermediate shaft of the outboard drive device.

Referring to Figure 2, the midsection 14 and a propeller shaft housing 15 of the outboard drive device 10 are shown in an exploded perspective view. Details such as a motor support 40 to support the motor has been included. A lateral support 41 for the fastening the forward gear 31, reverse gear 32 and the pulley 23 to the midsection 14 is also shown. In the illustrated embodiment, an optional intermediate support 42 is included in the midsection 14. The belt 24 has an inside 25 and an outside 26. For example, the belt 24 is a toothed belt, whereby it can engage with a first pulley 27 arranged on the output drive shaft 28 in the midsection 14 and a second pulley (not shown) arranged on the propeller shaft 17. Alternatively, the endless loop flexible belt 24 is provided as a flat belt, v-belt or other type of drive belt. The belt 24 comprises reinforcing fibers, such as carbon fibers, glass fibers or other types of fibers for reinforcement. For example, the fibers extend in the longitudinal direction of the belt, such as in loops along the belt. The belt 24 is made of a flexible material, such as rubber or other type of elastomer, wherein the fibers are embedded in the flexible material. For example, the belt 24 is made of rubber with carbon fibers. The fibers provide additional strength and a reinforcing effect. The belt is dimensioned according to the power to be transferred. For example, the belt 24 is arranged for transferring at least 50 hp, such as at least 100 or 200 hp. For example, the belt 24 is arranged for transferring 300 hp or more. According to one embodiment, the belt 24 has a width of 50-200 mm, such as 100-150 mm or around 130 mm.

The propeller shaft housing 15 comprises a propeller shaft cavity 29 (illustrated in Fig. 1) for receiving the propeller shaft 17. The propeller shaft cavity 29 is connected to a top opening 20 for receiving a portion of the belt 24. The propeller shaft cavity 29 of the propeller shaft housing 15 connects to the top opening 20. The top opening 20 is arranged in a top surface 19a of the propeller shaft housing 15. The propeller shaft cavity 29 connects to an opening (not shown) in a rear surface 19b of the propeller shaft housing 15 through which the propeller shaft can extend. The propeller shaft cavity 29 of the propeller shaft housing 15 is adapted to receive a part of the belt 24 and the propeller shaft 17, wherein the belt 24 is connected to the propeller shaft for driving thereof. The part of the belt 24 that is arranged in the propeller shaft cavity 27 of the propeller shaft housing 15 is arranged around the propeller shaft 17. An opposite part of the belt 24 is arranged around one shaft 28 of the midsection 14. Thus, the belt 24 is partially arranged in the propeller shaft housing 15. The propeller shaft 17 is arranged in the propeller shaft cavity 29 and the belt 24 is arranged around the propeller shaft 17. The propeller shaft 17 partially extends out from the propeller shaft housing 15 to receive the propeller 12. For example, the top opening 20 adapted to receive the belt 24 has a rectangular cross-section comprising a length side 20a and a width side 20b. The rectangular cross-section has a length 20a corresponding to or slightly larger than the width of the belt 24. For example, the length 20a is 1-5 mm larger than the width of the belt 24. For example, the length 20a is at least 50 mm, such as 100-200 mm, 100-150 mm or 130-150 mm, For example, the top opening 20 has a width 20b, through which the belt 24 must be bent to pass. Hence, the width 20b of the top opening 20 must house two legs of the belt 24. For example, the width 20b is 30-60 mm, or 40-50 mm, such as around 40 mm. The top opening 20 is further illustrated in Figures 2 and 3. Figure 3 illustrates the propeller shaft housing 15 and the belt 24 more in detail.

The belt 24 is adapted to be inserted into the propeller shaft cavity 29 through the top opening 20 so that planes of the legs of the belt 24 are arranged essentially parallel to the length sides 20a of the top opening 20. Thus, the outside surface 26 of the endless loop flexible belt 24 faces the length sides 20a of the top opening 20 of the propeller shaft housing 15. The width sides 20b are arranged substantially facing forward and rearward when the outboard drive device 10 is arranged attached to the stem of a boat, wherein the length sides 20a face port and starboard (when not turning).

To arrange the endless loop flexible belt 24 in the cavity of the propeller shaft housing 15, the belt 24 is stretched. When stretching the belt 24, compressive stress is applied to the inside 25 of the belt 24 and tensile stress is applied on the outside 26 of the belt 24. Compressive stress causes the fibres in the belt 24 to break, which is also referred to as overloading the belt in this disclosure. The tensile stress counteracts the compressive stress so that the belt 24 is not overloaded and the fibers do not break.

When the belt 24 is inserted into the top opening 20 and into the propeller shaft cavity 27, a mounting device 100 is used to prevent overloading and damaging the belt 24. The mounting device 100 is shown in Figure 4. The mounting device 100 comprises an elongated extendable body assembly 110. The elongated extendable body assembly 110 has a longitudinal axis X and is axially extendable.

The elongated extendable body assembly 110 has a first end 110a and a second end 110b. The first end 110a comprises a first support structure 115 and the second end 110b comprises a second support structure 120. The first support structure 115 and the second support structure 120 provide support for the belt 24 when the belt 24 is being tensioned by the mounting device 100. The first support structure 115 and the second support structure 120 extend in a radial direction Y in relation to the longitudinal axis X. The belt 24 is arranged on the first support structure 115 and the second support structure 120 when the belt 24 is being stretched by the mounting device 100.

The elongated extendable body assembly 110 comprises a first elongated part

111 and a second elongated part 112. For example, the first elongated part 111 and the second elongated part 112 are rods. The first elongated part 111 and the second elongated part 112 are connectable, e.g. by inserting the first elongated part 111 into the second elongated part 112. The first elongated part 111 and the second elongated part

112 of the extendable body assembly 110 are releasably connectable to each other.

The first elongated part 111 has a first end 110a and a second end I l la. Thus, the first end 110a of the first elongated part 111 corresponds to the first end 110a of the elongated extendable body assembly 110. The second elongated part 112 has a first end 112a and a second end 110b. Thus, the second end 110b of the second elongated part 112 corresponds to the second end 110b of the elongated extendable body assembly 110. In the illustrated embodiment, the second end 11 la of the first elongated part 111 comprises a protruding part 111b extending along the longitudinal axis X. The first end 112a of the second elongated part 112 comprises an opening 112b. The opening 112b receives the protruding part 11 lb to attach the first elongated part 111 to the second elongated part 112.

Depending on the length of the belt 24, an insert 113 might be needed to adapt the mounting device 100 to the length of the endless loop flexible belt 24. When the endless loop flexible belt 24 is arranged around the elongated extendable body assembly 110 prior to extending the elongated extendable body assembly 110 of the mounting device 100, the elongated extendable body assembly 110 need not be in contact with the belt 24. The elongated extendable body assembly 110 has extension means for progressively extending the elongated extendable body assembly 110 arranged in the belt 24. In the illustrated embodiment, the extendable body assembly 110 is extendable with means of an hydraulic jack arrangement 150. An adapter 151 may be used to couple the hydraulic jack arrangement 150 with an entry 118 on the elongated extendable body assembly 110 for connecting the hydraulic jack arrangement 150 to the elongated extendable body assembly 110. Other extension means may also be used, such as an electric motor or mechanical or pneumatic drive devices for extending the extendable body assembly 110.

However, in order to adapt to the length of the belt 24 in which the mounting device 100 is to be extended, the insert 113 can be provided between the first elongated part 111 and the second elongated part 112. The insert 113 is illustrated in Figure 4. The insert 113 can be fastened between the first elongated part 111 and the second elongated part 112. The insert 113 is also an elongated part and may have essentially the same shape as the first elongated part 111 and the second elongated part 112. Thus, the insert 113 is preferably provided as a rod that is arranged between the first elongated part 111 and the second elongated part 112 to provide additional extension means to the elongated extendable body assembly 110. The insert 113 comprises a first end 113a and a second end 113b. The first end 113a has an opening 113c to receive the protruding part 11 lb to the first elongated part 111. The second end 113b has a protruding part 113d to be received in the opening 112b of the second elongated part 112. More than one insert 113 could be arranged between arranged between the first elongated part 111 and the second elongated part 112. The inserts 113 are then attachable to one another and to the first elongated part 11 and the second elongated part 112.

It is to be understood, that other fastening means for attaching the first elongated part 111 and the second elongated part 112 to each other are within the scope of the invention. The first elongated part 111 need not be inserted into the second elongated part 112. To lock the protruding part 11 lb of the first elongated part 111 or the protruding part 113d of the insert 113 in the opening 113c of the insert 113 or the opening 112b of the second elongated part 112, a pin and slot mechanism may be used as in the illustrated embodiment. The pin 116 is a resilient pin extending from the protruding part 11 lb of the first elongated part 111 and/or the protruding part 113d of the insert 113 in a radial direction Y to the longitudinal axis X. The pin 116 is received in a slot 117 provided on the first end 113a or/and the first elongated end part 112a.

Figure 4 further illustrates the first support structure 115. The first support structure 115 provides a support for the belt 24 during tensioning. As previously mentioned, the first support structure 115 extends in a radial direction Y in relation to the longitudinal axis X of the elongated extendable body assembly 110. The first support structure 115 protrudes equally on both sides of the elongated extendable body assembly 110. This ensures a stable first support structure 115 that will provide equal support along the entire width of the belt 24. When the belt 24 is arranged around the mounting device 100 and the mounting device 100 is brought into contact with the belt 24 by extending mounting device 100, the first support structure 115 may extend along the entire width of the endless loop flexible belt 24, thus ensuring an uninterrupted and uniform support along the width of the endless loop flexible belt 24.

The mounting device 100 further comprises at least one resilient spring element 130 arranged on the first support structure 115 of the extendable body assembly 110. The resilient spring element 130 projects from the first support structure 115 of the extendable body assembly 110. For example, the spring element 130 projects in a direction that is essentially perpendicular to the radial direction Y of the first support structure 115 and the longitudinal axis X of the elongated extendable body assembly 110 when no load is applied. Alternatively, the spring element is arced and extends partially radially outward from the longitudinal axis and partially in the axial direction at opposite ends of the spring element 130. For example, the spring element 130 has a width that essentially corresponds to the length of the first support structure 115. A length of the spring element 130 is, e.g. bigger that the width or diameter of the first support structure 115 supporting the spring element 130. The spring element 130, at least in an unbiased position, projects from the first support structure at least partially in opposite radial directions.

Figure 5 is a schematic view of the mounting device 100 arranged in the endless loop flexible belt 24. In Figure 5, the elongated extendable body assembly 110 is provided in a collapsed state, i.e. without applying any load on the belt 24. When the belt 24 is arranged around the mounting device 100, the spring element 130, attached to the first support structure 115, and the second support structure face the inside 25 of the endless loop flexible belt 24. Thus, the spring element 130 is provided between the belt 24 and the first support structure 115. Figure 6 is a schematic view of the mounting device 100 arranged in the endless loop flexible belt 24, where the belt 24 is stretched by the mounting device 100. Thus, the mounting device 100 has been extended gradually inside the belt 24 in order to tension it and avoiding overloading the inside 25 of the belt 24 as it bends around the first support structure 115. The spring element 130 is sandwiched between the belt 24 and the first support structure 115.

In Figures 4-6, the second support structure 120 is illustrated. The second support structure 120 in the illustrated embodiment has an arced and toothed outer surface 121. The second support structure 120 supports the belt together with the first support structure 115 during tensioning thereof. The toothed outer surface 121 meshes with corresponding teeth 25a of the belt 24.

The second support structure 120 is releasably connected to the second end 110b of the extendable body 110. When the belt 24 is arranged around the mounting device 100 and the mounting device 100 is brought into contact with belt 24 by extending mounting device 100, the second support structure 120 extends along the width of the belt 24, such as the entire width for uninterrupted and uniform support along the width of the belt 24. The second support structure 120 is, e.g. a cylindrical body that extends in a radial direction Y to the longitudinal axis X. The second support structure 120 extends equally on both side of the extendable body 110. The second support structure 120 is a cylindrical body. Preferably, the second support structure 120 resembles a pulley.

In Figures 4-6, the at least one resilient spring element 130 is illustrated as well. The spring element 130 comprises one or more resiliently flexible plates, also called spring plates herein. In Figure 4, five spring plates 131-135 are illustrated. Namely, a first spring plate 131, a second spring plate 132, a third spring plate 133, a fourth spring plate 134 and a fifth spring plate 135. In Figures 5-6, three spring plates 131-133 are illustrated, that is the first spring plate 131, the second spring plate 132 and the third spring plate 133. As many spring plates as suitable could be arranged on the first support structure 115. By increasing the number of spring plates, the rigidity of the spring element 130 can be increased. Thus, the support for the belt 24 is increased and the deformation of the belt 24 will be slower. In other words, by increasing the number spring plates 131-135 of the spring element 130, a slower deformation of the belt 24 is provided.

The spring element 130 is releasably connected to the first support structure 115. As is illustrates in Figure 4, the spring plates 131-135 comprises holes 136 so that the screws 137 can be used to fasten the spring plates 131-135 to the first support structure 115. The first support structure 115 comprises holes to receive the screws 137.

Each of the spring plates 131-135, regardless of the number of spring plates 131-135 provided on the first support structure 115, extends from the first support structure 115 so that when the belt 24 is tensioned by the mounting device 100, the spring plates 131-135 provide a flexible and bendable support to the belt 24 being tensioned. Thus, the resilient spring element 130 provides a flexible and bendable support to the belt 24 being tensioned.

The plurality of spring plates 131-135 are superimposed onto one another and fixedly attached to the first support structure 150 of the extendable body assembly 110. Each of the spring plates 131-135 has a different size. The spring plates 131-135 are superimposed by increasing order of size starting from the spring plate 131 arranged closest to the first support structure 115. Thus, as can be seen in Figure 3, the first spring plate 131, arranged directly on the first support structure 115, is smaller than the second spring plate 132, the third spring plate 133, the fourth spring plate 134 and the fifth spring plate 135. The second spring plate 132, sandwiched between the first spring plate and the third spring plate 133, is larger than the first spring plate but smaller than the third spring plate 133. The third spring plate 133, sandwiched between the second spring plate 132 and the fourth spring plate 134, is larger than the second spring plate 132 but is smaller than the fourth spring plate 134. The fourth spring plate 134, sandwiched between the third spring plate 133 and the fifth spring plate 135, is larger than the third spring plate 133 but is smaller than the fifth spring plate 135. The fifth spring plate 135 arranged on the fourth spring plate 134 is larger than the first spring plate 131, the second spring plate 132, the third spring plate 133 and the fourth spring plate 134. In Figures 5, only the first spring plate 131, the second spring plate 132 and the third spring plate 133 are provided. The same applies to these three spring plates. Regardless of the number of spring plates 131-135 provided, the spring plates 131-135 are arranged by increasing order of size starting from the spring plate 131 arranged closest to the first support structure 115. The arrangement of several spring plates 131- 135 by increasing order of size starting from the spring plate 131 arranged closest to the first support structure 115, is used provided a support to the belt 24.

When the mounting device 100 is arranged around the endless loop flexible belt 24 and the extendable body 110 is extended inside the belt 24, the extension of the extendable body 110 will push the first support structure 115 with the spring element 130 and the second support surface 120 in opposite directions and to the inside of the endless loop flexible belt 24. Thus, stretching the belt 24. By progressively extending extendable body 110 in the endless loop flexible belt 24, the endless loop flexible belt 24 will thus be stretched progressively. Thus, the plurality of spring plates 131-135, extending essentially perpendicularly to the elongated extendable body assembly 110 when not subject to any load, will deform elastically towards the longitudinal axis X of the extendable body assembly 110 when subject to load from the belt 24. Each of the plurality spring plates 131-135 of the spring element 130 provides a support for the endless loop flexible belt 24 by having a certain rigidity when the load of the belt 24 is applied on the plurality spring plates 131-135. The plurality spring plates 131-135 deform progressively and thus provides support for the belt 24 being tensioned 24 to conform to the width of the top opening 20. Subsequently, preventing the overloading of the belt 24 and breakage or damage of the fibers arranged therein. As the plurality of spring plates 131-135 are stacked on each other, the resistance to deformation of the spring element 130 will increase as the load of the belt 24 increases by progressively extending the elongated extendable body assembly 110. This is due to the spring plates 131-135 being pushed towards the extendable body assembly 110 and thereby towards each other. Thus, the spring plates 131-135 cooperate to provide a counterforce as the load from the belt 24 applied thereon increases.

The initial load from the belt 24 will only apply to the fifth spring plate 135 that is bend around the extendable body assembly 110. As the load increases on the fifth spring plate 135, the fifth spring plate 135 will have to bring the fourth spring plate 134 with it in order to be able to bend further. Thus, the fourth spring plate 134 is slow down in the bending of the fifth spring plate 135 provided additional support to the belt 24 and prevents rapid deformation. This principal is valid for all spring plates. Thus the third spring plate 133 slows down the bending of the fourth spring plate 134 and the fifth spring plate 135 and provides support to the belt 24 and prevents rapid deformations. The second spring plate 132 slows down the bending of the third spring plate 133, the fourth spring plate 134 and the fifth spring plate 135 and provides support to the belt 24 and prevents rapid deformations. The first spring plate 131 slows down the bending of the second spring plate 132, the third spring plate 133, the fourth spring plate 134 and the fifth spring plate 135 and provides support to the belt 24 and prevents rapid deformations.

Expressed in a more general manner, the first spring plate 131 having a smaller size and being arranged closer to the first support structure 115 than the second spring plate 132 having a larger size and being superimposed onto the first spring plate 131 will slow down the bending of the second spring plate 132 and prevent rapid deformations of the belt 24 when the belt 24 is stretched by the mounting device 110.

The extendable body assembly is extendable with means of the hydraulic jack arrangement 150 or other means as mentioned above. The belt can be pretensioned to several hundred kg, such as at least 500 or at least 1000 kg, such as around 1200 kg. The pressure on the hydraulic jack arrangement 150 can then be 660 bar.

Figure 7 is a flow chart illustrating a method 200 for mounting the endless loop flexible belt 24 in the propeller shaft housing 15 of an outboard drive device 10 such as the one described by way of example above. The method 200 comprises the steps of arranging 202 the belt 24 around the extendable mounting device 100 described above.

As previously described, the mounting device 100 comprises the elongated and axially extendable body assembly 110 with the first end 110a and the second end 110b. The first end 110a comprises the first support structure 115 provided with at least one spring element 130, and the second end 110b comprises the second support structure 120.

The method 200 further includes bringing 204 the first and second support structures 115, 120 of the mounting device 100 to support the endless loop flexible belt 24, followed by extending 206 the mounting device 100 gradually inside the belt 24. The extendable body assembly 110 of the mounting device 100 is extendable by means of the hydraulic jack arrangement 150. The belt 24 should be pretensioned to 1215 kg. The pressure on the hydraulic jack arrangement 150 is then 660 bar.

Thereby, the belt 24 is tensioned and bent around the spring element 130 while deforming the spring element 130 gradually while the load increases. Thus, providing support for the belt 24 and preventing the carbon fibers of the belt 24 from being damaged.

Thereafter, a portion of the mounting device 100 and the tension belt 24 is partially inserted 208 into the opening 20 of the propeller shaft housing 15 adapted to receive the belt 24 and connecting to the propeller shaft cavity of the propeller shaft housing 15. The tension on the belt 24 by the mounting device 100 is released 210. Followed by releasing 212 the spring element 130 from the first support structure 115 and removing 214 the spring element 130 from the propeller shaft housing 15 through the propeller shaft cavity. Subsequently, the mounting device 100 is removed 216 from the belt 24 and from the propeller shaft housing 15.

A grease may be applied to the outside 26 of the belt 24 prior to partially inserting 208 a portion of the mounting device 100 and the tensioned belt 24 into the opening 20 of the propeller shaft housing 15 adapted to receive the belt 24.

The invention has mainly been described with reference to a few embodiments. However, as is readily understood by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended claims.

In the claims, the term "comprises/comprising" does not exclude the presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. The terms "a", "an", "first", "second" etc. do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.