Technical field of the invention

The invention relates to a transport and/or mounting device for bearings. The transport and/or mounting device is used to attach two bearing cages to each other which allows for a fixation of the rolling elements during

transportation and mounting of a bearing.

Background

Bearings are used in all types of mechanical applications to provide lower friction between moving parts therein. Today there is a large variation between different types of bearings which are suited for different applications. Some bearings are constructed to carry extreme loads, whereas others need to be able to withstand very corrosive environments. Depending on the requirements put on a bearing, different materials and construction types will be used.

Despite their different uses and constructions one thing which unites all types of bearings is the basic construction thereof comprising an inner ring, rolling elements, a cage holding or surrounding the rolling elements and an outer ring. To ensure that the bearing has a long liftime without failure, it is important that all components making upp the bearing have a good fit and are aligned correctly. Missalignment in a bearing will lead to increased friction in said bearing and in extreme cases to mechanical failure thereof.

When transporting and mounting a bearing there is a large risk that the rolling elements become missaligned due to movements which occur during handling of said bearing.

For bearings having more than one parallel row of rolling elements and wherein more than one bearing cage is used to align the rolling elements the problem is even more accute as it may be impossible to place the bearing such that gravity helps maintain the rolling elements in the correct position during transportation and mounting. One example of such a bearing type is a double direction sperical roller thrust bearing (DDSRTB) which has rolling elements placed on the same inner ring and where the rolling elements face two different directions. There is thus a need for a construction which secures that the rolling elements of a bearing remain correctly positioned during transportation and mounting to ensure that optimum performance of the bearing can be achieved without extra adjustment of the rolling elements. Specifically there is a need to secure the rolling elements for bearings which comprise multiple rows of rolling elements.

Summary of the invention

It is a general object of this invention to alleviate the above-mentioned problems.

According to a first aspect of the invention, there is provided a transport and/or mounting device for bearings wherein said transport and/or mounting device comprises a rod extending in a longitudinal direction comprising an upper portion, a central portion and a lower portion, wherein an upper member with a protrusion is positioned around the upper portion of the rod and a lower member with a protrusion is positioned around the lower portion of the rod, wherein the protrusion positioned around the upper portion is meant to grasp into a perforation of a first bearing cage of a bearing and wherein the protrusion positioned around the lower portion is meant to grasp into a perforation of a second bearing cage of the bearing in order to fix the two bearing cages to each other, wherein the longitudinal distance between the upper and lower protrusions can be varied using an adjustment member and wherein said adjustment member is situated on the lower portion of the rod in a longitudinal position below the lower member.

When using a device as described above, it is possible to fix two bearing cages to each other and hold the rolling elements into position during transport and during mounting of the bearing into its final use position. Said fixation amounts to a more secure transportation of the bearing and also it ensures that when a bearing is mounted into place all rolling elements remain in the correct position thereby allowing for a bearing with an optimum perfomance. Correct positioning of the rolling elements is essential not only to avoid the friction and wear caused by rolling elements which have slipped from their position but also to avoid time consuming adjustment of all rolling elements during mounting of the bearing. Once the bearing has been mounted into the correct position, the transport and/or mounting device is removed and the rolling elements are free to rotate around their axis leading to a fully functioning bearing.

According to one embodiment the transport and/or mounting device has a central member which is positioned around the rod in the central portion and situated in a longitudinal direction between the upper and lower members. An advantage of using a central member is that it provides extra stability to the transport and/or mounting device. Upon tightening the device when mounting it onto the bearing cages of a bearing the central members provides additional mechanical stability to the rod and the rod is therefore not bent even though a high force is exerted thereon. According to one embodiment the inside of the upper member and the exterior surface of the rod in the upper portion are threaded to allow for the upper member to move in a longitudinal direction of the rod when rotating said rod around its longitudinal axis. This specific construction allows for easy adaptation and adjustment of the distance allowing for easy usage of the device.

According to one embodiment the adjustment member is permanently fixed to the rod. This embodiment allows for simple manufacturing and ease of handling as the number of movable or adjustable parts is kept at a minimum.

According to one feature of the above embodiment the rod is rotated by turning the adjustment member around its longitudinal axis. When the adjustment member is fixed to the rod the adjustment member is easily accessed and can be used to turn rotate the rod and thereby adjust the distance di between the upper and lower members. According to one embodiment the central member and the lower member are unfixed to the rod such that they can move freely in a longitudinal direction along the rod. This specific construction allows the central member and the lower member to move freely and adjust to the movement of the upper member and the rod with the adjustment member as the device is tightened.

According to one embodiment the rod has a cross-section which is circular. A circular shape allows the lower member to rotate around the rod during the tightening of the device which allows the lower member to follow the movement of the upper member during tightening of the device.

According to one embodiment the protrusions on the upper and lower members extend outwards from the rod at a distance of 5 to 10 mm. This length is sufficient to allow for the protrusions to grasp into perforations present on a bearing cage while at the same time not being too long which requires a large space to mount and remove the devices. In well around the cage preferably they extend outward at a distance of 6 to 7 mm.

According to one embodiment the protrusions have an angle a as measured between the surface of the protrusion facing the central portion of the rod and the surface of the rod and wherein said angle a is from 45 ° to 90 °. An advantage is that at 90 ^° angle it is easier to insert the protrusion of the device into the perforations through the rim of the bearing cage. However, when increasing the angle up to 45 ^° the protrusion will grip around the edge of the perforation in the bearing cage the angle will also secure that the device does not slip out of the perforation as the attachment force thereof is increased.

According to one feature of the above embodiment the angle a between the surface of the protrusion and the rod is not the same for the upper protrusion surface and the lower protrusion surface. Having different angles can provide an advantage if there is a specifically challenging situation such as extremely small space when attaching or removing the device from the bearing cages. By adjusting the angels differently the device can be adapted to suit each specific need.

According to one feature of the above embodiment the angle a between the surface of the protrusion and the rod is the same for the upper protrusion surface and the lower protrusion surface. This feature allows for a

standardized solution which is simpler to manufacture and also allows for easier mounting as the device can be mounted in either direction as both upper and lower member are identical.

According to a second aspect of the invention there is provided a Double Direction Spherical Roller Thrust Bearing ("DDSRTB") which has an inner ring and on said inner ring two separate cages are present where said cages comprise windows in which rolling elements are present and wherein the cages are attached to each other by a removable transport and/or mounting device as defined in any of the embodiments or features above.

Brief description of the drawings

By way of example embodiments of the invention will now be described with the reference to the accompanying drawings in which:

Fig. 1 illustrates a steel bearing cage. Fig. 2 shows a DDSRTB with two steel cages holding the rolling elements and wherein the steel cages are attached to one another using cage clamps.

Detailed description

In the following detailed description preferred embodiments of the invention will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. It may also be noted that, for the sake of clarity, the dimensions of certain components illustrated in the drawings may differ from the corresponding dimensions in real-life implementations of the invention.

The present invention relates to a transport and/or mounting device to be used with roller bearings and will hereafter be described more in detail with reference to Figures 1 -2.

Figure 1 shows a transport and/or mounting device 1 for bearings wherein said transport and/or mounting device 1 comprises a rod 10 extending in a longitudinal direction. The rod is divided into three sections; an upper portion 1 1 , a central portion 12 and a lower portion 13. Around the upper portion 1 1 an upper member 21 with a protrusion 31 is positioned. Around the lower portion 13 of the rod 10 a lower member 23 with a protrusion 33 is positioned. In the figure a central member 22 positioned around the central portion 12 is also shown. The central member 22 is not essential for a functioning device 1 but it can be an advantage to have said central member 22 as it strengthens the mechanical properties of the rod 10 allowing the device 1 to be fastened using a higher force.

In figure 1 the rod 1 is illustrated with an adjustment member 43 fastened onto the lower portion 13 of the rod 1 in a longitudinal position below the lower member 23. Although the adjustment member 43 is attached onto the rod in the figure it is also possible that the adjustment member 43 is not fixed to the rod 10 but is a threaded bolt which can be moved up and down along the rod in a longitudinal direction by a turning action. In this alternative embodiment the rod 10 must also be threaded in the lower portion 13.

The upper member 21 has a protrusion 31 which extends radially outward from the rod 10. The lower member 23 has a similar protrusion 33 which extends radially outward from the rod 10. Each of the protrusions 31 ,33 extends radially outward at a distance In most instances d∑ is chosen to be between 5 to 10 mm and preferably the distance d∑ is 6 to 7 mm.

The distance d1 between the protrusions 31 ,33 of the upper 21 and lower 23 members can be adjusted using the adjustment member 43. When the adjustment member 43 is fixed onto the rod 10, the adjustment member 43 can be rotated around its axis to rotate the rod 10. When the rod is rotated the upper member 21 will rotate around the rod 10. Both the upper member 21 and the rod 10 are threaded 41 ,51 . The threads 41 ,51 of the upper member 21 and the rod 10 match each other and when the rod 10 is rotated by turning the adjustment member 43 the upper member 21 will move in a longitudinal direction along the rod 10 which leads to an adjustment of the distance di between the upper 31 and lower 33 protrusions. To avoid the upper member 21 from being twisted off the rod 10 a stopper or cap 71 is used. It is not necessary to use a cap 71 to create the stop at the top of the rod 10, alternative ways of creating a stop could be that the threads 41 on the rod 10 do not extend all the way to the top of the rod 10 or, alternatively, the top threads are damaged so that the upper member 21 cannot move past the top portion of the rod 10. In the alternative embodiment when the adjustment member 43 is not fixed to the rod 10, the turning of the adjustment member 43 will lead to the

adjustment member 43 moving in a longitudinal direction along the rod thereby altering the distance d-i .

The protrusions 31 ,33 have an angle a as measured between the surface of the protrusion facing the central portion of the rod 61 ,63 and the surface of the rod 10. It is preferable that the angle a is chosen somewhere between 45° and 90°. In figure 1 the angle a between the surface of both protrusions 61 ,63 and the rod 10 is the same but it is also possible that the angles are different.

Figure 2 shows a Double Direction Spherical Roller Thrust Bearing

(DDSRTB) 2 without the outer rings attached. For this specific embodiment one central ring 203 is used which has two surfaces angled in different directions. On each surface a number of rolling elements 204 are placed and are fitted into the windows 203 of the steel cages 201 ,202 to secure the rolling elements 204 in relation to each other. The steel cages 201 ,202 are attached to each other using mounting and/or transportation devices 1 as described above. The mounting and/or transportation devices 1 are fitted into perforations 206 situated along the lower rims 208,209 of the steel cages 201 ,202. During use of a roller bearing 2 these devices 1 are to be removed but they will ensure that all rolling elements 204 are maintained in the correct position during transportation and mounting thereby ensuring optimum performance of the roller bearing 2. When using said devices 1 it is not necessary to manually verify and adjust each rolling element 204 after transportation or when the roller bearing 2 is mounted into position for use.

Figure 3 shows a cross-section of a DDSRTB 2 where the connection between the transport and/or mounting device 1 is illustrated. The transport and/or mounting device 1 is placed in the perforations 206 situated along the lower rims 208,209 of the steel cages 201 ,202. The adjustment member 243 has been tightened to reduce the distance di and the steel cages 201 ,202 press the rolling elements 204 against the inner ring 203. The pressure will fixate the rolling elements 204 tightly against the inner ring 203 thus blocking them from any movement during either transportation or mounting of the roller bearing.