GB2333812A

GB2333812A - Axially locked, radial displacement released, bearing and housing

Info

Publication number: GB2333812A
Application number: GB9901959A
Authority: GB
Inventors: Jens Schindler
Original assignee: Schindler & Wagner & Co GmbH
Current assignee: Schindler & Wagner & Co GmbH
Priority date: 1998-01-30
Filing date: 1999-01-29
Publication date: 1999-08-04
Anticipated expiration: 2019-01-29
Also published as: DE19902595A1; GB2333812B; GB9901959D0; DE19902595B4

Abstract

A bearing unit 50 comprises a bearing housing 58 which has bearing 64 which is radially movable in one direction. Movement of the bearing 64 in said radial direction disengages the bearing 64 from behind an axially acting locking rib 68 for quick and easy replacement of the bearing 64. The bearing can be radially biased towards the operative position behind the locking rib 68 by prestressing of loop belts 22, 24 of a continuous conveyor, a steel or rubber-elastic spring cushion (84 fig 8), a leaf spring (86 fig 9), locking screws/rods (88/90 fig 10) or a wire bow spring (figs 11, 12). The radial extension of the locking rib 68 is smaller than the radial clearance between the bearing 64 and the fitting aperture 70 of the housing 58. There may be two such bearings 64 applied to the housing, each being biased in opposite radial directions with locking ribs 68 facing opposite directions. The bearings 64 may be ball, roller or sliding bearings.

Description

Bearing Unit The invention relates to a bearing unit comprising a bearing receptacle and a bearing arranged therein, the bearing comprising an outer surface which cooperates with the bearing receptacle and an inner surface which receives a part which is to be mounted. In known bearing units of this type, the bearing receptacle usually comprises a recess in a bearing plate, and the outer race of the bearing is held with a press-fit in the bearing receptacle.

A disadvantage in these known bearing units is that the replacement of the bearing is time-consuming. In particular in fast-running high capacity machines, which comprise a large number of bearings, undesirable periods of inoperation result overall.

It is therefore the object of the present invention to further develop a bearing unit comprising a bearing receptacle and a bearing arranged therein, the bearing comprising an outer surface which cooperates with the bearing receptacle and an inner surface which receives a part which is to be mounted in such a manner that a defective bearing can be rapidly replaced.

This object is attained according to the invention by providing a bearing unit with a bearing receptacle and a bearing arranged therein, the bearing comprising an outer surface which cooperates with the bearing receptacle and an inner surface, which receives a part which is to be mounted, characterised in that the bearing receptacle encloses the bearing in at least one direction with radial clearance (e); the bearing receptacle having a fitting aperture which is provided over part of its circumferential extension with an axially acting locking means, the radial extension of the locking means being smaller than the radial clearance between the bearing and the bearing receptacle in the said one direction; and means are provided which hold the bearing 64 in the bearing receptacle in an operative position lying behind the locking means.

In order to replace a bearing in the bearing unit according to the invention, it is merely necessary to move the bearing in a radial direction within the bearing receptacle, rendering the retaining means inoperative.

With this movement, the bearing is then released from the locking means retaining the bearing in the axial direction and can be withdrawn in the axial direction from the part which is to be mounted. The fitting of a new bearing is effected in the reverse direction, the bearing being placed axially onto the part which is to be mounted and then as a result of the force of the retaining means acting in the radial direction being automatically forced into the axially locked position again.

Preferably the outer surface of the bearing is cylindrical.

Preferably the inner surface of the bearing is cylindrical.

Preferably the radial dimension of the locking means at its highest point above the circumferential wall of the bearing receptacle measures approximately 1 to 3 mm, more preferably 3mm. This is advantageous in that it is only necessary to overcome short radial distances in order to free the bearing from the associated locking means.

Consequently, the bearing unit as a whole also has a compact structure and spring means with a short stroke can be used in order to prestress the bearing into the locked position.

Preferably the locking means is formed by a radial flange, whose edge defines the fitting aperture which is eccentric in relation to the axis of the bearing, and the diameter of the fitting aperture is slightly, preferably lmm, larger than the external diameter of the bearing. Such a locking means can be mechanically manufactured in a particularly simple manner.

The eccentricity of the fitting aperture can measure approximately 1 to 3mm, preferably approximately 2mlm. This is advantageous as regards a short-stroke release of the bearing.

Preferably the inner surface of the bearing accommodates the part which is to be mounted with a slight side fit.

This is advantageous as only low axial forces are required in order to remove the bearing unit from the part which is to be mounted. This is advantageous with regard to a rapid loading and unloading of the bearing, in particular where it is necessary to deflect the bearing against a prestressing force.

The base wall of the bearing receptacle can comprise an opening whose diameter is smaller than the external diameter of the bearing. This enables easy access to the rear side of the bearing, so that a releasing tool can be easily applied in this region.

Preferably, a spacing disk is arranged between the opening in the base wall and the bearing, the diameter of said spacing disk being greater than the diameter of the opening provided in the base wall. This enables the bearing to be easily pushed off the part which is to be mounted, even though the base of the bearing receptacle is closed.

The spacing disk can have a smaller external diameter than the bearing. This ensures that the spacing disk can also be displaced to the required degree in the radial direction together with the bearing when the latter is to be removed or fitted.

Preferably the spacing disk closes the opening provided in the base wall in a sealing-tight manner. More preferably, the sealing disk cooperates with the outer surface of the part which is to be mounted with a tight slide fit. This has the advantage that the bearing receptacle is closed in a sealing-tight manner on its base.

Preferably the retaining means is formed by elastic prestressing mean, more particularly a spring cushion or a wire bow spring or a leaf spring. This allows for a particularly compact construction of the prestressing means and therefore also of the bearing unit as a whole.

The retaining means can be formed by a locking element which is releasably fitted into the intermediate space between the outer surface of the bearing and the inner surface of the bearing receptacle. This has the advantage that the bearing unit can be arranged in any spatial alignment and can also be used to mount rotating parts which are not subjected to any external force which could hold the bearing behind the locking means.

The locking element can be a rod or a screw which is releasably held by a wall of the bearing receptacle. This has the advantage that the locking element is secured in a simple manner in the circumferential direction. It can also be simply removed from the bearing receptacle in the axial direction.

The locking element can be a prismatic element which is fitted with positive locking between the outer surface of the bearing and the inner surface of the bearing receptacle. This has the advantage that a large-surface force transmission from the outside of the bearing to the inside of the bearing receptacle is attained. This is advantageous if the bearing is subjected to large radial forces under operating conditions, which attempt to force the bearing away from the locking means.

Preferably the retaining means is constructed as a wire bow spring which engages with at least one axial end section in the intermediate space between the bearing receptacle and the bearing. This is advantageous in that the retaining means can be manufactured particularly simply, namely from wire material. The at least one end section of the wire bow spring extending in the axial direction can find the location in the sickle-shaped intermediate space between the bearing receptacle and the bearing outer surface where a clamping effect is attained. A precise adaptation of the geometry of the retaining means to the geometry of this sickle-shaped intermediate space is therefore unnecessary.

The wire bow spring can comprise two end sections extending in the axial direction and these end sections are prestressed with radial outward components. This enables an elastic prestressing of the axially extending end sections of the wire bow spring in a simple manner in the fitted state, without having to provide any spring seats in the bearing receptacle.

Preferably the end sections of the wire bow spring extending in the axial direction have diameters such that the said end sections lie in the sickle shaped intermediate space between the bearing receptacle and the bearing in such a manner that the connecting lines to the bearing axis form an angle of approximately 45 degrees with the straight line connecting the end sections. This has the advantage that on the one hand an adequate clamping effect is obtained in the tapering, sickle-shaped intermediate space between the bearing receptacle and the bearing outer surface, whilst on the other hand the intermediate space is still of sufficient radial size for the diameter of the end sections to ensure sufficient mechanical strength of said end sections.

The wire bow spring can comprise a retaining section which endages over the end face of the bearing and preferably has the form of an open ring. This has the advantage that the retaining section of the wire bow spring having the shape of a split ring simultaneously provides for an additional axial securing of the bearing. Furthermore, the retaining section can be used as a grip for compressing and axially removing the wire bow spring when the bearing is to be removed.

If, according to claim 19, bearing units according to the invention are used in pairs, then it is possible by pushing a wedge between the two parts mounted by the bearing units to simultaneously release the two adjacent bearings from the associated locking means. This is again advantageous in view of a rapid replacement of the bearings of a machine having a plurality of bearings, e.g. a conveyor.

If the bearing unit according to the invention is used as disclosed in claim 20, then it is unnecessary to provide prestressing means in the bearing unit per se.

The use with continuous loop belts made of polyurethane as disclosed in claim 21 is particularly suitable for use in conveyers transporting foodstuffs. Polyurethane loop belts also produce a suitable prestressing force.

The invention will be explained in further details in the following with the aid of embodiments with reference to the drawings, in which: Figure 1: is a horizontal section through the adjacent end sections engaging in one another of two loop belt continuous conveyors, showing details of the bearing of the two reversing rollers; Figure 2: is a side view of the conveyor intersection shown in Figure 1 from the right in Figure 1; Figure 3: is an enlarged view of the right-hand section of Figure 1; Figure 4: is a plan view of the outer end face of a bearing box of a first type of bearing unit, which is used in the conveyor arrangement according to Figure 1; Figure 5: is an axial section through the bearing box according to Figure 4; Figure 6: is a plan view of the outer end face of a bearing box of a second type of bearing unit, which is used in the conveyor arrangement according to Figure 1; Figure 7: is an axial section through the bearing box according to Figure 6; Figures 8 and 9: are front views of modified bearing boxes with integrated bearing prestressing springs; Figure 10: is a similar view to Figure 3, in which two further modified variants of the easily releasable locking of a bearing in a bearing receptacle are shown; Figure 11: is an axial view of a further modified bearing unit; and Figure 12: is a perspective view of a wire bow spring used for securing the bearing in the bearing unit according to Figure 11.

In Figures 1 to 3, the reference 10 designates lateral longitudinal beams of a conveyor arrangement. The section of the conveyor arrangement reproduced in the drawing shows the intersection between two overlapping continuous loop conveyors 12, 14. 16 designates, for example, the downstream reversing roller 16 of the upstream continuous conveyor 12, whilst 18 designates the upstream reversing roller of the downstream continuous conveyor 14.

The reversing rollers 16, 18 have circumferential grooves 20, in which loop belts 22, 24 run, which belong to the continuous conveyor 12 and the continuous conveyor 14 respectively. The loop belts 22, 24 are manufactured from polyurethane and are prestressed by a tensioning device not shown in the drawing.

The downstream reversing roller 16 of the continuous conveyor 12 is connected to a gearing motor 20, whose housing 28 supports a coupling housing 30. In said coupling housing 30, the motor shaft 32 is connected to an extended shaft section 34 of the reversing roller 16 by means of a coupling sleeve 35. The shaft section 34 is mounted in a ball bearing 36, which sits in a bearing box 38 supported by the coupling housing 30. The bearing box 38 is in turn fitted into one of the longitudinal beams of the conveyor arrangement 12, 14.

The right-hand end of the reversing roller 16 in Figure 1 supports a shaft stump 40, which is mountd in a bearing unit designated in its entirety by the reference 42. The latter is fitted into a matching opening in the right-hand longitudinal beam 10.

At its ends, the reversing roller 18 supports two shaft stumps 44, 46, of which the right-hand stump is mounted via a further bearing unit 42 in the right-hand longitudinal beam 10, the left0-hand stump via a earing unit 48 in the left-hand longitudinal beam.

The bearing units 42 and 48 differ in respect of the geometry of the bearing boxes 50 and 50' seated in the longitudinal beams 10, but otherwise have the same construction, so that it will suffice to describe the bearing unit 42 in further detail.

As shown in Figures 2 to 5, the bearing box 50 has a circumferential wall 52, which comprises an end section 54 of reduced diameter, which fits into a matching opening 56 in the longitudinal beam 10. The circumferential wall 52 defines a bearing receptacle 58. The bearing receptacle 58 has a lower receiving section 60, which is part-cylindrical and corresponds to the external diameter of the outer race 62 of a ball bearing, designated in its entirety by the reference 64. A receiving section 66 of the bearing receptacle 58 lying on the right-hand side in Figures 2 to 5 is arranged eccentrically in relation to the axis of the bearing box 50. For a ball bearing 64 having an external diameter of 40 mm, the eccentricity e of the receiving section 66 lying at the top in Figures 2 to 5 in relation to the axis of the bearing box 50 measures approximately 2.3 mm.

The end of the circumferential wall 52 lying on the left in Figures 2 to 5 supports, in the circumferential region remote from the receiving section 66, a radially inwardly extending locking rib 68. Viewed in the axial direction, this locking rib 68 has a sickle-shaped form, as shown in Figures 2 to 4. The edge of the locking rib 68, together with the section of the circumferential wall 52 lying on the right in Figures 2 to 5, defines a fitting aperture 70, which corresponds to a circle, whose diameter is somewhat greater than the external diameter of the ball bearing 64, for example approximately 41 mm in the case of a bearing external diameter of 40 mm. The ball bearing 64 can therefore be moved in the axial direction through the fitting aperture 70 into the bearing receptacle 58, until it comes to rest against a base wall 72 of the bearing box 50. By way of a radial movement to the left in Figures 2 to 5, the bearing can then be brought into abutment against the inner surface of the receiving section 60 and is then secured against axial withdrawal by the locking rib 68.

As shown in Figure 1, an inner race 74 of the ball bearing 64 receives the shaft stump 34 of the reversing roller 16, namely with a slight slide-fit.

In order to be able to introduce the shaft stump 40 into the bearing receptacle 58 and to displace the ball bearing 64 together with the shaft stump 40 in the radial direction between the receiving sections 60 and 66, the base wall 72 is provided with a generously sized opening 76.

Arranged between the rear side of the ball bearing 64 and the remaining edge of the base wall 72 is a spacing disk 78, whose external diameter is larger than the internal diameter of the opening 76 but smaller than the external diameter of the ball bearing 64. The end face of the spacing disk 78 facing the reversing roller 16 cooperates closely with the base wall 72, whilst an inner sealing collar 80 of the spacing disk 78 runs with a narrow sliding clearance upon the outer surface of the shaft stump 40.

When the bearing unit is in the fitted state, the ball bearing 64 is held with the elastic prestressing of the loop belts 22 running over the reversing roller 16 in abutment against the inner surface of the receiving section 60.

Similar conditions prevail in respect of the bearing units 42 and 48 of the reversing roller 18. In this case, the ball bearings 64 are held behind the locking rib 68 by the prestressing of the continuous belts 24.

If it is necessary to replace a ball bearing, then this can be easily effected as follows: An expanding wedge 82 (cf. Figure 2) is pushed between the two reversing rollers 16, 18 and forces the two shaft stumps 40, 44 apart. The shaft stumps 40, 44 displace the ball bearings 64 mounted thereon, so that the outer races 62 of the ball bearings 64 are simultaneously released from the associated locking ribs 68, since the bearing units 42 for the reversing rollers 16, 18 are fitted with opposing alignment, i.e. with the locking ribs 68 facing one another and lying on the connecting line of the axes of the adjacent bearing units 42.

It is then possible to apply a releasing tool (not shown) to the rear side of the bearing unit in which the ball bearing is to be replaced, and the defective ball bearing 64 is simply pushed downwards from the associated shaft stump via the spacing disk 78. If both ball bearings need to be replaced, then the release of the second ball bearing can be effected in a similar manner. The new ball bearing or bearings is/are then pushed onto the shaft stump and the expanding wedge 82 inserted between the reversing rollers 16, 18 is withdrawn. The ball bearings 64 then run under the prestressing force of the loop belts 22, 24 under the associated locking ribs 68 again. The bearing units are then ready for use again.

It can be seen that the replacement of the bearings can thus be effected in a very simple manner.

In the modified embodiment according to Figure 8, a spring cushion 84 is fitted in the bearing box 50 in the region of the right-hand receiving section 66, which cushion prestresses the ball bearing 64 behind the locking rib 68.

The spring cushion 84 can be a rubber-elastic spring element or a spring cushion made of steel. By moving the ball bearing 64 to the right, the spring cushion 84 can be pushed fully into a chamber 85 of the bearing box 50 which accommodates said cushion.

Other springs are also conceivable for prestressing the ball bearing 64 into the operative position lying behind the locking rib 68, e.g. a leaf spring 86, as shown in Figure 9. The latter is fitted with its ends in slots 88 in the circumferential wall 52. A recess 90 is machined into the internal surface of the circumferential wall 52 in the region of the leaf spring 86, into which recess the leaf spring 88 can be fully pushed by moving the ball bearing 64 to the right.

In the embodiments described above, the ball bearing 64 was elastically prestressed into the operative position lying behind the locking rib 68. Instead, the ball bearing 64 can also be locked in the operative position by a locking element, as shown in Figure 10 by way of two embodiments.

In the bearing unit 42, a locking screw 88 parallel to the axis of the shaft 16 is fitted into the intermediate space between the left-hand section of the inner surface of the bearing box 50 and the left-hand section of the outer surface of the ball bearing 64, which locking screw 88 is screwed with a threaded section of reduced diameter into a threaded bore (without reference numeral) in the base wall 72. As a result of the locking screw 88, a movement of the ball bearing 64 to the left in Figure 10 is prevented, so that the ball bearing 64 is securely held behind the locking rib 68.

Instead of a locking screw, in a modification a locking rod can be used, which is fitted with frictional locking or a press fit into a retaining bore in the base wall 72.

In the right-hand variant in Figure 10, a prismatic locking element is fitted in the intermediate space between the right-hand section of the inner surface of the bearing box 50 and the right-hand section of the outer surface of the ball bearing 64, the cross sectional shape of the locking element, viewed in the direction of the axis of the reversing roller 18, being sickle-shaped, corresponding to the geometry of the intermediate space between the ball bearing and the bearing receptacle. The locking element 90 also prevents a movement of the ball bearing 64 out of the operative position illustrated in Fig. 10 into a removal position, in which it is released from the locking rib 68.

As a result of the fact that the locking element 90 fills the sickle-shaped gap between the ball bearing 64 and the receiving section 66 in a positive-locking manner, even large forces acting in the radial direction can be transmitted from the ball bearing 64 to the bearing box 50.

Both the locking screw 88 and the locking element 90 have an actuating section 92 or 94, which projects axially beyond the bearing receptacle 58 and is thus easily accessible. Alternatively, the locking screw 88 and locking element 90 can be provided with a positive locking element (square end, driving aperture or the like), with which a tool can cooperate.

In the further embodiment shown in Figures 11 and 12, components which have already been referred to in connection with other embodiments are again provided with the same reference numerals. These elements are not described in detail again.

In the bearing unit shown in Figure 11, a wire bow spring, designated in its entirety by the reference 92, is provided in order to secure the ball bearing 64.

This substantially has the shape of an omega with a retaining section 94, which covers the end face of the ball bearing 64 and has the form of a split ring. Symmetrically formed onto the retaining section 94 are two limbs 96, 98 lying in the same plane. These in turn support spring end sections 100, 102 lying perpendicular to the plane of the drawing of Figure 11.

The spring sections 100, 102 engage in the sickle-shaped intermediate space, which is defined by the inner surface of the receiving section 66 and the outer surface of the ball bearing 64. In this respect, the thickness of the wire from which the wire bow spring 92 is manufactured is selected in such a manner that radii from the spring end sections 100, 102 to the axis of the ball bearing 64 form an angle in the order of 45 with the connecting line of the two spring sections, as shown in the drawing.

In the fitted state, the wire bow spring 92 is compressed in the vertical direction in Figure 11 (i.e. perpendicular to its plane of symmetry). As a result of this prestressing, the two limbs 96, 98 attempt to move upwards and downwards respectively in Figure 11. As a result of the course of the part of the receiving section 66 adjacent the spring end sections 100, 102, a force is thereby generated, which attempts to force the spring end sections 100, 102 further into the tapering section of the sickleshaped intermediate space. Consequently, the spring end sections 100, 102 are blocked. If the ball bearing 64 attempts to move to the left in Figure 11, then the spring end sections 100, 102, which cannot move to the left or downwards as a result of self-locking, counteract a movement of this type.

If the ball bearing 64 is to be removed, then the wire bow spring 92 is compressed at the retaining section 94 manually or in the transition region between the retaining section 94 and the limbs 96, 98 by using pointed pliers.

This compression causes the spring end sections 100, 102 to move to the left in Figure 11 into wider sections of the sickle-shaped intermediate space. The frictional locking between the spring end sections 100, 102 and the bearing receptacle 58 or the outer surface of the ball bearing 64 is thereby released, and the wire bow spring 92 can then be easily removed from the bearing unit in the axial direction. The further dismantling of the ball bearing 64 is effected as above in connection with the other embodiments already described.

Common to the embodiments described above is that the ball bearings 64 of the bearing units 42, 48 can be very easily and rapidly replaced.

The invention has been explained above with reference to ball bearings. It goes without saying that the invention can be equally applied to other roller bearings or sliding bearings.

Claims

Claims 1. A bearing unit with a bearing receptacle 58 and a bearing 64 arranged therein, the bearing comprising an outer surface which cooperates with the bearing receptacle 58 and an inner surface, which receives a part 40; 44; 46 which is to be mounted, characterised in that the bearing receptacle 58 encloses the bearing 64 in at least one direction with radial clearance (e); the bearing receptacle 58 having a fitting aperture 70 which is provided over part of its circumferential extension with an axially acting locking means 68, the radial extension of the locking means 68 being smaller than the radial clearance between the bearing 64 and the bearing receptacle 58 in the said one direction; and means 22, 24; 84; 86; 88; 90 are provided which hold the bearing 64 in the bearing receptacle 58 in an operative position lying behind the locking means 68.
2. A bearing unit as claimed in claim 1, wherein the outer surface of the bearing is cylindrical.
3. A bearing unit as claimed in either of claims 1 or 2, wherein the inner surface of the bearing is cylindrical.
4. A bearing unit as claimed in any one of claims 1 to 3, wherein the radial dimension of the locking means 68 at its highest point above the circumferential wall of the bearing receptacle 58 measures approximately 1 to 3 mm, preferably approximately 2 mm.
5. A bearing unit as claimed in any one of claims 1 to 4, characterised in that the locking means 68 is formed by a radial flange, whose edge defines the fitting aperture 70 which is eccentric in relation to the axis of the bearing, and the diameter of the fitting aperture 70 is slightly, preferably approximately 1 mm larger than the external diameter of the bearing 64.
6. A bearing unit as claimed in claim 5, wherein the eccentricity of the fitting aperture 70 measures approximately 1 to 3 mm, preferably approximately 2 mm.
7. A bearing unit as claimed in any one of claims 1 to 6, wherein the inner surface of the bearing 64 accommodates the part 40; 44; 46 which is to be mounted with a slight slide-fit.
8. A bearing unit as claimed in any one of claims 1 to 7, wherein a base wall 72 of the bearing receptacle 58 comprises an opening 76, whose diameter is smaller than the external diameter of the bearing 64.
9. A bearing unit as claimed in claim 8, wherein a spacing disk 78 is arranged between the opening 76 in the base wall 72 and the bearing 64, the diameter of said spacing disk 78 being greater than the diameter of the opening 76 provided in the base wall 72.
10. A bearing unit as claimed in claim 9, wherein the spacing disk 78 has a smaller external diameter than the bearing 64.
11. A bearing unit as claimed in either of claims 9 or 10, wherein the spacing disk 78 closes the opening 76 provided in the base wall 72 in a sealing-tight manner.
12. A bearing unit as claimed in any one of claims 9 to 11, wherein the spacing disk 78 cooperates with the outer surface of the part 40; 44; 46 which is to be mounted with a tight slide-fit.
13. A bearing unit as claimed in any one of claims 1 to 12, wherein the retaining means is formed by elastic prestressing means, more particularly a spring cushion 84 or a wire bow spring XX or a leaf spring 86.
14. A bearing unit as claimed in any one of claims 1 to 12, wherein the retaining means is formed by a locking element 88; 90 which is releasably fitted into the intermediate space between the outer surface of the bearing 62 and the inner surface of the bearing receptacle 58.
15. A bearing unit as claimed in claim 14, wherein the locking element is a rod or a screw 88, which is releasably held by a wall 72 of the bearing receptacle 58.
16. A bearing unit as claimed in claim 14, wherein the locking element is a prismatic element 90, which is fitted with positive locking between the outer surface of the bearing 64 and the inner surface of the bearing receptacle 58.
17. A bearing unit as claimed in any one of claims 1 to 13, wherein the retaining means is constructed as a wire bow spring 92, which engages with at least one axial end section 100, 102 in the intermediate space between the bearing receptacle 58 and the bearing 64.
18. A bearing unit as claimed in claim 17, wherein the wire bow spring 92 comprises two end sections 100, 102 extending in the axial direction and these end sections are prestressed with radial outward components.
19. A bearing unit as claimed in either of claims 17 or 18, wherein the end sections 100, 102 of the wire bow spring 92 extending in the axial direction have diameters such that the said end sections lie in the sickle-shaped intermediate space between the bearing receptacle 58 and the bearing 64 in such a manner that the connecting lines to the bearing axis form an angle of approximately 45 degrees with the straight line connecting the end sections.
20. A bearing unit as claimed in any one of claims 17 to 19, wherein the wire bow spring 92 comprises a retaining section 94, which engages over the end face of the bearing 64 and preferably has the form of an open ring.
21. Use of bearing units as claimed in any one of claims 1 to 20 as bearing parts 16, 18 which are spaced apart parallel to one another, characterised in that the two bearing units (42) are arranged adjacent one another in such a manner that the two locking means (68) lie facing one another on the connecting line of the two bearing axes.
22. Use of bearing units according to any one of claims 1 to 20, for bearing reversing rollers 16, 18 of at least one continuous conveyor 12, 14, more particularly of loop belt conveyors, characterised in that the prestressing means are formed by elastic belts 22, 24 of the continuous conveyors 12, 14.
23. Use according to claim 22 wherein the continuous belts are loops made of polyurethane.
24. A bearing unit substantially as hereinbefore described.
25. A bearing unit substantially as hereinbefore described with reference to the drawings.