DE2834209A1 - Ball bearing supporting longitudinal movements - has recirculating ball tracks in cage and extra track for torque transmission - Google Patents

Abstract

The bearing for longitudinal movements on a cylindrical shaft consists of several (five) groups of recirculating balls in a cage and outer race. If a torque is also to be transmitted between shaft and housing, a set of recirculating balls inserted between a flat on the shaft, with a central track groove, and a gap in the cage and outer race. The outer race (1) is secured against rotation by a detent (28) in the housing (29). It has longitudinal grooves (13) for ribs (12) on the cage (7) to secure the latter against rotation. The cage has slots for loaded recirculating balls (4) and grooves (9) for unloaded returning balls (10). When a torque is to be superimposed to the longitudinal motion, a flat (31) with a running groove (27) is provided on the shaft. A cage (15), consisting of one centre piece (18) and two side pieces (21, 22) for recirculating balls (25, 26), is inserted in the gap (14) between this flat and the housing. This cage is extracted when no torque is to be transmitted.

Description

Rolling bearings for longitudinal movements

The present invention relates to a rolling bearing for longitudinal movements on a cylindrical shaft, consisting of an outer sleeve with in the bore axially extending raceways in which the loaded rolling elements from the circumference distributed, endless rows of rolling elements are arranged and one in the outer sleeve built-in cage for guiding the rolling elements of the rolling element rows, with outer sleeve and cage have at least one axially extending slot.

A roller bearing of the specified type is known in which one of the arranged on the circumference of the roller bearing endless rows of rolling elements is equipped with larger balls, which are used to transfer torque to a engage axially extending groove of the shaft (JP-OS S 47-23736). This well-known Rolling bearing is only suitable for applications where a twist-proof Connection of the rolling bearing with the shaft for the transmission of a torque between Rolling bearings and shaft is required.

In other cases where no torque is transmitted or in addition to Longitudinal movement a rotary movement between the roller bearing and the shaft must take place a differently designed roller bearing can be provided, e.g. in DE-OS 2 649 245 is disclosed, in which all rows of rolling elements on the circumference of the rolling bearing are arranged such that the loaded rolling elements on the cylindrical outer surface run of the shaft and small rolling movements within their installation clearance in the cage can run in the circumferential direction.

Again, this other known rolling bearing can only be used if no torque is to be transmitted between the roller bearing and the shaft, because a torque would be in contact between the rolling elements and the cylindrical Cause shaft sliding movements and thus harmful sliding scratches.

The range of application of the known rolling bearings is therefore limited and a production of the rolling bearings for certain applications with or without transmission of the torque is only possible in small, uneconomical quantities.

The object of the invention specified in claim 1 is to provide an improved To create rolling bearings for longitudinal movements of the type mentioned, both in the case where a longitudinal movement with transmission of a torque is required, as well as in the case where such transmission is not desired. This rolling bearing should also be of simple construction and economical to manufacture.

With the arrangement according to claim 1 it is possible one and the same Rolling bearings for longitudinal movements with or without transmission of a torque to the use a fully cylindrical shaft by placing this in the closed bore a housing, e.g. B.

with one inserted into the slot, the roller bearing in the bore bracing intermediate piece, is fixed. In the slot of the roller bearing can but also intervene a retaining web for the shaft, which the rotary movements of the roller bearing limited by the contact between the outer sleeve and the cage on the retaining bar.

In other applications, the same roller bearing can be used to transfer a torque an insert piece can be installed in the slot.

Advantageous further developments of the invention are set out in the subclaims described.

With the embodiment according to claim 2, a roller bearing with particularly Narrow slot can be created because the associated insert piece in the circumferential direction takes up a relatively small space. This means that the cylindrical shaft through the loaded rolling elements of the rolling element rows also for given the case that the rolling bearing is used piece without insert. The runway plate of the insert piece can, by the way, e.g. by cutting profiled bar material made of steel, can be manufactured economically.

The embodiment according to claim 3 aims to provide a fixed radial Support of the raceway plate of the insert in the bore of the outer sleeve create. With the embodiments according to claims 4 and 5 it is achieved that the insert against displacement in the circumferential direction securely held in the slot of the roller bearing is.

Finally, it is achieved with the embodiment according to claim 6 that the guide strips of the insert made of a wear-resistant and shock-absorbing Plastic produced economically and when it is installed on the track plate can be attached in such a way that the insert in question with the associated Rolling element rows form a self-retaining, easy-to-install unit.

The rolling bearing according to the invention for longitudinal movements is described in the following Description of two exemplary embodiments, which are shown in the drawings, explained in more detail.

The figures show: FIG. 1 a cross section through a roller bearing for longitudinal movements for transmitting the torque, Fig. 2 shows a longitudinal section along the line A-A by the roller bearing shown in Figure 1, Fig. 3 is a plan view of a guide bar of the single piece of the rolling bearing shown in Figure 1 in the unmounted state, FIG. 4 shows a cross section along the line B - B through the guide strip shown in FIG. 3, Fig. 5 is a cross section through a modified, rolling bearing for longitudinal movements to Transferring the torque, Fig. 6 is a plan view of a guide bar of the Insert piece of the rolling bearing shown in Figure 5 in the unmounted state, Fig. 7 shows a cross section along the line C - C through the guide bar shown in FIG 8 shows a cross section through a roller bearing for longitudinal movements without transmission of torques and FIG. 9 shows a cross section through a further modified roller bearing for longitudinal movements to transmit the torque.

1 with the outer sleeve of the roller bearing 2 is referred to in Figures 1 and 2, which has axially extending raceways 3 in its bore, in which the loaded Rolling bodies 4, in the present case balls, distributed on the circumference of the rolling bearing 2, endless rows of rolling elements 5 run. The cross-section of these raceways is circular formed with the center of curvature on the axis of the shaft 6. In the outer sleeve 1, the cage 7 is installed, which is made of a wear-resistant, shock-absorbing plastic is made. This cage 7 has axially extending guide tracks 8 for loaded rolling elements 4 and axially extending guideways 9 for the return unloaded rolling elements 10 of the rolling element rows 5, as well as the deflecting tracks 11, which each connect a guideway 8 to the associated guideway 9.

The cage 7 has longitudinally directed radial projections 12, which engage in corresponding longitudinal grooves 13 in the bore of the outer sleeve 1 and thus Secure the cage 7 against twisting in the outer sleeve 1.

Outer sleeve 1 and cage 7 have an axially extending slot 14, in which in the present case an application of the rolling bearing with torque transmission the insert 15 is installed.

As particularly illustrated in Figure 2, are at both axial ends of the roller bearing 2 end rings 16 placed on the cage 7, between which the outer sleeve 1 is recorded. In the bore of each end ring 16 is an elastic sealing ring 17 snapped.

The insert 15 extends in the axial direction of the shaft 6 extending raceway plate 18. The raceway plate 18 has that of the shaft 6 facing groove-shaped raceway 19 running in the axial direction. Radial Projections 20 are attached to the raceway plate 18 radially on the outside.

These radial projections 20 fit between the end faces of the Slot 14 of the outer sleeve 1 and thus hold the raceway plate 18 in the circumferential direction fixed in the roller bearing 2.

The insert 15 also has two symmetrically constructed guide strips 21, 22 on. These encompass one each in the bore of the outer sleeve 1 supported Kantan section 23 on both sides of the track plate 18 protrudes in the circumferential direction and is supported in the bore of the outer sleeve 1. The guide strips 21, 22 are made of plastic and are on the circumferential side Projections 24, see Figures 3 and 4, mutually in the ultrasonic welding process connected with each other.

These thus form guide rails that are guided around the raceway plate 18. and deflection tracks for receiving the spherical in the present embodiment Rolling bodies 25 and 26 of an endless row of rolling bodies of the insert 15. To transfer a torque between roller bearing 2 and shaft 6 engage the loaded rolling elements 26 of this row of rolling elements in an axially extending groove 27, which is in the flat 31 of the shaft 6 is incorporated.

The cylindrical locking pin 28 in the housing 29 protrudes into the the outer surface of the sleeve 1 incorporated recess 30 and thus ensures the Ball bearing 2 against twisting in the housing 29.-In the event that between rolling bearings 2 and shaft 6 no torque is to be transmitted, the insert 15 is simple taken out of the rolling bearing 2, i.e. the rolling bearing 2 is without the insert 15 built into the housing 29. The shaft 6 then does not need a flattening 31 To have groove 27, but can be fully cylindrical.

In another application - see FIG. 8 - is in the slot 14 of the roller bearing 2, an intermediate piece 36 without a row of rolling bodies installed, which the Outer sleeve 1 of roller bearing 2 clamped in the bore of housing 29. The roller bearing 2 therefore cannot transmit any torque from the shaft 6 to the housing 29.

The roller bearing 2 then leaves the rolling elements within the game 4 in the cage 7 small rotary movements of the shaft 6 relative to the housing 29, wherein The rolling elements 4 still do not slide on the shaft 6.

In Figure 5, a modified roller bearing 32 is shown which just as in the case described above from an outer sleeve 1 with built-in Cage 7 for guiding the rolling elements of the endless rows of rolling elements distributed around the circumference 5 exists. In the common slot 14 of the outer sleeve 1 and the cage 7, however, there is an insert piece 32 with an endless row of rolling elements installed, its made of elastic, shock-absorbing Plastic-made guide strips 33 have a protruding nose in the circumferential direction 34, which is clearly shown in FIGS.

When assembling the insert 32 as a structural unit, the two Guide strips 33 in the ultrasonic welding process at their projections 24 with one another connected so that these over the radial projections 20 of the track plate 18 held against displacement in the circumferential direction on the raceway plate 18 are.

The track plate 18 is on the two guide strips 33 to the the slot 14 forming end faces of the outer sleeve 1 held in the circumferential direction.

The lugs 34 of the guide strips 33, which are made of elastic, shock-absorbing plastic are made between the radial projections 20 and the end faces of the outer sleeve 1 to the plant, so that in an advantageous manner a play-free, Noise-damping, shock-proof guidance of the insert 32 in the slot 14 is given is. The raceway plate 18 is supported in the bore of the outer sleeve 1.

The loaded spherical rolling elements 26 in the insert 32 built-in row of rolling elements guided around the raceway plate 18 in the present case in an axially extending flat 35 of the cylindrical shaft 6; they can thus transmit a torque between shaft 6 and ball bearing 32.

If no torque is transmitted between shaft 6 and roller bearing 31 should be, or if a limitation of the rotary movement of the shaft by a the slot 14 gripping, attached to the shaft 6 holding web (not shown) is to take place, the insert piece 32 only needs to be removed from the slot 14 and to be left out.

In Figure 9 is another modified rolling bearing for longitudinal movements shown that for the purpose of transmitting a torque, the insert 15 with a having endless rolling elements. The loaded rolling elements 26 run in one axially extending groove of the shaft 6 and are on the raceway plate 18 in the Bore of the housing 29 is supported. Incidentally, the raceway plate 18 engages in the Longitudinal groove 38 of the housing 29 and thus secures the roller bearing against rotation in housing 29.

The rolling bearing according to the invention for longitudinal movements has the great Advantage that this both in the case where the longitudinal movement with transmission of a torque is required, as well as in the case where such a transfer is not desired, can be used.

Within the scope of the inventive concept, the roller bearing described can can be largely modified for longitudinal movements. For example, the rolling elements need not to be spherical in the cage 7 or in the insert 15, 32, rather these can also be used as rollers that have a cylindrical or spherical outer surface, be installed in the correspondingly shaped cage 7 or insert 15, 32.

In addition, the guide strips of the insert pieces by per se known snap connections in which projecting pins of one insert piece in a corresponding recess of the associated other insert piece positively intervene, be connected to each other.

The track plate of the insert piece can also be attached to it in the circumferential direction facing end faces on the opposite end faces forming the slot of the cage.

Finally, the slot 14 in the roller bearing can be fitted with an insert be filled, in which an endless row of rolling elements is installed, their loaded Balls run on the fully cylindrical shaft in the same way as the loaded balls the rows of rolling elements arranged in the cage. The roller bearing then does not transmit any torque, but is radially load-bearing over the entire circumference and accordingly just as load-bearing like a closed rolling bearing without a slot.

Blank page

Claims (6)

Rolling bearings for longitudinal movements Patent claims 1. Rolling bearings for longitudinal movements on a cylindrical shaft, consisting of an outer sleeve with in the bore axially extending raceways in which the loaded rolling elements from the circumference distributed, endless rows of rolling elements are arranged and one in the outer sleeve built-in cage for guiding the rolling elements of the rolling element rows, with outer sleeve and cage have at least one axially extending slot, characterized in that that optionally for transmitting a torque in the slot (14) an insert (15, 32) installed with at least one endless row of rolling elements and the shaft (6) is provided with an axially extending flat (35) or groove (27) into which the rolling elements (26) of the row of rolling elements arranged in the insert (15, 32) engage. 2. Rolling bearing according to claim 1 for the transmission of torque , characterized in that the insert (15, 32) has a track plate (18) with one of the shaft (6) facing groove-shaped raceway (19) and two axially straightened guide strips (21, 22, 33) with guided around the track plate (18) Guide and deflection tracks for the rolling elements of the rolling element rows of the insert (15, 32). 3. Rolling bearing according to claim 2, characterized in that the raceway plate (18) protruding in the circumferential direction on both sides in the bore of the outer sleeve (1) has supporting edge sections (23). 4. Rolling bearing according to claim 2 or 3, characterized in that the Raceway plate (18) on their circumferential end faces on the opposite, the slot (14) forming end faces of the cage (7) is held. 5. Rolling bearing according to claim 2 or 3, characterized in that the Track plate (18) over the guide strips (33) to the slot (14) forming End faces of the outer sleeve (1) is held in the circumferential direction. 6. Rolling bearing according to claim 2 to 5, characterized in that the Guide strips (21, 22, 33) of one or more rows of rolling elements of the insert (15, 32) made of plastic and, for example, in the ultrasonic welding process, together are connected.