DE102007045655A1 - Device for compensating for axial thermal expansion of a rolling bearing assembly - Google Patents

Abstract

The invention relates to a device for compensating for axial thermal expansion of a roller bearing assembly with a bearing ring (6) having a receiving space for a thermal expansion element (10). In order to provide a compensation device which also allows the use of a thermal expansion element made of inexpensive material with lower resistance and / or lower temperature coefficient with a simple and cost-effective construction, the bearing ring (6) consists of two bearing part rings (6a, 6b). In this case, the first bearing part ring (6a) has a rolling body running surface (7) and the second bearing part ring (6b) has an outer jacket surface (13). The bearing part rings (6a, 6b) delimit between them the receiving space (21) and are due to thermally induced volume changes of the thermal expansion element (10) at least in the axial direction (A) relative to each other displaceable.

Description

Name of the invention

contraption to compensate for axial thermal expansion of a rolling bearing assembly

description

Field of the invention

The The invention relates to a device for compensating for axial thermal expansion a rolling bearing assembly with a bearing ring with a Receiving space for a thermal expansion element.

Background of the invention

at Machine elements made of materials with different thermal expansion or exist with different temperature coefficients occur different with changing operating temperatures relative change in length (axial thermal expansion) and thus distance changes. This phenomenon is especially in fast-running arrangements, where a precise Storage is required - such as vehicle differentials or transfer cases - undesirable. In the Usually exist in a motor vehicle transmission gearbox made of die-cast aluminum; which are made of steel gear shafts mounted by means of employed tapered roller bearings. Here it is the approximately twice the thermal expansion of the aluminum housing significantly noticeable and changed compared to the steel shafts the set preload or the set bearing clearance of Roller bearing. This leads to reduced bearing life, worst case to an axial wave ideal meshing and noise generation.

To compensate for these effects are from the U.S. Patent 5,028,152 Devices of the type mentioned above, in which a circumferential recess is formed in a bearing ring, in which a thermal expansion element is used in the form of an expansion ring, on the other hand is supported on a shoulder of a transmission housing.

The expansion ring must be made of high-quality material, which has the highest possible temperature coefficient and a high resistance to aggressive external operating conditions - especially a high oil resistance. Therefore, the strain rings of the known device are preferably made of a marketed under the trade name VITON ^® from DuPont elastomer. This material is relatively expensive.

Object of the invention

In front This is the object of the present invention in the creation of a compensation device that is simple and inexpensive construction, the use of a thermal expansion element from inexpensive material with less resistance and / or lower temperature coefficient allows.

Description of the invention

These The object is achieved by a device having the features of patent claim 1.

Accordingly the bearing ring composed of two bearing part rings, wherein the first bearing part ring a rolling element tread and the second bearing part ring an outer Mantle surface of the rolling bearing assembly forms, wherein the bearing part rings confine the receiving space between them and after encapsulate the outside and wherein the bearing part rings due to thermal Conditional change in volume of the thermal expansion element are displaceable relative to each other at least in the axial direction.

Under outer The lateral surface of the rolling bearing assembly is in the frame the invention in contact with the machine elements to be stored Understand standing surface, so usually the cylindrical outer circumferential surface, with the Bearing z. B. sitting in a bearing bore, or the cylindrical lateral surface the bearing inner ring bore, in the z. B. recorded a shaft to be stored is.

One An essential advantage of the invention is that the Bearing rings form an encapsulated receiving space in which the Thermal expansion element against external influences is largely protected and secluded houses. This can for the device according to the invention a thermal expansion element of a much cheaper Material, such as thermoplastic elastomer, with significant lower resistance to external influences, especially low oil resistance used become.

One Another significant advantage of the invention Device is that a pre-assembled and transportable Assembly unit is created, which is easy to handle during final assembly can be.

The inventive design of the device also allows to optimize the recess and thus the axial extent of the thermal expansion element with respect to the axial thermal expansion. In other words: As a thermal expansion element, a ring or a sleeve with egg ner comparatively small wall thickness or small radial extent and correspondingly long ausgestalteter axial extent can be used. This leads to the additional advantage that the material used for the thermal expansion element, for example, thermoplastic elastomers can be used, which have a lower thermal expansion. For example, materials known under the trade names Hytrel, Elastollan, TPSiV or Zeotherm may be used.

By the dimensions of the first and second bearing part ring can the fit or the seat of the second bearing part ring on the first Bearing ring are designed. In addition, a slight radial excess of the Provided thermal expansion element, so that in the Assembly of the rolling bearing assembly an additional radial pressure z. B. from the outer bearing part ring is exerted on the inner bearing part ring. In the assembled Installation position are the two bearing rings then z. B. by a fixed corresponding press fit.

A technically preferred embodiment of the invention provides that the one bearing part ring in the axial direction over the entire length of the other bearing part ring extends.

A in terms of the compensation efficiency preferred embodiment the invention provides that the one bearing part ring a circumferential Has recess in which the thermal expansion element at least partially received, and that the other bearing part ring this Recess completely covered.

The Bearing part rings may preferably at least at one point be connected with each other. Manufacturing technology is preferred first bearing part ring a separate outer sleeve.

A further optimization of the compensation efficiency leaves according to a further preferred embodiment of the invention achieve by the bearing part rings a conical receiving space limit.

advantageously, the bearing part rings can be an approximately L-shaped Have cross-section.

constructive Preferably, the bearing part rings on side walls, the are connected to the other bearing ring part, that is move the bearing rings axially and radially relative to each other can, while the receiving space to the outside remains encapsulated.

To an advantageous embodiment of the invention is between a Bearing part ring and the receiving space a separate intermediate sleeve arranged. This embodiment has the advantage that standard Bearings can be used and the compensation device forms a separate entity for itself. In addition, this is Design no weakening of the actual bearing ring to accept. This embodiment is particularly suitable for highly stressed bearing assemblies or for the subsequent Retrofitting of rolling bearings.

To an advantageous embodiment of the invention is within the Encapsulation of a piston between a bearing ring and the thermal expansion element arranged, which transmits compressive forces in the axial direction. As a result, thermal flow and unwanted Setting the thermal expansion element particularly well prevented. In addition, the piston can act in addition sealing, so that prevents that material of the thermal expansion element in any gaps between the outer sleeve and can dodge or flow the bearing-side ring.

manufacturing technology is preferred according to a further advantageous embodiment of the Invention bent at least one edge region of a bearing ring part, to support one end face of the other bearing part ring. The other, in the axial direction opposite edge region of a bearing part ring can for transport or assembly relief be caulked.

A advantageous development of the invention provides that the edge region of a bearing part ring is axially stepped, the step with a substantially radially extending step portion inside in contact with the heat medehnungselement. The step-like Formation of the edge region forms a defined contact surface, on the thermal expansion element, the compensation forces, the caused by its thermal expansion, transmitted directly can. This design is particularly suitable for the cases on, in which waived a piston.

Brief description of the drawings

Further Advantages and aspects of the invention are also or supplementary from the following description of the invention with reference to the enclosed drawings. Showing:

1 in a perspective view a partial longitudinal section of a tapered roller bearing with a device according to the invention;

2 in perspective an exploded view of components of the arrangement according to 1 ;

3 in a perspective view a partial longitudinal section of a tapered roller bearing with a further device according to the invention;

4 in perspective an exploded view of components of the arrangement according to 3 ;

5 in a perspective view a partial longitudinal section of a tapered roller bearing with a further device according to the invention;

6 in perspective an exploded view of components of the arrangement according to 5 ;

7 in a perspective view a partial longitudinal section of a tapered roller bearing with a further device according to the invention;

8th in longitudinal section different operating situations of the device according to 7 ;

9 a comparative representation of the Axialkraftflusses the embodiments of the 1 to 6 ,

Detailed description the drawings

In The following descriptions of the figures are the same or the same function Elements provided with the same reference numerals.

That in the 1 and 2 illustrated first embodiment of a device according to the invention shows a trained as a tapered roller bearing per se known rolling bearing 1 with a bearing inner ring 2 with a tread 3 , On the tread roll designed as tapered rolling elements 4 starting in a storage cage 5 are held. A bearing outer ring 6 consists of two bearing ring parts, a first bearing ring part 6a and a second bearing ring part 6b , The bearing ring part 6a has a tread called outer tread 7 on, on which the rolling elements 4 roll. Seen in the radial direction outer shell of the bearing ring part 6a is also referred to as a groove circumferential radial recess 8th intended. In the recess 8th is one made of an elastomer 9 existing thermal expansion element 10 at least partially introduced. The thermal expansion element 10 is (compare also 2 ) formed by a thin-walled ring or sleeve. Their radial extent is very small compared to the axial extent.

The arrangement of the first bearing ring part 6a and thermal expansion element 10 is from the second bearing ring part 6b completely surrounded in the axial direction A.

The second storage part 6b extends axially completely over the length of the first bearing ring part 6a and embraces it at least so far that the recess 8th completely under him and completely covered. The storage part 6b forms with its outer surface, the outer surface 13 of the bearing ring 6 and is with its rear end or edge area 14 with the rear edge or bridge 15 of the bearing ring part 6a connected. In the front, gearbox side area of the Lageringteil based 6b with its bent or beaded edge 18 at the front 19 a warehouse shelf 20 of the ring 6a from. The bearing ring parts 6a . 6b thus form in cooperation with the recess 8th a closed recording room 21 which extends axially.

The two bearing ring parts 6a . 6b are designed in their outer dimensions so that there is a fit between them, which allows a sufficient axial displacement with a tight fit. The thermal expansion element 10 has a small radial excess, so that this generates an additional radial pressure force in the mounted state. As a result, the outer bearing ring part 6b Taut on the inner bearing ring part 6a held. In mounted in a bearing assembly state, the bearing ring parts 6a . 6b be provided in their functional position holding interference fit. Separate mounting or holding parts between the bearing ring parts are thus not required in operation, they can be configured in the form of overarching beads, beadings, locking lugs or hooks at most, to secure the bearing ring parts during transport relative to each other.

to Guide the bearing ring parts in the axial direction relative serve each other their respective casserole or contact surfaces.

To the extent desired in a temperature increase in the axial direction A and the axial force generated thereby as possible wear-free for the material of the thermal expansion element 10 on the edge 18 and thus to transfer to the non-illustrated contact surface, for example, a transmission, is an annular piston 22 provided on which the front end 23 the thermal expansion element 10 supported. With its back end 24 the thermal expansion element is supported on the inside vertical wall of the web 15 from.

Due to the considerable axial extent of the recess 8th and the through the outer sleeve 12 in interaction with the recess 8th formed encapsulation - its shielding ability by the piston 22 is considerably increased - can be used as a material for the thermal expansion element 10 comparatively inexpensive material can be chosen because the material does not have very high mechanical resistance and a high temperature coefficient must be. This has an overall cost-reducing effect.

In the 3 and 4 is a second, compared to the first embodiment modified embodiment of a device shown. Here is the basic structure of the camp 1 unchanged and will therefore not be described again. However, the bearing part ring 30 modified by its front edge area 32 a twofold grading 43 having. The step is supported by its lower end 34 on the front bearing shelf 20 of the ring 6a from. The substantially horizontally extending step shoulder 35 lies on the lateral surface 36 of the ring 6 axially displaceable. A back to the step heel 35 subsequent, substantially radially extending step section 38 acts as a counter-stop for the thermal expansion element 10 by the end 23 on the inside 40 of the step section 38 is applied. In a thermally induced expansion of the thermal expansion element 10 in the one of the rings 6a and 6b limited recording room 21 in the axial direction A, this causes an immediate axial displacement of the end portion 34 , which can be supported for temperature compensation in a conventional manner to a transmission housing-side stop surface, not shown.

The 5 and 6 Finally, show a further modification of a device according to the invention, in which a first bearing part ring 6a ' a bearing outer ring 6a ' with a constant concentric, ie offset-free outer surface 41 is used. This has the advantage that the lateral surface does not need to be additionally processed. On the ring 6a ' is a separate (inner) sleeve 42 deferred, in the rear area a flange 44 for the back end 24 the thermal expansion element 10 having. The sleeve 42 has a bend 46 with which she is at a recess 47 on board 48 of the ring 6a ' supported. Otherwise it finds in connection with the 3 and 4 detailed bearing ring 30 Use and serves with its vertical, radially extending step section 38 inside as a stop 39 for the other end 23 the thermal expansion element 10 ,

The 7 shows in a perspective view a partial longitudinal section of a tapered roller bearing with a further device according to the invention, wherein the bearing outer ring 50 is designed as a split outer ring by two trained as metal sleeves bearing part rings 50a . 50b mesh. The partial rings are in their respective cross section 51 . 52 L-shaped. They are so interlaced that they have a recording room 53 form between themselves and complete to the outside. This has longitudinally tapered walls 56 . 57 coming from the axial inner walls of the partial rings 50a . 50b are formed. This results in a recording room 53 which has a conical shape. The receiving space is with a material, such as an elastomer, (thermal expansion element) 58 Filled, which has a high thermal expansion coefficient (z. B. VITON ^® with α = 1.5 × 10 ^-4 × 1 / K). With temperature-dependent expansion of the material, the rings move 50a . 50b relative to one another, the walls of which, as indicated only schematically, provide a permanent and sealing contact by cooperating form elements (eg grooves and webs).

8th shows (in terms of extent in exaggerated representation) in longitudinal section two operating situations of the device according to 7 at a temperature of 20 ° C or 120 ° C. At a temperature of 20 ° C (see left part of the 8th ) sits a camp 60 with a device according to the invention fixed to its bearing inner ring 61 on one end 62 a shaft to be stored 63 , The bearing outer ring 50 is part rings as previously described by second camp 50a . 50b formed, wherein the second, outer part ring 50b in a tight fit in a hole 64 an aluminum housing 66 is included. Between the partial rings is the thermal expansion element 58 in the recording room 53 recognizable.

When the temperature rises to 120 ° C, the case is 66 axially and radially much more expanded than the shaft 63 , Therefore, the results in the right part of 8th - greatly exaggerated - widening of the bore 64 with the result that the bearing assembly without temperature compensation would be taken only with play and thus a possible original bearing preload would be changed. The extent of the thermal expansion element 58 leads to an increase in pressure in the recording room 53 , due to which the relatively movable bearing part rings 50a . 50b as indicated in the axial A and R radial direction away, so that a resulting shift (arrow V) of the partial ring 50a leads to a compensation of these effects.

In 9 the three previously described embodiments are shown in a combined longitudinal section, wherein the arrow F each symbolizes the flow of force at axial load.

In the left part of the 9 (Embodiment according to the 1 and 2 ) is the power flow through the bearing inner ring 2 , the rolling elements 4 , the bearing outer ring 6 , the thermal expansion element 10 and the ring piston 22 shown, with this over bearing part ring 6b or its bend 18 supported on the outside on a housing section, not shown.

9 shows in the central region (according to the embodiments according to 3 and 4 ) the basically same power flow over the bearing inner ring 2 , the rolling elements 4 , the bearing outer ring 6 , the thermal expansion element 10 however, about the grading 33 of the edge 32 of the partial ring 30 runs.

In 9 on the right is the first over the bearing inner ring 2 , the rolling elements 4 , the bearing outer ring 6 ' , the thermal expansion element 10 , the separate sleeve 42 and the grading 33 extending force flow visible.

It can be seen that due to the relatively large axial extent of the receiving space 21 for the thermal expansion element 10 even with inexpensive materials a magnitude relatively long length and thus temperature compensation exists. In contrast, the required additional radial space of the device according to the invention is very low. The devices according to the invention are also characterized by the fact that they require no additional axial space.

The separate bearing part rings form a reliably encapsulated receiving space in design and manufacturing technology simple manner 21 , so that the material of the thermal expansion element 10 no high resistance requirements have to be made with regard to external media.

The sealing essentially takes place via a steel / steel contact between the partial rings. partial ring 6b respectively. 30 Can easily with the tapered roller bearing in a z. B. housing side provided receiving bore be pressed.

Even though in the context of embodiments with configurations arranged on the outer bearing ring temperature compensation devices are shown in the same way, a realization on Inner bearing ring conceivable.

1

roller bearing

2

Bearing inner ring

3

tread

4

rolling elements

5

bearing cage

6 6 '

Bearing outer ring

6a, 6a '

Bearing part ring

6b

Bearing part ring

7

tread

8th

recess

9

elastomer

10

Thermal expansion element

12

outer sleeve

 13

outer lateral surface

14

Border area v. 6b

 15

Back edge / bridge v. 6a

18

bent-over edge

19

front

20

bearing board

21

accommodation space

22

annular piston

23

front end v. 10

 24

rear The End

30

Bearing part ring

32

border area

33

step

34

end

35

stepped shoulder

36

Coat of v. 6

38

step portion

39

Stop in inside 38

40

Inside v. 38

 41

Lateral surface v. 6a '

 42

shell

44

flange

46

bend

47

recess

48

Warehouse v. 6a '

 50

Bearing outer ring

50a, 50b

Bearing part rings

51 52

cross-section

53

accommodation space

56 57

Walls v. 53

 58

Thermal expansion element

60

camp

61

Bearing inner ring

62

The End

63

wave

64

drilling

66

aluminum housing

A

axial direction

F

arrow power flow

 R

radial direction

V

arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 5028152 [0004]

Claims (12)

Device for compensating axial thermal expansions of a rolling bearing arrangement - with a bearing ring ( 6 ) having a receiving space for a thermal expansion element ( 10 ), characterized in that - the bearing ring ( 6 ) from two bearing rings ( 6a . 6b ), the first bearing part ring ( 6a ) a rolling body tread ( 7 ) and the second bearing part ring ( 6b ) an outer circumferential surface ( 13 ) forms the rolling bearing assembly, - wherein the bearing part rings ( 6a . 6b ) the recording room ( 21 ) between them and encapsulate to the outside and - whereby the bearing part rings ( 6a . 6b ) due to thermally induced volume changes of the thermal expansion element ( 10 ) are displaceable relative to each other at least in the axial direction (A). Apparatus according to claim 1, characterized in that - the one bearing part ring ( 6b ) in the axial direction (A) over the entire length of the other bearing part ring ( 6a ). Apparatus according to claim 1 or 2, characterized in that - a bearing part ring ( 6a ) a circumferential recess ( 8th ), in which the thermal expansion element ( 10 ) is at least partially included, - and that the other bearing part ring ( 6b ) this recess ( 8th completely covered. Device according to one of the preceding claims, characterized in that - the bearing part rings ( 6a . 6b ) are connected to each other at least at one point. Device according to one of the preceding claims, characterized in that - the first bearing part ring ( 6a ) is a separate outer sleeve. Device according to one of the preceding claims, characterized in that - the bearing part rings ( 50a . 50b ) a conical receiving space ( 53 ) limit. Device according to one of the preceding claims, characterized in that - the bearing part rings ( 50a . 50b ) have approximately L-shaped cross-section. Device according to one of the preceding claims, characterized in that - the bearing part rings ( 50a . 50b ) Side walls ( 56 . 57 ), which with the respective other bearing part ring ( 50b . 50a ) cooperate so that the bearing rings ( 50a . 50b ) axially and radially relative to each other, while the receiving space ( 53 ) remains encapsulated to the outside. Device according to one of the preceding claims, characterized in that - between a bearing part ring ( 6a ' ) and the recording room ( 8th ) a separate intermediate sleeve ( 42 ) is arranged. Device according to one of the preceding claims, characterized in that - between a bearing part ring ( 6b ) and the thermal expansion element ( 10 ) in the axial direction (A) force-transmitting piston (A) 22 ) is arranged. Device according to one of the preceding claims, characterized in that - at least one edge region ( 18 ) of a bearing part ring ( 6b ) is bent over to a front side ( 19 ) of the other bearing part ring ( 6a ). Device according to one of the preceding claims, characterized in that - the edge region ( 32 ) of a bearing part ring ( 6b ) is stepped axially, wherein a substantially radially extending step portion ( 38 ) on the inside in contact with the thermal expansion element ( 10 ).