DE10260904A1 - Compressor for vehicle air conditioning system has crankshaft roller bearing held in contact with bearing race surface by spring washer - Google Patents

Abstract

A vehicle has an air conditioning system with an air compressor linked via an electromagnetic clutch between crankshaft and compressor. The crankshaft has a roller bearing (11) that is held in contact with the roller bearing race surface by a spring washer (18).

Description

The invention relates to a device with a rotating element around a piston machine, especially an electromagnetically actuated friction disc clutch, e.g. Compressor clutch, a tension pulley or a vibration damper with at least one comprising an inner ring, an outer ring and rolling elements roller bearing according to the preamble of claim 1.

State of the art:

Devices of the type described in the introduction are diverse in vehicles embodiments already known.

For example, in air conditioning for vehicles Air conditioning compressors over Belt drives or cardan shafts powered by the vehicle engine are connected. Turning the compressors on and off, which are regular piston compressors are trained, e.g. about an electromagnetically operated Friction disc clutch.

A common embodiment of an electromagnetically actuated friction disc clutch is constructed as follows:
An annular electromagnet, which comprises an annular coil, which lies in a U-shaped circular ring, is screwed tightly to a compressor housing. A rotor is mounted on a compressor shaft, e.g. via a conical seat with an additional disc spring as an anti-rotation device and a clamping screw. The rotor encloses the ring-shaped electromagnet in a U-shaped cross section. A flange for mounting a belt pulley is rotatably mounted on a roller bearing on the hub of the rotor. An armature disk with an air gap to the rotor is arranged on the flange in the radial direction in the area of the ring-shaped electromagnet. The armature disk is connected to the flange via one or more springs. When the electromagnet is energized, the armature disk is pulled against the rotor, which brings the rotor and thus the drive shaft of the compressor to the same speed as the flange of the pulley.

When the electromagnet is not energized the flange with the armature disk rotates at idle, i.e. the compressor shaft stands.

Double-row bearings are regularly used Angular contact ball bearings or two deep groove ball bearings are used. When not switched the friction disc clutch (electromagnet is not energized) is running outer ring of the bearing at the speed of the flange, with the inner ring standing. With the friction disc clutch switched (electromagnet is energized) there is no relative speed between the inner ring and outer ring of the rolling bearing on, i.e. the rolling elements between Inner and outer ring of the rolling bearing do not Roll out. This represents for the rolling bearing is a problematic condition because the compressor and also the Drive motor generate vibrations that lead to micro movements of the rolling elements in the roller bearing to lead can what damage in the rolling bearing can entail, which are referred to as standstill vibration damage. This damage does not occur regularly with rolling elements rolling during operation on.

To avoid damage from standstill vibrations, is trying the rolling bearings very precise to build a too big one Game of rolling elements between Inner ring and outer ring, which favors standstill vibrations, to avoid. Already a play of more than 10 μm can follow in normal operational use short time to vibration damage to lead.

Task and advantages of Invention:

The invention is based on the object Devices with rotating elements in the area of piston machines are arranged and which have at least one roller bearing on which Standstill vibrations can occur, if possible extensive prevention or total avoidance of damage to achieve through standstill vibrations.

This task is due to the characteristics of claim 1, 2 and 8 solved. In the subclaims are advantageous and expedient further training specified the invention.

The invention is initially based on a device with a rotating element in the vicinity of a piston machine, in particular an electromagnetically actuated friction disc clutch, for example a compressor clutch, a tensioning roller or a vibration damper, which has at least one roller bearing comprising an inner ring, an outer ring and rolling elements, which has a first Operating state shows in which the inner ring has no relative rotational movement with the piston machine running and can assume a second operating state in which there is a relative rotational movement between the inner ring and the outer ring. The essential aspect of the invention is that tensioning means are provided which preload the at least one roller bearing in such a way that at least in the first operating state of the roller bearing there is essentially no play between the roller bodies and a respective raceway of the inner and outer ring. Backlash-free means that the rolling elements lie against the respective raceways. A desired rolling motion of the rolling elements is to be distinguished from this. This procedure is based on the knowledge that even with a manufacturing process, however precise, a play of the rolling elements in a state in which they do not perform a rolling movement cannot be avoided and thus the risk of damage to standstill vibrations due to precise manufacturing can never be eliminated with certainty. At the proposed In this way, the rolling bearings, which are considered in isolation, manufacturing inaccuracies and thus a certain amount of play can be permitted, since clamping devices ensure that this play cannot have an effect by preloading the rolling bearing parts. The tensioning means are preferably designed so that acceleration forces, especially when the rolling elements are at a standstill, do not become so great that they can overcome the preload of the bearing and, in turn, micro-movements of the roller bearing elements with corresponding damage are possible.

In another essential embodiment The invention proposes that the at least one rolling bearing two parallel careers for Includes rolling elements, being the inner ring or the outer ring is divided between the raceways and has a gap. In particular in connection with an angular contact ball bearing this approach already brings decisive advantages without clamping devices, because of the due to the sharing of the interior or outer ring changed Direction of the support forces on the Rolling elements the "base distance" of the rolling bearing be enlarged can. By enlarging Base distance becomes the load-bearing capacity of the rolling bearing elevated, it is particularly against tipping forces and therefore corresponding vibration forces more stable, e.g. of Standstill vibrations originate. additionally can also be a roller bearing, in particular angular contact ball bearings, with split inner or outer ring can be provided with clamping devices, which in itself is sufficient vibration-stable bearing is further improved or the possibility results in a rolling bearing, e.g. an angular contact ball bearing with reduced precision use. Because about the clamping devices become the rolling bearing parts then so braced against each other that the normally occurring free play never comes to fruition.

In a further preferred embodiment at least two rolling bearings provided that against each other the clamping devices are clamped. As a bearing types are principally Angular contact ball bearings prefers. It can but also other types of ball bearings such as Deep groove ball bearings, shoulder ball bearings, cylindrical roller bearings or tapered roller bearings can be used to advantage.

The clamping devices can be between and / or on the Sides of the rolling bearings to be ordered.

With a side arrangement should care should be taken that an outer or inner ring of a rolling bearing narrower than the corresponding one Inner or outer ring is. The degree of width reduction is preferably so too dimension that the respective narrowed outer rings or inner rings at a play-free concern of the rolling elements the respective careers by appropriate preloading touch. This can ensure that the pre-tensioning the rolling bearing elements Always move it far enough so that the rolling elements are free of play.

In a particularly preferred Embodiment of the invention, the clamping means comprise a spring element, e.g. a disc spring, a spiral spring and / or an elastomer spring and / or another element that at least temporarily relates to a Inner or outer ring of the rolling bearing can exert an, in particular axial, force.

The spring elements are preferred designed so that in addition the corresponding bearing against the influences of outside, like e.g. the ingress of dirt and possibly water, in particular additionally protects to a bearing seal. The spring element can fulfill this purpose in particular if it on the outside the rolling bearing is arranged. For example, disc springs are dimensioned so that the end face of a rolling bearing is covered at least in the open areas of the rolling bearing.

An improvement on conventional rolling bearings with regard to standstill vibration damage can also be achieved that parts of the rolling bearing covered with a wear-reducing layer become. Rolling bearings also have advantages with parts made of rustproof materials. That by an appropriate one Material selection of the complete parts or a coating of the Parts the service life of the rolling bearings continue to improve.

In the case of an introductory device designated type is another essential aspect of the invention in that the rolling bearing comprises an intermediate ring and braking means are provided which are connected to the intermediate ring and make sure that at the same Speed rotating outdoor and the inner ring of the intermediate ring performs a relative rotary movement to this and with rotating outer ring the intermediate ring does not assume the speed of the outer ring. By this variant of the invention becomes a standstill of the rolling elements in the rolling bearing independently from the operating state of the rolling bearing avoided. This is e.g. achieved by that on the intermediate ring a fan wheel is attached, which generates a braking torque. This braking moment reduces the speed of the intermediate ring when the inner and the outer ring of the rolling bearing would move at the same speed, with what all rolling elements primarily between the intermediate ring and the outer ring and between the intermediate ring and roll inner ring. When the outer ring rotates, this always prevents existing bearing friction that the intermediate ring remains and such a situation could arise that the rolling elements do not roll between the intermediate ring and the inner ring. on the other hand The braking torque prevents the intermediate ring from being the same Speed rotates like the outer ring, when the inner ring is standing.

An alternative or additional option for generating a braking torque on Bearing intermediate ring can be realized with an eddy current brake. This is connected to the intermediate bearing ring and preferably acts on a non-rotatable counter element, for example a counter ring washer.

Drawings:

Several embodiments of the invention are shown in the drawings and indicating other advantages and details closer explained. It demonstrate:

1 a compressor clutch with partially shown compressor elements and a drive wheel, which is arranged with two preloaded roller bearings, in a sectional side view along a plane in which the axis of the drive shaft of the compressor lies,

2 one too 1 correspondingly shown compressor coupling with a different rolling bearing structure,

3a - 3c one too 1 corresponding representation, but with two roller bearings that are preloaded in the middle,

4 one too 1 corresponding representation, but with an angular contact ball bearing with a split inner ring and

5 one too 1 correspondingly shown compressor clutch, but with a double roller bearing.

Description of the embodiments:

In 1 is a section of a compressor 1 with a compressor clutch 2z .B. shown an air conditioning system for a vehicle.

The compressor clutch 2 is designed as a friction disc clutch and is used to switch the compressor on and off. The compressor clutch 2 comprises an annular electromagnet 3 which is an annular coil 3a has in a U-shaped annulus 4 is arranged, which via holding means 5 with the housing 6 of the compressor 1 is screwed tight. On a compressor shaft 7 is about a cone seat 7a with additional disc spring 8th as an anti-rotation device and a clamping screw 9 a rotor 10 appropriate.

The rotor 10 includes on its outer circumference in a U-shaped circular ring profile 10a the electromagnet 3 on three sides. On the hub 10b is about two rolling bearings 11 . 12 a rotary flange 13 for the assembly of a pulley (not shown) rotatably arranged. On the flange 10 is about one or more flat springs 14 a circular washer 15 with air gap 16 the electromagnet 3 positioned opposite.

In the non-switched state of the compressor clutch 2 is the electromagnet 3 not energized, causing the flange 13 with feather 14 and armature disk 15 Turn empty and the compressor shaft is stopped. By energizing the electromagnet 3 forms over the circular ring 4 the circular ring profile 10a of the rotor 10 and the anchor ring washer 15 a magnetic circle, bringing the armature disc to the annulus profile 10a of the rotor 10 is pulled and thus a frictional connection between the rotor 10 and rotary flange 13 manufactures. This allows the rotary flange to rotate 13 on the rotor 10 transmitted, with which the compressor 1 via the compressor shaft 7 is driven.

With regard to the rolling bearings 11 . 12 is available according to the switched or not switched compressor clutch 2 also two operating states. In the non-switched state of the compressor clutch 2 the rolling bearings are running 11 . 12 with the speed of the rotary flange 13 , ie the outer rings 11a . 12a rotate at the speed of the rotary flange 13 where the inner rings 11b . 12b stand. With the compressor clutch switched 2 there is no relative speed between the outer and inner rings of the roller bearings 11 . 12 ,

The condition in which there is no relative speed between the inner and outer ring represents the problematic condition for operation. The compressor and the drive motor transmit vibrations to the naturally non-rolling rolling elements 11c . 12c the rolling bearing 11 . 12 , In a conventional construction, the vibrations in this operating state can lead to micro-movements of the rolling elements 11c . 12c lead between the respective outer and inner ring, which can result in bearing damage, which is referred to as standstill vibrations. With rolling elements rolling 11c . 12c Such damage usually does not occur.

In order to avoid the standstill vibrations, it must be prevented that rolling elements are stationary 11c . 12c cannot form micro movements.

This is in 1 thereby achieved that on the inner ring of the rolling bearing 12 via a spacer washer 17 two pre-tensioned disc springs 18 . 19 press down on the hub 10b of the rotor 10 on a support element 20 support. This will make the inner ring 12b in 1 pushed to the left, causing over the ball 12c a corresponding force to the left on the outer ring 12a acts on the outer ring 11a of the second rolling bearing 11 supports and over its ball 11c a shifting force, also to the left, on the inner ring 11b of the rolling bearing 11 acts. This is based on a paragraph 21 on the hub 10b of the rotor 10 from. The inner rings 11b . 12b are compared to the outer rings 11a . 12b slightly smaller in width, creating a gap 22 arises. This ensures that when the spring force is exerted by an always existing play, the inner rings 11b . 12b do not touch each other, but the power transmission described can take place to compensate for the game to zero. When dimensioning the disc springs 18 . 19 a variety of other spring elements or elastic organs can be used. However, it should preferably be ensured that the pretensioning force is so high that acceleration forces on the individual parts essentially cannot overcome the pretensioning forces in order to always avoid the development of play in the problematic situations that normally occur.

If the game is blocked, then also standstill vibrations due to the lack of play and thus avoidance of relative movements of the individual bearing elements no harm to each other cause on the bearings.

In the following figures there is always the same compressor with compressor clutch 2 shown, only the storage between the rotary flange 13 and hub 10b is designed differently.

In 2 is a double row rolling bearing instead of two rolling bearings 23 used, in which the outer ring 23a is in one piece. On the other hand, the inner ring is divided into two, the two inner rings 23b . 23c divided up. According to a corresponding power transmission as in the embodiment 1 can be reached between the inner rings 23b . 23c A gap 24 provided the compensatory movements of the parts of the rolling bearing 23 to reduce the game to zero.

In the 3a to 3c come two rolling bearings each 30 . 31 respectively. 32 . 33 respectively. 34 . 35 for use in which spring elements between the respective roller bearings 36 . 37 . 38 are arranged to preload the roller bearings between the roller bearings. The force effect of the spring elements is an example 3a are explained. The spring elements 36 in 3a include two preloaded Belleville washers 36a . 36b , On the rotary flange 13 the disc springs are supported 36a . 36b on a securing element 39 from which, on the one hand, the spring force on the outer ring 31a of the rolling bearing 31 , but in the same way on the outer ring 30a of the rolling bearing 30 is transmitted. This is because in relation to the outer ring 31a the rotary flange 13 together with the securing element 39 can move axially freely. As a result, the rolling elements are each of the spring elements 36 seen pushed outwards. This happens to the same extent with the respective inner rings 30c respectively. 31c , This outward movement on the inner rings 30c . 31c is on the one hand through the paragraph 21 on the hub 10b of the rotor 10 and on the other hand by another holding means 40 prevented.

The holding device 40 is exemplary as a security element 41 designed, in front of which a cover washer 42 is arranged. The structure of the bearings according to 3b and 3c is essentially identical with regard to the basic force effect of the spring elements with the difference that instead of two angular contact ball bearings, as in 3a , in 3b Tapered roller bearings and in 3c Deep groove ball bearings are used.

In 4 becomes a double row angular contact ball bearing 43 for the storage of the rotary flange 13 used. The double row angular contact ball bearing has a one-piece outer ring 43a , On the inside are two spaced inner rings 43b and 43c intended. By dividing the inner ring, the rolling element running surface and thus the base spacing b of the angular contact ball bearing can be achieved with otherwise the same dimensions 43 be enlarged. With regard to standstill vibrations, the enlarged rolling element running surface is advantageous because the load capacity of the bearing is increased, which is thus also more stable against tilting forces and corresponding vibratory forces.

In 5 is an embodiment of a compressor 1 with compressor clutch 2 shown, in which the bearing of the rotary flange 13 on the hub 10b of the rotor 10 a double ball bearing 50 (Three-ring bearing) is provided. With this bearing variant, the rolling elements come to a standstill 51a to 51d with the compressor clutch switched 2 as well as when the compressor clutch is not actuated 2 avoided. With the compressor clutch switched 2 would the outer ring in a conventional embodiment with a simple rolling bearing 52a as well as the inner rings 52b and 52c Rotate together at the same speed, causing the rolling elements 51a to 51d would not roll. Even when inserting an intermediate ring 53 nothing would change at first in this operating state, ie the rolling elements would still 51a to 51d do not roll.

The intermediate ring 53 but is with a fan wheel 54 connected, which generates a braking torque. This braking torque reduces the speed of the intermediate ring, so that all rolling elements 51a to 51d roll, although the outer ring 52a and the inner rings 52b and 52c turn at the same speed.

When the compressor clutch is not switched 2 the rotary flange turns 13 on the stationary compressor shaft 7 , The bearing friction in the double ball bearing 50 on the rolling elements 51a and 51b however prevents the intermediate ring 53 just like the two inner rings 52b and 52c not rotating. Through the fan wheel 54 however, it is avoided that the intermediate ring 53 as fast as the rotary flange 13 rotates.

1

compressor

2

compressor clutch

3

electromagnet

3a

Kitchen sink

4

annulus

5

holding means

6

casing

7

compressor shaft

7a

conical seat

8th

Woodruff

9

clamping screw

10

rotor

10a

Annulus profile

10b

hub

11

roller bearing

11a

outer ring

11b

inner ring

11c

rolling elements

12

roller bearing

12a

outer ring

12b

inner ring

12c

rolling elements

13

rotary flange

14

flat spring

15

Anchor washer

16

air gap

17

spacer

18

Belleville spring

19

Belleville spring

20

supporting

21

paragraph

22

gap

23

double row roller bearing

23a

outer ring

23b

inner ring

23c

roller bearing

24

gap

30

roller bearing

30a

outer ring

30b

rolling elements

30c

inner ring

31

roller bearing

31a

outer ring

31b

rolling elements

31c

inner ring

32

roller bearing

33

roller bearing

34

roller bearing

35

roller bearing

36

spring element

36a

Belleville spring

36b

Belleville spring

37

spring element

38

spring element

39

fuse element

40

holding means

41

fuse element

42

Abdeckringscheibe

43

double row Angular contact ball bearings

43a

outer ring

43b

inner ring

43c

inner ring

50

Dual ball bearing

51a

rolling elements

51b

rolling elements

51c

rolling elements

51d

rolling elements

52a

outer ring

52b

inner ring

52c

inner ring

53

intermediate ring

54

Luftrad

Claims (10)

Contraption ( 2 ) with a rotating element ( 13 ) around a piston machine ( 1 ) with at least one inner ring ( 11b . 12b . 23b . 30c . 31c . 43b . 43c . 52b . 52c ), an outer ring ( 11a . 12a . 23a . 30a . 31a . 43a . 42a ) and rolling elements ( 11c . 12c . 30b . 31b . 51a to 51d ) comprehensive rolling bearings ( 11 . 12 . 23 . 30 . 31 . 32 . 33 . 34 . 35 . 43 . 50 ), which shows a first operating state in which the inner ring ( 11b . 12b . 30c . 31c . 43b . 43c . 52b . 52c ) to the outer ring ( 11a . 12a . 23a . 30a . 31a . 43a . 42a ) no relative rotation when the piston machine is running ( 1 ) and can assume a second operating state in which a relative rotary movement between the inner ring ( 11b . 12b . 23b . 30c . 31c . 43b . 43c . 52b . 52c ) and the outer ring ( 11a . 12a . 23a . 30a . 31a . 43a . 42a ) is given, characterized in that clamping means ( 18 . 19 . 36 . 36a . 36b . 37 . 38 ) are provided, which the at least one rolling bearing ( 11 . 12 . 23 . 30 . 31 . 32 . 33 . 34 . 35 . 43 . 50 ) preload in such a way that at least in the first operating state of the rolling bearing ( 11 . 12 . 23 . 30 . 31 . 32 . 33 . 34 . 35 . 43 . 50 ) between the rolling elements ( 11c . 12c . 30b . 31b . 51a to 51d ) and a respective raceway of the inner and outer ring essentially no play occurs. Device according to the preamble of claim 1, in particular according to claim 1, characterized in that at least one rolling bearing ( 23 . 43 . 50 ) two parallel raceways for rolling elements ( 51a to 51d ), the inner ring ( 53b . 53c . 43b . 43c . 52c . 52b ) is divided between the raceways and a gap ( 24 ) having. Device according to claim 1 or 2, characterized in that at least two rolling bearings ( 11 . 12 . 30 . 31 . 32 . 33 . 34 . 35 ) are provided, which are mutually over the clamping means ( 18 . 19 . 36 . 36a . 36b . 37 . 38 ) are tense. Device according to one of the preceding claims, characterized in that the clamping means ( 36 . 36a . 36b . 37 . 38 ) between the roller bearings ( 30 . 31 . 32 . 33 . 34 . 35 ) are arranged. Device according to one of the preceding claims, characterized in that an outer or inner ring ( 11b . 12b ) narrower than the corresponding inner or outer ring ( 11a . 12a ) is. Device according to one of the preceding Claims, characterized in that the clamping means a spring element ( 18 . 19 . 36 . 36a . 36b . 37 . 38 ) or include another element that at least temporarily exerts a force on an inner or outer ring. Device according to one of the preceding claims, characterized in that the spring element ( 18 . 19 ) is designed such that there is at least one bearing ( 11 . 12 ) protects against external influences. Device according to the preamble of claim 1, in particular according to one of the preceding claims, characterized in that the roller bearing ( 50 ) an intermediate ring ( 53 ) includes and brake means ( 54 ) are provided which are connected to the intermediate ring ( 53 ) and ensure that the outer and inner rings rotate at the same speed ( 52a . 52c . 52b ) the intermediate ring ( 53 ) performs a relative rotary movement and with the outer ring rotating ( 52a ) the intermediate ring the speed of the outer ring ( 52a ) does not accept. Apparatus according to claim 8, characterized in that the braking means a fan wheel ( 54 ) include. Device according to claim 8 or 9, characterized in that that the braking means comprise an eddy current brake.