CN105299069B

CN105299069B - Coupling device

Info

Publication number: CN105299069B
Application number: CN201510305612.6A
Authority: CN
Inventors: 安德烈亚斯·特林肯舒
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2014-06-12
Filing date: 2015-06-05
Publication date: 2020-08-18
Anticipated expiration: 2035-06-05
Also published as: CN105299069A; DE102014211272A1; DE102014211272B4

Abstract

A coupling for compensating radial offset, said coupling having two discs, a driving disc and a driven disc; and a compensating element which can be displaced in the radial direction relative to each of the disks, wherein the two disks lie in a common plane and are coupled to the compensating element by means of cylindrical rolling bodies, the axes of which are oriented parallel to the axes of the disks.

Description

Coupling device

Technical Field

The present invention relates to a coupling which allows a radial offset between two shafts coupled to each other. Couplings with this function are known as oldham couplings or oldham couplings, for example from DE 1704337U and from EP 1225357B 1.

Background

A coupling for compensating radial deviations generally comprises two discs, a driving disc and a driven disc, and a compensating element which is movable in a radial direction relative to each disc. For example, DE 19857248C 2 discloses that the compensating elements of the oldham coupling can interact with shafts coupled to one another via a tongue and groove system. For the production of the compensation element, plastics can also be used in addition to the metal raw material. For example, reference is made herein to EP 0416125 a 1.

In all the raw materials used to produce the parts of the coupling that compensate for the radial offset between the two shafts, the friction occurring between the individual parts during operation of the coupling is not negligible. Precautions which should ensure favorable lubrication conditions are described, for example, in the so-called DE 19857248C 2. In addition to the lubrication conditions, surface compression, which may be associated with radial offset between the shafts, is also considered in the design of the oldham coupling. Typically, the radial and axial dimensions of the coupling to overcome the radial offset between the two shafts are related to the torque transmitted between the shafts.

Disclosure of Invention

The basic object of the present invention is to provide a coupling which is improved with respect to the prior art, in particular with respect to the relationship between installation space and torque transmission performance and friction, and which enables torque transmission between shafts which are parallel to one another.

According to the invention, this object is achieved by a coupling for compensating radial offset according to the invention. The coupling provided for compensating for the varying radial offset between the two shafts comprises two discs, a drive disc and a driven disc. The terms driving disk and driven disk are only chosen here to distinguish the two disks verbally and do not relate to conclusions about the direction of torque transmission. In addition to the two disks, the coupling comprises a preferably likewise disk-shaped compensating element which can be moved in the radial direction of the coupling. The compensation element is located on the end sides of the two disks, wherein the two disks lie in a common plane. The force-transmitting connection between the compensating element and the disk is established by cylindrical rolling elements, the axis of which is parallel to the axis of the disk.

Each rolling element, which engages on the one hand into the compensating element and on the other hand into a disk, contacts at least one notch-like contour on the side of the compensating element and/or of the disk, that is to say of the driving disk or of the driven disk. As a result, during operation of the coupling, the rolling bodies roll on at least one surface which shows a notch-like contour when the compensating element moves radially. Preferably, not only the compensating element but also each disk is configured such that the cylindrical rolling bodies can be moved in the radial direction of the respective component.

The use of rolling bodies for the transmission of force between the drive disk and the compensating element and between the compensating element and the driven disk ensures that the coupling operates with very low friction with simultaneously high transmissible torques. At the same time, the coupling is designed in an extremely space-saving manner in the axial direction by engaging the drive disks and the driven disks with one another. Furthermore, the small installation space occupied by the coupling in the axial direction ensures that only small tilting moments act on the cylindrical rolling bodies oriented along the shafts coupled to one another during the transmission of torque between the shafts.

According to one possible embodiment, one disk is non-circularly shaped, in particular at least approximately rectangularly shaped, and is arranged in a correspondingly shaped recess of the other disk. In this case, circumferential gaps are formed between the disks, which allow a variable offset between the disks, each connected to one shaft.

The connection between the disk and the shaft can be realized by different connection mechanisms. For example, the larger of the two disks can have a hole that can be used for screwing or riveting with a flange that is connected with one of the shafts. The smaller disk, which preferably has a rectangular basic shape, can instead have, for example, a flange which passes through a central opening in the compensating element. The flange can be connected to one of the shafts, for example, by means of an internal toothing.

As long as the shafts coupled to one another by the coupling are aligned with one another, the rolling bodies held in the first disk and the rolling bodies held in the second disk preferably lie on a common pitch circle. This means that the center axis of each cylindrical rolling element lies on a single, virtual cylinder. In a possible, constructionally simple embodiment, exactly one pitch circle is present, on which a total of four cylindrical rolling elements are present. Two of the rolling bodies are guided in the drive disk and the other two rolling bodies are guided in the driven disk. Simultaneously, all rolling elements contact the compensating element.

According to a further improved embodiment, two rolling element arrangements offset by 180 degrees relative to one another are guided in the drive disk. In a corresponding manner, two rolling element arrangements are also guided in the driven disk, wherein the rolling element arrangements of the driving disk are twisted by 90 ° relative to the rolling element arrangements of the driven disk. Each of the so-called rolling element arrangements comprises a plurality of rolling elements, in particular two rolling elements, which are offset with respect to one another in the radial direction. The cylindrical rolling bodies belonging to the rolling body arrangement are preferably guided in a common, elongated recess of the drive disk or the driven disk and in a further likewise elongated recess of the compensating element. In contrast, separate recesses can also be provided on the disk or on the compensating element for different rolling bodies of the same rolling body arrangement.

In an advantageous embodiment, the compensation elements arranged on the end sides of the two disks have a punching point which minimizes the friction between the compensation elements and the disks. In the same way, the drive disk and the driven disk can also have approximately punctiform elevations, which contact the compensation element. In any case, a small number of punching points is sufficient, since the coupling generally does not have to absorb high axial forces. In contrast, the cylindrical surfaces of the rolling bodies and the surfaces of the disks and of the compensating elements that interact with the cylindrical surfaces of the rolling bodies are subjected to significantly higher surface loads during operation of the coupling. For this purpose, the respective surfaces can be subjected to a surface treatment and/or coating in the manufacture of the components of the coupling.

In a preferred embodiment, a total of, for example, four or eight cylindrical rolling bodies of the coupling are guided in a common rolling body retaining device. The rolling element retaining device comprises retaining elements which are arranged on both end sides of the coupling and are each substantially annular, said retaining elements being connected to one another by pins. In this case, each pin passes through the compensating element and the drive disk or the driven disk. A cylindrical rolling body is supported on each pin. By means of suitable materials and component cross sections, the rolling element retaining device is preferably at least slightly elastically formed. In this way, the force peaks during operation of the coupling can be smoothed and also an at least slightly flexible behavior of the coupling in the axial direction of the shaft is formed. This allows small angular errors between the shafts to be tolerated at the same time.

In a simple embodiment, the cylindrical rolling bodies are mounted directly on the pins of the rolling body retaining device. In contrast, a complex embodiment, which is further optimized with respect to friction, proposes the use of additional bearing elements between the cylindrical rolling elements and the pins. The bearing element can be a sliding bush or a bearing pin. The two retaining elements of the rolling element retaining device which are located on the same side of the coupling are preferably each designed and arranged such that a majority thereof lies in a common plane. The plane is located in close proximity to the plane in which the compensation element is located or in which the driving disk and the driven disk are located, wherein the retaining element can have a plurality of raised points, similar to the stamped points of the compensation element, for minimizing friction and contacting one of the disks or the compensation element.

The coupling is suitable for installation in a drive train of a hybrid vehicle, for example. The coupling can be located between a hybrid module and a transmission of the vehicle. A particular advantage of the coupling is that it transmits high torques and at the same time generates only very small forces in the radial direction in an extremely compact construction in the axial direction, which advantageously act on the bearing loads in the drive train. Furthermore, the coupling can be mounted and dismounted in the drive train in a simple manner.

Various embodiments of the present invention are set forth in detail below with reference to the accompanying drawings.

Drawings

Fig. 1 shows a perspective view of a coupling for compensating radial offset twice in each case;

fig. 2 shows two cross-sectional views of the coupling according to fig. 1;

fig. 3 shows an exploded view of the coupling according to fig. 1;

fig. 4 to 6 show different variants of the bearing mechanism for the cylindrical rolling bodies in the coupling;

figures 7 and 8 show perspective cross-sectional views of different details of the coupling;

fig. 9 to 14 show views similar to fig. 1 to 6 of a second embodiment of the coupling;

fig. 15 shows the various components of the coupling according to fig. 9 to 14; and

fig. 16 shows parts of the coupling according to fig. 1 and 9.

Detailed Description

Parts which correspond to one another and which in principle have the same function are denoted by the same reference numerals in all the figures. Unless otherwise stated, the following statements relate not only to the exemplary embodiment according to fig. 1, but also to the exemplary embodiment according to fig. 9. In both cases, the coupling, generally designated by reference numeral 1, has the function of an oldham coupling. With regard to the technical background, reference is made to the prior art cited at the outset.

The coupling 1 has two

discs

2, 3, a drive disc 2 and a driven disc 3, which can be connected to a shaft, not shown. The variable offset between the axes parallel to one another is compensated for by the coupling 1.

The disc, which is denoted without loss of generality as the drive disc 2, has an approximately rectangular, rounded base plate 4, from the center of which a flange 5 projects, which extends in the axial direction of the coupling 1. The base plate 4 and the flange 5 can be fixedly connected to one another, for example by welding, or can be formed as a one-piece component, for example produced by molding and/or machining. In the exemplary embodiment shown, the base plate 4 has a circular recess in its center, i.e., in the region of the transition to the collar 5. In contrast, the substrate 4 can also be closed at the corresponding points. In both cases, the flange 5 can have internal toothing, not shown, for connection to a corresponding shaft with external toothing.

The base plate 4 of the drive disk 2 is located in a recess of the driven disk 3, which recess corresponds to the approximately rectangular shape of the base plate 4, wherein a gap 6 is formed between the base plate 4 and the driven disk 3, which gap enables a movement of the drive disk 2 relative to the driven disk 3 in the radial direction of the coupling 1. The base plate 4 and the driven disk 3 thus engage in one another, the base plate and the driven disk lying in a common plane perpendicular to the axis of rotation of the coupling 1. The driven disk 3 has a bore 7 in its radial region outside the base plate 4, which can be used for connection to a flange, not shown. The flange can be connected fixedly to a driven shaft, which is likewise not shown, or via a vibration-damping element. On one of the end sides of the arrangement of the two

disks

2, 3 there is a likewise disk-shaped compensating element 8, the outer diameter of which corresponds approximately to the maximum dimension of the base plate 4 in the radial direction. The compensating element 8 has four recesses 9 extending in the radial direction, which are distributed symmetrically about the circumference of the compensating element 8. One (fig. 1 to 8) or two (9 to 15) cylindrical rolling bodies 10 engage in each of the recesses 9, the center axis of each cylindrical rolling body 10 being oriented parallel to the rotational axis of the coupling 1. Two rolling elements 10 located in the same recess 9 are referred to as a rolling element arrangement 11. In the exemplary embodiments shown in fig. 1 to 8, each rolling element arrangement 11 is identical to a single rolling element 10.

One rolling element 10 of the rolling element arrangement 11 or two rolling elements 10 of the rolling element arrangement 11 (fig. 9 and the following figures) engage in an elongated recess 12 in the base plate 4 of the drive disk 2 or in an likewise elongated recess (ausbuching) 13 in the driven disk 3. Each recess 12 in driving disk 2 has a closed edge, while notch 13 transitions into a central opening of driven disk 3, in which opening base plate 4 is arranged.

Two diametrically opposed rolling-body arrangements 11 interact with the compensating element 8 on the one hand and the drive disk 2 on the other hand, while two other, likewise diametrically opposed rolling-body arrangements 11 interact with the compensating element 8 on the one hand and the driven disk 3 on the other hand, respectively. The rolling-element assembly 11 interacting with the drive disk 2 is twisted by 90 ° relative to the rolling-element assembly 11 interacting with the driven disk 3. All rolling bodies 10 of the coupling 1 are guided in a rolling body retaining device 14. On each end side of the coupling 1, the rolling element retaining device has two substantially

annular retaining elements

15, 16, namely an inner retaining element 15 and an outer retaining element 16. The two inner holding elements 15 are connected to each other by a pin 17 which passes through the coupling 1 in the axial direction. The same applies to the connection between the two outer holding elements 16.

The rolling bodies 10, which effect the transmission of force between the compensating element 8 and the drive disk 2, are guided by external retaining elements 16. Each outer holding element 16 is approximately completely annular and accordingly lies in a single plane. Only in two circumferential regions, centrally between the rolling element arrangements 11 guided through the outer retaining element 16, the outer retaining element 16 has two offset sections 18 which slightly protrude in the axial direction relative to the remaining sections of the outer retaining element 16. By means of the projections of the offset portions 18, which can be easily realized by means of a molding technique, a free space in each of the portions is realized into which the internal holding element 15 can engage. In this case, the radially oriented projections 19 of the inner holding element 15 each extend into the free space formed by the offset portion 18. Furthermore, the inner holding element 15 is formed in an annular manner and is located radially inside the outer holding element 16. In this case, the entire inner holding element 15 and the approximately entire outer holding element 16, except for the offset section 18, lie in one and the same plane.

Due to the described design of the base plate 4 of the driven disk 3, of the compensating element 8 and of the rolling element retaining device 14, all rolling element arrangements 11 have the same spacing from the rotational axis of the coupling 1, provided that the shafts coupled to one another by means of the coupling 1 have the same rotational axis.

Different embodiments of the rolling elements 10 supported on the pins 17 of the rolling element retaining device 14 are illustrated in fig. 4 to 6 and in fig. 10 to 12. As can be seen from the figures, the rolling bodies 10 are supported either directly (fig. 4, 12), by means of sliding bushings 20 (fig. 5, 13) or by means of carrier pins 21 (fig. 6, 14). The sliding bush 20 and the carrier pin 21 are generally referred to as bearing elements.

In order to minimize the friction between the compensating element 8 and the

disks

2, 3, optionally, punch points are provided on the compensating element 8, as can be seen in fig. 7

22. A similar purpose is fulfilled by a raised spot (analaufpunkte) 23, which is formed in the holding

element

15, 16. Reference is made herein to fig. 8 and 16. The upper half of figure 16 shows parts according to the embodiment of figure 1; the lower half shows parts of the embodiment according to fig. 9, each with a similar function. The inner holding element 15 is shown in the left half of fig. 16, and the holding element 16 is shown in the right half. Openings 24, in which the pins 17, not shown in fig. 16, are fastened in each case, can be seen in all the holding

elements

15, 16. The fixing of the pin 17 in the opening 24 can be performed, for example, by caulking or welding. The entire rolling element holding device 14, including the holding

elements

15, 16 and the pins 17, is of somewhat elastic design, which is advantageous in particular in the case of rapid geometry changes and load changes absorbed by the coupling 1.

List of reference numerals

1 coupler

2 drive disk

3 driven plate

4 base plate

5 Flange

6 gap

7 holes

8 compensating element

9 concave part

10 rolling element

11 rolling element device

12 recess

13 notch

14 rolling element retaining device

15 internal holding element

16 external holding element

17 Pin

18 offset section

19 projecting block

20 sliding bush

21 bearing needle

22 punching point

23 raised points

24 opening

Claims

1. A coupling (1) for compensating radial offset, having two discs (2, 3), a driving disc (2) and a driven disc (3); and having a compensating element (8) which is movable in the radial direction relative to each of the disks (2, 3),

characterized in that the two disks (2, 3) lie in a common plane and are coupled to the compensating element (8) by means of cylindrical rolling bodies (10), the axes of which are oriented parallel to the axes of the disks (2, 3), wherein one of the disks has a non-circular shape and is arranged radially inside the other disk.

2. A coupling (1) according to claim 1, characterized in that the non-circular disc has a flange (5) through the compensating element.

3. A coupling (1) according to claim 1, characterized in that the rolling bodies (10) held in the driving discs (2) and the rolling bodies (10) held in the driven discs (3) lie in a common pitch circle.

4. A coupling (1) according to claim 3, characterized in that there is exactly one pitch circle on which there are a total of four rolling bodies (10).

5. A coupling (1) according to claim 3, wherein each disc (2, 3) is coupled with the compensating element (8) by two rolling element arrangements (11), respectively, wherein each rolling element arrangement (11) comprises a plurality of rolling elements (10) spaced from each other in a radial direction of the discs (2, 3).

6. A coupling (1) according to any of the claims 1 to 5, characterized in that the compensating element (8) has a punching point (22) provided for contacting at least one of the discs (2, 3).

7. A shaft coupling (1) according to any one of claims 1 to 5, characterized in that the cylindrical rolling bodies (10) are guided in a rolling body retaining device (14) comprising retaining elements (15, 16) which are respectively annular and are arranged on the end side of the compensating element (8) and on the end side of the two discs (2, 3) opposite the end side, wherein the two opposite retaining elements (15, 16) are respectively connected to one another by a pin (17) and the cylindrical rolling bodies (10) are supported on the pin (17).

8. Coupling (1) according to claim 7, characterized in that it has a bearing mechanism of the cylindrical rolling bodies (10) on the pin (17), which bearing mechanism has separate bearing elements (20, 21), wherein the bearing elements (20, 21) belong to the group comprising sliding bushings (20) and bearing elements carrying needles (21).

9. The coupling (1) according to claim 7, wherein the holding elements (15, 16) have a protruding point (23) arranged for contacting at least one of the following elements: a drive disk (2), a driven disk (3) and a compensating element (8).