CN106838032A - Coupling device - Google Patents

Abstract

Couplings for compensating radial misalignment comprising two discs, namely a drive disc and a driven disc, and two parallel, respectively annular discs which can be offset in radial direction with respect to each of these discs Shaped compensating elements, wherein the two disks are arranged in a common plane which lies between the two compensating elements.

Description

Coupling

technical field

The invention relates to a coupling arranged to compensate for radial misalignment between two shafts or other rotatable parts coupled to each other. This type of coupling is also known as an Oldham coupling.

Background technique

Oldham couplings, also known as Oldham couplings, are known, for example, from DE 1 704 337 U and from EP 1225 357 B1.

Couplings for compensating radial misalignment generally comprise two discs, namely a drive disc and a driven disc, and a compensating element which is displaceable in radial direction relative to each of the discs. The compensating element of the Oldham coupling, as disclosed, for example, in DE 198 57 248 C2, can interact via a groove and key system with the shafts to be coupled to each other. In addition to metal materials, plastics can also be used for the production of the compensation element. By way of example, reference is made in this regard to EP 0 416 125 A1.

Those materials from which the components of a coupling for compensating radial misalignment between two shafts are made play a non-negligible role in the friction that occurs between the individual components during operation of the coupling. Precautions against favorable lubrication conditions are to be provided, as described, for example, in the aforementioned DE 198 57 248 C2. In this case, the radial grooves which should be used for the lubricant feed are omitted in the Oldham. Lubricant supply to the coupling affects the service life and torque transmission capability of the coupling.

Contents of the invention

The object of the present invention is to specify an improved Oldham coupling with respect to the mentioned prior art, which is distinguished in particular by the configuration, in particular in the axial direction, of shafts or other rotating machine elements coupled to each other There is a favorable relationship between space requirement and torque transfer capability.

This object is solved according to the invention by a coupling suitable for compensating a radial misalignment between two shafts, that is to say an Oldham coupling, having the features of claim 1 . The coupling has two disks, namely a drive disk and a driven disk, which are provided for a rotationally fixed connection each to one of the shafts to be coupled to each other. The terms drive disk and driven disk are here chosen merely for the purpose of a linguistic distinction between two drive or output elements and do not relate to the expression regarding the direction of torque transmission. Furthermore, the term "shaft" is also to be understood purely functionally, wherein one of the two rotating parts referred to as shaft acts as a drive part and the other mentioned shaft acts as a driven part.

Furthermore, the coupling has two compensating elements, each in the form of an annular disk, which are parallel to each other and to the disks and which are offset in their radial direction with respect to each of the disks. The disks connected to the two shafts are arranged axially between the compensation elements, wherein the disks lie in a common plane.

The two compensating elements are functionally Oldham elements that are separated in the axial direction with respect to the shafts coupled to each other and the disks connected to these shafts. In this case, the two compensating elements are non-rigidly connected to one another, but (ignoring possible play) are coupled to one another in a rotationally fixed manner.

The element extending in the axial direction of the coupling, which couples the two compensating elements to one another, can in principle interact directly with the two disks connected to the shaft, whereby a sliding contact results. Due to the symmetrical arrangement of the two annular disk-shaped compensating elements on the two end faces of the disk, disturbing tilting moments during operation of the coupling are avoided. Furthermore, due to the arrangement of the two discs in a common plane, the coupling requires very little space in the axial direction of the shafts to be coupled to each other, which is extremely important especially in automotive applications.

According to an advantageous refinement which is distinguished by a particularly low-friction operation, pairs of annular retaining elements are arranged axially outside the two compensating elements. Cylindrical or barrel-shaped rolling bodies are preferably supported by means of the retaining element, which contact the compensating element and the disk for force and torque transmission, wherein the axes of rotation of the rolling bodies are oriented parallel to the disk and thus also parallel to each other The orientation of the axis to join.

In an advantageous configuration, each rolling element embedded in both compensating elements on the one hand and in one of the discs on the other hand is in an advantageous configuration with the side of the compensating element and/or the disc (that is to say the drive disc or output disc). At least one slit-like profile on the contact. Thus, during radial movement of the compensating element during operation of the coupling, the rolling bodies roll on at least one surface that describes the gap-like contour. Preferably, the compensating element and each disk therein are designed in such a way that the cylindrical or barrel-shaped rolling bodies can be displaced in the radial direction of the associated component.

Considered in the axial direction of the coupling, viewed from the drive end to the driven shaft, this results in the following construction of the coupling:

· two retaining elements nested in one another, lying essentially in a common plane,

a first compensating element in the shape of an annular disc,

· two disks lying in a common plane, connected to one of the two shafts respectively,

a second compensating element in the shape of an annular disc,

a second system consisting of two retaining elements nested inside each other,

In this case, the rolling bodies extend from the first compensating element to the second compensating element via the system of drive and driven discs.

With respect to the plane in which the two disks are arranged, the coupling is thus designed essentially mirror-symmetrically, wherein the two disks do not necessarily have a mirror-symmetric shape with respect to the mentioned plane. The use of rolling bodies for the force transmission between the drive disk and the compensating element and between the compensating element and the driven disk provides for a very low-friction operation of the coupling and at the same time enables the transmission of high torques.

Each pair of annular retaining elements is formed from a first type of retaining element and a second type of retaining element. In this case, a holding element of the first type on the first end side of the coupling is connected to a holding element of the same type on the second end side of the coupling. The same applies to the two holding elements of the second type. Pins, especially stepped pins, are suitable for connecting two retaining elements of the same type, on which the rolling bodies are supported. In this case, sliding bearings or rolling bearings, for example in the form of needle bearings, are suitable for supporting the rolling bodies. Each annular holding element is connected to a second holding element of the same type via two diametrically opposite connecting elements, in particular stepped pins. In this case, the connecting elements between the holding elements of the first type are twisted by 90° relative to the connecting elements between the holding elements of the second type. Accordingly, each compensating element has four openings through which the rolling bodies pass. Each opening has an elongated shape and is oriented in the radial direction of the compensating element in the shape of an annular disk. Significant weight savings with sufficient stability can be achieved by additional cutouts in the compensating element which are located in the circumferential direction on the mentioned receiving rolling bodies, in particular receiving cylinders. between the openings of the rollers. Preferably, the further openings each have an elongated shape extending in the circumferential direction of the compensation element.

A total of eight thrust washers are preferably arranged between the system of two disks, which are flexibly coupled to each other and lie in a common plane, and the two compensating elements in the form of annular disks, the thrust washers enclosing the Four rolling elements supported by retaining elements.

Two disks that are flexibly coupled to one another are preferably nested in one another, wherein one of the disks has a non-circular shape and is arranged radially inside the other disk. In this case, the inner disk has two recesses which are open to the outside, and the outer disk has two recesses which are open to the inside. A system of rolling elements. The recesses of the inner disk which are open to the outside and the recesses of the outer disk which are open to the inside intersect a single imaginary circle which lies in a plane which is normal to the two disks and thus also to the axis . In the case that a single rolling element, in particular a cylindrical roller, is present in each cutout, the imaginary circle is ie The pitch circle is then precisely described by the axis of symmetry of the rolling elements. In this way, all rolling elements for torque transmission between the two disks are loaded evenly.

The connection between the disk and the shaft can be realized by different connection mechanisms. For example, the larger of the two discs has holes that can be used to screw or rivet a flange attached to one of the shafts. On the other hand, a smaller disk, preferably having a rectangular basic shape, can have, for example, a collar extending through a central opening in the or one of the compensating elements. For example, the flange can be connected to one of the shafts by means of an internal toothing.

In order to facilitate the assembly of the coupling, according to an advantageous development, each cutout of the two disks is partially closed by a spring element. In particular leaf springs are suitable as spring elements, the leaf springs being connected to the disk by means of a clamping connection. The leaf springs ensure the concentric pre-centering of the rollers or roller units (consisting of rollers, stepped pins and annular retaining elements) within the radial misalignment compensation during assembly and transport. Design the leaf springs in such a way that on the one hand the rollers cannot be eccentrically positioned inside the radial misalignment compensation due to their own weight and on the other hand no significant interfering forces are exerted on the shaft during operation of the coupling. on the rolling body.

The coupling is particularly suitable for use in a hybrid module which is located in the drive train of a motor vehicle and includes an electric motor and a separating clutch. In principle, hybrid modules for motor vehicles are known, for example, from WO 2014/026685 A1, WO 2012/167767 A1, DE 10 2013 215 737 A1 and DE 10 2012 207 941 A1.

Description of drawings

Below, the embodiments of the present invention will be described in detail in conjunction with the accompanying drawings. in:

Figure 1 shows in an exploded view a coupling arranged to compensate for radial misalignment between shafts;

Figure 2 shows the coupling in cross-section;

Figure 3 shows the coupling in perspective view;

Figures 4 and 5 show in different views the system of a coupling consisting of a plurality of components transmitting force and torque;

Figure 6 shows the first outer disc of the coupling;

Figure 7 shows the inner second disc of the coupling;

Figure 8 shows a hybrid module with a coupling.

detailed description

The coupling shown in FIGS. 1 to 3 , designated as a whole with the reference number 1 , is designed to compensate for radial misalignment between two shafts not shown and is also known as an Oldham coupling . Even slight axial misalignments between two coupled shafts and small angular errors can be compensated by means of the coupling 1 .

The coupling 1 comprises two discs 2, 3 which are each connected to a shaft or another rotating part, wherein one of these parts acts as a driving part and the other as a driven part . The common axis of rotation of the disks 2 , 3 is marked with A ( FIG. 2 ). In the following, without limitation, disk 2 is referred to as driving disk and disk 3 as driven disk.

The two disks 2 , 3 lie in a common plane and are nested within each other, wherein the drive disk 2 represents the outer disk and the driven disk 3 represents the inner disk. The outer disc 2 has a circular outer circumference and a non-circular inner circumference which substantially matches the contour of the inner disc 3 . The profile of the disc 3 is defined as a profile modified from a rectangular basic shape, wherein on the two longitudinal sides of the rectangle there are arc-shaped flares which together describe the relative axis of rotation A Concentric circles.

In its outer region, the drive disk 2 has fastening holes 4 which are used for connecting components not shown in FIGS. 1 to 3 to be driven, that is to say for connecting two one of the axes. In contrast to this, a flange 5 with internal toothing 6 is present on the inner circumference of the output disk 3 in order to connect the output disk 3 to the output shaft in a rotationally fixed manner. The driven shaft is, for example, the transmission input shaft.

A radial offset between the disks 2 , 3 relative to the axis of rotation A can be achieved by means of a pair of annular disk-shaped compensating elements 7 , 8 which surround the system of disks 2 , 3 on both sides. Each compensating element 7 , 8 has a different type of opening 9 , 10 , namely four elongated openings 9 extending in radial direction and a total of eight likewise elongated openings but extending in circumferential direction The opening 10. The openings 9 are used for force and torque transmission between the transmission discs 2 , 3 by means of rolling bodies 11 , ie cylindrical rollers, while the purpose of the openings 10 is only to reduce the mass of the compensating elements 7 , 8 .

The rolling elements 11 passing through the compensating elements 7 , 8 and the system of the two disks 2 , 3 are guided by means of the first pair of annular retaining elements 12 , 13 and the second pair of annular retaining elements 14 , 15 . A first pair of annular holding elements 12 , 13 is formed by an inner holding element 12 and an outer holding element 13 . In a corresponding manner, the second pair of annular holding elements 14 , 15 is formed by an inner holding element 14 and an outer holding element 15 . Each of the retaining elements 12 , 13 , 14 , 15 has a ring-shaped basic shape. The two inner retaining elements 12 , 14 are connected to one another via a stepped pin 16 . In the same way, the two outer retaining elements 14 , 15 are also connected to one another via a stepped pin 16 . A stepped pin 16 , which connects the inner holding elements 12 , 14 to one another, is arranged on diametrically opposite sides of the two holding elements 12 , 14 . Likewise, the step pins 16 which connect the outer retaining elements 13 , 15 to one another are diametrically opposite one another.

In an embodiment, each rolling body 11 is supported slidingly on a stepped pin 16 . The stepped pin 16 protrudes slightly beyond the two retaining elements 12 , 13 , 14 , 15 on the end side. On the inner side of the compensating elements 7, 8, that is to say on that side of the compensating elements 7, 8 facing the disc 2 respectively, a thrust washer 17 is placed between the disc 2 and the compensating elements 7, 8, respectively. The push washer fits over the rolling elements 11. Thus, there are eight thrust washers 17 in total.

The rolling bodies 11 guided by means of the retaining elements 12 , 13 , 14 , 15 and the compensating elements 7 , 8 in particular pass through the recesses 18 , 19 in the disks 2 , 3 , which can be seen in FIGS. 5 to 7 . In this case, the outer disks 2 each have inwardly open cutouts 18 in their substantially arcuately curved sections. In contrast, the inner disk 3 has, on its narrow side, a recess 19 which is open to the outside.

Each of the cutouts 18 , 19 is partially closed by a spring element 20 , ie a leaf spring, in order to facilitate the assembly of the coupling 1 . The spring element 20 is held on the disk 2 , 3 by means of a clamping element 21 . Unlike the exemplary embodiment shown, the spring and clamping element can also be embodied in one piece.

FIG. 8 shows the installation of the coupling 1 in a hybrid module 22 which is provided for installation in a motor vehicle and has an input shaft 23 driven by the crankshaft of the internal combustion engine. The output shaft (not shown) of the hybrid module 22 , which is connected to or identical to the transmission input shaft, can be connected to the inner disc 3 of the coupling 1 by means of the internal toothing 6 . An electric motor 24 and a separating clutch 25 , which is designed as a friction clutch, are located within the hybrid module 22 . The coupling 1 is used to compensate possible radial misalignments between the input shaft 23 and the flange 5 within the drive train of a motor vehicle.

List of reference signs

1 coupling

2 drive disk, outer disk

3 Driven disc, inner disc

4 fixing holes

5 flanges

6 Internal teeth

7 Compensation element

8 compensation element

9 Openings extending in radial direction

10 Openings extending in the circumferential direction

11 Rolling elements

12 Ring-shaped inner retaining element

13 Ring-shaped outer retaining element

14 Ring-shaped inner retaining element

15 Ring-shaped outer retaining element

16-step shape pin

17 Thrust washer

18 Empty part of the outer plate

19 Empty portion in the inner tray

20 spring elements

21 Clamping element

22 Hybrid Module

23 input shaft

24 electric motor

25 Disconnect clutch

A axis of rotation

Claims (10)

1. a kind of shaft coupling for compensating radial misalignments, the shaft coupling has two disks (2,3), that is, drive disk (2) and Clutch plate (3), the shaft coupling also has that two parallel to each other, wherein each described disk (2,3) can be radially relatively Compensating element, (7,8) offseting, distinguishing plate-like in a ring, wherein, two disks (2,3) are arranged substantially at common putting down In face, the plane is located between two compensating element,s (7,8).

2. shaft coupling according to claim 1, it is characterised in that the cylinder and compensating element, (7,8) and described The rolling element (11) of disk (2,3) contact is supported by two pairs of holding elements (12,13,14,15) in a ring, the rolling element Diameter parallel in the disk (2,3) axis ground extend.

3. shaft coupling according to claim 2, it is characterised in that each pair holding element (12,13,14,15) is by stepped Pin (16) is connected to each other, and the rolling element (11), particularly cylindrical roller are supported on the stepped pin.

4. shaft coupling according to any one of claim 1 to 3, it is characterised in that each compensating element, (7,8) is with four What the individual opening (9) for extending in a radial direction and circumferentially direction that is a number of, being arranged between the opening (9) extended Opening (10).

5. shaft coupling according to any one of claim 1 to 4, it is characterised in that one of disk (3) is with non-circular Shape, and be arranged radially at the inside of other disk (2).

6. shaft coupling according to claim 5, it is characterised in that inner disk (3) is with outwardly open portion of leaving a blank (19), outer disk (2) is with inwardly unlimited portion of leaving a blank (18).

7. shaft coupling according to claim 6, it is characterised in that two leave a blank portion and the common, positions of disk (2,3) Circle in the normal plane of relatively described disk (2,3) intersects.

8. the shaft coupling according to claim 6 or 7, it is characterised in that in the portion of leaving a blank (18,19) each of pass through Spring element (20) is partially closed.

9. shaft coupling according to claim 7, it is characterised in that the spring element (20) is configured to leaf spring, and leads to Cross to be clamped and connected and be connected with the disk (2,3).

10. shaft coupling according to claim 1 motor vehicle with electro-motor (24) and separate clutch (25) Hybrid power module (22) in application.