WO2021148079A1

WO2021148079A1 - Torque limiter

Info

Publication number: WO2021148079A1
Application number: PCT/DE2021/100015
Authority: WO
Inventors: Romain Kaufmann; Alain Rusch; Michael Kessler
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2020-01-20
Filing date: 2021-01-12
Publication date: 2021-07-29
Also published as: CN218294258U; DE102020101155B4; DE102020101155A1

Abstract

The invention relates to a torque limiter (1), in particular for a drive train (3), in particular of a motor vehicle, which can be rotated about an axis of rotation (18) and comprises two lateral elements (6, 20, 22) that are spaced apart from one another in the direction of the axis of rotation (18) and a friction plate (4) formed between the lateral elements (6) in the direction of the axis of rotation (18), wherein friction linings (5) are formed that can be detachably frictionally locked to the friction plate (4), wherein a detachable connection between the lateral elements (6, 20, 24) and the friction plate (4) can be produced by the friction lock, wherein the friction plate (4) has at least one first spring element (10) that exerts a pressing force on the friction linings (5) in the direction of the axis of rotation (18), characterised in that a friction lining (5) is rotationally fixed to a support disc (21), which is formed between the friction lining (5) and a first lateral element (20) in the direction of the axis of rotation (18), and a second spring element (23) is formed between the first lateral element (20) and the support disc (21), which exerts a pressing force in the direction of the support disc (21).

Description

Torque limiter

The present invention relates to a torque limiter, in particular for a drive train of a motor vehicle.

Known torque limiters have a friction plate which is formed between two friction linings, which in turn are rotatably connected to side elements. Friction plates and friction linings are pressed against one another with a pressing force in order to transmit torque from the friction plate via the friction linings to the side elements and via this to a drive train. If the torque applied to the friction plate exceeds a limit value that is defined by the pressing force, the friction plate and friction linings start to slip so that torque peaks above the limit value are not transmitted. In this way, damage to the electric motor due to torque peaks in the internal combustion engine can be prevented, particularly in hybrid drive trains.

From EP 1 176339 A1 a torque limiter is known in which the pressing force is generated by a plate spring. This has the disadvantage that if there are geometrical errors, an uneven pressing force results in the circumferential direction, which makes it difficult to determine the limit value of the torque. This disadvantage can be overcome in that a friction plate is formed with an integrated spring element, as is known, for example, from the unpublished patent application DE 102019 119826.7. In this embodiment, however, the maximum pressing force that can be applied by the spring element is limited.

On the basis of this, the present invention is based on the object of at least partially overcoming the problems known from the prior art and, in particular, of specifying a torque limiter which is flexible in design.

This object is achieved with the features of independent claim 1. Further advantageous embodiments of the invention are specified in the dependent claims. The individually listed in the dependently formulated claims Led features can be combined with one another in a technologically meaningful way and can define further embodiments of the invention. In addition, who the features specified in the claims in the description Sized and explained in more detail, further preferred embodiments of the invention are Darge.

The torque limiter according to the invention, in particular for a drive train, in particular a motor vehicle, is rotatable about an axis of rotation, comprises two side elements which are spaced apart in the direction of the axis of rotation and a friction plate formed in the direction of the axis of rotation between the side elements, with friction linings being formed which can be releasably brought into frictional engagement with the friction plate, with a releasable connection between the side elements and the friction plate being able to be established through the frictional engagement, the friction plate having at least one first spring element which exerts a pressing force in the direction of the axis of rotation on the friction linings. One of the friction linings is non-rotatably attached to a support disc which is formed in the direction of the axis of rotation between this friction lining and a first side element, with a second spring element being formed between the first side element and the support disc, which exerts a pressing force in the direction of the support disc.

The at least one first spring element is preferably rotationally cyclical with respect to the axis of rotation. The friction plate is preferably non-rotatably connected to a flywheel of an internal combustion engine, for example riveted, so that the friction plate fulfills two functions, namely the complete transmission of the torque from an internal combustion engine and the application of the pressing force. The torque limiter is designed so that when an upper limit value of the torque is exceeded, the sum of the pressing force and the contact force is no longer sufficient and slip occurs between the friction plate and the friction linings. This prevents torque peaks from breaking through, which can result in damage, particularly in motor vehicles with a flybrid drive.

The combination of the first and second spring element allows a high degree of flexibility in the design, especially taking into account the available space. By combining the first and second spring elements high torque limit values can also be achieved without requiring a large installation space in the direction of the axis of rotation.

Preferably, the second spring element is formed out as a plate spring or a spring ring.

The use of a disc spring as the second spring element is advantageous because a high contact pressure can be achieved in the direction of the axis of rotation with a small installation space. Furthermore, a disc spring allows a simple definition of the spring characteristic. A spring ring as a second spring element is easy to manufacture and allows the limit value of the torque to be increased in a simple manner.

The at least one first spring element preferably has a corrugation which has a radial orientation with respect to the axis of rotation.

The friction plate is preferably designed in one piece, for example the at least one first spring element is formed by deformation from a neutral plane of the friction plate which is perpendicular to the axis of rotation. Such a configuration is preferred when the at least one first spring element forms a complete circular ring. Such a design of the friction plate is easy to manufacture.

Alternatively, it is preferred that the friction plate comprises at least one first spring element, which is designed as a circular ring segment. This has the advantage that the freedom of design when designing the friction plate is increased.

Alternatively, it is also preferred that the friction plate is constructed in several parts. It is particularly preferred in this context that the friction plate comprises a base plate which is surrounded in the direction of the axis of rotation by two corrugated washers as first spring elements, which are non-rotatably connected to the base plate, preferably riveted. The corrugated washers have a structure with corrugations with bending lines, which preferably run radially with respect to the axis of rotation.

Furthermore, a multi-part construction of the friction plate is preferred, in which it comprises at least one base plate which comprises at least one first spring element, which is designed as a circular ring segment. A multi-part structure consisting of at least one For example, a base plate with circular ring segments as the first spring elements can be made in one piece, with several, in particular two, base plates being mounted to form the friction plate, for example being riveted to one another. Furthermore, it is possible, please include, to attach circular ring segment-shaped first spring elements to the base plate in a rotationally fixed manner, for example by riveting. The first spring elements can be designed in one or two layers.

An embodiment is preferred in which the friction plate is formed from two base plates, each of which comprises at least one first spring element, which is formed as a circular ring segment.

Furthermore, a drive train is proposed, in particular for a motor vehicle, with a torque limiter according to the present invention, in which a flywheel connected to an output shaft is formed, which is connected non-rotatably to the friction plate.

The details and advantages disclosed for the torque limiter can be transferred and applied to the drive train and vice versa.

As a precaution, it should be noted that the numerals used here (“first”, “second”, ...) primarily (only) serve to distinguish between several similar objects, sizes or processes, i.e. in particular no dependency and / or sequence of these objects , Parameters or processes to each other. Should a dependency and / or sequence be required, this is explicitly stated here or it is obvious to the person skilled in the art when studying the specifically described embodiment.

The invention and the technical environment are explained in more detail below with reference to the figures. It should be pointed out that the invention is not intended to be restricted by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description and / or figures. In particular, it should be pointed out that the figures and in particular the illustrated size ratios are only schematic. Identical reference symbols denote identical counterparts so that explanations from other figures can be used in addition, if necessary. Show it:

1a and 1b: each a partial section of a first and second example of a torque limiter mounted on a flywheel;

Fig. 2-4: a first example of a friction plate of a torque limiter in ver different views;

5-7: a second example of a friction plate of a torque limiter in different views;

8-9: a third example of a friction plate of a torque limiter in different views;

10-14: a fourth example of a friction plate of a torque limiter in different views; and

15-20: a fifth example of a friction plate of a torque limiter in different views.

1a shows a view of a first example of a torque limiter 1 which is mounted on a flywheel 2 of a drive train 3 of a motor vehicle. The flywheel 2 is non-rotatably connected to a shaft which rotates about an axis of rotation 18 during operation. The torque limiter 1 has a friction plate 4, which lie between two side elements 6 which are formed from sheet metal. In the direction of the axis of rotation 18 between a first side element 20 of the side elements 6 and the friction plate 4, a support disk 21 is also formed. On an inner side 19 of the support disk 21, which faces the friction plate 4, a friction lining 5 is ausgebil det, which is rotatably connected to the support disk 21. A second friction lining 5 is formed on an inner side 19 of the second side element 22 of the side elements 6 facing the friction plate 4 and is connected to it in a rotationally fixed manner, so that a frictional connection between the friction linings 5 and the friction plate 4 can be releasably established. The drive train 3 is preferably a hybrid drive train with at least one electric motor. The torque limiter 1 is connected via the side elements 6 to a damper 27, the output of which is connected to the rest of the drive train 3.

The friction plate 4 has at least one integrated first spring element, by means of which a pressing force is exerted on the friction linings 5. Furthermore, a second spring element 23 is formed between the first side element 20 and the support disk 21, which causes a pressing force from the first side element 20 on the support disk 21. In the example from FIG. 1 a, the spring element 23 is designed as a spring ring 24.

In the assembled state, the side elements 6 are frictionally connected via the support disk 21 and the friction linings 5 to the friction plate 4, which is non-rotatably connected to the flywheel 2, so that torque can be transmitted from the flywheel 2 via the torque limiter 1 during operation. The sum of the pressing force of the at least one first spring element 10 and the pressing force of the second spring element 23 defines a maximum torque which, when exceeded, sets in slip between the friction linings 5 and the friction plate 4, so that when this limit value is exceeded, the torque is transmitted is closed. The formation of the friction plate 4 is explained in connection with FIGS. 2 to 20 using several examples.

1 b shows a view of a second example of a torque limiter 1. Only the differences from the first example are to be described here; for the rest, reference is made to the statements made for the first example. In contrast to the first example, the second spring element 23 is designed as a plate spring 25. Furthermore, further support disks 26 are formed which are connected to the friction plate 4 in a rotationally fixed manner. The further support disks 26 improve the pressure between the friction plate 4 and the friction linings 5, since the pressing force applied by the at least one first spring element of the friction plate 4 is transmitted to a larger area of the friction linings 5. In the assembled state, the side elements 6 are frictionally connected to the friction plate 4 via the support disk 21, the friction linings 5 and the other support disks 26, which is connected to the flywheel 2 so that, during operation, torque from the flywheel 2 via the torque limiter 1 is transferable. The sum of the pressing force of the at least one first spring element 10 and the pressing force of the second spring element 23 defines a maximum torque, when it is exceeded, slip between the friction linings 5 and the friction plate 4 sets in, so that when this limit value is exceeded, the torque is transmitted is excluded. The formation of the friction plate 4 is explained in connection with FIGS. 2 to 20 with the aid of several examples.

FIGS. 2 to 4 show an example of a friction plate 4 made of sheet metal in different views. FIGS. 3 and 4 show the sections marked accordingly in FIG. The friction plate 4 is formed in one piece and has an inner region 7 and an outer region 8 formed radially outside of the inner region 7. Inner area 7 and outer area 8 are designed in the shape of a circular ring. The outer area 8 has several connection areas 9, which are formed here as openings that enable a connection to the flywheel 2. The inner area 7 comprises two first spring elements 10, which exert a pressing force on the friction linings 5 in the installed state. The first spring elements 10 are formed by deformation of the inner region 7 out of the plane of the outer region 8.

The first spring elements 10 act as leaf springs. In the installed state, the first spring elements 10 are pressed against the friction linings 5. The first spring elements 10 have a corrugation 28 which has a radial direction with respect to the axis of rotation 18, as shown in particular in FIG. The first spring elements 10 are designed to be cyclical in rotation.

FIGS. 5 to 7 show a second example of a friction plate 4 made of sheet metal in different views. FIGS. 6 and 7 show the sections marked accordingly in FIG. Only the differences from the first example are to be described here; for the rest, reference is made to the statements made for the first example. In the second example, too, the friction plate 4 is formed in one piece from, but the outer area 8 is not circular, but rather from a plurality of tabs 11 are formed in which the connecting areas 9 are ausgebil det. This simplifies the manufacture of the friction plate 4.

FIGS. 8 and 9 show a third example of a friction plate 4 in different views. FIG. 8 shows a top view and FIG. 9 shows a side view. Only the differences from the first example are to be described here, otherwise reference is made to the first example referenced statements made. The friction plate 4 is made in several parts. The friction plate 4 comprises a base plate 12 to which two corrugated washers 13 are connected on both sides. The corrugated washers 13 are attached to the base plate 12 with rivets 14. The corrugated washers 13 form the first spring elements 10. The height of the corrugated washers 13 is selected so large that the rivets 14 do not come into contact with the friction linings 5 in the installed state.

Figures 10 to 14 show a third example of a friction plate 4 in different designs and views. The friction plate 4 is constructed from a base plate 12 (FIGS. 10 to 12) or from two base plates 12 (FIGS. 13 and 14) which are placed on top of one another and connected to one another. The base plates 12 do not have a circular ring-shaped inner region 7, but rather the inner region 7 is made up of circular ring segments 15 which do not form a complete circular ring. FIG. 10 shows a top view of a base plate 12, FIG. 11 shows the section of the base plate 12 identified in FIG. 10 as "AA", while FIG. 12 shows the section of the base plate 12 identified in FIG. 10 as "BB" . The first spring elements 10 have a contour 16 in the circumferential direction, which leads to the formation of a pressing force in the assembled state on the friction linings 5. The contours 16 are chosen so that no edge touches the friction linings 5, as this leads to irregularities in the event of slippage and to possible uneven wear. The con turations 16 are designed as corrugations 28 which are essentially radial to the axis of rotation 18.

Fig. 13 shows the section of the friction plate 4 marked as “AA” in Fig. 10, consisting of two interconnected base plates 12, Fig. 14 shows the section of the friction plate 4 marked in Fig. 10 as “BB” consisting of two interconnected base plates 12, the first spring elements 10 of which with contours 16 in the assembled state of the torque limiter 1 exert a pressing force on the friction would be 5 can apply. In addition, reference is made to the description of the other case of the friction plate 4.

FIGS. 15 to 20 show a fifth example of a friction plate 4, which is constructed similarly to the fourth example of the friction plate 4. Here, too, the first spring elements 10 are designed as circular ring segments 15 which do not form a complete circular ring. However, the friction plate is made in several parts. A base plate 17 forming the outer area 8 is connected non-rotatably to individual first spring elements 10, for example connected by rivets 14. The first spring elements 10 can be designed as single segments (FIGS. 16, 17, 18) or as double segments (FIGS. 19, 20). In the case of double segments, the first spring elements 10 lie one above the other in the direction of the axis of rotation. 16 shows the section “AA” from FIG. 15 for individual segments, and FIG. 17 shows the section “CC” from FIG. 15 for individual segments. 18 shows the section “AA” from FIG. 15 for double segments, FIG. 19 shows the section “BB” from FIG. 15 for double segments and FIG. 20 shows the section “CC” from FIG. 15 for double segments. For the rest, reference is made to the description of the fourth example.

Bezuqszeichenliste Torque limiter flywheel drive train friction plate friction lining side element inner area outer area connecting areas first spring element tab base plate corrugated washer rivet circular ring segment contouring base plate axis of rotation inside first side element support washer second side element second spring element spring washer disc spring support washer damper corrugation

Claims

1. Torque limiter (1), in particular for a drive train (3), in particular a motor vehicle, which is rotatable about an axis of rotation (18), comprising two side elements (6, 20, 22) which extend in the direction of the axis of rotation (18) are spaced apart and a friction plate (4) formed in the direction of the axis of rotation (18) between the side elements (6), friction linings (5) being formed which can be releasably brought into frictional engagement with the friction plate (4), the frictional engagement a releasable connection between the side elements (6, 20, 24) and the friction plate (4) can be produced, the friction plate (4) having at least one first spring element (10) which exerts a pressing force in the direction of the axis of rotation (18) Exercises friction linings (5), characterized in that a friction lining (5) is non-rotatably attached to a support disc (21) which is formed in the direction of the axis of rotation (18) between the friction lining (5) and a first side element (20), where between the first be th element (20) and the support disk (21) a second spring element (23) is formed, which exerts a pressing force in the direction of the support disk (21).

2. Torque limiter (1) according to claim 1, wherein the second spring element (23) is designed as a plate spring (25).

3. torque limiter (1) according to claim 1, wherein the second spring element (23) is designed as a spring ring (24).

4. torque limiter (1) according to any one of the preceding claims, wherein the at least one first spring element (10) has a corrugation which has a radial orientation with respect to the axis of rotation (18).

5. Torque limiter according to one of the preceding claims, in which the friction plate (4) is formed in one piece.

6. torque limiter (1) according to claim 5, wherein the at least one first spring element (10) is formed by deformation from a neutral plane of the friction plate (4) which is perpendicular to the axis of rotation (18).

7. torque limiter (1) according to claim 5, wherein the friction plate (4) comprises at least one first spring element (10) which is designed as a circular ring segment (15).

8. torque limiter (1) according to one of claims 1 to 4, in which the friction plate (4) is constructed in several parts.

9. Torque limiter (1) according to claim 8, wherein the friction plate (4) comprises a base plate (12) which is surrounded in the direction of the axis of rotation (18) by two corrugated disks (13) as the first spring elements (10), which is rotationally fixed are connected to the base plate (12).

10. Drive train (3), in particular for a motor vehicle, with a torque limiter (1) according to one of the preceding claims, in which a flywheel connected to an output shaft (2) is formed which is rotatably connected to the friction plate (4).