Spring damper with two overload protection couplings and power train

Abstract

The invention relates to a spring damper (1) for a motor vehicle powertrain (2), comprising a primary part (3), a secondary part (4) rotatably received in a spring-damped manner relative to the primary part (3), and a first overload protection coupling (6) operatively interposed between the secondary part (4) and a hub element (5) and permanently closed below a threshold of the torque to be transmitted at least in the event of a sudden occurrence of the torque to be transmitted and releasing the relative rotation between the secondary part (4) and the hub element (5) above said threshold, wherein a second overload protection coupling (7) is operatively radially interposed within the first overload protection coupling (6) between an output (8) of the first overload protection coupling (6) and the hub element (5). The invention also relates to a powertrain (2) comprising said spring damper (1).

Description

Technical Field

[0001] This invention relates to a spring damper for a motor vehicle drivetrain, preferably for a hybrid drivetrain of a motor vehicle such as an automobile, truck, bus, or other commercial vehicle. The spring damper includes a main portion, a secondary portion rotatably received relative to the main portion in a spring-damped manner, and a first overload protection coupling operatively inserted between the secondary portion and a hub element. The first overload protection coupling is permanently closed at least when the torque to be transmitted is below a threshold value in the event of a sudden occurrence of the torque to be transmitted, and releases relative rotation between the secondary portion and the hub element when the torque is above the threshold value. Furthermore, this invention relates to a drivetrain having this spring damper. Background Technology

[0002] The type of spring damper discussed for use in transmission systems is well known in the art. For example, EP 2 765 331 A2 discloses a power transmission device having a damping component, a hysteresis generating component, and a speed limiting component.

[0003] Therefore, spring dampers with torque limiters in the form of overload protection couplings are known, and these torque limiters can also be used in different locations. However, it has been found that the spring dampers used typically have relatively complex structures with a large number of components and relatively high mass inertia. The torque limiter is also usually positioned as close as possible to the damper spring to adequately protect that area in the event of a torque pulse. However, this means that the components of the spring damper that are further connected to the transmission input shaft during operation have relatively high mass inertia, which in turn can lead to relatively high torque loads on the portion of the transmission input shaft and further to relatively high torque loads in the transmission. The transmission input shaft, and therefore the connecting elements in the transmission, such as gears, can thus be overloaded under certain operating conditions. Summary of the Invention

[0004] Therefore, the object of the present invention is to provide a spring damper that is as robust and durable as possible, and that prevents overload of the transmission connected during operation even when torque pulses occur.

[0005] According to the invention, this is achieved by operatively inserting a second overload protection coupling radially into the first overload protection coupling between the output portion of the first overload protection coupling and the hub element. Thus, the second overload protection coupling is now inserted in series with the preceding first overload protection coupling. The second overload protection coupling is also designed such that, at least in the event of a sudden occurrence of the torque to be transmitted, particularly during traction operation, it permanently closes when the torque is below a threshold value and releases relative rotation between the output portion and the hub element when the torque is above the threshold value.

[0006] The advantage of this is that one overload protection connector, in this case the first overload protection connector, is inserted as close as possible to the damping mechanism of the spring damper, i.e., the damper spring, and another overload protection connector, in this case the second overload protection connector, is inserted as close as possible to the transmission input shaft. This provides reliable protection for both the transmission input shaft and the damping mechanism of the spring damper. Another positive aspect is that the damper spring can be designed to be weaker and therefore more compact than previously known variations.

[0007] Other advantageous embodiments are claimed by the dependent claims and are explained in more detail below.

[0008] To further reduce torque load, it is also considered advantageous if the secondary part has a flange element directly supported on the damper spring in the circumferential direction, which in turn directly forms the input of the first overload protection connector.

[0009] If the output section of the first overload protection connector is formed by multiple support sections and the input section of the second overload protection connector is formed at the same time, the overload protection connector can also be manufactured as easily as possible.

[0010] Also advantageously, the support section has a first disc-shaped region and a second disc-shaped region connected to the first disc-shaped region, wherein a secondary portion, preferably a flange element, is axially held between the first and second disc-shaped regions. More preferably, the first and second disc-shaped regions are each formed as sheet-like metal elements / from sheet metal. This allows for the manufacture of the disc-shaped regions as easily as possible.

[0011] To make the first overload protection connection as effective as possible, it is beneficial if the first disc area and the second disc area each receive (directly) friction pads abutting against the secondary support.

[0012] If the first and second disc-shaped regions are each formed from a single sheet, axially spaced apart in the region of the friction liner that houses the flange element, and radially contacting / axially abutting each other within the friction liner and directly connected there, preferably directly connected by riveting, then manufacturing is further simplified. This allows the first and second disc-shaped regions to be effectively assembled and attached to each other.

[0013] If the first disc-shaped area also comes into contact with the main part via the friction device, the damping effect of the spring damper is further improved.

[0014] Furthermore, it is advantageous if the support section has a third disc-shaped region connected to the second disc-shaped region, wherein the hub element is axially clamped between the second and third disc-shaped regions. More preferably, the third disc-shaped region is also formed of a single sheet directly connected to the sheet of the second disc-shaped region. This also has a positive impact on the assembly and structure of the second overload protection connector.

[0015] In this regard, it is further advantageous if the second and third disc-shaped regions, or the sheets forming these second and third disc-shaped regions, directly abut against each other on the radially outer side of the plurality of friction pads of the second overload protection connector and are attached thereto, preferably by means of riveting.

[0016] Correspondingly, it is also advantageous if the second and third disc-shaped regions each receive friction linings supported by the hub element.

[0017] Furthermore, the present invention relates to a transmission system for a motor vehicle having a spring damper according to at least one embodiment of the above-described embodiments, wherein a main portion is connected to the output shaft of a motor and a hub element is connected to the input shaft of a transmission device.

[0018] In other words, the present invention thus realizes a spring damper preferably in the form of an arcuate spring damper, having a first radially outward sliding coupling (first overload protection coupling) arranged near the arcuate spring (damper spring) and a second radially inward sliding coupling (second overload protection coupling) arranged near the output shaft (i.e., near the transmission input shaft). The two sliding couplings are connected in series and adjusted such that both the arcuate spring flange (flange element) and the transmission input shaft can slide with a very low moment of inertia under impact in each case. Attached Figure Description

[0019] The invention will now be explained in more detail below with the aid of the accompanying drawings.

[0020] singleFigure 1 A longitudinal cross-sectional view of a spring damper according to the invention, based on a preferred exemplary embodiment, is shown, in which the detailed structure of the two inserted overload protection couplings can be clearly seen. Detailed Implementation

[0021] Figure 1 The spring damper 1 according to the invention shown is inserted into the transmission system 2 of a motor vehicle, in this case a hybrid powertrain 2, as indicated in principle. The spring damper 1 is operatively inserted between the output shaft of a motor, preferably an internal combustion engine, and the input shaft of the transmission, which is not shown here for clarity. Therefore, the spring damper 1 is used to dampen certain torque peaks that occur between the motor and the transmission during operation.

[0022] according to Figure 1 The spring damper 1 has a housing-shaped main portion 3, which is preferably directly connected in a non-rotatable manner to the output shaft of a motor (not shown further for clarity). In addition to the main portion, the spring damper 1 also has a secondary portion 4 that is rotatably received relative to the main portion 3 in a spring-damped manner. The main portion 3 and the secondary portion 4 are supported relative to each other in a spring-damped manner by means of a plurality of damper springs 9 arranged circumferentially in the form of arcuate springs.

[0023] In addition to the main part 3 being elastically supported relative to the secondary part 4 by the damper spring 9, an additional friction device 17 is used to generate the necessary damping effect, that is, to convert kinetic energy into waste heat. The friction device 17 is operatively inserted between the main part 3 and the secondary part 4 and has a suppressive effect on the relative rotation of the main part and the secondary part.

[0024] Secondary portion 4 is essentially formed by a flange element 10 extending radially inward away from the area in contact with the damper spring 9. A first overload protection coupling 6 is directly disposed / inserted onto the flange element 10. The flange element 10 thus directly forms the input portion 11 of the first overload protection coupling 6 and is operatively connected to the output portion 8 of the first overload protection coupling 6 via two (first and second) friction pads 16a, 16b. The first overload protection coupling 6 is implemented as a conventional sliding coupling that permanently closes below a certain threshold of the torque to be transmitted, and permanently connects the flange element 10 in a non-rotatable manner through frictional engagement with the output portion 8 of the first overload protection coupling 6, and releases / realizes relative rotation between the flange element 10 and the output portion 8 of the first overload protection coupling 6 when the threshold is exceeded, particularly when a torque pulse above the threshold occurs.

[0025] Regarding the output portion 8 of the first overload protection connector 6, it is further shown that this output portion is also formed by a multi-part support section 12. The support section 12 has a first disc-shaped region 14 and a second disc-shaped region 15 fixedly connected to the first disc-shaped region. The first disc-shaped region 14 and the second disc-shaped region 15 are radially guided to each other within the first friction pad 16a and the second friction pad 16b, thereby forming an axial shoulder 19 for each (first and second) disc-shaped region 14, 15, and the first disc-shaped region and the second disc-shaped region are in contact with each other. The two first disc-shaped regions 14 and the second disc-shaped region 15 are connected together in this contact area by a first riveting portion 20.

[0026] On the radially outer side of the first riveting portion 20, the first disc-shaped region 14 and the second disc-shaped region 15 are axially spaced apart from each other by the formation of the shoulder portion 19, and the flange element 10 is axially received between the two disc-shaped regions when the corresponding first friction pads 16a and second friction pads 16b are inserted. The flange element 10 is thus clamped between the first disc-shaped region 14 and the second disc-shaped region 15.

[0027] Regarding the first disc-shaped region 14, it is also apparent that the first disc-shaped region extends radially outward from the first friction lining 16a and the second friction lining 16b and forms a component of the friction device 17. The first disc-shaped region 14 therefore also comes into frictional contact with the main part 3.

[0028] The support section 12 also forms an input portion 13 for the second overload protection connector 7, such that the second overload protection connector 7 is arranged in series with the first overload protection connector 6. For this purpose, a third disc-shaped region 18 is attached to the second disc-shaped region 15 on the axial side opposite to the first disc-shaped region 14. The second disc-shaped region 15 is connected to the third disc-shaped region 18 via another (second) riveting portion 21. In this embodiment, the second riveting portion 21 is arranged radially at the same level as the first friction lining 16a and the second friction lining 16b.

[0029] On the radially inner side of the second riveting portion 21, the second disc-shaped region 15 and the third disc-shaped region 18 are axially spaced apart from each other by correspondingly forming shoulders 19, and the hub element 5 or the flange region 22 of the hub element 5 is axially received between the second disc-shaped region and the third disc-shaped region. It should be noted that the first riveting portion 20 is radially located at the level of the third friction lining 16c and the fourth friction lining 16d.

[0030] The flange region 22 is clamped between the second disc region 15 and the third disc region 18 in a manner similar to that in which the flange element 10 is clamped between the first disc region 14 and the third disc region 18. Therefore, the flange region 22 is axially clamped between the second disc region 15 and the third disc region 18 with the third friction lining 16c and the fourth friction lining 16d inserted.

[0031] The second overload protection connector 7 functions similarly to the first overload protection connector 6. When a certain threshold of the torque / torque pulse to be transmitted is exceeded, the second overload protection connector 7 automatically opens, thus allowing the hub element 5 to rotate relative to the support section 12 and therefore relative to the secondary portion 4, while below this threshold, a non-rotatable connection exists between the hub element 5 and the support section 12. Therefore, the hub element 5 forms the output portion 23 of the second overload protection connector 7.

[0032] The third friction liner 16c and the fourth friction liner 16d are radially located within the first friction liner 16a and the second friction liner 16b. Furthermore, the friction liner assembly having the first friction liner 16a and the second friction liner 16b is arranged to at least partially overlap axially with the friction liner assembly having the third friction liner 16c and the fourth friction liner 16d.

[0033] Regarding the (first, second, and third) disc-shaped regions 14, 15, and 18, it should also be noted that they are each formed from a sheet of metal. In this respect, the shoulder 19 is preferably manufactured using cold forming.

[0034] In other words, according to the present invention, a damper (spring damper 1) with dual torque limiters (first overload protection connector 6 and second overload protection connector 7) is realized. In this case, there is one torque limiter (second overload protection connector 7) protecting the input shaft of the transmission device and another torque limiter (first overload protection connector 6) protecting the arc spring (damper spring 9).

[0035] The structure of this concept is as follows: A hub (hub element 5) serves as the rotating part in the torque limiter. The hub element is positioned between two connecting bushings (third friction bushing 16c and fourth friction bushing 16d) to ensure sliding function in the event of an impact. The connecting bushings are mounted on support plates (second disc-shaped region 15 and third disc-shaped region 18). The support plates are connected to each other by riveting (second riveting 21). These parts form the (second) torque limiter, which protects the transmission.

[0036] The support sheet (second disc region 15) is connected to the support sheet (first disc region 14) via a riveting part (first riveting part 20). Two connecting pads (first friction pad 16a and second friction pad 16b) are mounted on the support sheet (first disc region 14 and second disc region 15). An arc-shaped spring flange (flange element 10) is located between the two connecting pads (first friction pad 16a and second friction pad 16b). This serves as a rotating part in the torque limiter, ensuring sliding function in the event of an impact. These parts form the (first) torque limiter, which protects the arc-shaped spring of the damper.

[0037] The two torque limiters are connected to each other via a support sheet (second disc-shaped area 15) and form an identical part (rigid connection) during normal traction operation. Therefore, during traction operation, the mass moment of inertia of components 5, 18, 15, 20, 16c, 16d, 14, 21, 16a, 16b, and 10 acts on the input shaft of the transmission.

[0038] In the event of an impact (e.g., during emergency braking), the transmission input shaft and hub can slide on the transmission input shaft with a very low moment of inertia. Simultaneously, the arcuate spring flange can also slide independently on the arcuate spring with a very low moment of inertia. This concept allows for the design of optimal and soft arcuate spring characteristics with best protective performance.

[0039] List of reference numerals

[0040] 1. Spring damper

[0041] 2. Transmission system

[0042] 3 Main Parts

[0043] 4 Secondary Parts

[0044] 5 hub components

[0045] 6 First overload protection connector

[0046] 7 Second overload protection connector

[0047] 8 Output section of the first overload protection connector

[0048] 9 Damper Spring

[0049] 10 Flange elements

[0050] 11 Input section of the first overload protection connector

[0051] 12 Support Sections

[0052] 13 Input section of the second overload protection connector

[0053] 14 First disc-shaped region

[0054] 15 Second disc-shaped region

[0055] 16a First Friction Liner

[0056] 16b Second Friction Liner

[0057] 16c Third Friction Liner

[0058] 16d Fourth Friction Liner

[0059] 17 Friction Device

[0060] 18 Third disc-shaped region

[0061] 19. Shoulders

[0062] 20 First riveting part

[0063] 21 Second riveting part

[0064] 22 Flange area

[0065] 23 Output section of the second overload protection connector

Claims

1. A spring damper (1) for a motor vehicle transmission system (2), the spring damper comprising a main portion (3), a secondary portion (4) rotatably received relative to the main portion (3) in a spring-damped manner, and a first overload protection coupling (6), the first overload protection coupling being operatively inserted between the secondary portion (4) and a hub element (5), and the first overload protection coupling being permanently closed at least when the torque to be transmitted is below a threshold value in the event of a sudden occurrence of the torque to be transmitted, and releasing relative rotation between the secondary portion (4) and the hub element (5) when the torque is above the threshold value, characterized in that, The second overload protection connector (7) is operatively inserted radially into the first overload protection connector (6) between the output portion (8) of the first overload protection connector (6) and the hub element (5).

2. The spring damper (1) according to claim 1, characterized in that, The secondary part (4) has a flange element (10) that is directly supported on the damper spring (9) in the circumferential direction, and the flange element (10) directly forms the input part (11) of the first overload protection connector (6).

3. The spring damper (1) according to claim 1, characterized in that, The output section (8) of the first overload protection connector (6) is formed by multiple support sections (12), and simultaneously forms the input section (13) of the second overload protection connector (7).

4. The spring damper (1) according to claim 3, characterized in that, The support section (12) has a first disc-shaped region (14) and a second disc-shaped region (15) connected to the first disc-shaped region (14), wherein the secondary portion (4) is axially held between the first disc-shaped region (14) and the second disc-shaped region (15).

5. The spring damper (1) according to claim 4, characterized in that, The first disc-shaped region (14) and the second disc-shaped region (15) each receive a friction pad supported against the secondary portion (4).

6. The spring damper (1) according to claim 5, characterized in that, The first disc-shaped region (14) also contacts the main part (3) via a friction device (17).

7. The spring damper (1) according to any one of claims 4 to 6, characterized in that, The support section (12) has a third disc-shaped region (18) connected to the second disc-shaped region (15), wherein the hub element (5) is axially clamped between the second disc-shaped region (15) and the third disc-shaped region (18).

8. The spring damper (1) according to claim 7, characterized in that, The second disc-shaped region (15) and the third disc-shaped region (18) each receive a friction liner supported against the hub element (5).

9. A transmission system (2) for a motor vehicle, said transmission system having a spring damper (1) according to any one of claims 1 to 8, wherein, The main part (3) is connected to the output shaft of the motor and the hub element (5) is connected to the input shaft of the transmission device.

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