CN212509409U - Hydrodynamic torque converter for a motor vehicle and motor vehicle comprising same - Google Patents

Abstract

The present disclosure relates to a hydrodynamic torque converter for a motor vehicle, comprising: a cover driven by a drive member on an engine side of the motor vehicle; a pump wheel connected in a rotationally fixed manner with the cover; a turbine including a turbine shell that outputs torque to an input shaft of a transmission of a motor vehicle; a piston disc including friction surfaces that are actuatable to switch the torque converter between a fluid transmission mode and a mechanical transmission mode in which the friction surfaces abut the cover such that the cover rotates integrally with the piston disc; at least one torsional vibration damper held between the piston disc and the turbine, comprising at least one spring. The piston disc is provided with a first stop projection integrally formed therewith and the turbine housing is provided with a second stop projection integrally formed therewith, the first and second stop projections cooperating with each other to limit the amount of compression of the spring. The disclosure also relates to a motor vehicle comprising said torque converter.

Description

Hydrodynamic torque converter for a motor vehicle and motor vehicle comprising same

Technical Field

The present disclosure relates to a torque converter for a motor vehicle. In particular, the torque converter is provided with integrally formed stopper protrusions on the piston disc and the turbine housing for limiting the compression amount of the spring of the torsional damper. The disclosure also relates to a motor vehicle comprising such a hydrodynamic torque converter.

Background

In general, a torque converter is provided between an engine and a transmission of an automatically shifting motor vehicle. The torque converter is used for transmitting driving power of an engine to a transmission, and can play a role in transmitting torque and converting torque. The hydrodynamic torque converter comprises a cover driven by a drive member on the engine side, a pump impeller connected in a rotationally fixed manner with the cover, and a turbine wheel connected to the transmission input shaft, and can be switched between a fluid transmission mode and a mechanical transmission mode by means of a piston disc. During a launch phase of the motor vehicle, the torque converter operates in a fluid transmission mode. At this time, the impeller of the torque converter drives the turbine wheel through fluid (usually oil). After the engine reaches a higher speed, the torque converter switches to a mechanical transmission mode. In the mechanical drive mode, torque is mechanically transferred from the cover to the turbine through the piston disc and/or other drive mechanism without passing through the impeller.

The torque produced at the motor vehicle engine is generally not constant. In particular, in mechanical transmission modes, such non-constant torque may be transmitted into the transmission, causing vibrations of the transmission gearbox and thus generating particularly undesirable noise or bumps, etc. In order to reduce the adverse effects of vibrations and to improve the driving comfort of motor vehicles, it is known to provide torsional vibration dampers in torque converters. Torsional vibration dampers may allow for the absorption and mitigation of vibrations generated by an automotive engine. Torsional vibration dampers are typically disposed between a piston disc and a turbine and include a resilient member, such as a spring, to transmit torque therebetween.

In order to avoid shortening the service life of the torsional damper as a result of the torsional damper transmitting too much torque, it is known to provide a stop mechanism such that the amount of compression of the elastic component does not exceed a predetermined threshold value. Chinese patent CN104235301B discloses a torque converter comprising two torsional vibration dampers and two stop mechanisms. Holding plates for holding springs of the torsional damper are fixed to the piston disc and the turbine wheel by rivets, respectively. The holding plate is formed with a notch portion that penetrates therethrough, the turbine is fixedly welded with a plurality of transmission claws, the transmission claws extend into the notch portion and engage with the notch portion, and both the transmission claws and the notch portion constitute a first stopper mechanism. Further, rivets for fixing the retainer plate on the turbine wheel extend into through holes formed in the output side plate of the turbine wheel hub, thereby constituting a second stopper mechanism. It can be seen that the first and second stop mechanisms comprise two stop members of different types and require different processes (e.g., the transfer pawl requires welding, the rivet requires riveting, and the cut-out requires stamping or machining) to manufacture, thereby making the torque converter complicated to manufacture and prone to damage. In addition, additional components such as a retainer plate and an input side plate need to be arranged in the axial direction, which increases the axial dimension of the torque converter, compressing space for mounting other torque transmitting components such as a transmission.

SUMMERY OF THE UTILITY MODEL

Accordingly, the present disclosure is directed to solving the above-mentioned problems occurring in the conventional torque converter, and an object thereof is to provide a torque converter in which stopper protrusions integrally formed are provided on a piston disc and a turbine housing for realizing a stopper function of limiting a compression amount of a spring of a torsional damper.

The object is achieved by a torque converter including a torsional vibration damper according to one embodiment of the present disclosure, comprising: a cover driven by a drive member on an engine side of the motor vehicle to rotate about a rotational axis of the torque converter; a pump wheel rotationally fixedly connected with the cover so as to rotate together with the cover; a turbine driven to rotate about the axis of rotation and transmit torque to an input shaft of a transmission of a motor vehicle; a piston disc including a friction surface, the piston disc being actuatable to operatively switch the torque converter between a fluid transmission mode in which rotation of the pump impeller about the axis of rotation generates a flow of fluid to drive the turbine wheel and a mechanical transmission mode in which the friction surface bears against the cover such that the cover rotates integrally with the piston disc; at least one torsional vibration damper retained between the piston disc and the turbine and transmitting torque from the piston disc to the turbine, the torsional vibration damper including at least one spring. The piston disc is provided with one or more first stop protrusions formed integrally therewith, the turbine housing is provided with one or more second stop protrusions formed integrally therewith, and the first and second stop protrusions are capable of cooperating with each other to limit the amount of compression of the spring of the torsional damper. Specifically, when the amount of compression of the spring reaches a predetermined threshold, the first stopper projection and the second stopper projection interfere, limiting relative displacement between the turbine housing and the piston disc in the circumferential direction, so that the spring cannot continue to be compressed.

Since the first stopper protrusion and the second stopper protrusion are of the same type, they can be manufactured in the same process, and the manufacturing steps of the torque converter are simplified. Meanwhile, the first and second stopper protrusions are integrally provided on the piston disc and the turbine housing, respectively, without additionally providing a special holding element and a torque transmission element to provide a stopper mechanism, thereby compressing the axial size of the torque converter and increasing the installation space of other torque transmission components.

A torque converter according to the present disclosure may also have one or more of the following features, alone or in combination.

According to an embodiment of the disclosure, the first stop projection is a first stop boss projecting from the piston disc towards the turbine housing, and the second stop projection is a second stop boss projecting from the turbine housing towards the piston disc. The radial positions of the first stop boss and the second stop boss correspond to each other. When the compression amount of the spring reaches a predetermined threshold value, the opposite side walls of the first stop boss and the second stop boss abut against each other, and the function of limiting the compression amount of the spring of the torsional damper is realized. Preferably, the side walls of the first and second stop bosses lie on a radial plane passing through the rotational axis of the torque converter. Therefore, the opposite side walls of the first stop boss and the second stop boss can be abutted in a fitting manner, the contact area is increased, and the damage to the stop bosses possibly caused by overlarge torque is reduced.

According to another embodiment of the present disclosure, the piston disc comprises an axial extension at its radially inner edge extending towards the turbine wheel, the first stop projection is a first stop tooth extending axially at an end of the axial extension, and the second stop projection is a second stop tooth extending radially at the radially inner edge of the turbine shell. When the compression amount of the spring reaches a predetermined threshold value, the opposite side walls of the first stop tooth and the second stop tooth abut against each other, and the function of limiting the compression amount of the spring of the torsional damper is achieved. Preferably, the side walls of the first and second stop teeth lie on a radial plane passing through the rotational axis of the torque converter. Therefore, the opposite side walls of the first stop tooth and the second stop tooth can be abutted in a fitting manner, the contact area is increased, and the damage to the stop teeth caused by overlarge torque is reduced.

According to an embodiment of the disclosure, the piston disc is provided with three first stop protrusions evenly distributed in the circumferential direction, and the turbine shell is provided with three second stop protrusions evenly distributed in the circumferential direction. It is conceivable that the piston disc can also be provided with a different number of first stop projections and/or that the turbine housing can also be provided with a different number of second stop projections.

The torque converter may also include a plurality of torsional vibration dampers to further enhance the damping effect. For example, the torsional vibration damper located on the radially outer side is a first torsional vibration damper, and the torque converter further includes a second torsional vibration damper located on the radially inner side. The second torsional vibration damper may have a similar configuration to the first torsional vibration damper.

According to one embodiment of the disclosure, the piston disc and/or the turbine housing of the hydrodynamic torque converter are manufactured by stamping. Specifically, the first and second stopper bosses are formed by punching the piston disc and the turbine housing, respectively, in the axial direction. The piston disc and the turbine housing are not broken during the punching process and the punch used is selected to be adapted to the shape of the first and second stop ledges. The first stop tooth may be formed by punching out a portion of material at the axial extension of the piston disc in the radial direction, and the second stop tooth may be formed by punching out a portion of material at the radially inner edge of the turbine shell in the axial direction. After stamping, the thickness of some portions of the piston disc and/or turbine shell may be reduced accordingly. Preferably, in order to increase the strength of the piston disc and/or the turbine shell, the piston disc and/or the turbine shell may be strengthened by a heat treatment process after stamping.

The present disclosure also relates to a motor vehicle comprising a hydrodynamic torque converter as described above.

The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the present teachings when taken in connection with the accompanying drawings.

Drawings

FIG. 1 is a schematic illustration in partial cutaway of a torque converter according to one embodiment of the present disclosure.

Fig. 2A-2D illustrate a first stop tab and a second stop tab according to one embodiment of the present disclosure.

Fig. 3A-3C illustrate a first stop tab and a second stop tab according to another embodiment of the present disclosure.

FIG. 4 illustrates a schematic partial cut-away view of a torque converter according to another embodiment of the present disclosure.

In the various figures, identical or similar components are denoted by the same reference numerals.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be described below in detail and completely with reference to the accompanying drawings of the embodiments of the present disclosure.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of the terms "a" and "an" or "the" and similar referents in the description and claims of the present disclosure also do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item preceding the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The directions "axial direction", "radial direction", and "circumferential direction" are defined with respect to the rotation axis RO of the torque converter, i.e., the direction in which the rotation axis RO extends, the radial direction is a direction perpendicular to the rotation axis RO, and the circumferential direction is a circumferential direction around the rotation axis RO.

FIG. 1 is a schematic illustration in partial cutaway of a torque converter according to one embodiment of the present disclosure. For clarity, various components of the structure of the torque converter that are not relevant to understanding the technical aspects of the present disclosure have been omitted.

As shown in fig. 1, the torque converter includes a cover 1, a pump impeller 2, a turbine runner 3, a piston disc 4, a torsional damper 5 disposed between the turbine runner and the piston disc, and a stator 6. The cover 1 is driven in rotation by a drive member on the engine side of the motor vehicle, while the pump wheel 2 is connected rotationally fixed to the cover 1, for example by welding. Thus, torque is input to the torque converter through the cover 1 and the impeller 2. The turbine 3 is driven to rotate about the rotation axis RO and transmits torque to an input shaft of a transmission of a motor vehicle through the turbine hub 30, i.e., torque is output from the torque converter through the turbine 3 and the turbine hub 30.

The torque transmission from the cover 1 and the pump impeller 2 to the turbine wheel 3 can be switched between both a fluid transmission mode and a mechanical transmission mode depending on the running condition of the motor vehicle. This switching is achieved by actuating (e.g. hydraulically actuating) the piston disc 4 in the axial direction.

Specifically, the pump impeller 2, the turbine runner 3, and the stator 6 define an annular passage in which the working fluid of the torque converter circulates. In the fluid transmission mode, the piston disc 4 is actuated out of contact with the cover 1, being free to rotate relative to each other. At this time, the rotation of the pump impeller 2 about the rotation axis RO causes the flow of the working fluid, which in turn drives the turbine 3. That is, in the fluid transmission mode, the torque transmission path of the torque converter is: torque input → cover 1 → impeller 2 → (working fluid) → turbine 3 → turbine hub 30 → torque output. The solid lines in fig. 1 show the torque transmission paths in the fluid transmission mode.

In the mechanical transmission mode, the piston disc 4 is actuated towards the cover 1 such that the friction surface 41 abuts the cover 1. The piston disc 4 and the cap 1 rotate as a unit by frictional contact therebetween. The piston disc 4 transmits torque to the turbine 3 through the torsional vibration damper 5. That is, in the mechanical transmission mode, the torque transmission path of the torque converter is: torque input → cap 1 → piston disc 4 → (torsional damper 5) → turbine 3 → turbine hub 30 → torque output. The torque transmission paths in the mechanical transmission mode are shown in dashed lines in fig. 1.

To transmit torque and to mitigate torque variations transmitted to the torque output, the torsional vibration damper 5 includes one or more springs 51, such as helical compression springs. The piston disc 4 compresses the spring 51, which spring 51 further exerts a spring force to the turbine 3, thereby achieving a torque transmission from the piston disc 4 to the turbine 3. To extend the life of the torsional damper, the amount of compression of the spring 51 should not exceed a predetermined threshold. For this purpose, a first stop projection 8 and a second stop projection 9 are provided on the piston disk 4 and the turbine housing 31, respectively. When the amount of compression of the spring 51 reaches a predetermined threshold, the first stopper projection 8 and the second stopper projection 6 abut against each other, thereby restricting relative displacement between the turbine shell 31 and the piston disc 4 in the circumferential direction, so that the spring 51 cannot be compressed any further.

Fig. 2A and 2B show a piston disc 4 provided with a first stop protrusion 8 and a turbine housing 31 provided with a second stop protrusion 9, respectively, according to a first embodiment of the present disclosure. In the embodiment shown, said first stop projection 8 has the form of a boss protruding from the piston disc 4, i.e. the first stop projection is a first stop boss 81. Similarly, the second stop projection 9 has the form of a boss protruding from the turbine shell 31, i.e. it is a second stop boss 91. The piston disc 4 is provided with three first stopping bosses 81 uniformly distributed along the circumferential direction, and the turbine housing 31 is provided with three second stopping bosses 91 uniformly distributed along the circumferential direction. It is conceivable that the piston disc 4 and the turbine housing 31 may also have a different number of first and second stop cams 81, 91, respectively. Fig. 2C shows a partial cross-sectional view of the torque converter in an assembled configuration with the amount of compression of the spring 51 reaching a predetermined threshold. As shown, the radial positions of the first and second stop bosses 81, 91 correspond to each other, and opposite side walls thereof abut against each other, so that the spring 51 cannot be further compressed. In the enlarged view of fig. 2D, the side walls of the first and second stop bosses 81, 91 lie on a radial plane passing through the center axis of the torque converter. Therefore, the opposite side walls of the two can be abutted in a fitting manner, the contact area is increased, and the damage to the stop boss caused by overlarge torque is reduced.

Fig. 3A-3C show a first stop protrusion 8 and a second stop protrusion 9 in the form of stop teeth according to a second embodiment of the disclosure. In this second embodiment, as shown in fig. 3A, the piston disc 4 comprises at its radially inner edge an axial extension 42 extending towards the turbine 3. At the end of this axial extension 42 an axially extending projection is provided, namely a first stop tooth 82 as a first stop projection 8. Correspondingly, the axially extending portion 42, as shown in fig. 3B, the turbine shell 31 is provided at its radially inner edge with a radially inwardly extending projection, i.e., a second stop tooth 92 as the second stop projection 9. The piston disc 4 is provided with three first stop teeth 82 distributed uniformly in the circumferential direction on the axial extension 42, and three second stop teeth 92 distributed uniformly in the circumferential direction on the turbine housing 31. It is conceivable for a person skilled in the art that the piston disc 4 and the turbine housing 31 can also have a different number of first stop teeth 82 and second stop teeth 92, respectively. Fig. 3C shows an assembled configuration of the turbine housing 3 and the piston disc 4. As shown, the first stop tooth 82 extends axially into the gap of the adjacent second stop tooth 92. If the amount of compression of the spring 51 reaches its predetermined threshold, the side wall of the first stop tooth 82 abuts against the side wall of the second stop tooth 92, so that the spring 51 cannot be compressed any further. Similar to the embodiment shown in fig. 2A-2D, the side walls of the first stop tooth 82 and the second stop tooth 92 also lie in radial planes passing through the center axis of the torque converter, thereby increasing the contact area and reducing the damage that may be caused to the stop teeth when the torque is excessive.

Although not shown, it is contemplated that the torque converter may be provided with both the stopper projection according to the first and second embodiments of the present disclosure. That is, the piston disc 4 and the turbine shell 3 are provided at radially intermediate positions thereof with a first stopper boss 81 and a second stopper boss 91, respectively, and at radially inner positions thereof with a first stopper tooth 82 and a second stopper tooth 92, respectively.

Fig. 4 shows a hydrodynamic torque converter comprising two torsional vibration dampers to further enhance the damping effect. The torsional vibration damper 5 described above is located radially outward and is the first torsional vibration damper. The second torsional vibration damper 7 is located radially inward and has a similar configuration to the first torsional vibration damper. The first stop projection 8 and the second stop projection 9 described above likewise prevent the spring compression of the second torsional vibration damper 7 from exceeding a predetermined threshold value.

One particular advantage provided by the torque converter described above is that the catch mechanism includes two catch members of the same type, such as the first catch projection 81 and the second catch projection 91, or the first catch tooth 82 and the second catch tooth 92. Thus, the two stopper members can be manufactured in the same process, so that the manufacturing steps of the torque converter are simplified. For example, both the first stop boss 81 and the second stop boss 91 may be manufactured on the piston disc 4 and the turbine shell 31, respectively, by stamping in the axial direction. The punches used may be selected to be of a shape suitable for forming the first and second stop bosses 81, 91. On the other hand, the first stopper tooth 82 may be formed by punching out a portion of the material at the axially extending portion 42 of the piston disc 4 in the radial direction, and the second stopper tooth 92 may be formed by punching out a portion of the material at the radially inner edge of the turbine shell 31 in the axial direction. In this way, the body of the piston disc 4 and the turbine shell 31 and the various formations thereon can be manufactured by stamping, thereby eliminating the need for additional processes and the need for special stop mechanisms. After stamping, the thickness of some parts on the piston disc 4 and/or the turbine shell 31 may be reduced accordingly. Preferably, in order to increase the strength of the piston disc 4 and/or the turbine shell 31, the piston disc 4 and/or the turbine shell 31 may be strengthened by a heat treatment process after stamping.

It is to be understood that the structures described above and shown in the drawings are merely examples of the present disclosure, which can be substituted with other structures exhibiting the same or similar function for achieving the desired end result. Furthermore, it should be understood that the embodiments described above and shown in the drawings are to be regarded as merely constituting non-limiting examples of the present disclosure and that it can be modified in a number of ways within the scope of the patent claims.

Claims (10)

1. A torque converter for a motor vehicle comprising:

a cover (1) driven by a drive member on the engine side of a motor vehicle to rotate about a rotational axis (RO) of a torque converter;

a pump wheel (2) which is connected to the cover (1) in a rotationally fixed manner;

a turbine (3) comprising a turbine shell (31), the turbine (3) being driven in rotation about the axis of Rotation (RO) to output torque to an input shaft of a transmission of a motor vehicle;

a piston disc (4) comprising a friction surface (41), the piston disc (4) being actuatable to operatively switch the torque converter between a fluid transmission mode in which rotation of the pump impeller (2) about the axis of Rotation (RO) generates a flow of fluid, thereby driving the turbine wheel (3), and a mechanical transmission mode in which the friction surface (41) bears against the cover (1) such that the cover (1) rotates integrally with the piston disc (4);

at least one torsional vibration damper (5) which is held between the piston disc (4) and the turbine (3) and which transmits torque from the piston disc (4) to the turbine (3), the torsional vibration damper (5) comprising at least one spring (51),

characterized in that the piston disc (4) is provided with one or more first stop protrusions (8) formed integrally with the piston disc (4), the turbine housing (31) is provided with one or more second stop protrusions (9) formed integrally with the turbine housing (31), and the first stop protrusions (8) and the second stop protrusions (9) cooperate with each other to limit the amount of compression of the spring (51).

2. A hydrodynamic torque converter for a motor vehicle according to claim 1,

the first stop projection (8) is a first stop boss (81) projecting from the piston disc (4) towards the turbine housing (31), and the second stop projection (9) is a second stop boss (91) projecting from the turbine housing (31) towards the piston disc (4).

3. The torque converter for a motor vehicle according to claim 2,

the side walls of the first stop projection (81) and the second stop projection (91) are located on a radial plane passing through the rotational axis (RO) of the torque converter.

4. A hydrodynamic torque converter for a motor vehicle according to claim 1,

the piston disc (4) comprises an axial extension (42) extending at its radially inner edge towards the turbine wheel (3), the first stop protrusion (8) being a first stop tooth (82) extending axially at the end of the axial extension (42), the second stop protrusion (9) being a second stop tooth (92) extending radially at the radially inner edge of the turbine shell (31).

5. A hydrodynamic torque converter for a motor vehicle according to claim 4,

the side walls of the first and second stop teeth (82, 92) lie in a radial plane passing through the rotational axis (RO) of the torque converter.

6. The torque converter for a motor vehicle according to any one of claims 1 to 5,

the piston disk (4) has 3 first stop projections (8) distributed uniformly in the circumferential direction, and the turbine housing (31) has 3 second stop projections (9) distributed uniformly in the circumferential direction.

7. The torque converter for a motor vehicle according to any one of claims 1 to 5,

the torsional vibration damper (5) is a first torsional vibration damper and the hydrodynamic torque converter further comprises a second torsional vibration damper (7) located radially inside the first torsional vibration damper.

8. The torque converter for a motor vehicle according to any one of claims 1 to 5,

the turbine housing (31) and/or the piston disk (4) are produced by stamping.

9. A hydrodynamic torque converter for a motor vehicle according to claim 8,

the turbine shell (31) and/or the piston disk (4) are strengthened by a heat treatment process after the stamping.

10. A motor vehicle characterized in that it comprises a hydrodynamic torque converter for a motor vehicle according to any one of claims 1 to 9.

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