Actuation device and transmission system of a vehicle

Abstract

The present invention relates to an assembly comprising an actuation device (100) and a transmission system (200) for a motor vehicle. The actuation device (100) comprises an actuation housing (10), an electric motor (11), a drive shaft (19) rotating about a Y-axis, a torque output element (50), and a reduction mechanism (20) disposed between the drive shaft (19) and the torque output element (50). The transmission system (200) comprises a transmission housing (60), a sliding sleeve (80) movable axially between two extreme positions about an X-axis substantially perpendicular to the Y-axis, and a receiving housing (81) for the torque output element (50). According to the invention, a portion of the drive shaft (19) extends axially along the Y-axis inside the torque output element (50). Figure for the abbreviation: Figure 1

Description

Title of the invention: Actuation device and transmission system of a vehicle

[0001] The invention relates to the field of actuation devices for transmission systems. The invention is of particular interest in the field of motor vehicles, especially electric or hybrid vehicles.

[0002] Electric or hybrid four-wheel-drive vehicles are equipped with electric motors at the front and rear, which are generally divided into a main drive motor and an auxiliary drive motor that, in some cases, can be inactive. For example, the auxiliary motor can be engaged during acceleration or under certain specific conditions. However, when this auxiliary motor stops operating, the wheels continue to drive the auxiliary differential, which turns all the drive mechanisms connected to it, as well as the motor, resulting in power losses. In order to improve efficiency, actuation devices, also called disconnection mechanisms, are added to the powertrain of electric vehicles to reduce drag losses.

[0003] The actuation devices are for example inserted into a transmission system of the type connecting clutch interposed between the output of a speed reducer and a wheel of the vehicle.

[0004] Alternatively, the actuation device is for example used in addition to an actuation fork for changing a gear ratio within a gearbox.

[0005] An actuator is known for connecting and disconnecting a coupling between two coaxial shafts by means of an axially movable sleeve. The actuator comprises an electric motor, and the motor shaft is connected to a rotating actuating rod. This rod is provided at its end with an eccentric that cooperates with the coupling sleeve. Rotation of the actuating rod by means of the electric motor causes the coupling to engage or disengage.

[0006] Between the electric motor and the eccentric is a reduction mechanism in the form of an epicyclic gear train. This mechanism is complex, difficult to assemble and relatively expensive.

[0007] Furthermore, the force applied to the eccentric of the torque output element of the actuator is significant, on the order of 600N and potentially up to 1200N at the level of the bearing(s) guiding the rotation of this torque output element, which can generate misalignment or tilting of the torque output element. relative to its axis of rotation. In other words, the torque output element is exposed to a ball-and-socket effect when under stress and there is a risk of binding at the level of the teeth of the torque output element which can lead to premature wear of the teeth of the actuator.

[0008] It is therefore necessary to propose a solution to remedy the aforementioned problems by proposing an actuation device associated with a transmission system whose torque output element is perfectly guided in rotation in a relatively simple, easy-to-assemble and robust manner over time.

[0009] Thus, the invention proposes an assembly comprising an actuation device and a transmission system for a motor vehicle, - The actuation device comprises an actuating housing, an electric motor, a motor shaft rotating about a Y-axis, a torque output element, a reduction mechanism disposed between the motor shaft and the torque output element; - The transmission system comprises a transmission housing, a sliding sleeve that is axially movable between two extreme positions about an X-axis substantially perpendicular to the Y-axis; the sliding sleeve includes a housing for receiving the torque output element. a portion of the drive shaft extends axially along the Y-axis inside the torque output element.

[0010] This design allows for improved rotational guidance of the torque output element because the radial forces of the torque output element are partially absorbed by the drive shaft. Indeed, the fact that a portion of the drive shaft extends axially along the Y-axis inside the torque output element prevents the torque output element from becoming spherical. Furthermore, this architecture also makes the actuator more axially compact.

[0011] In the context of the invention, the reduction mechanism means that the rotational speed of the torque output element is reduced relative to the rotational speed of the drive pinion, thereby increasing the torque. For example, the reduction ratio of the reduction mechanism is 12:1. Other reduction ratios are possible depending on the torque to be transmitted.

[0012] According to the invention, the torque output element rotates about the Y-axis and is guided in rotation by both the transmission housing or the actuator housing and the motor shaft. The fact that the torque output element is guided by two elements improves guidance and minimizes the risk of misalignment or tilting with respect to its axis of rotation.

[0013] According to the invention, the torque output element comprises an axial bore along the Y-axis in which a portion of the drive shaft extends. The drive shaft may be in direct or indirect contact with the axial bore of the torque output element. It is It is important to note that the drive shaft is inserted into the axial bore of the torque output element without radial play, except for assembly tolerances. The bore is preferably of the blind type.

[0014] According to an additional feature, a first bearing is disposed between the torque output element and the transmission housing or the drive housing, and a second bearing is disposed between the torque output element and the drive shaft. The first bearing may be, for example, a ball bearing, and the second bearing may be, for example, a plain bearing. Alternatively, the first bearing may be a plain bearing and the second bearing may be a roller bearing. According to another embodiment, both the first and second bearings may be roller bearings or plain bearings.

[0015] The first bearing absorbs the majority of the applied radial load, and the second bearing limits the spherical effect of the torque output element. The second bearing also limits wear between the motor shaft and the torque output element, which rotate at different speeds.

[0016] According to the invention, the reduction mechanism of the actuation device comprises a drive pinion rotationally linked to the drive shaft, a gear that permanently meshes with the drive pinion, and the torque output element. Of course, it is entirely possible to provide a plurality of gears in parallel between the drive pinion and the torque output element in order to reduce the forces applied to the teeth.

[0017] According to the invention, the torque output element comprises teeth and an actuation profile cooperating with the receiving housing of the sliding sleeve. Preferably, the teeth are located at the periphery of the torque output element at a first axial end along the Y-axis, and the actuation profile is located at a second axial end opposite to that where the teeth are located. Preferably, the teeth are formed from the same material as the torque output element.

[0018] According to the invention, the gear is double-stage; the first stage meshes with the drive pinion and the second stage meshes with the torque output element. Preferably, the gear is made of plastic or metal. Preferably, the gear has straight teeth.

[0019] According to the invention, the gear rotates around a pin. The pin is fitted into a transmission housing. Alternatively, the pin may be fitted only into the actuating housing. In another embodiment, the pin may be fitted into both the actuating housing and the transmission housing. The pin extends in a direction parallel to the Y-axis.

[0020] According to an additional feature of the invention, a cavity is formed at the interface of the actuating housing and the transmission housing and the reducing mechanism is disposed in this cavity.

[0021] According to another feature of the invention, the actuation profile of the torque output element is a cam or an eccentric. The actuation profile may be formed from the same material as the torque output element or attached and held in place by means of fastening.

[0022] Advantageously, the torque output element includes two learning stops provided at the level of the teeth and spaced angularly.

[0023] According to the invention, the sliding sleeve is a part of revolution about the X axis and the receiving housing is a circumferential groove. The circumferential groove is defined by two walls that serve as contact surfaces for the actuation profile of the torque output element.

[0024] According to the invention, the sliding sleeve comprises at least one first connecting spline arranged to rotationally couple a driving shaft and a second connecting spline arranged to couple a driven shaft. The first and second connecting splines are engaged when the sliding sleeve is in a first extreme coupling position, and one of the first and second connecting splines is disengaged when the sliding sleeve is in a second extreme disengagement position.

[0025] Other features and advantages of the invention will become apparent from the following detailed embodiment, with reference to the attached figures:

[0026] Fig. 1 represents a cross-sectional view of an assembly comprising an actuation device and a transmission system according to the invention;

[0027] Fig. 2 represents a perspective view of the reduction mechanism of the actuation device.

[0028] It should be noted that the figures disclose the invention in sufficient detail for its implementation, and that the figures help to further define the invention if necessary. However, the invention should not be limited to the embodiment disclosed in the description.

[0029] In the description and claims, the terms "external" and "internal" and the orientations "axial" and "radial" will be used to designate, according to the definitions given in the description, elements of the actuation device or transmission system.

[0030] By convention, the "radial" orientation is directed orthogonally to the X or Y axis defining the "axial" orientation of the rotation axis of the transmission system and the rotation axis of the drive shaft of the actuation device, respectively. The "circumferential" orientation is directed orthogonally to the principal X axis.

[0031] Fig. 1 illustrates an assembly comprising an actuation device 100 and a transmission system 200. The transmission system 200 is here a connecting clutch between two shafts 70, 90 which is used, in a transmission chain of a vehicle, to transmit torque from an electric or thermal motor, not illustrated, to a wheel shaft of a motor vehicle.

[0032] Such a transmission system can, for example, be part of an auxiliary transmission chain capable of transmitting torque from an auxiliary motor of the vehicle, such as an electric motor, to a rear or front axle of a vehicle while a primary transmission chain is capable of transmitting torque from a main motor, for example a heat engine, to the wheel shafts of another axle of the vehicle.

[0033] When the auxiliary motor is inactive, there is no advantage to leaving it connected to the vehicle wheel. The connecting clutch is then disengaged. The transmission system 200 is kinematically interposed between a speed reducer (not visible) and the vehicle's wheel shaft (not visible).

[0034] The output shaft of the speed reducer is called the driving shaft 70 and is rotatable about the X-axis. The driving shaft 70 of the transmission system 200 includes a first external spline 71 machined on its end. The transmission system 200 also includes a driven transmission shaft 90 coaxial with the driving shaft 70, which includes a second external spline 91. In the example of [Fig. 1], the driven shaft 90 is inserted into the driving shaft 70 and guided in rotation by a bearing 62. The driven transmission shaft 90 includes an internal torque output spline 92 rotationally connected with the vehicle's wheel shaft (not visible).

[0035] The transmission system 200 comprises a transmission housing 60, a sliding sleeve 80 that is axially movable between two extreme positions along the X axis. The sliding sleeve 80 allows the two shafts 70, 90 to be coupled or uncoupled, thus performing the function of a connecting clutch.

[0036] The driving shaft 70 is guided in rotation in the transmission housing 60 by a bearing 61. The driven shaft 90 is guided in rotation in the transmission housing 60 by a bearing 63.

[0037] In order to actuate the sliding sleeve 80, that is to say in order to make it slide along the X axis, an electrically powered actuating device 100 is used.

[0038] The actuation device 100 comprises an actuation housing 10 in which is housed an electric motor 11 comprising a stator 12 and a rotor 13. The electric motor 11 is preferably a brushless DC electric motor. The rotor 13 is coupled to a motor shaft 19 rotating about a Y-axis substantially perpendicular to the X-axis. The motor shaft 19 is guided in rotation by a first bearing 17 fitted into a transverse wall 14 and by a second bearing 18 fitted into the actuation housing 10.

[0039] The stator 12 of the electric motor 11 is connected to an electronic board 15 which controls the electric motor 11. The electronic board 15 is located in a defined electronic space between the transverse wall 14 and a cover 16. The cover 16 includes an electrical connector. The transverse wall 14 and the cover 16 are preferably made of plastic. This electronic space is located axially along the Y-axis at one end of the drive housing 10 opposite the transmission system 200.

[0040] At the other axial end of the actuator housing 10 is the torque output element 50 of the actuator device 100. A reduction mechanism 20 is disposed between the motor shaft 19 and the torque output element 50. A cavity is formed at the interface of the actuator housing 10 and the transmission housing 60, the reduction mechanism 20 is disposed in this cavity.

[0041] The reducing mechanism 20 and the rotational guidance of the torque output element 50 will be described in relation to [Fig.2].

[0042] The torque output element 50 comprises a toothed section 51 and an actuation profile 54 in the form of a cam or an eccentric. The toothed section 51 and the actuation profile 54 are made of the same material as the torque output element 50. In other words, they are one piece.

[0043] The actuator housing 10 is mounted on the transmission housing 60. The transmission housing 60 is cylindrical with its axis coinciding with the X-axis and has an opening for the torque output element 50 of the actuator 100. The transmission housing 60 is mounted on a housing of the vehicle's speed reducer. The actuator housing 10 can be made of plastic or metal. The transmission housing 60 is made of metal.

[0044] The sliding sleeve 80 includes a receiving housing 81 for the torque output element 50. More specifically, the actuation profile 54 of the torque output element 50 cooperates with the receiving housing 81 of the sliding sleeve 80. The sliding sleeve 80 moves axially along the X axis between its two extreme positions when the torque output element 50 pivots about its axis of rotation Y.

[0045] The sliding sleeve 80 comprises at least one first internal connecting spline 83 arranged to rotationally couple the driving shaft 70 and a second internal connecting spline 84 arranged to couple the driven shaft 90. The first and second connecting splines 83, 84 are engaged when the sliding sleeve 80 is in a first extreme coupling position and one of the first and second connecting splines 83, 84 being disengaged when the sliding sleeve 80 is in a second extreme disengaged position.

[0046] The first and second connecting splines 83, 84 are engaged respectively in the first external spline 71 of the driving shaft 70 and the second external spline 91 of the driven shaft 90 when the sliding sleeve 80 is in a first extreme position, this first extreme position being called the extreme coupling position.

[0047] The second connecting spline 84 is disengaged from the second external spline 91 of the driven shaft 90 when the sliding sleeve 80 is in a second extreme position, this second extreme position being called the extreme disengagement position.

[0048] In the embodiment shown in [Fig. 1], the sliding sleeve 80 is a part of revolution about the main axis X. The sliding sleeve 80 is driven in rotation by the driving shaft 70 via the internal spline 83, which meshes with the first external spline 71. Since the receiving housing 81 is formed in the form of an annular groove, a relative rotational movement about the main axis X between the receiving housing 81 and the actuating profile 54 is possible. In the example of [Fig. 1], the actuating profile 54 is received directly in the receiving housing 81. Alternatively, not shown, the actuating profile can be received in an intermediate component connected to the receiving housing 81.

[0049] Fig. 2 shows more precisely the reduction mechanism 20 mounted in the cavity formed at the interface of the actuator housing 10 and the transmission housing 60 and in particular the cooperation between the motor shaft 19 and the torque output element 50.

[0050] The motor shaft 19 includes a motor pinion 23 disposed at one end of the motor shaft 19 opposite the electric motor 11. The motor pinion 23 is rotationally linked to the motor shaft 19.

[0051] A gear 30 permanently meshes with the drive pinion 23 in order to transmit the torque generated by the electric motor 11. The gear 30 is double-stage, the first stage 31 meshing with the drive pinion 23 and the second stage 32 meshing with the teeth 51 of the torque output element 50. The diameter of the first stage 31 is greater than the diameter of the second stage 32.

[0052] The gear 30 is preferably made of plastic. The drive pinion 23 is preferably made of plastic. The torque output element 50 and its actuation profile are preferably made of plastic. The teeth of the reduction mechanism 20 are straight teeth. The sliding sleeve 80 is preferably made of metal.

[0053] The toothed wheel 30 is rotatable around a pin 21 fitted into the transmission housing 60. The pin is located at a distance from the Y axis and extends in a direction parallel to the Y axis.

[0054] A portion of the motor shaft 19 extends axially along the Y axis inside the torque output element 50. More specifically, the free end of the motor shaft 19 on the side of the motor pinion 23 is located axially along the Y axis in the torque output element 50.

[0055] The torque output element 50 rotates about the Y-axis and is guided in rotation by both the transmission housing 60 and the drive shaft 19. A first bearing 41 is located between the torque output element 50 and the transmission housing 60. The first bearing 41 is a bearing, for example, a ball bearing. In other words, the drive shaft 19 and the torque output element 50 both pivot about the same Y-axis, i.e., coaxially, at different speeds due to the reduction ratio of the gear 30.

[0056] The torque output element 50 includes a blind bore 40 in which a portion of the free end of the drive shaft 19 extends. This blind bore 40 includes a machined seat on which radial contact is made with the drive shaft 19. A second bearing 42 is disposed in the seat of the blind bore between the torque output element 50 and the drive shaft 19. This second bearing 42 is a plain bearing, for example made of plastic or bronze.

[0057] Alternatively, not shown, the drive shaft 19 can be mounted directly in the machined seat of the blind bore 40. For this purpose, the outside diameter of the drive shaft 19 is substantially equal to the diameter of the blind bore 40.

[0058] The sliding sleeve 80 is a part of revolution about the X axis and the receiving housing 81 is a circumferential groove defined by two walls which serve as a contact surface for the actuating profile 54 of the torque output element 50. The actuating profile 54 is always in contact with at least one of the two walls depending on the direction of translation of the sliding sleeve 80.

[0059] Although the invention has been described in connection with a particular embodiment, it is clearly evident that it is by no means limited to it and that it includes all technical equivalents of the means described.

[0060] In the claims, the reference symbols in parentheses shall not be interpreted as a limitation of the claim.

Claims

Demands

1. Assembly comprising an actuation device (100) and a transmission system (200) of a motor vehicle, - the actuation device (100) comprises an actuation housing (10), an electric motor (11), a motor shaft (19) rotating about an axis Y, a torque output element (50), a reduction mechanism (20) disposed between the motor shaft (19) and the torque output element (50), - the transmission system (200) comprises a transmission housing (60), a sliding sleeve (80) movable axially between two extreme positions about an axis X substantially perpendicular to the axis Y, the sliding sleeve (80) comprises a receiving housing (81) for the torque output element (50), characterized in that a portion of the motor shaft (19) extends axially about the axis Y inside the torque output element (50).

2. Assembly according to claim 1, characterized in that the torque output element (50) is rotatable about the Y axis and guided in rotation by both the transmission housing (60) or the actuator housing (10) and the motor shaft (19).

3. Assembly according to claim 1 or 2, characterized in that the torque output element (50) comprises a bore (40) in which extends a portion of the drive shaft (19).

4. Assembly according to any one of the preceding claims, characterized in that a first bearing (41) is disposed between the torque output element (50) and the transmission housing (60) or the actuation housing (10) and a second bearing (42) is disposed between the torque output element (50) and the drive shaft (19).

5. Assembly according to any one of the preceding claims, characterized in that the reduction mechanism (20) of the actuation device (100) comprises a drive pinion (23) rotationally linked to the drive shaft (19), a gear (30) which permanently meshes with the drive pinion (23) and the torque output element (50).

6. Assembly according to any one of the preceding claims, characterized in that the torque output element (50) comprises a toothed (51) and an actuation profile (54) cooperating with the receiving housing (81) of the sliding sleeve (80).

7. Assembly according to claim 5, characterized in that the toothed wheel (30) is double-stage, the first stage (31) meshes with the drive pinion (23) and the second stage (32) meshes with the torque output element (50).

8. Assembly according to claim 5, characterized in that the toothed wheel (30) is rotatable around a pin (21), the pin (21) is fitted into the actuating housing (10) and / or into the transmission housing (60).

9. Assembly according to any one of the preceding claims, characterized in that a cavity is formed at the interface of the actuating housing (10) and the transmission housing (60), the reducing mechanism (20) is disposed in this cavity.

10. Assembly according to claim 6, characterized in that the actuation profile (54) of the torque output element (50) is a cam or an eccentric.

11. Assembly according to any one of the preceding claims, characterized in that the sliding sleeve (80) is a part of revolution about the X axis and the receiving housing (81) is a circumferential groove.

12. Assembly according to any one of the preceding claims, characterized in that the sliding sleeve (80) comprises at least one first connecting spline (83) arranged to rotationally couple a driving shaft (70) and a second connecting spline (84) arranged to couple a driven shaft (90), the first and second connecting splines (83, 84) being engaged when the sliding sleeve (80) is in a first extreme coupling position and one of the first and second connecting splines (83, 84) being disengaged when the sliding sleeve (80) is in a second extreme discoupling position.