Transmission system equipped with a coupling device

Abstract

The present invention relates to a transmission system (1) of an automobile, wherein the transmission system comprises: a first element (4) and a second element (5) rotatable about each other about an axis (X); a coupling device (6), wherein the coupling device (6) comprises: a first coupling portion (18) which is rotatably locked to the first element (4) and movable about the first element between a coupled position and a separated position; a disk (36) comprising a fixed area axially fixed to the first coupling portion (18), wherein the disk (36) comprises an annular portion (37) forming a target (34) and at least one elastic return portion (41) configured to elastically return the first coupling portion (18) to a separated position; and a sensor (35) positioned toward the annular portion of the disk (36).

Description

Technology Field

[0001] The present invention relates to the field of vehicle drivetrains.

[0002] More specifically, the present invention relates to a transmission system comprising a first element configured to be driven by a motor, a second element configured to drive at least one wheel shaft of a vehicle, and a coupling device capable of optionally coupling the first element to the second element.

[0003] The present invention relates particularly to a differential transmission system for transmitting and distributing the torque of a motor to two wheel shafts of a vehicle axle. Background Technology

[0004] Document US 2015114786 discloses a differential transmission system. The transmission system comprises a differential housing, which is rotatably mounted about an axis (A) and is driven by a motor of the vehicle. Inside the housing accommodates a carrier ring that is rotatably guided within the housing, two planetary gears that are rotatably mounted on the carrier ring about an axis (B) perpendicular to the axis (A), and two sun gears that each mesh with the two planetary gears and are rotatably locked to the wheel shafts. Additionally, the transmission system comprises a coupling device that connects the housing of the transmission system to the carrier ring to enable the transmission and distribution of torque from the engine to the two wheel shafts of the axle, or to disconnect them to cut off the transmitted torque between the motor and the wheel shafts.

[0005] The coupling device is a dog clutch device. This clutch device comprises an annular portion disposed outside the housing and a first coupling portion having a protruding element extending from the annular portion and passing through an orifice formed within the housing, thereby enabling rotational fixation of the first coupling portion and the housing. The protruding element includes a toothed portion configured to cooperate with a complementary groove formed in a carrier ring. The first coupling portion is axially movable relative to the housing between a coupling position and a separation position in which the toothed portion of the first coupling portion engages with the groove of the carrier ring.

[0006] The electromagnetic actuator can apply an axial force to the first coupling portion to move the first coupling portion from a separated position to a coupled position. Additionally, the transmission system includes an annular target axially fixed to the annular portion of the first coupling portion. The annular target is positioned to face a sensor, such as a Hall effect sensor, axially, thereby transmitting a signal indicating the axial distance between the sensor and the annular target.

[0007] The transmission system further includes an elastic washer positioned between the annular target and the axial direction of the housing. The function of this elastic washer is to enable the first coupling part to be returned to a separated position by applying a return force to the first coupling part, particularly when the electromagnetic actuator no longer applies force to the first coupling part.

[0008] This transmission system is not entirely satisfactory.

[0009] In particular, the coupling device of a transmission system has many different parts to ensure the return function and target of the coupling device, especially in the disengagement position, which increases complexity, cost, and / or volume.

[0010] The basic idea of ​​the present invention is to propose a transmission system equipped with a coupling device, a target, and a sensor capable of transmitting a signal indicating the state of the coupling device, wherein the transmission system is simpler and / or smaller in volume.

[0011] According to one embodiment, the present invention provides a transmission system for an automobile, wherein the transmission system comprises:

[0012] · A first element and a second element rotatable about each other around an axis (X)—one of the first element and the second element is configured to be driven by a motor, and the other of the first element and the second element is configured to drive at least one wheel shaft of a vehicle—; and

[0013] · Includes a coupling device,

[0014] The above coupling device is:

[0015] · A first coupling portion rotatably locked to a first element, and a second coupling portion rotatably locked to a second element—the first coupling portion is movable relative to the first element between a coupling position in which the first coupling portion is coupled to the second coupling portion to transmit torque between the first element and the second element, and a separation position in which the first coupling portion and the second coupling portion are separated from each other—and,

[0016] · A disk comprising a fixed region axially fixed to a first coupling portion—the disk comprises an annular portion forming a target, and at least one elastic return portion configured to exert a return force capable of elastically deforming while the first coupling portion moves from a separated position to a coupled position and elastically returning the first coupling portion to a separated position.

[0017] Therefore, the disc has a dual function: on the one hand, it forms a target whose position can be detected by a sensor to transmit a signal indicating the position of the first part of the coupling device, and on the other hand, it enables the first coupling part to return to its separated position. This allows for a reduction in the cost, complexity, and volume of such a transmission system.

[0018] According to various embodiments, such a transmission system may have one or more of the following features.

[0019] According to one embodiment, the transmission system includes a sensor positioned toward an annular portion of a disc, and the sensor is configured to transmit a signal indicating the distance between the sensor and the annular portion forming the target.

[0020] According to one embodiment, the sensor is positioned so that the annular portion of the disk faces axially.

[0021] According to one embodiment, while the first coupling portion moves from a separated position to a coupled position, the elastic return portion receives elastic stress between the bearing area and the fixed area of ​​the transmission system. Preferably, the bearing area is axially fixed with respect to the second coupling portion.

[0022] According to one embodiment, the disk is made of spring steel such as advantageously pre-hardened XC 70 steel. According to one embodiment, the disk has a thickness of 0.4 to 1.2 mm, for example, about 0.8 mm. According to one embodiment, the disk is made of stainless steel, which is a non-magnetic metal, which also limits undesirable leakage of magnetic flux.

[0023] According to one embodiment, the disc includes a plurality of elastic return portions, each comprising an elastic blade capable of supporting a bearing area of ​​the transmission system. Accordingly, the elastic blade receives an increasing bending force while the first coupling portion moves from a separated position to a coupled position.

[0024] According to one embodiment, the bearing region is fixed axially with respect to the second coupling portion.

[0025] According to one embodiment, each elastic blade includes a free end. Preferably, the elastic blade is supported against a bearing area of ​​the transmission system through the end of the elastic blade.

[0026] According to one embodiment, each elastic blade is formed within a window formed in a disk.

[0027] According to one embodiment, the elastic blades are regularly distributed around the axis (X) so as not to cause imbalance.

[0028] According to one embodiment, the coupling device includes at least two elastic blades, preferably four elastic blades, which are regularly distributed around the axis (X) and preferably symmetrically arranged in pairs with respect to the axis (X).

[0029] According to one embodiment, the elastic blade is positioned radially inside the annular portion forming the target, thereby limiting the radial volume of the disk.

[0030] According to one embodiment, each elastic blade extends in a direction having a circumferential component centered on an axis (X). Thus, for a given radial volume, the elastic blade can obtain a greater length and consequently lower stiffness.

[0031] According to one embodiment, the disk and the elastic blade are dimensioned to generate stiffness (K1) that opposes axial movement of the first coupling portion from the separation position to the coupling position, which is between 5 and 50 N / mm.

[0032] According to one embodiment, the first element includes a housing in which a second coupling portion is received, and the first coupling portion includes an inner portion received inside the housing, an outer portion disposed outside the housing, and a plurality of connecting portions connecting the inner portion and the outer portion of the first coupling portion in an axial direction, and each connecting portion passes through a corresponding through-opening formed in the housing.

[0033] According to one embodiment, one of the inner and outer parts of the first coupling part is annular, and the other includes a lug that extends axially in a continuous manner from the connecting part.

[0034] According to one embodiment, the disk is disposed outside the housing and fixed to the outer part of the first coupling portion, and each bearing area is disposed on the housing.

[0035] According to one embodiment, the housing includes a stud protruding axially toward the outside of the housing in the direction of the disk, and each stud has one end forming one of the bearing regions. By doing this, folding the elastic blade during disc manufacturing can be avoided.

[0036] According to one embodiment, when the first coupling portion is in a separated position, the elastic blade extends substantially in the plane of the annular portion of the target forming disk.

[0037] According to one embodiment, the stud has an axial dimension greater than or equal to the travel distance of the first coupling portion between the coupling position and the separation position.

[0038] According to one embodiment, the first element is a differential housing.

[0039] According to one embodiment, the second element comprises a carrier ring rotatably guided about an axis (X) inside a housing, two planetary gears rotatably mounted on the carrier ring about an axis (Z) perpendicular to the axis (X), and two sun gears rotatably rotatably guided about the axis (X), each meshing with the two planetary gears and rotatably locked to the wheel shafts. Thus, the transmission system forms a differential so that the wheel shafts can rotate at different speeds.

[0040] According to one embodiment, two planetary gears each include a bevel gear tooth that meshes with the complementary bevel gear tooth of two sun gears.

[0041] According to one embodiment, the second coupling portion of the coupling device is rotationally locked with the carrier ring with respect to the shaft (X). Thus, when the coupling device is in the coupled position, the transmission system distributes torque from the engine toward the two wheel shafts. Conversely, when the coupling device is in the separated position, the transmission of torque between the housing and the carrier ring is interrupted.

[0042] According to one embodiment, the second coupling portion of the coupling device is formed integrally with the carrier ring.

[0043] According to another embodiment, the second coupling portion is rotationally locked with one of the sun gears. In this embodiment, when the latter is in the coupled position, torque is transmitted between the first and second elements through the gear, but the differential function is blocked by the coupling device to prevent the wheel shafts from rotating at different speeds.

[0044] According to one embodiment, the disk includes a plurality of fixed tabs that are fixed to a first coupling portion.

[0045] According to one embodiment, each fixed tab includes a proximal end connected to an annular portion forming a target and a free end fixed to a first coupling portion.

[0046] According to one embodiment, each fixed tab is formed in a window formed on the disk.

[0047] According to one embodiment, the fixing tab extends radially. It is preferable that the fixing tab extends radially inward from the radially outer edge of the window.

[0048] According to one embodiment, the fixed tabs are regularly distributed around the axis (X) so as not to cause imbalance.

[0049] According to one embodiment, the coupling device includes at least two fixed tabs, preferably four fixed tabs, and these fixed tabs are regularly distributed around the axis (X) and are symmetrical in pairs with respect to the axis (X).

[0050] According to one embodiment, the fixing tab is located radially inside the annular portion forming the target, thereby limiting the radial volume of the disk.

[0051] According to one embodiment, the fixing tab is fixed to the outer part of the first coupling part, in particular to the lug.

[0052] According to one embodiment, the outer portion of the first coupling portion includes a lug that extends axially in continuity with the connecting portion, and the lug penetrates a window through which a fixing tab extends.

[0053] It is preferable that each fixed tab be positioned between the circumferential directions of the two elastic blades. It is preferable that there be a circle centered on an axis (X) that intersects all elastic blades and all fixed tabs.

[0054] According to one embodiment, the free end of each fixed tab is fitted into a groove formed in a first coupling part, in particular in its lug. The groove may be radially recessed.

[0055] According to another embodiment, the free end of each fixed tab is secured to a first coupling part, specifically one of its lugs, by a fixing member such as a screw.

[0056] According to one embodiment, the coupling device comprises a casing configured to be fixed to the chassis of a vehicle, and an actuator comprising a piston axially movable with respect to the casing between a retracted position and an extended position, wherein the piston is supported against the operating area of ​​the disc in such a manner that when the piston moves from the retracted position to the extended position, the first coupling portion of the coupling device moves from the separated position to the coupled position. Thus, the disc enables the transmission of operating force between the actuator and the first coupling portion, thereby significantly reducing the cost, complexity, and volume of the transmission system.

[0057] According to one embodiment, the actuator includes an electromagnet defining a housing, and a piston within the housing can move axially between a retracted position and an extended position, and the piston includes an annular body made of a ferromagnetic material. Such an electromagnetic actuator is particularly advantageous in that it is highly responsive.

[0058] According to one embodiment, the actuator includes a paramagnetic end piece that is fixed to the body of the piston and cooperates with the operating area of ​​the disk. This prevents unwanted magnetic flux leakage.

[0059] According to one embodiment, the actuator includes a magnetic cap that comes into contact with the body of the piston when the piston is in the extended position. Thus, the magnetic cap allows the electromagnet to be switched off by maintaining the piston in the extended position.

[0060] According to one embodiment, the magnetic cap includes a shoulder that contacts the shoulder of the piston body when the piston is in the unfolded position.

[0061] According to one embodiment, the disc can be elastically deformed between the operating region and the fixed region of the disc while the piston of the actuator moves from the retracted position to the extended position. Thus, the disc enables the manufacturing tolerance of the coupling device to be compensated.

[0062] According to one embodiment, the operating area of ​​the disk is separated from the contact area of ​​the first coupling part by an axial clearance that is dimensioned such that the disk is deformed while the piston of the actuator moves from a retracted position to an extended position to compensate for the axial manufacturing tolerance of the coupling device, and the operating area of ​​the disk comes into contact with the contact area of ​​the first coupling part when the axial manufacturing tolerance of the coupling device is compensated.

[0063] According to one embodiment, the axial clearance is between 0.2 and 1.5 mm.

[0064] According to one embodiment, the disk is dimensioned to generate a stiffness (K2) that resists the axial approach of the piston toward the first coupling portion, which is between 50 and 500 N / mm.

[0065] The stiffness (K2) is greater than the stiffness (K1). Advantageously, the stiffness (K2) is 4*K1 to 20*K1 (e.g., 10*K1).

[0066] According to one embodiment, the operating area of ​​the disk is an internal annular portion. This allows the radial volume of the coupling device to be limited.

[0067] According to one embodiment, the inner annular portion includes an oil passage groove. The presence of oil can limit friction that may occur between the piston and the disc.

[0068] According to one embodiment, the coupling device is a dog clutch device, wherein one of the first and second coupling parts includes a toothed portion, and the other includes a corresponding groove that engages with the toothed portion when the first coupling part is in a coupling position.

[0069] According to one embodiment, the coupling device is a disconnecting device capable of selectively blocking torque transmission between a first element and a second element.

[0070] According to one embodiment, the present invention also relates to an automobile and the aforementioned transmission system.

[0071] According to one embodiment, the vehicle includes an electric machine, and a first element of the transmission system can be driven by the electric machine.

[0072] The electric machine and transmission system can be integrated within the electric axle.

[0073] According to a second aspect, the present invention also provides a transmission system for an automobile, wherein the transmission system comprises:

[0074] · A first element and a second element rotatable about each other around an axis (X)—one of the first element and the second element is configured to be driven by a motor, and the other of the first element and the second element is configured to drive at least one wheel shaft of a vehicle—; and

[0075] · Includes a coupling device,

[0076] The above coupling device is:

[0077] ·A first coupling portion rotatably locked to a first element, and a second coupling portion rotatably locked to a second element—the first coupling portion is movable relative to the first element between a coupling position in which the first coupling portion is coupled to the second coupling portion to transmit torque between the first element and the second element, and a separation position in which the first coupling portion and the second coupling portion are separated from each other—and,

[0078] · A transmission member comprising a fixed region axially fixed to the first coupling portion, and

[0079] · An actuator comprising a casing configured to be fixed to the chassis of a vehicle, and a piston axially movable with respect to the casing between a retracted position and an extended position—the piston is supported with respect to an operating area of ​​a transmission member such that when the piston moves from the retracted position to the extended position, a first coupling portion of the coupling device moves from a separated position to a coupled position, and the transmission member can be elastically deformed between an operating area and a fixed area of ​​the transmission member while the piston of the actuator moves from the retracted position to the extended position.

[0080] Therefore, the transmission member enables compensation for the manufacturing tolerances of the coupling device.

[0081] The transmission member is preferably a disk. The outer part can form a sensor target.

[0082] This second aspect of the present invention may include one or more of the features mentioned in the context of the first aspect of the present invention.

[0083] According to a third aspect, the present invention also provides a transmission system for an automobile, the transmission system being:

[0084] ·A first element and a second element rotatable about each other around an axis (X)—one of the first element and the second element is configured to be driven by a motor, and the other of the first element and the second element is configured to drive at least one wheel shaft of a vehicle—; and

[0085] · Includes a coupling device,

[0086] The above coupling device is:

[0087] · A first coupling portion rotatably locked to a first element, and a second coupling portion rotatably locked to a second element—the first coupling portion is movable relative to the first element between a coupling position in which the first coupling portion is coupled to the second coupling portion to transmit torque between the first element and the second element, and a separation position in which the first coupling portion and the second coupling portion are separated from each other—and,

[0088] · A disk comprising a fixed region axially fixed to a first coupling portion and an annular portion forming a target, and

[0089] · It includes a casing configured to be fixed to the chassis of a vehicle, and an actuator comprising a piston axially movable with respect to the casing between a retracted position and an extended position—the piston is supported with respect to the operating area of ​​a disc such that when the piston moves from the retracted position to the extended position, a first coupling portion of the coupling device moves from a separated position to a coupled position.

[0090] Therefore, the disc has a dual function of forming a target whose position is detected by a sensor to transmit a signal indicating the position of the first part of the coupling device on the one hand, and transmitting an operating force between the piston of the actuator and the first coupling part on the other, thereby reducing the cost, complexity, and volume of the transmission system.

[0091] This third aspect of the present invention may include one or more of the features mentioned in the context of the first aspect of the present invention.

[0092] In particular, the disc is capable of elastically deforming between the operating and fixed regions of the disc while the actuator's piston moves from the retracted position to the extended position.

[0093] According to a fourth aspect, the present invention also provides a transmission system for an automobile, wherein the transmission system comprises:

[0094] · A first element and a second element rotatable about each other around an axis (X)—one of the first element and the second element is configured to be driven by a motor, and the other of the first element and the second element is configured to drive at least one wheel shaft of a vehicle—; and

[0095] · Includes a coupling device,

[0096] The above coupling device is:

[0097] · A first coupling portion rotatably locked to a first element, and a second coupling portion rotatably locked to a second element—the first coupling portion is movable relative to the first element between a coupling position in which the first coupling portion is coupled to the second coupling portion to transmit torque between the first element and the second element, and a separation position in which the first coupling portion and the second coupling portion are separated from each other—and,

[0098] · A transmission member comprising a fixed region axially fixed to the first coupling portion—the transmission member comprises an elastic return portion configured to exert a return force capable of elastically deforming while the first coupling portion moves from a separated position to a coupled position and elastically returning the first coupling portion to a separated position—and,

[0099] ·It includes a casing configured to be fixed to the chassis of a vehicle, and an actuator comprising a piston axially movable with respect to the casing between a retracted position and an extended position—the piston is supported with respect to the operating area of ​​a transmission member such that when the piston moves from the retracted position to the extended position, a first coupling portion of the coupling device moves from a separated position to a coupled position.

[0100] Therefore, the transmission member has a dual function of returning the first coupling part to its separated position on the one hand and transmitting operating force between the actuator piston and the first coupling part on the other, thereby reducing the cost, complexity, and volume of the transmission system.

[0101] This fourth aspect of the present invention may include one or more of the features mentioned in the context of the first aspect of the present invention.

[0102] In particular, the transmission member is capable of elastic deformation between the operating and fixed regions of the disc while the actuator's piston moves from the retracted position to the extended position. Therefore, there are two different elastic stiffnesses that, on the one hand, ensure the elastic return of the first coupling part, and on the other hand, compensate for the tolerance of the dimensional chain.

[0103] The transmission member is preferably a disk. The outer part of the disk can form a sensor target. Brief explanation of the drawing

[0104] The present invention will be better understood from the following description of various specific embodiments of the invention provided only as non-limiting examples with reference to the accompanying drawings, and further objects, details, features, and advantages of the invention will become more clearly apparent. [Fig. 1] Fig. 1 is a cross-sectional view of a transmission system equipped with a coupling device according to one embodiment. [Fig. 2] Fig. 2 is a cross-sectional view of the plane of the transmission system of Fig. 1 when the coupling device is in the separated position. [Fig. 3] Fig. 3 is a cross-sectional view similar to Fig. 2 when the coupling device is in the coupled position. [Fig. 4] Fig. 4 is a partial side view of the coupling device of Figs. 1 to 3, showing the disk and the first coupling portion of the coupling device. [Fig. 5] Fig. 5 is a cross-sectional view taken by cutting a plane along the VV cross section of Fig. 4, and in particular shows a housing, a disk, and a first coupling part of a coupling device. [Fig. 6] Fig. 6 is a partial side view of a coupling device according to a modified embodiment, showing a housing, a disk, and a first coupling portion of the coupling device. [Fig. 7] Fig. 7 is a cross-sectional view taken by cutting the plane along section VII-VII of Fig. 6. Specific details for implementing the invention

[0105] In the description and claims, the terms “external,” “internal,” “axial,” and “radial” will be used to designate elements of the transmission system according to the definitions given in the description. Typically, the “radial” orientation is orthogonal to the axis of rotation (X) of the transmission system that determines the “axial” orientation, and the “circumferential” orientation from the inside out of the axis of rotation is orthogonal to the axis of rotation (X) and orthogonal to the radial direction.

[0106] FIGS. 1 through 5 illustrate a transmission system (1) according to a first embodiment. As specified herein, a transmission system is a differential used in the drivetrain of a vehicle to transmit and distribute torque generated from a motor (not shown) to two wheel shafts (2, 3) of the vehicle's axles. Such a transmission system may form part of an auxiliary drivetrain capable of transmitting torque from an auxiliary motor of the vehicle, such as an electric motor, to the rear or front axle of the vehicle, while the main drivetrain may transmit torque from a main motor, such as an internal combustion engine, to the wheel shaft of the other axle of the vehicle. According to other embodiments not shown, the transmission system may take a form other than a differential.

[0107] The transmission system includes a first element (4) which is rotatable about an axis (X) and configured to be driven by a motor such as an electric motor (not shown), a second element (5) which is also rotatable about an axis (X) and configured to drive a wheel shaft (2, 3), and a coupling device (6) which can selectively combine or separate the first element (4) and the second element (5).

[0108] The first element (4) includes a gear wheel (toothed wheel: 7) configured to be driven by a motor through a reduction gear train not illustrated. This first element (4) also includes a housing (8) that is rotatably fixed (fixed in rotation) to the gear wheel (7). The housing (8) includes two parts (9, 10) fixed to each other. To this end, in the illustrated embodiment, each of the two parts (9, 10) includes an outer flange (11, 12), thereby fixing the two parts (9, 10) to the gear wheel (7) and fixing them to each other.

[0109] The second element (5) includes an annular carrier ring (13) that is rotatably guided about an axis (X) inside the housing (8). To this end, the housing (8) includes an inner cylindrical portion that cooperates with the cylindrical outer surface of the carrier ring (13) to rotatably guide the carrier ring (13) relative to the housing (8). The second element (5) further includes two planetary gears (14, 15) as seen in FIG. 1, which are rotatably mounted on the carrier ring (13) about an axis (Z) perpendicular to the axis (X). The two planetary gears (14, 15) each include bevel gear teeth that mesh with the bevel gear teeth complementary to the two sun gears (16, 17). The two sun gears (16, 17) are rotatable about the axis (X) and are each rotatably locked to one of the two wheel shafts (2, 3). The carrier ring (13), planetary gears (14, 15) and sun gears (16, 17) form a differential so that the two wheel shafts (2, 3) can rotate at different speeds.

[0110] Additionally, the transmission system (1) includes a coupling device (6) that enables torque to be transmitted between one of the elements of the first element (4) and the second element (5) (in this case, the carrier ring (13)) in a coupled position. Thus, the transmission system enables torque to be transmitted from the motor to the wheel shafts (2, 3) by exercising a differential function that allows different rotational speeds of the wheel shafts (2, 3) when the coupling device (6) is in a coupled position. However, in another embodiment (not shown), the coupling device is configured to couple the first element (4) to one of two sun gears (16, 17). The sun gears (16, 17) have two sets of teeth, which are preferably axially consecutive. One works with the planetary pinion and the other works with the first coupling part. In this embodiment, the carrier ring (13) is rotationally locked to the housing (8), and the coupling device aims to prevent the two wheel shafts (2, 3) from rotating at different speeds.

[0111] Returning to the illustrated embodiment, it can be seen that the coupling device (6) is axially movable along the axis (X) relative to the housing (8) but includes a first coupling part (18) that is rotationally locked with the housing (8). The first coupling part (18) is movable between the separated position illustrated in FIG. 2 and the coupled position illustrated in FIG. 3. In the separated position, the first coupling part (18) is separated from the carrier ring (13) and the rotationally locked second coupling part (19), so that the transmission of torque between the housing (8) and the carrier ring (13) is interrupted. Meanwhile, in the coupled position, the first coupling part (18) is coupled to the second coupling part (19) so that torque can be transmitted between the housing (8) and the carrier ring (13).

[0112] In the illustrated embodiment, the coupling device (6) is a dog clutch device. Accordingly, one of the first and second coupling parts (18, 19) includes a toothed portion and the other includes a corresponding groove, and when the first coupling part (18) is in a coupling position, the toothed portion engages within the groove. In the illustrated embodiment, the second coupling part (19) is formed integrally with the carrier ring (13). That is, the toothed portion or the groove is formed on the side of the carrier ring (13) facing the first coupling part (18). However, although the present invention has been described in relation to a dog clutch coupling device, it is not limited thereto, and the coupling device may be of a different type and, in particular, may be a friction coupling device.

[0113] As illustrated in FIG. 5, the first coupling portion (18) comprises an inner portion (20) accommodated inside the housing (8), an outer portion (21) disposed outside the housing (8), and connecting portions (22) that are regularly distributed around an axis (X) and pass through corresponding through-openings (23) formed in the housing (8), thereby rotatably fixing the first coupling portion (18) to the housing (8) while allowing relative axial movement between the first coupling portion (18) and the housing (8). In the illustrated embodiment, the inner portion (20) is annular, while the outer portion (21) includes a lug that extends axially in a continuous manner from the connecting portion (22). However, according to another variant embodiment, the structure is reversed so that the outer portion (21) is annular, while the inner portion (20) includes a plurality of axially oriented lugs that extend in a continuous manner from the connecting portion (22).

[0114] Additionally, the coupling device (6) may include an actuator (24) illustrated in FIGS. 1 to 3 to move the first coupling part (18) axially. The actuator (24) is configured to be mounted to the chassis of a vehicle by means of a fixed member (not shown) and includes a casing (25) rotatably fixed to the latter. The casing (25) includes an inner skirt (26) fitted around a portion of the part (9) of the housing (8). The inner skirt (26) includes a cylindrical guide portion that cooperates with a corresponding cylindrical portion of the housing (8) to allow the housing (8) to rotate relative to the fixed casing (25) of the actuator (24).

[0115] The actuator (24) is an electromagnetic actuator. It includes an electromagnet (27) defining an inner housing, and a piston (28) movable axially within the inner housing between the retracted position shown in FIG. 2 and the deployed position shown in FIG. 3. The actuator (24) further includes a magnetic cap (29) closing the inner housing, which includes a stop (30), such as a shoulder, to define the deployed position of the piston (28). The piston (28) includes an annular body (31) made of a ferromagnetic material, such as iron or steel, for example. The piston (28) also further includes an annular paramagnetic end piece (32) fixed to the body (31) of the piston (28), thereby transmitting the operating force to the first coupling part (18). Therefore, the paramagnetic end piece (32) of the piston (28) can prevent undesirable leakage of magnetic flux toward other components of the coupling device (6). Additionally, the body (31) of the piston (28) includes a shoulder (33) configured to come into contact with the shoulder (30) of the magnetic cap (29) when the piston (28) is in the unfolded position.

[0116] When the electromagnet (27) is activated with a current greater than the critical current, the piston (28) can be moved from the retracted position shown in FIG. 2 to the extended position shown in FIG. 3. When the piston (28) is in the extended position, the magnetic cap (29) exerts an attractive force on the body (31) of the piston (28) to maintain the piston in the extended position. Then, the current supplied to the electromagnet (27) can be reduced as long as it remains greater than the critical current. When the electromagnet (27) is deactivated or a current lower than the critical current is supplied, the attractive force between the magnetic cap (29) and the body (31) of the piston (28) can be overcome by the elastic return means described later, which returns the first coupling part (18) to the separated position, and the piston (28) can be returned from the extended position to the retracted position.

[0117] The coupling device (6) also comprises a target (34) that is axially fixed to the first coupling portion (18). Additionally, the coupling device (6) includes a non-contact sensor (35) (shown in FIG. 1) positioned to face the target (34) axially, and the sensor is configured to transmit a signal indicating the axial distance between the target (34) and the sensor (35). Thus, the sensor (35) can transmit a signal indicating the position of the first coupling portion (18), and such a signal is used to ensure the reliability of the control of the coupling device (6) and, in particular, to verify whether the coupling device (6) is actually in a separated position or a coupled position. The sensor (35) is, for example, a Hall effect sensor.

[0118] Additionally, the coupling device (6) includes a disk (36) that is shown in its entirety in FIG. 4, which is formed as a single piece and axially fixed to the first coupling part (18). Since the disk (36) provides various functions as described below, the cost, complexity, and volume of the coupling device (6) can be limited.

[0119] First, the disk (36) performs the function of a target (34). To this end, the disk includes an annular portion (37) formed on the radial outer periphery of the disk (36). This annular portion (37) is arranged so as to face the sensor (35) axially to form a target (34).

[0120] Second, the disc (36) functions as an elastic return means, so that when the piston (28) of the actuator (24) returns to the retracted position, the first coupling part (18) can be returned to the separated position.

[0121] To this end, the disk (36) includes elastic blades (41), and in the illustrated embodiment, there are four of them. Each elastic blade (41) has a free end (42) supported against the bearing area of ​​the housing (8) and a proximal end connected to the rest of the disk (36). Each elastic blade (41) is formed in a window (43) positioned radially inside the annular portion (37). Since the elastic blade (41) extends circumferentially around the axis (X), it is possible to obtain an elastic blade (41) that is longer and consequently has lower stiffness for a given radial volume. As illustrated in FIGS. 2, 3 and 5, the free end (42) of the elastic blade (41) is supported against the end of a stud (44) that protrudes axially from the housing (8) toward the disk (36). The stud (44) protrudes by an axial dimension greater than the travel distance of the first coupling portion (18) between the separation position and the coupling position. Beneficially, as illustrated in FIG. 3, the axial dimension of the stud (44) is configured so that when the coupling device (6) is in the separated position, the elastic blade (41) extends substantially within the plane of the annular portion (37) forming the target (34).

[0122] Accordingly, the elastic blade (41) forms an elastic return portion configured to bend elastically while the first coupling portion (18) moves from a separated position to a coupled position. In response to this, the elastic blade (41) exerts a return force capable of returning the first coupling portion (18) to a separated position.

[0123] Additionally, the disk (36) includes a plurality of fixed tabs (38) as illustrated in FIG. 4, and in the illustrated embodiment, the number is also four. The fixed tabs (38) are distributed circumferentially around an axis (X), and each includes a free end (39) that defines a fixed area fixed to the outer part (21) of the first coupling part (18). The fixed tabs (38) are formed within a window (40) formed in a portion of the disk (36) arranged radially inside the annular part (37) forming the target (34). Thus, each window (40) associated with the tab is positioned between the circumferential direction of two windows (43) associated with the elastic blade. The fixed tabs (38) protrude radially inward from the radially outer edge of the window (40). Additionally, the lugs of the outer part (21) pass through the window (40). Additionally, as shown in FIGS. 2, 3 and 4, the lugs of the outer part (21) each include a groove into which the free end (39) of one fixed tab (38) is fitted, so the disk (36) can be simply fixed to the first coupling part (18) without an additional fixing member.

[0124] For example, according to one embodiment, the disk (36), more specifically the fixed tab (38) and the elastic blade (41) are dimensioned to produce a stiffness (K1) of 5 to 50 N / mm that opposes axial movement of the first coupling part (18) toward the coupling position.

[0125] Third, the disk (36) also enables the transmission of an actuating force between the piston (28) of the actuator (24) and the first coupling part (18). To this end, the piston (28) of the actuator (24) contacts the inner annular part (45) of the disk (36) which defines the operating area. Additionally, the disk (36) can be elastically deformed between the operating area and the free end (39) of the fixed tab (38) as the piston (28) of the actuator (24) moves from the retracted position to the extended position. This allows the piston (28) and the first coupling part (18) to move through the entire travel distance during their respective movements toward the extended position and the coupled position, thereby compensating for the tolerance of the dimensional chain of the coupling device (6). That is, this ensures that the piston (28) is in contact with the magnetic cap (29) of the actuator (24) in the unfolded position, and that the first coupling portion (18) is in contact axially with the second coupling portion (19) in the coupled position. As shown in FIG. 5, the inner annular portion (45) of the disk (36) is separated from the contact area of ​​the first coupling portion (18) by an axial clearance (49) that is greater than the axial manufacturing tolerance of the coupling device (6). The axial clearance (49) is, for example, 0.2 to 1.5 mm. Accordingly, while the piston (28) of the actuator (24) moves from the retracted position to the extended position, the disk (36) and in particular its inner annular portion (45) are deformed to compensate for the axial manufacturing tolerance of the coupling device, and the inner annular portion (45) of the disk (36) comes into contact with the contact area of ​​the first coupling portion (18) when the axial manufacturing tolerance of the coupling device (6) is compensated.

[0126] According to an advantageous embodiment, the disk (36) has a cutout (46) extending circumferentially in an area positioned between the inner annular portion (45) of the disk (36) defining the operating area and the window (43), particularly as illustrated in FIG. 4. This cutout (46) is advantageous in that it further increases the flexibility of the disk (36).

[0127] For example, according to one embodiment, the disk (36) is dimensioned to produce a stiffness (K2) between 50 and 500 N / mm to resist axial approach of the piston (28) of the actuator (24) toward the first coupling portion (18). The stiffness (K2) is greater than the stiffness (K1). Inferiorly, the stiffness (K2) is between 4*K1 and 20*K1.

[0128] Fourth, the disc (36) proposes a sliding interface that limits frictional force caused by the relative rotation of the disc (36) [rotatably about the axis (X)] with respect to the piston (28) [part of which is rotatably fixed]. According to a favorable variation, to further limit friction that is likely to occur between the piston (28) and the disc (36), the annular portion (45) of the disc (36) includes an oil passage groove (47) shown in FIG. 4 on the surface facing the piston (28).

[0129] The disc (36) is made of spring steel, such as XC 70 steel, for example, and is advantageously pre-hardened. For example, the thickness of the disc (36) is 0.4 to 1.2 mm, for example, about 0.8 mm. Alternatively, the disc (36) is made of stainless steel.

[0130] FIGS. 6 and 7 illustrate a coupling device (6) according to another embodiment. This coupling device (6) differs from the one described above in relation to FIGS. 1 to 5 only in the manner in which the disk (36) is fixed to the first coupling portion (18). In this embodiment, the free end (39) of each fixing tab (38) is fixed to the outer portion (21) of the first coupling portion (18) by a fixing member (48), such as a screw, so that the disk (36) can be fixed more firmly to the first coupling portion (18).

[0131] Although the present invention has been described in relation to several specific embodiments, it is evident that the invention is not limited thereto and includes all technical equivalents of the described means and combinations thereof that fall within the scope of the invention as defined in the claims.

[0132] Reference symbols within parentheses in the scope of the claim should not be interpreted as limiting the claim.

Claims

Claim 1 In a transmission system (1) for an automobile, · A first element (4) and a second element (5) rotatable about each other around an axis (X)—one of the first and second elements (4, 5) is configured to be driven by a motor, and the other of the first and second elements (4, 5) is configured to drive at least one wheel shaft (2, 3) of a vehicle—and; · It includes a coupling device (6); the coupling device, · A first coupling part (18) that is rotatably locked with a first element (4) and a second coupling part (19) that is rotatably locked with a second element (5)—the first coupling part (18) is movable with respect to the first element (4) between a coupling position where the first coupling part (18) is coupled to the second coupling part (19) to transmit torque between the first element (4) and the second element (5), and a separation position where the first coupling part (18) and the second coupling part (19) are separated from each other—and, · A disk (36) including a fixed region axially fixed to a first coupling portion (18)—the disk (36) includes an annular portion (37) forming a target (34), and at least one elastic return portion configured to exert a return force capable of elastically returning the first coupling portion (18) to a separated position while the first coupling portion (18) moves from a separated position to a coupled position—the first element (4) includes a housing (8) in which a second coupling portion (19) is received, the housing (8) includes a stud (44) protruding axially toward the outside of the housing (8) in the direction of the disk (36), each stud (44) having one end forming a bearing area of ​​the transmission system (1), and the disk (36) includes a plurality of elastic return portions each including an elastic blade (41) that can be supported against the bearing area of ​​the transmission system (1), the bearing area being axially with respect to the second coupling portion (19). Fixed transmission system. Claim 2 A transmission system according to claim 1, further comprising a sensor (35) positioned toward an annular portion of the disk (36), wherein the sensor (35) is configured to transmit a signal indicating the distance between the sensor (35) and the annular portion forming the target (34). Claim 3 delete Claim 4 A transmission system according to claim 1 or 2, wherein the first coupling portion (18) comprises an inner portion (20) accommodated inside the housing (8), an outer portion (21) disposed outside the housing (8), and a plurality of connecting portions (22) connecting the inner portion (20) and the outer portion (21) of the first coupling portion (18) in an axial direction, and each of the connecting portions (22) passes through a corresponding through-opening (23) formed in the housing (8). Claim 5 In paragraph 4, the disc (36) is positioned outside the housing (8) and fixed to the outer part (21) of the first coupling part (18), and each bearing area is located on the housing (8), in a transmission system. Claim 6 delete Claim 7 In claim 4, the second element (5) comprises a carrier ring (13) that is rotatably guided around an axis (X) inside a housing (8), two planetary gears (14, 15) that are rotatably mounted on the carrier ring (13) around an axis (Z) perpendicular to the axis (X), and two sun gears (16, 17) that are rotatably rotatably guided around the axis (X), each meshing with the two planetary gears (14, 15) and configured to be rotatably locked with the wheel shafts (2, 3). Claim 8 In claim 7, the second coupling portion (19) of the coupling device (6) is rotatably locked with the carrier ring (13) with respect to the shaft (X), in a transmission system. Claim 9 A transmission system according to claim 1 or 2, wherein the disk (36) comprises a plurality of fixing tabs (38) that are fixed to the first coupling portion (18). Claim 10 A transmission system according to claim 1 or 2, wherein the coupling device (6) further comprises an actuator (24) comprising a casing (25) configured to be fixed to the chassis of a vehicle and a piston (28) axially movable with respect to the casing (25) between a retracted position and an extended position, wherein the piston (28) is supported with respect to an operating area of ​​a disk (36) such that when the piston (28) moves from a retracted position to an extended position, a first coupling portion (18) of the coupling device (6) moves from a separated position to a coupled position; and the disk (36) can be elastically deformed between an operating area and a fixed area of ​​the disk (36) while the piston (28) of the actuator (24) moves from a retracted position to an extended position. Claim 11 A transmission system according to claim 10, wherein the disc (36) is deformed while the piston (28) of the actuator (24) moves from a retracted position to an extended position to compensate for the axial manufacturing tolerance of the coupling device (6), and the operating area of ​​the disc (36) is separated from the contact area of ​​the first coupling part (18) by an axial clearance (49) that is dimensioned such that when the axial manufacturing tolerance of the coupling device (6) is compensated, the operating area of ​​the disc (36) comes into contact with the contact area of ​​the first coupling part (18). Claim 12 A transmission system according to claim 10, wherein the disc (36) is dimensioned to generate a stiffness of 50 to 500 N / mm against axial approach of the piston (28) toward the first coupling portion (18). Claim 13 In item 10, the operating area of ​​the above-mentioned disk (36) is an internal annular portion (45), in a transmission system. Claim 14 In paragraph 13, the internal annular portion (45) includes an oil passage groove (47), in a transmission system. Claim 15 A transmission system according to claim 1 or 2, wherein the coupling device (6) is a dog clutch device, and one of the first and second coupling parts (18, 19) includes a toothed portion, and the other includes a corresponding groove that engages with the toothed portion when the first coupling part (18) is in a coupled position. Claim 16 A transmission system according to claim 1 or 2, wherein the coupling device is a disconnecting device capable of selectively blocking the transmission of torque between a first element and a second element. Claim 17 A vehicle comprising an electric machine and a transmission system (1) described in claim 1 or 2, wherein the first element of the transmission system is driven by the electric machine.

Images