Torque transmission device between a torque generator and a torque adapter, particularly for motor vehicles

Abstract

A torque transmission device between a torque generator (10) and a torque adapter (12), the device comprising a shaft (14) of said torque generator (10), a shaft (16) of said torque adapter (12), and a coupling piece (18), said shaft (10) of the torque generator (12) having a first recess (28), said shaft (16) of the torque adapter (12) having a second recess (30), said coupling piece (18) being housed in said first and second recesses (28, 30) so as to transmit torque between said shafts (14, 16) of the torque generator (10) and the torque adapter (12), said coupling piece (18) being configured to mesh with said first and / or said second shaft by means of teeth (32a, 34a, 32b, 34b) mutually allowing a movable connection between said coupling piece (18), of a on the one hand, and the first and / or said second tree, on the other hand. Figure for the abbreviation: Figure 2

Description

Title of the invention: Torque transmission device between a torque generator and a torque adapter, particularly for motor vehicles

[0001] The invention relates to a torque transmission device between a torque generator and a torque adapter, particularly for motor vehicles.

[0002] In this area, as illustrated in [Fig. 1], it is known to transmit torque between an electric motor 1 and a gearbox 2 by axially inserting a shaft 3, from the gearbox 2, into a bore 5 formed in a shaft 7, from the motor 1. However, this connection, made at a designated area 8, presents risks of jamming of the shafts 3 and 7, particularly due to coaxiality defects and runout. Furthermore, it allows axial impacts to occur between the two shafts 3 and 7. Such impacts are likely to damage adjacent parts.

[0003] The invention aims to overcome at least in part the previous drawbacks and proposes for this purpose a torque transmission device between a torque generator and a torque adapter, the device comprising a shaft of said torque generator, a shaft of said torque adapter and a coupling piece, said shaft of the torque generator having a first recess, said shaft of the torque adapter having a second recess, said coupling piece being housed in said first and second recesses so as to transmit a torque between said shafts of the torque generator and the torque adapter, said coupling piece being configured to mesh with said first and / or said second shaft by means of teeth mutually allowing a movable connection between said coupling piece, on the one hand, and the first and / or said second shaft, on the other hand.

[0004] Thanks to said teeth, the coupling piece provides a drive of the shaft of the torque adapter by the shaft of the torque generator with degrees of freedom allowing to compensate for axial movements or misalignment of the shafts, this in a reduced environment due to the positioning of the coupling piece inside the shafts.

[0005] According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention: - said moving link is a double annular linear link, - a portion, called the end portion, of said torque adapter shaft is housed in the first recess, a portion of said second recess extends axially along said end portion of said torque adapter shaft, The first of said teeth are located on said shaft of the torque generator and a first drive zone of said coupling part, said first drive zone extends axially between a free axial end of said shaft of the torque adapter and a bottom of said first recess, of the second of said teeth are located on said shaft of the torque adapter and a second drive zone of said coupling part, said first drive zone having a diameter greater than a diameter of said second drive zone, said teeth comprise a plurality of teeth angularly distributed over at least a part of a circumference of said coupling part, of said first recess and / or of said second recess, some at least of said teeth have convex surfaces so as to realize said movable linkage, These convex surfaces are present on two opposite sides of the teeth, said curved surfaces extend, on the one hand, between two opposite axial edges and, on the other hand, between a basic active edge and a free active edge, each of said active edges connecting said axial edges, said curved surfaces have a first curved profile connecting said axial edges, said curved surfaces have a second curved profile connecting said active edges, said convex surfaces have a vertex resulting from said first and second profiles, said apex is located substantially at a center of said curved surfaces, said coupling piece, in particular said first zone, has a free face, opposite a side connected to said second zone, said free face of the first zone is curved, said device has a first channel for the passage of a lubricating liquid arranged between, on the one hand, the coupling piece and, on the other hand, a lateral surface of said first recess and / or a lateral surface of said second recess, said first passage channel comprises a first longitudinal portion formed in the first drive zone between two of said teeth having an angular spacing greater than an angular spacing provided between the other teeth of said first drive zone, said first passage channel includes a second longitudinal portion formed in the second drive zone between two of said teeth having an angular spacing greater than an angular spacing provided between the other teeth of said second drive zone, the first portion of the first channel is angularly offset with respect to the second portion of said first channel, said device has an annular groove, located axially between the first drive zone and the second drive zone, said annular groove connecting said first and second portions of said first channel, said coupling part has a second channel for the passage of the lubricating fluid. said second channel extends linearly along a longitudinal axis of said coupling piece, said first channel is connected to the second channel by a bore formed in said coupling piece such that the lubricating fluid passing through the first channel is subjected to a suction effect by the lubricating fluid passing through the second channel. said device includes at least one stop enabling the axial movement of said coupling piece to be limited in the first recess and / or the second recess, A first of said stops is located at the level of a first axial end of said second drive zone, a second of said stops is located at a second axial end of said second drive zone, opposite the first end, said device includes a sealing joint between said end portion of the torque adapter shaft and the shaft of said torque generator, said joint is formed of an elastomer seal, said joint has a straight section with several lobes, an axial end of the teeth of the first drive zone is configured as a point to guide the coupling piece into the first recess when mounting the coupling piece in the shaft of the torque generator, said coupling piece includes a toothed ring intended to guide the coupling piece in the second recess when mounting the coupling piece in the shaft of the torque adapter.

[0006] The invention also relates to an assembly of a torque generator, in particular an electric machine, a torque adapter, in particular a gearbox, and a coupling component for the torque transmission device described above. Said electric machine comprises, for example, a stator and / or an axial flux rotor.

[0007] The invention also relates to a vehicle, in particular an automobile, comprising an assembly as described above.

[0008] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the course of the detailed explanatory description that follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the accompanying schematic drawings, among which:

[0009] [Fig.1], already commented on, illustrates schematically, according to an axial section plane, an electrical machine linked to a gearbox according to the state of the art;

[0010] [Fig.2] schematically illustrates an example, along an axial cross-sectional plane, a example of a transmission device according to the invention;

[0011] [Fig.3] schematically illustrates, in perspective, a coupling piece of the device of the [Fig.2];

[0012] [Fig.4] schematically illustrates a tooth of a tooth of the part of [Fig.3], In detail: - in figure 4a, a first curvature of a surface of said tooth, illustrated in perspective, - Figure 4b shows a profile of said first curvature, - in figure 4c, a second curvature of a surface of said tooth, illustrated in perspective, - in figure 4d, a profile of said second curvature;

[0013] [Fig.5] illustrates schematically, from the side and in exploded view, the part of coupling of the [Fig.3] with a shaft of the transmission device according to the invention, the shaft being illustrated partially and according to an axial cutting plane;

[0014] [Fig.6] schematically illustrates, in perspective, a cross-section of a joint used in the device of [Fig.2];

[0015] [Fig.7] illustrates schematically, along an axial section plane, another example of a transmission device according to the invention.

[0016] As illustrated in [Fig. 2], the invention relates to a torque transmission device between a torque generator 10, in particular an electric machine, and a torque adapter 12, in particular a gearbox. It will find particular application in motor vehicles.

[0017] Said device comprises a shaft 14 of said torque generator 10, a shaft 16 of said torque adapter 12 and a coupling piece 18. They are aligned along a longitudinal axis X-X' around which they are driven in rotation as shown by the arrow R. In [Fig. 2], the generator and the torque adapter 10, 12 are only partially illustrated. Apart from their shaft 14, 16, these are, for example, the electric machine and the gearbox illustrated in [Fig. 1].

[0018] The shaft 14 of the torque generator 10 is configured here to be driven by a rotor of the electric machine. The machine further comprises, in particular, a stator 20 and a bearing assembly 22, located between the stator 20 and the shaft 14 of the torque generator 10. The shaft 16 of the torque adapter 12 is configured to be driven by a primary shaft of the gearbox. The gearbox further comprises, in particular, a housing 24 and a bearing assembly 26, located between the housing 24 and the shaft 16 of the torque adapter 12.

[0019] Said shaft 14 of the torque generator 10 has a first obviously 28. It can be noted that the shaft 14 of the torque generator 10 is only slightly modified compared to that of the state of the art, which will make it possible to avoid a complete development of a new part.

[0020] According to the invention, the shaft 16 of the torque adapter 12 is also hollow. The shaft 16 of the torque adapter 12 thus has a second recess 30, and the coupling piece 18 is housed in the first and second recesses 28, 30 so as to transmit torque between the shafts 14, 16 of the torque generator 10 and the torque adapter 12. The rotation of the shaft 14 of the torque generator 10 is thus transmitted to the shaft 16 of the torque adapter 12 via the coupling piece 18. The first and second recesses 28, 30 are preferably formed by a substantially cylindrical bore.

[0021] A portion 16', referred to as the end portion, of the shaft 16 of the torque adapter 12 is advantageously housed within the first recess 28, along part of its length. Inside the shaft 16 of the torque adapter 12, a portion of the second recess 30 extends axially along the end portion 16' to open onto the first recess 28. The first recess 28 is located at a portion 14d, referred to as the distal portion, of the shaft 14 of the torque generator 10, which axially extends a portion 14p, referred to as the proximal portion, intended to be connected to the rotor of the electric machine. Here, the shaft 14 of the torque generator 10 is hollow along its entire length. In the distal portion 14d, it has a diameter greater than that of the proximal portion 14b, internally and / or externally.

[0022] Furthermore, according to the invention, said coupling piece 18 is configured to engage with said first and / or said second shaft by means of teeth mutually enabling a movable link between said coupling piece 18, on the one hand, and the first and / or said second shaft, on the other hand.

[0023] In the illustrated embodiment, such teeth 32a, 34a are more clearly visible [Fig.3] as regards the teeth of the cutting piece 18. They are visible [Fig.2] for the teeth 32b, 34b of the shafts 14, 16 of said torque generator 10 and of said torque adapter 12.

[0024] Thus, thanks to said teeth, the coupling piece 18 provides a drive of the shaft 16 of the torque adapter 12 by the shaft 16 of the torque generator 10 with degrees of freedom allowing to compensate for axial movements or misalignment of the shafts, this in an environment reduced by the positioning of the coupling piece 18 inside the shafts 14, 16.

[0025] Said movable link is, for example, a double annular linear link, namely a first annular linear link between said link piece 18 and the shaft 14 of the torque generator 10 and a second annular linear link between said link piece 18 and the shaft 16 of the torque adapter 12. Said annular linear links thus provide axial and radial degrees of freedom between said link piece 18 and each of the shafts 14, 16 of the torque generator 10 and of the torque adapter 12.

[0026] In the illustrated embodiment, as already stated, the first of said teeth are located on said shaft 14 of the torque generator 10 and on said coupling piece 18. These are the teeth shown 32a, 34a. The teeth 32a of the coupling piece 18 are located at the level of a first drive zone 18a of said coupling piece 18. Said first drive zone 18a extends axially between a free axial end 36 of said shaft 16 of the torque adapter 12 and a bottom 38 of said first recess 28. The second of said teeth are located on said shaft 16 of the torque adapter 12 and said coupling piece 18. These are the teeth 32b, 34b. The teeth 32b of the coupling piece 18b are located at the level of a second drive zone 18b of said coupling piece, namely that extending inside said second housing 30.

[0027] Said coupling piece 18 preferably has a circular cross-section forming a base from which the teeth 32a, 32b extend radially outwards. The same is true for said first and second recesses 28, 30 in which said teeth 34a, 34b extend radially inwards (as is more clearly seen in [Fig. 5] for the second recess 30).

[0028] Said first zone 18a has a diameter greater than a diameter of said second zone 18b. Such a configuration is associated here with the insertion of the shaft 16 of said torque adapter into the shaft 14 of said torque generator 10, already mentioned above. Alternatively, not illustrated, it may have a relatively constant cross-section, particularly in cases where the shaft 16 of said torque adapter and the shaft 14 of said torque generator 10 have the same internal diameter and are in the axial extension of one another instead of one being inserted into the other.

[0029] Said first zone 18a has a free face 19, opposite a side 20 connected to said second zone 18b. Said free face 19 of the first zone 18a is convex. An advantage of such a configuration will be discussed later.

[0030] It is noted that said coupling piece 18 here has a shape of champagne cork and / or mushroom.

[0031] Said teeth 32a, 32b, 34a, 34b comprise a plurality of teeth 40 angularly distributed over at least a part of a circumference of said coupling piece 18, of said first recess 28 and / or of said second recess 30.

[0032] As illustrated in Figures 4a and 4c, at least some, preferably all, of said teeth 40 have convex surfaces 42 so as to provide said movable connection. Said convex surfaces 42 of the teeth 40 of the coupling piece 18 and said convex surfaces 42 of the teeth 40 of said first recess 28 and / or said second recess 30 are located opposite each other, and said teeth 40 of the teeth 32a, 32b, 34a, 34b of the coupling piece 18 and of said first recess 28 and / or said second recess 30 engage with each other respectively by means of said convex surfaces.

[0033] Said teeth 40 have a substantially trapezoidal shape. They are provided with a plane of symmetry passing through the longitudinal axis X-X'. Said convex surfaces 42 are present here at the level of two large opposite sides of the teeth 40. They extend, on the one hand, between two opposite axial edges 48, 50 and, on the other hand, between a basic active edge 52 and a free active edge 54, each of said active edges 52, 54 connecting said axial edges 48, 50.

[0034] As can be seen more clearly in Figures 4a and 4b, said curved surfaces 42 have a first curved profile 56 connecting said axial edges 48, 50. A vertex 58 of said first profile 56 is located here in the middle of said first profile. Such a first profile 58 is found on said curved surfaces 42 of said active base edge 52 of said free active edge 54. Its height, namely a distance between its chord 60 and its vertex 58, is optionally variable between the active base edge 52 and said free active edge 54. It is exaggerated in figure 4b and is preferably much less than a length of said strings 60. Said first profile 56 favors an axial degree of freedom between said teeth 32a, 32b, 34a, 34b of the coupling piece 18 and said first recess 28 and / or said second recess 30.

[0035] As can be seen more clearly in Figures 4c and 4d, said curved surfaces 42 have a second curved profile 62 connecting the active base edge 52 and said free active edge 54. A vertex 64 of said second profile 62 is located here in the middle of said second profile. Such a second profile 62 is found on said curved surfaces 42 between said axial edges 48, 50. Its height, namely a distance between its chord 66 and its apex 64, is possibly variable between the said axial edges 48, 50. It is exaggerated in figure 4d and is preferably much less than a length of the said chords 66. The said second profile 62 promotes a radial degree of freedom between the said teeth 32a, 32b, 34a, 34b of the coupling piece 18 and the said first recess 28 and / or the said second recess 30.

[0036] Although they are illustrated separately in Figures 4a and 4c to make them more visible, the first and second profiles 56, 62 are present in combination on the curved surfaces 42. It is understood that the curved surfaces 42 thus have a vertex resulting from the first and second profiles 56, 62. The vertex of the curved surfaces 42 is advantageously located substantially at a center of the curved surfaces 42.

[0037] Referring again to [Fig. 3], it can be seen that the device has a first channel 68 for the passage of a lubricating fluid. This first channel 68 is provided between, on the one hand, the coupling piece 18 and, on the other hand, a lateral surface of the first recess 28 and / or a lateral surface of the second recess 30. This first channel 68 allows lubrication of the gear teeth 32a, 32b, 34a, 34b, in particular by means of the lubricating fluid circulating inside the shafts 14, 16.

[0038] Said first passage channel 68 comprises a first longitudinal portion 68a, formed in the first drive zone 18a between two of said teeth 40 having an angular spacing greater than an angular spacing provided between the other of said teeth 40 of said first drive zone 18a.

[0039] Said first passage channel 68 includes a second longitudinal portion 68b formed in the second drive zone 18b between two of said teeth 40 having an angular spacing greater than an angular spacing provided between the other of said teeth 40 of said second drive zone 18b.

[0040] In other words, the said first and second portions 68a, 68b of the channel 68 correspond to the absence or suppression of one or more of the said teeth 60 compared to a configuration with a regular angular distribution of the said teeth 60 over the entire circumference of the first and second drive zones 18a, 18b.

[0041] The first portion 68a of the channel 68 is here angularly offset with respect to the second portion 68b of said channel 68, for example by 90°.

[0042] If we refer again to [Fig.2], we see that said device also has an annular groove 70, located axially between the first drive zone 18a and the second drive zone 18b, outside of said coupling piece 18. Said groove 70 and said angular offset of the different portions 68a, 68b of the channel 68, taken together or separately, promote a good distribution of the lubricating fluid at the level of all the teeth 32a, 32b, 34a, 34b.

[0043] Said coupling piece 18 advantageously has a second channel 72 of passage of the lubricating fluid. Said second channel 72 extends linearly along the longitudinal axis X-X' of the coupling piece 18. It serves as a lubricant supply between the torque generator 10 and the torque adapter 12.

[0044] Said first channel 68, in particular said second portion 68b of said first channel 68, is connected to the second channel 72 by a bore 74 formed in said coupling piece 18 such that the lubricating fluid passing through the first channel 68 is subjected to a suction effect by the lubricating fluid passing through the second channel 72, notably by a Venturi effect. A compromise is made between the cross-sections of the passage of the first channel 68 and the second channel 72 to minimize pressure losses on the lubricating fluid while maintaining sufficient flow in each of said first and second channels 68, 72. The convex shape of the free surface 19 also contributes to good distribution of the lubricating fluid.

[0045] As illustrated [Fig.5], said device advantageously includes at least one stop, here two stops 76, 78, allowing to limit an axial displacement of said coupling piece 68 in the first recess 20 and / or the second recess 30.

[0046] The said stop(s) 76, 78 comprise, for example, at least one circular groove 80 and a shoulder 82 formed opposite it. They further comprise a ring, not illustrated, housed in said groove 80, preferably with axial and / or radial clearance, and intended to come into contact with said shoulder 82.

[0047] One of said grooves 80 or shoulder 82 is located on said coupling piece 18, and the other on said shaft(s) 14, 16 of the torque generator 10 and / or the torque adapter 12. Here, said grooves 80 are located on said coupling piece 18 and the shoulder 82 on said shaft 16 of the torque adapter 12.

[0048] More specifically, a first of said stops 78 is located at a first free axial end 84 of said second drive zone 18b. A second 76 of said stops is located at a second axial end of said second drive zone 18b, opposite the first axial end 84 and corresponding to said side 20 of said first zone 18a in connection with said second zone 18b. Even more specifically, said stops 76, 78 are located on either side of said teeth 34a, 34b of said second drive zone 18b and said second internal housing 30. Said shoulders 82 are optionally formed from an axial end of the teeth 34b of said second internal housing 30.

[0049] In the illustrated embodiment, an axial end of the teeth 40 of the gear teeth 32a of the first drive zone 18a is configured as a point to guide the coupling piece 18 in the first recess 28 when the coupling piece 18 is mounted in the shaft 14 of the torque generator 10. Said coupling piece 18 further comprises a toothed ring 89 for guiding the coupling piece 18 in the second recess 30 when the coupling piece 18 is mounted in shaft 16 of torque adapter 12.

[0050] Referring again to [Fig.2], it can be seen that said device further includes here a sealing gasket 90 between said end portion 16' of the shaft 16 of the torque adapter 12 and an end portion of the shaft 14 of said torque generator 10. It is located, in particular, between an external surface of said shaft 16 of the torque adapter 12 and an internal surface of said shaft 14 of the torque generator 10, for example in a groove, here formed in said shaft 16 of the torque adapter 12.

[0051] As illustrated in [Fig. 6], said seal 90 preferably has a straight section with several lobes 92. It is, for example, quadrilobe. Said seal 90 is formed, for example, of an elastomeric seal.

[0052] The invention also relates to an assembly of a torque generator 10, a torque adapter 12 and a coupling piece 18 of the torque transmission device as described above. As already indicated, apart from their shaft 14, 16, this is, for example, the electric machine and the gearbox illustrated in [Fig. 1].

[0053] As illustrated in [Fig.7], alternatively, the electric machine 10 comprises a stator and / or an axial flux rotor 100.

[0054] The performance of an axial flux electric machine is particularly linked to the axial position of the rotor 100 equidistant from two stators of the machine. The device according to the invention makes it possible to reduce the forces transmitted by the gearbox and limits their influence on the axial position of the rotor 100. It thus contributes to good overall efficiency.

Claims

Demands

1. A torque transmission device between a torque generator (10) and a torque adapter (12), the device comprising a shaft (14) of said torque generator (10), a shaft (16) of said torque adapter (12), and a coupling piece (18), said shaft (10) of the torque generator (12) having a first recess (28), said shaft (16) of the torque adapter (12) having a second recess (30), said coupling piece (18) being housed in said first and second recesses (28, 30) so as to transmit torque between said shafts (14, 16) of the torque generator (10) and the torque adapter (12), said coupling piece (18) being configured to mesh with said first and second shafts by means of teeth (32a, 34a, 32b, 34b) mutually allowing a movable connection between said coupling piece (18), on the one hand, and the first and said second tree, on the other hand.

2. Device according to claim 1 in which said movable link is a double linear annular link.

3. Device according to any one of the preceding claims wherein a portion (16'), referred to as the end portion, of said shaft (16) of the torque adapter (12) is housed in the first recess (28), a portion of said second recess (30) extending axially along said end portion (16').

4. Device according to any one of the preceding claims wherein the first (32a, 32b) of said teeth are located on said shaft (14) of the torque generator (10) and a first drive zone (18a) of said coupling piece (18) and / or the second (34a, 34b) of said teeth are located on said shaft (16) of the torque adapter (12) and a second drive zone (18b) of said coupling piece (18).

5. Device according to any one of the preceding claims wherein said teeth (32a, 34a, 32b, 34b) comprise a plurality of teeth (40) angularly distributed over at least a part of a circumference of said coupling piece (18), said first recess (28) and / or said second recess (30), at least some of said teeth (40) having convex surfaces (42) so as to achieve said movable link.

6. Device according to the preceding claim in which said surfaces curved surfaces (42) extend, on the one hand, between two opposite axial edges (48, 50) and, on the other hand, between a basic active edge (52) and a free active edge (54), each of said active edges (52, 54) connecting said axial edges (48, 50), said curved surfaces (42) having a first curved profile (56) connecting said axial edges (48, 50) and / or a second curved profile (62) connecting said active edges (52, 54).

7. Device according to any one of the preceding claims in which said coupling piece (18) has a domed free face (19).

8. Device according to any one of the preceding claims having a first channel (68) for the passage of a lubricating liquid provided between, on the one hand, the coupling piece (18) and, on the other hand, a lateral surface of said first recess (28) and / or a lateral surface of said second recess (30).

9. Device according to the preceding claim in which said coupling piece (18) has a second channel (72) for the passage of the lubricating fluid, said second channel (72) extending linearly along a longitudinal axis of said coupling piece (18).

10. Device according to the preceding claim in which said first channel (68) is connected to the second channel (72) by a bore (74) formed in said coupling piece (18) so that the lubricating fluid passing through the first channel (68) undergoes a suction effect by the lubricating fluid passing through the second channel (72).

11. Device according to any one of the preceding claims comprising at least one stop (76, 78) allowing to limit an axial deflection of said coupling piece (18) in the first recess (28) and / or the second recess (30).

12. Device according to any one of the preceding claims comprising a sealing gasket (90) between the shaft (16) of the torque adapter (12) and the shaft (14) of said torque generator (10), said gasket (90) having a straight section provided with several lobes (92).

13. Assembly of a torque generator (10), a torque adapter (12) and a coupling piece (18) of the torque transmission device according to any one of the preceding claims.

14. Assembly according to the preceding claim in which the torque generator (10) comprises an electric machine, said electric machine comprising an axial flux stator and / or rotor (100).

15. Vehicle comprising an assembly according to any one of claims 13 or 14.

Images