Cardan joint with oblong openings and sliding pivot joints

Abstract

The invention relates to a universal joint (10) comprising a first sliding pivot joint (5a, 5b) allowing the first part (1) to pivot and the first part (1) to translate about the third axis (C), and a second sliding pivot joint (6a, 6b) allowing the second part (2) to pivot and the second part (2) to translate about the fourth axis (D); the third axis (C) and the fourth axis (D) being perpendicular to each other, the first sliding pivot joint (5a, 5b) being inserted into each oblong opening (3a) of the first part (1), the second sliding pivot joint (6a, 6b) being inserted into each oblong opening (3b) of the second part (2). Abstract figure: Fig. 1

Description

Title of the invention: Cardan joint comprising oblong openings and sliding pivot joints

[0001] The invention relates to cardan-type transmission joints intended for the transmission chains of motor vehicles.

[0002] Prior art data is known from French patent application FR3128259, which describes a universal joint for correcting angular and axial misalignment between two rotating shafts. The universal joint comprises a first sleeve including a first connecting device. Furthermore, the universal joint includes a second connecting device fixed to a first external shaft. The first and second connecting devices together form a first pivot joint. The universal joint also includes an internal shaft, the distal end of which includes a third connecting device. A fourth connecting device is fixed to a second external shaft. The third and fourth connecting devices together form a second pivot joint. The internal shaft is positioned in the first sleeve so as to form a sliding joint. However, a drawback remains.The universal joint cannot correct radial misalignments. In a motor vehicle, it is therefore necessary to add an Oldham joint to the drive chain, which complicates the assembly and increases the weight of the drive chain.

[0003] The objective of the present invention is to remedy these drawbacks and to solve the problems of angular, axial and radial misalignments with a single part.

[0004] To achieve this objective, the invention proposes a universal joint comprising a first part intended to be coupled to a first transmission shaft having a first longitudinal axis and a second part intended to be coupled to a second transmission shaft having a second longitudinal axis, the first part and the second part each having two openings positioned opposite each other, said universal joint comprising a connecting member positioned between the first part and the second part, notable in that the connecting member comprises: - a first sliding pivot joint allowing the pivoting of the first part around a third axis perpendicular to the first axis and the translation of the first part along the third axis; - a second sliding pivot joint allowing the pivoting of the second part around a fourth axis perpendicular to the second axis and the translation of the second part along the fourth axis; the third axis and the fourth axis being perpendicular to each other, the first sliding pivot joint being inserted into each opening of the first part, the second sliding pivot joint being inserted into each opening of the second part, the openings of the first part and the openings of the second part having an oblong shape, the openings of the first part allowing the translation of the first sliding pivot joint along the first axis, the openings of the second part allowing the translation of the second sliding pivot joint along the second axis.

[0005] Thanks to the invention, the cardan joint is able to simultaneously correct axial, radial and angular misalignment defects.

[0006] Preferably, the first sliding pivot joint comprises a first cylindrical part defining the third axis and a first sleeve mounted freely in translation and rotation around the first cylindrical part, the first sleeve being fixed to the second sliding pivot joint.

[0007] Preferably, the second sliding pivot joint comprises a second cylindrical piece defining the fourth axis and a second sleeve mounted freely in translation and rotation around the second cylindrical piece, the second sleeve being fixed to the first sliding pivot joint.

[0008] Such links are effective in enabling pivoting movements of the first part and the second part around, respectively, the third axis and the fourth axis.

[0009] Advantageously, the first cylindrical piece has a first predetermined length, the second cylindrical piece has a second predetermined length, the translational stroke of the first cylindrical piece being between 0.1 and 0.8 times the first predetermined length, the translational stroke of the second cylindrical piece being between 0.1 and 0.8 times the second predetermined length.

[0010] Preferably, the translational stroke of the first cylindrical piece is equal to 0.5 times the first predetermined length and the translational stroke of the second cylindrical piece is equal to 0.5 times the second predetermined length.

[0011] Such values ​​are sufficient to compensate for misalignments while allowing easy arrangement of the cardan joint in a transmission chain of a motor vehicle.

[0012] Advantageously, the first sliding pivot joint and the second sliding pivot joint each have a circular section.

[0013] This allows good cooperation of the first sliding pivot joint and the second sliding pivot joint in oblong openings.

[0014] Advantageously, the first part and the second part each have an internal surface comprising splines configured to cooperate with the splines present on the first transmission shaft and on the second transmission shaft.

[0015] This helps to make the first transmission shaft fixed to the first part and the second transmission shaft fixed to the second part.

[0016] The invention further relates to a motor vehicle comprising a transmission chain including a cardan joint previously described, remarkable in that said transmission chain comprises a first transmission shaft and a second transmission shaft, the first transmission shaft being coupled to the first part, the second transmission shaft being coupled to the second part.

[0017] Thus, the universal joint makes it possible to correct all alignment defects. No other device is therefore necessary for this purpose, which makes it possible to reduce the mass of the transmission chain and, consequently, the overall mass of the vehicle.

[0018] Preferably, said vehicle comprises a wheel assembly coupled to the transmission chain and a leaf spring damping system.

[0019] This type of vehicle is particularly known for experiencing frequent axial, radial, and angular misalignment. Therefore, the previously described universal joint is particularly suitable for this type of vehicle.

[0020] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig. 1] schematically illustrates a cardan joint according to a first embodiment of the invention; - [Fig.2] schematically illustrates three top views of the cardan joint shown in [Fig.1] in three different axial configurations; - [Fig.3] schematically illustrates two top views of the cardan joint shown in [Fig.1] in two different angular configurations; - [Fig.4] schematically illustrates in three top views the cardan joint shown in [Fig.1] in three different radial configurations.

[0021] Figure 1 schematically illustrates a universal joint 10 comprising a first part 1 and a second part 2. The first part 1 is intended to be coupled to a first transmission shaft. The second part 2 is intended to be coupled to a second transmission shaft. The first part 1 has a first longitudinal axis A. The second part 2 has a second longitudinal axis B. Both the first part 1 and the second part 2 have two Openings 3a, 3b are positioned opposite each other. Furthermore, the universal joint 10 includes a connecting member 4 for joining the first part 1 and the second part 2. The connecting member 4 is therefore positioned between the first part 1 and the second part 2 as illustrated in [Fig. 1]. The connecting member 4 includes a first sliding pivot joint 5a, 5b allowing the first part 1 to pivot about a third axis C and to translate along the third axis C. In [Fig. 1], the first sliding pivot joint 5a, 5b is inserted into each opening 3a of the first part 1. Preferably, and as illustrated in [Fig. 1], the first sliding pivot joint 5a, 5b comprises a first cylindrical part 5a and a first sleeve 5b. The first cylindrical part 5a has the longitudinal third axis C.The first sleeve 5b is mounted freely in translation and rotation about the first cylindrical part 5a. The first sleeve 5b is fixed to the second sliding pivot joint 6a, 6b. Furthermore, the connecting member 4 includes a second sliding pivot joint 6a, 6b allowing the second part 2 to pivot about a fourth axis D, the fourth axis D being perpendicular to the second axis B, and to translate the second part 2 along the fourth axis D. The third axis C and the fourth axis D are perpendicular to each other. The second sliding pivot joint 6a, 6b is inserted into each of the openings 3b in the second part 2. Preferably, the second sliding pivot joint 6a, 6b comprises a second cylindrical part 6a and a second sleeve 6b. The second cylindrical part 6a has the fourth axis D longitudinal. The second sleeve 6b is fixed to the first sliding pivot joint 5a, 5b.Even more preferably, the first sleeve 5b and the second sleeve 6b are fixed to each other. Optionally, the first cylindrical part 5a has a predetermined first length and the second cylindrical part 6a has a predetermined second length. The translational stroke of the first cylindrical part 5a is between 0.1 and 0.8, preferably 0.5, times the first predetermined length. Similarly, the translational stroke of the second cylindrical part 6a is between 0.1 and 0.8, preferably 0.5, times the second predetermined length. As an example, mounting the first sleeve 5b on the first cylindrical part 5a and mounting the second sleeve 6b on the second cylindrical part 6a each allow a translational stroke between 10 mm and 30 mm, preferably 20 mm. The openings 3a of the first part 1 and the openings 3b of the second part 2 have an oblong shape, which therefore allows a translation of the first sliding pivot joint 5a, 5b along the first axis A and a translation of the second sliding pivot joint 6a, 6b along the second axis B. Optionally, the first sliding pivot joint 5a, 5b and the second sliding pivot joint 6a, 6b have Each has a circular cross-section, which facilitates the arrangement of the connecting element 4 between the first part 1 and the second part 2. The first drive shaft and the second drive shaft may each have splines. In this case, and optionally, the first part 1 and the second part 2 each have an internal surface comprising splines configured to cooperate with the splines present on the first and second drive shafts.

[0022] Figures 2 to 4 schematically illustrate the different configurations of the cardan joint 10 to correct misalignment defects of the first transmission shaft and the second transmission shaft.

[0023] In [Fig. 2], three views of the cardan joint 10 are shown in which the second sliding pivot joint 6a, 6b, in particular the second cylindrical part 6a, moves in one of the openings 3b of the second part 2. In illustration A of [Fig. 2], the second cylindrical part 6a is positioned at the center of the oblong opening 3b of the second part 2. In illustrations B and C of [Fig. 2], the second cylindrical part 6a is positioned respectively at one end and the other of the opening 3b of the second part 2. Such translational movement is made possible by the oblong shape of the openings 3a, 3b and allows for the correction of axial misalignment between the first transmission shaft and the second transmission shaft.Similarly, the first cylindrical part 5a is able to move within the openings 3a of the first part 1 to correct any misalignment of the first and second drive shafts.

[0024] Two top views of the universal joint 10 are shown in [Fig. 3], in which the universal joint 10 exhibits different angular configurations. In illustration A of [Fig. 3], the second part 2 is inclined relative to the first part 1. In other words, the first axis A and the second axis B (not shown in [Fig. 3]) form an angle with respect to each other. Conversely, in illustration B of [Fig. 3], the first part 1 is aligned with the second part 2. In other words, the first axis A and the second axis B are parallel to each other, or even coincident. The rotation of the second part 2 around the second cylindrical piece 6a allows this angular mobility, and thus the correction of any potential angular misalignment of the first and second drive shafts.Similarly, rotating the first part 1 around the first cylindrical piece 5a allows such misalignment to be corrected.

[0025] Figure 4 illustrates three top views of the cardan joint 10 in which said cardan joint 10 has three different radial configurations. Indeed, in illustrations A, B, and C of Figure 3, the second sleeve 6b moves along the second cylindrical part 6a. In other words, the second part Cylindrical part 6a moves along the fourth axis D (not shown in [Fig. 4]). Similarly, the movement of the first sleeve 5b along the first cylindrical part 5a is possible and allows for the correction of radial misalignment.

[0026] All the movements illustrated in Figures 2 to 4 are permitted simultaneously, allowing for immediate correction of axial, radial, and / or angular misalignment without the need to add an additional device to the first and / or second drive shaft. This simplifies assembly and reduces the overall mass of the assembly formed by the universal joint 10, the first drive shaft, and the second drive shaft.

[0027] Furthermore, the invention relates to a motor vehicle comprising a drive chain including the universal joint 10 described above. The drive chain therefore comprises the first drive shaft and the second drive shaft. As described above, when mounted on the vehicle, the first drive shaft is coupled to the first part 1 and the second drive shaft is coupled to the second part 2. Such an assembly is particularly suitable for a vehicle comprising a drive train coupled to the drive chain and a leaf spring suspension system.

Claims

Demands

1. Cardan joint (10) comprising a first part (1) intended to be coupled to a first transmission shaft having a first longitudinal axis (A) and a second part (2) intended to be coupled to a second transmission shaft having a second longitudinal axis (B), the first part (1) and the second part (2) each comprising two openings (3a, 3b) positioned opposite each other, said cardan joint (10) comprising a connecting member (4) positioned between the first part (1) and the second part (2), characterized in that the connecting member (4) comprises: - a first sliding pivot joint (5a, 5b) allowing the pivoting of the first part (1) around a third axis (C) perpendicular to the first axis (A) and the translation of the first part (1) along the third axis (C);- a second sliding pivot joint (6a, 6b) allowing the pivoting of the second part (2) around a fourth axis (D) perpendicular to the second axis (B) and the translation of the second part (2) along the fourth axis (D); the third axis (C) and the fourth axis (D) being perpendicular to each other, the first sliding pivot joint (5a, 5b) being inserted into each opening (3a) of the first part (1), the second sliding pivot joint (6a, 6b) being inserted into each opening (3b) of the second part (2), the openings (3a) of the first part (1) and the openings (3b) of the second part (2) having an oblong shape, the openings (3a) of the first part (1) allowing the translation of the first sliding pivot joint (5a, 5b) along the first axis (A), the openings (3b) of the second part (2) allowing the translation of the second sliding pivot joint (6a, 6b) along the second axis (B).;

2. Cardan joint (10) according to claim 1, characterized in that the first sliding pivot joint (5a, 5b) comprises a first cylindrical piece (5a) defining the third axis (C) and a first sleeve (5b) mounted freely in translation and rotation around the first cylindrical piece (5a), the first sleeve (5b) being integral with the second sliding pivot joint (6a, 6b).

3. Cardan joint (10) according to claim 1 or 2, characterized in that the second sliding pivot joint (6a, 6b) comprises a second cylindrical piece (6a) defining the fourth axis (D) and a second sleeve (6b) mounted freely in translation and rotation around the second cylindrical piece (6a), the second sleeve (6b) being integral with the first sliding pivot joint (5a, 5b).

4. Cardan joint (10) according to claims 2 and 3, characterized in that the first cylindrical piece (5a) has a first predetermined length, the second cylindrical piece (6a) has a second predetermined length, the translational stroke of the first cylindrical piece (5a) being between 0.1 and 0.8 times the first predetermined length, the translational stroke of the second cylindrical piece (6a) being between 0.1 and 0.8 times the second predetermined length.

5. Cardan joint (10) according to claim 4, characterized in that the translational stroke of the first cylindrical piece (5a) is equal to 0.5 times the first predetermined length and the translational stroke of the second cylindrical piece (6a) is equal to 0.5 times the second predetermined length.

6. Cardan joint (10) according to any one of claims 1 to 5, characterized in that the first sliding pivot joint (5a, 5b) and the second sliding pivot joint (6a, 6b) each have a circular section.

7. Cardan joint (10) according to any one of claims 1 to 6, characterized in that the first part (1) and the second part (2) each have an internal surface comprising splines configured to cooperate with the splines present on the first transmission shaft and on the second transmission shaft.

8. Motor vehicle comprising a transmission chain including a universal joint (10) according to any one of claims 1 to 7, characterized in that said transmission chain comprises a first transmission shaft and a second transmission shaft, the first transmission shaft being coupled to the first part (1), the second transmission shaft being coupled to the second part (2).

9. Vehicle according to claim 8 characterized in that said vehicle comprises a wheel assembly coupled to the transmission chain and a leaf spring damping system.