Tripod shaft

Abstract

The present invention relates to a tripod joint (100) comprising: a joint housing (1), a drive shaft (2) whose drive shaft end (2.1) is arranged in the joint housing (1) and is rotationally fixed to the joint housing (1) via a tripod coupling (3), and a connecting device (4) via which the drive shaft end (2.1) is connected to the joint housing (1), wherein both a shear load and a tensile load can be transmitted between the drive shaft end (2.1) and the joint housing (1) via the connecting device (4), wherein the connecting device (4) comprises a spring element (4.1) which is configured to cushion both a transmitted shear load and a transmitted tensile load, and wherein the spring element (4.1) is a disc spring and has a plurality of spokes (4.1.3).

Description

[0001] The present invention relates to a tripod joint comprising: a joint housing and a drive shaft, the end of which is arranged in the joint housing and is coupled to the joint housing in a rotationally fixed manner via a tripod coupling.

[0002] Such a tripod joint is known from DE 29 50 222 C2, wherein the end of the drive shaft is acted upon by a spring device which rests on the end of the drive shaft via a concave disk and points away from the joint housing.

[0003] A tripod joint according to the preamble of claim 1 is known from DE 10 2011 052 474 A1.

[0004] From US 4 932 922 A, a tripod joint is known which includes a connecting device by which the end of the drive shaft is connected to the joint housing.

[0005] The present invention is based on the objective of realizing a tripod joint with low axial force pulsation in the drive shaft.

[0006] This problem is solved according to the invention by a tripod joint having the features of claim 1.

[0007] The tripod joint according to the invention comprises a joint housing and a drive shaft, the end of which is arranged in the joint housing and coupled to the joint housing in a known manner via a tripod coupling in a rotationally fixed manner. The tripod coupling comprises three receptacles formed on a radial inner surface of the joint housing and three radially extending pins fixed to a radial outer surface of the drive shaft, each of which engages in one of the receptacles for torque transmission. Typically, the tripod coupling includes a preferably annular separate tripod element, which is attached to the end of the drive shaft and on which the three pins are formed. Preferably, the pins are provided with balls, rollers, or ball bearings to reduce friction.

[0008] According to the invention, the tripod joint comprises a connecting device by means of which the end of the drive shaft is permanently connected to the joint housing, wherein the connecting device is designed such that both a shear load and a tensile load can be transmitted between the end of the drive shaft and the joint housing via the connecting device. The connecting device typically comprises an elongated, rigid connecting element that is arranged in a linear position of the tripod joint, coaxial to a drive shaft axis of rotation and a joint housing axis of rotation, and is pivotally connected to the drive shaft and the joint housing.

[0009] In the operation of a tripod joint, the joint housing and the drive shaft are typically not arranged coaxially, but at an angle to each other. This results in an axial load on the joint that alternates between shear and tensile loads three times per revolution when a rotary motion is transmitted via the tripod joint. At high speeds, this leads to a very high-frequency and material-stressing alternating load. Additionally, external influences can also cause alternating axial loads on the joint.

[0010] According to the invention, the connecting device therefore comprises a spring element designed to absorb both transmitted shear loads and transmitted tensile loads. The spring element is thus designed and arranged such that it deforms elastically both when a shear load is transmitted between the end of the driveshaft and the joint housing, and when a tensile load is transmitted between the end of the driveshaft and the joint housing. Preferably, the spring element is arranged between a rigid connecting element of the connecting device and the driveshaft, or between a rigid connecting element of the connecting device and the joint housing. However, it is also conceivable that the connecting device comprises several rigid connecting elements and that the spring element is arranged between two rigid connecting elements.

[0011] The connection device according to the invention effectively reduces axial force pulsations in the drive shaft.

[0012] According to the invention, the spring element is a disc spring. Preferably, the spring element is connected to the drive shaft, the joint housing, or a rigid connecting element via an edge region of the disc spring, and to another of the aforementioned components via an inner region of the disc spring.

[0013] According to the invention, the spring element comprises a spoke structure with a plurality of radially extending spokes. The spoke structure makes it possible to adapt the spring characteristics of the spring element particularly well to the respective geometry of the tripod joint and the resulting specific load directions and load intensities.

[0014] Particularly preferably, the spring element designed as a disc spring is arranged in a recess or opening of the joint housing or the end of the drive shaft and is held in the joint housing or the end of the drive shaft via its outer circumference, preferably in an annular groove formed on the joint housing or the end of the drive shaft.

[0015] In a preferred embodiment, the connecting device comprises a rigid connecting element which is connected at one end to the driveshaft end or to the driveshaft housing via a ball joint. The rigid connecting element is preferably rod-shaped, pin-shaped, or sleeve-shaped. Preferably, a ball element of the ball joint has a bore and is slid onto the rigid connecting element. Preferably, the ball joint has an annular socket element which is received in a recess or opening of the joint housing or the driveshaft end.

[0016] Particularly preferably, the rigid connecting element is firmly connected at one end, away from the ball joint, to a spring element designed as a disc spring. Preferably, the spring element has a centrally located opening and is pushed onto the rigid connecting element.

[0017] An embodiment of the present invention is described below with reference to the attached Fig. 1 described, which schematically shows a tripod joint according to the invention in a partially cutaway view.

[0018] Fig. Figure 1 shows a tripod joint 100 according to the invention with a joint housing 1 and a drive shaft 2 designed as a hollow shaft, the drive shaft end 2.1 of which is arranged in the joint housing 1.

[0019] The joint housing 1 and the drive shaft 2 are coupled to each other in a rotationally fixed manner via a tripod coupling 3 designed in a generally known way.

[0020] The tripod coupling 3 comprises a tripod element 3.1 attached to the end of the cardan shaft 2.1 with three pins 3.1.1, wherein a roller element 3.2 is rotatably held on each pin 3.1.1.

[0021] The tripod coupling 3 further comprises three receptacles 3.3 formed on the joint housing 1, in each of which one of the three pins 3.1.1 is received in a known manner and guided over the roller element 3.2.

[0022] The end of the drive shaft 2.1 is further connected to the joint housing 1 via a connecting device 4.

[0023] The connecting device 4 comprises a spring element 4.1 designed as a disc spring, which is arranged in an opening 1.1 formed in the joint housing 1, wherein the spring element 4.1 is held in the joint housing 1 over its outer circumference 4.1.1.

[0024] The spring element 4.1 comprises a central opening 4.1.2 and a plurality of radially extending spokes 4.1.3.

[0025] The connecting device 4 comprises a sleeve-shaped or tubular rigid connecting element 4.2, which is in a Fig.The tripod joint 100 is arranged in the linear position shown in 1, coaxial to a rotation axis of the drive shaft 2 and a rotation axis of the joint housing 1.

[0026] The rigid connecting element 4.2 is arranged with a first end 4.2.1 in the opening 4.1.2 of the spring element 4.1 and is firmly connected to the spring element 4.1.

[0027] A second end 4.2.2 of the rigid connecting element 4.2, opposite the first end 4.2.1, is connected to the end of the drive shaft 2.1 via a ball joint 4.3, wherein a ball element 4.3.1 of the ball joint 4.3 is pushed onto the second end 4.2.2 of the rigid connecting element 4.2 and a socket element 4.3.2 of the ball joint 4.3 is held in the hollow end of the drive shaft 2.1 via its outer circumference.

[0028] The connecting device 4 is therefore designed to transmit both a shear load and a tensile load between the end of the drive shaft 2.1 and the joint housing 1, whereby both a transmitted shear load and a transmitted tensile load are cushioned by the spring element 4.1.

[0029] Furthermore, the spring element 4.1 ensures a defined contact between the ball element 4.3.1 and the socket element 4.3.2 at all times.

[0030] It is pointed out that a comparable mode of action can be achieved if the connecting device 4 is reversed, i.e. if a correspondingly designed spring element 4.1 is arranged in the end of the drive shaft 2.1 and the ball joint 4.3 is arranged in a correspondingly designed opening 1.1 of the joint housing 1.

Claims

[1] Tripod joint comprising (100): a joint housing (1), a cardan shaft (2) whose cardan shaft end (2.1) is arranged in the joint housing (1) and is coupled to the joint housing (1) in a rotationally fixed manner via a tripod coupling (3), and a connecting device (4) via which the end of the drive shaft (2.1) is connected to the joint housing (1), wherein via the The connecting device (4) can transmit both a shear load and a tensile load between the end of the drive shaft (2.1) and the joint housing (1), and wherein the connecting device (4) comprises a spring element (4.1) which is configured to cushion both a transmitted shear load and a transmitted tensile load, characterized by , that the spring element (4.1) is a disc spring and has a plurality of spokes (4.1.3). [2] Tripod joint (100) according to claim 1, wherein the spring element (4.1) is held in the joint housing (1) or in the end of the drive shaft (2.1) via its outer circumference (4.1.1). [3] Tripod joint (100) according to one of the preceding claims, wherein the connecting device (4) comprises a rigid connecting element (4.2) which is connected at one end (4.2.2) to the end of the drive shaft (2.1) or to the joint housing (1) via a ball joint (4.3). [4] Tripod joint (100) according to claim 3, wherein the rigid connecting element (4.2) is rigidly connected to the spring element (4.1) at an end (4.2.1) facing away from the ball joint (4.3).

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