Length adjustment for a drive shaft

Abstract

A length adjustment for a drive shaft, wherein the length adjustment has the following: a first rotary element with a first longitudinal toothing and a second rotary element with a second longitudinal toothing. The first longitudinal toothing and the second longitudinal toothing mesh with each other and are axially displaceable to each other. In an end portion of the first rotary element a tooth gap between two longitudinal teeth of the first longitudinal toothing is obstructed. The radial height of a longitudinal tooth of the second longitudinal toothing is reduced relative to the residual longitudinal teeth such that only the longitudinal tooth reduced in radial height can be axially inserted into the obstructed tooth gap. The tooth gap is obstructed by a locking portion of the first rotary element, produced by forming or a material connection a pin resting in a bore of the first rotary element. The locking portion or the pin is arranged in the tooth gap or in axial extension to the tooth gap.

Claims

1. A length adjustment for a drive shaft, the length adjustment comprising: a first rotary element with a first longitudinal toothing and a second rotary element with a second longitudinal toothing, wherein the first longitudinal toothing and the second longitudinal toothing mesh with each other and are axially displaceable to each other, wherein in an end portion of the first rotary element a tooth gap between two longitudinal teeth of the first longitudinal toothing is obstructed, and wherein the radial height of a longitudinal tooth of the second longitudinal toothing is reduced relative to the residual longitudinal teeth such, that only the longitudinal tooth reduced in radial height can be axially inserted into the obstructed tooth gap, wherein said tooth gap is obstructed by a locking portion of the first rotary element, the locking portion produced by forming an indentation in an axial end face of the end portion of the first rotary element, such that the locking portion radially extends into the tooth gap wherein the locking portion is arranged in the tooth gap or in axial extension to the tooth gap.

2. The length adjustment according to claim 1, wherein the longitudinal tooth with reduced height of the second longitudinal toothing, is formed such, that during a torque transmission between the first longitudinal toothing and the second longitudinal toothing the longitudinal tooth with reduced height comes into abutment with one of the longitudinal teeth forming the obstructed tooth gap.

3. The length adjustment according to claim 1, wherein two diametrically opposite tooth gaps of the first longitudinal toothing are obstructed; and wherein the radial height of two diametrically opposite longitudinal teeth of the second longitudinal toothing is reduced.

4. The length adjustment according to claim 1, wherein the longitudinal teeth of the first longitudinal toothing extend from the end face.

5. The length adjustment according claim 1, wherein the first rotary element is a shaft journal and the first longitudinal toothing is an outer longitudinal toothing; and wherein the second rotary element is a hub sleeve and the second longitudinal toothing is an inner longitudinal toothing.

6. The length adjustment according to claim 5, wherein the inner longitudinal toothing of the hub sleeve is produced by means of cold pressing.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) A preferred embodiment of a drive shaft with a length adjustment according to the invention is described in detail in the following with reference to the drawings.

(2) FIG. 1 is a longitudinal sectional view of a drive shaft with a length adjustment according to the invention,

(3) FIG. 2 is a cross-sectional view through the length adjustment along the sectional line II-II of FIG. 1, and

(4) FIG. 3 is a portion of a longitudinal sectional view through a shaft journal of the length adjustment of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a drive shaft 1 with three joints, namely a first joint 2, a second joint 3 and a third joint 4. All joints 2, 3, 4 are universal joints and separate the drive shaft 1 into a first drive shaft portion 5 between the first joint 2 and the second joint 3 and a second drive shaft portion 6 between the second joint 3 and the third joint 4.

(6) In the first drive shaft portion 5 a length adjustment 7 is provided, so that the first joint 2 and the third joint 5 can be axially displaced to each other along a longitudinal axis L. The second drive shaft portion 6 is not adjustable in length.

(7) In the area of the length adjustment 7, the drive shaft 1 is supported via a support bearing 8.

(8) The length adjustment 7 has a first rotary element 9 in form of a shaft journal as well as a second rotary element 10 in form of a hub sleeve. The hub sleeve 10 rests in this case on the journal 9 and is held displaceably in axial direction. For this, the shaft journal 9 has a first longitudinal toothing 11. The hub sleeve 10 has a second longitudinal toothing 12. The two longitudinal toothings 11, 12 are arranged complementary to each other and mesh in each other, so that a torque can be transmitted around the longitudinal axis and a displacing of the two rotary elements 9, 10 is ensured relative to each other in direction of the longitudinal axis L.

(9) The first longitudinal toothing 11 has longitudinal teeth 13, which extend starting from an end face 14 of the shaft journal 9 and in axial direction. The first longitudinal toothing 11 is formed as an outer longitudinal toothing.

(10) The second longitudinal toothing 12 has longitudinal teeth 24, which are formed complementary to the longitudinal teeth 13 of the first longitudinal toothing 11, wherein the second longitudinal toothing 12 is formed as an inner longitudinal toothing.

(11) The hub sleeve 10 is rigidly connected to a tube 15, which is connected at an end facing away from the hub sleeve 10 to an inner yoke 16 of the first joint 2. The inner yoke 16 is connected via a cross 17 in an articulated manner to an outer yoke 18. The outer yoke 18 has a flange 19 for connecting the drive shaft 1 to a driven or driving component.

(12) The shaft journal 9 of the length adjustment 7 is connected to a first yoke 20 of the second joint 3. The first yoke 20 is connected via a cross 21 in an articulated manner to a second yoke 22. The second yoke 22 is connected via a tube 23 to the third joint 4, wherein the third joint 4 can be connected to a driven or a driving element.

(13) To ensure a uniform rotational movement at the element connected to the first joint 2 and at the element connected to the third joint 4, it has to be ensured, that the angles of articulation at the first joint 2 and at the third joint 4 are of the same size. Furthermore, the outer yoke of the first joint 2 and of the third joint 4 have to be aligned parallel to each other. Thus during the assembly of the length adjustment 7 it is important, that the first rotary element 9 and the second rotary element 10 can only be assembled in two angular positions.

(14) In the present embodiment this is achieved such, that, as shown in FIGS. 2 and 3, an indentation 26 is worked into the end face 14 by forming. The indentation 26 is aligned, when seen in axial direction, with a tooth gap 25 between two longitudinal teeth 13, 13 of the first longitudinal toothing 11.

(15) As especially visible in FIG. 3, a material accumulation is achieved radially outward by means of working the indentation 26 into the end face 14, which forms an obstructing portion 27, which is arranged between the longitudinal teeth 13, 13 of the tooth gap 25.

(16) Generally it is also possible, that the indentation 26 is worked into an end face, which forms part of a cylindrical projection, to which the longitudinal teeth 13, 13 follow only with an axial distance to the end face. Essential is, that the locking portion 27 is aligned with the tooth gap 25 in axial direction.

(17) The second longitudinal toothing 12 has an longitudinal tooth 28 reduced in the radial height. This shortened longitudinal tooth 28 has a smaller radial height than the residual longitudinal teeth 24 of the second longitudinal toothing 12. In this case, the radial height of the obstructing portion 27 is formed such, that the longitudinal teeth 24 of the second longitudinal toothing 12, which are not shortened, cannot be inserted axially into the tooth gap 25. During the assembly of the shaft journal 9 in the hub sleeve 10, thus, the longitudinal teeth 24, not shortened, would collide with the obstructing portion 27, whereby an assembly is prevented.

(18) In contrast thereto, the shortened longitudinal tooth 28 has a radial height, which is so low, that the shortened longitudinal tooth 28 can be pushed over the obstructing portion 27.

(19) In other words, the non-shortened longitudinal teeth 24 of the second longitudinal toothing 12 have a head circle diameter, which is smaller than the head circle diameter of the obstructing portion 27, whereas the head circle diameter of the shortened longitudinal tooth 28 is larger than the head circle diameter of the obstructing portion 27.

(20) Generally it is also possible, that the obstructing portion 27 is arranged on the inner longitudinal toothing and the outer longitudinal toothing has a shortened longitudinal tooth.

(21) In total two indentations 26 are provided in the end face 14, which are arranged diametrically opposite to each other. Equivalent thereto, two shortened longitudinal teeth 28 are provided, which are also arranged diametrically to each other. Thus, the shaft journal 9 and the hub sleeve 10 can be mounted in two angular positions, rotated by 180 to each other.