Journal cross and universal joint comprising the same

Abstract

A space-saving method for early determination of wear of a universal joint with four journals projecting from a base is provided and relates to the field of drive technology. The journal cross of the universal joint is provided with a temperature sensor for the purpose of determining wear of the universal joint.

Claims

1. A journal cross of a universal joint with four journals projecting from a base, comprising: at least one temperature sensor fastened to the journal cross, wherein the temperature sensor comprises at least one sensor element which is arranged in a lubricant channel that is recessed in the journal cross and is assigned to one of the journals, a logic is mounted on the journal cross for processing the signals of the at least one temperature sensor, wherein the logic is coupled data-wise with several sensor elements detecting the temperature, and wherein the sensor elements are connected data-wise via data lines to the logic, which are guided through the material forming the base in a sealed manner from the lubricant channel to the outside of the journal cross.

2. The journal cross according to claim 1, wherein the logic has a memory and an evaluation unit which evaluates signals from the sensor elements and generates an output signal which indicates a fault state.

3. The journal cross according to claim 1, wherein at least one sensor element is assigned to each of the journals and the logic indicates a fault state if the signal of at least one sensor element exceeds a temperature threshold value.

4. The journal cross according to claim 1, wherein the logic and at least one sensor element are mounted on a common printed circuit board.

5. The journal cross according to claim 1, wherein a protective cover is associated with the logic and/or at least one of the sensor elements.

6. A universal joint, comprising two fork-shaped yokes which are each mounted pivotally on opposite journals of a journal cross according to one of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is explained in more detail below on the basis of embodiments in conjunction with the drawings. Therein:

(2) FIG. 1: shows a perspective side view of a first embodiment of a universal joint;

(3) FIG. 2: shows a perspective top view of a second design embodiment of a universal joint, and

(4) FIG. 3: shows a perspective side view of a journal cross, which can be used in the universal joints according to FIG. 1 or 2.

DETAILED DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows an example of a universal joint 2 with two fork-shaped yokes 4, each of which is pivotally mounted on opposite journals 6 of a journal cross 8. The fork-shaped yokes 4 comprise receptacles 10 for the torque-proof accommodation of a non-shown shaft body.

(6) FIG. 2 shows an alternative example of a universal joint 2 with a journal cross 8, the journal 6 of which each is accommodated in journal receptacles 12, which can be mounted on the drive or output side via non-shown fastening screws. Compared to the embodiment shown in FIG. 1, the embodiment shown in FIG. 2 has a smaller axial structure. Both embodiments can, however, realize the invention explained below with reference to FIG. 3.

(7) FIG. 3 shows an embodiment of a journal cross 8 with four journals 6 defining a plane E1 containing the central longitudinal axes of the journals 6. The journals 6 project from a middle base 14 and are realized with base 14 in a uniform forged component. The surface of base 14 is essentially unfinished. The circumferential surface of the journals 6 is turned down on a lathe to accommodate bearings.

(8) As shown in FIG. 3, the base 14 is penetrated by intersecting lubricant channels 16. Inside the machined journals 6, i.e. circumferentially surrounded by the machined mounting surface of the journal 6, there is a sensor element 18 that is not shown in detail, for detecting the temperature of the base 14 at this point. The sensor element 18 is usually arranged in the lubricant channel 16 by gluing the sensor element 18 against the inner circumferential surface of the lubricant channel 16. A data line 20 connected to the sensor element 18 is guided from the inside of the base 14 to the outside through a bore identified by reference sign 22 and is connected data-wise to a logic 24 in the form of an equipped circuit board 30 which is applied, for example glued, to the outside of the base 14 in the center of the base 14. After mounting the data line 20 in the manner described above, the bore 22 is sealed with a hardening compound which is inserted into the bore 22 and identified with reference sign 26 in FIG. 3.

(9) The sensor elements 18 provided for each of the journals 6 are each coupled data-wise with the logic 24 in the manner described above. Thus, the logic 24 evaluates the measuring signals of each individual sensor element 18. The logic may have a memory 32 and an evaluation unit 34.

REFERENCE SIGN LIST

(10) 2 universal joint

(11) 4 fork-shaped yoke

(12) 6 journal

(13) 8 journal cross

(14) 10 receptacle

(15) 12 journal receptacle

(16) 14 base

(17) 16 lubricant channel

(18) 18 sensor element

(19) 20 data line

(20) 22 bore

(21) 24 logic

(22) 26 hardening compound

(23) E1 plane containing the central longitudinal axes of the journals 6