Drive unit for testing transmissions and device for testing transmissions

The Invention relates to a drive unit for testing transmissions, according to the preamble of patent claim 1, and to a device for testing transmissions, according to the preamble of patent claim 14.

It is known that the functioning and load-bearing capacity of transmissions are tested after they have been assembled, this being carried out by means of corresponding test arrangements. The applicant's WO 2005/119198 Al disclosed a device for testing transmissions, by means of which transmissions are tested at the end of the assembly process. The known device has a vertically adjustable gantry, on both sides of which are arranged driving and driven motors which are in each case connected, in turn, to driving and driven center sleeves arranged, offset, in parallel. The driving and driven center sleeves are connected by docking and coupling to the driving and driven shaft of the transmission to be tested. The test run then takes place. After the conclusion of the test run, the driving and driven center sleeves are separated from the transmission again. The known testing device still has potentials in terms of the production costs and also in terms of flexible use in the manufacturing process.

Further devices for testing transmissions or transmission test benches became known from the applicant's DE 195 37 639 Al, and from DE 39 05 983 Al and DE 43 28 537 Al.

The object of the invention is to simplify a device for testing transmissions, in particular to provide a simplified and cost-effective drive unit for testing transmissions.

The object of the invention is achieved by means of the features of patent claim 1. Advantageous refinements may be gathered from the subclaims.

According to the invention, the electric motor is arranged on the driving shaft and is designed as a spindle motor. A spindle motor is a commercially available electric motor which is arranged directly on the driving shaft. This affords the advantage of a compact type of construction for the drive unit. Moreover, cost benefits arise, since transmission means between the driving motor and the center sleeve arranged so as to be offset (cf. the prior art) are dispensed with. The driving shaft and electric motor of\ the drive unit are thus arranged coaxially with respect to the driving shaft of the transmission to be tested. According to an advantageous refinement, the driving shaft is designed as a hollow shaft, so that access to the transmission testpiece is afforded. In particular, an actuating rod is arranged in the hollow shaft and is actuated preferably via a pneumatic or hydraulic servomotor. A coupling element can thereby be actuated.

The spindle motor is distinguished by a compact type of construction, in which the rotor is arranged directly on the hollow shaft and the stator is arranged in a motor housing. Preferably, cooling ducts for cooling the windings in the stator are integrated into the stator. The hollow shaft is advantageously mounted in cover disks which are arranged on the end faces and which therefore also function as bearing plates.

The drive unit may preferably be fastened to a carrying structure, for example in the form of a gantry, vertical and lateral adjustment for bringing the drive unit up to the transmission testpiece being possible.

Alternatively, the drive unit may be fastened to handling appliance, in particular to a bending arm of a robot. This achieves the possibility of versatile movement to the drive unit which is thus not only vertically and laterally adjustable, but also pivotable. Many different possibilities of use for carrying out transmission testing are consequently obtained.

Advantageously, the drive unit may be used for the input drive and for the output drive of the transmission, for example in the event of overrun simulation. The drive unit can thus be used in many different ways as the module, thus resulting in cost savings.

According to a further advantageous embodiment, the drive unit has a lifting arrangement, by means of which the drive unit can be displaced in the longitudinal direction of the driving shaft (hollow shaft). Consequently, the drive unit can be moved up to the transmission testpiece, that is to say its drive side and driven side, and moved away again, that is to say for docking and separation.

The object of the invention is also achieved by means of a device having the features of patent claim 14. What is advantageous in this combination is that a gantry known per se or a handling appliance known per se can be equipped with the drive unit according to the invention, a drive module, while the drive module can be adapted to the respective transmission type. The mounting of the drive module and, likewise, demounting and exchange for another drive module take place simply and quickly. A high flexibility of the testing device is consequently achieved.

Exemplary embodiments of the invention are illustrated in the drawing and are described in more detail below. In the drawing:
fig. 1 shows a longitudinal section through the drive unit according to the invention,
fig. 2a, 2b show perspective illustrations of the drive unit with and without a housing cladding,
fig. 3a shows a perspective illustration of the drive unit, looking toward a lifting arrangement,
fig. 3b shows a perspective view of the lifting arrangement,
fig. 4a, 4b show different perspective illustrations of a carrying structure with the drive unit, and
fig. 5 shows a perspective illustration of a robot with a bending arm and with a drive unit fastened to it.

Fig. 1 shows a drive unit 1 which is arranged on the holding arm 2 of a carrying structure, not illustrated, for testing transmissions. The drive unit 1 has a driving shaft 3 which is designed as a hollow shaft and which is mounted via rolling bearings 4, 5 in cover disks 6, 7 (partially also designated as bearing plates).

The driving shaft 3 is driven by an electric motor 8, which is known as a spindle motor, which has a rotor 8a fastened directly on the hollow shaft 3 and a stator 8b designed as a circular body. The stator 8b is received in a cylindrical motor housing 9 which is supported on the end faces on the two cover disks 6, 7. The stator 8b has integrated into it on its outer circumferential surface cooling ducts 10 which are connected via bores 11, 12 to a cooling system, not illustrated. Within the hollow shaft 3 is arranged an actuating rod 13 which is guided longitudinally displaceably and which is actuated by a pneumatic or hydraulic servomotor 14. The servomotor 14 is supported on a rear wall 15 of the drive unit 1. The actuating rod 13 projects out of the hollow shaft 3 on the end face and is connected to a coupling element 16. The drive unit 1 has a clamping or docking arrangement 17 which is connected to the front cover disk 6 via a tubular piece 18. The hollow shaft 3 can be connected on the end face to the coupling element 16 via positive elements 3a (claws) .

The coupling element 16 is arranged in a rotatably arranged sleeve 19 which can be brought into engagement on the end face with the hollow shaft 3 via positive elements 19a.

The drive unit 1 comprises, furthermore, a lifting arrangement 20 which is arranged above the motor housing 9, in the drawing, and which is fastened to the outer cover disk 6 and to the rear wall 15. The lifting arrangement 20 has a flange plate 21, by means of which the entire drive unit 1 is fastened to the carrying arm 2.

The lifting arrangement 20 has a spindle 22 which is fastened to the cover disk 6 and the rear wall 15 and on which a spindle nut 24 drivable via a servomotor 23 is fastened. The lifting arrangement 20 comprises, furthermore, a slide 25 which is arranged slidably in the direction of the spindle 22 and which is guided and held in the drive unit 1 via laterally arranged guide elements which cannot be seen here. By means of the lifting arrangement 20, it is possible to displace the drive unit 1 in relation to the holding arm 2 horizontally, that is to say in the direction of the longitudinal axis of the hollow shaft 3, and thus to move said drive unit up to a transmission testpiece, not illustrated here, and move it back again.

Fig. 2a shows the drive unit 1 in a housing 26 which is upwardly open and which has a rectangular orifice 27 for the movement of the lifting arrangement 20 or of the slide 25. Further parts are identified by the reference numerals from fig. 1, such as the tubular piece 18 and the clamping arrangement 17 which is fastened to it and which receives the transmission testpiece, not illustrated.

Fig. 2b shows the drive unit 1 without a housing cladding, so that the motor housing 9, the cover disks 6, 7, the rear wall 15 and the servomotor 14 can be seen. In the region of the lifting arrangement 20, a laterally arranged guide rail 28 can be seen in fig. 2a and 2b, whereas an opposite guide rail 29, which is not visible here, can be seen in fig. 3a.

Fig. 3a shows the drive unit 1 in a perspective illustration from above, the lifting arrangement 20 being partially exposed, so that it is possible to see the slide 25 which has on its sides guide jaws 30, 31, 32, 33 which are guided on the guide rails 28, 29. As mentioned above, the actuating movement takes place via the spindle 22 and the spindle nut 24.

Fig. 3b shows the lifting arrangement 20 as an enlarged detail, the guide jaws 30, 32, 33 and the guide rail 28 being clearly visible.
Fig. 4a and fig. 4b show an example of the use of the drive unit 1 in conjunction with a carrying structure 34, also called a gantry, 34. The gantry 34 has a column 34a and a carrying arm 34b, to which the holding arm 2 (cf. fig. 1) is fastened so as to be vertically and laterally adjustable. The drive unit 1 is fastened as a finished and exchangeable module to the lower end of the holding arm 2 and can likewise be demounted easily and quickly.

Fig. 5 shows a further example of the use of the drive unit 1 in conjunction with a robot 35 which is designed as a bending arm robot and which has a multiplicity of rotary and pivoting joints. The bending arm 35 has a reception head 35a, to which the drive unit 1 is fastened by the flange plate 21. The combination of the drive unit 1 according to the invention with a robot 35 designed as a bending arm affords many different possibilities of movement, so that, by means of this appliance, it is possible to react in a flexible way to the most diverse possible situations and configurations in the testing of the transmissions.

Reference symbols
1 Drive unit
2 Holding arm
3 Hollow shaft
3a Claw
4 First bearing
5 Second bearing
6 Cover disk, outer
7 Cover disk, inner
8 Spindle motor
8a Rotor
8b Stater
9 Motor housing
10 Cooling duct
11 Bore
12 Bore
13 Actuating rod
14 Servomotor
15 Rear wall
16 Coupling element
17 Clamping/docking arrangement
18 Tubular piece
19 Sleeve
19a Claw
20 Lifting arrangement
21 Flange plate
22 Spindle
23 Servomotor
24 Spindle nut
25 Slide
26 Housing
27 Orifice
28 Guide rail
29 Guide rail
30 Guide jaw
31 Guide jaw
32 Guide jaw
33 Guide jaw
34 Carrying structure/gantry
34a Column
34b Carrying arm
35 Bending arm robot
35a Reception head

Patent Claims

1. A drive unit (1) for testing transmissions, comprising a driving shaft (3) which can be driven by an electric motor and which is designed as a hollow shaft which can be coupled to the transmission to be tested, the electric motor being arranged on the driving shaft (3) and being designed as a spindle motor (8), and an actuating rod (13) being guided through the driving shaft (3) designed as a hollow shaft.

2. The drive unit as claimed in claim 1, characterized in that the spindle motor (8) has a rotor (8a) which is arranged fixedly to the rotation on the hollow shaft (3) and a stator (8b) which is arranged in a motor housing (9).

3. The drive unit as claimed in claim 2, characterized in that the motor housing (9) is closed off on the end faces by means of cover disks (6, 7) in which the hollow shaft (3) is mounted.

4. The drive unit as claimed in claim 2 or 3, characterized in that the stator is designed as a circular body (8b) with integrated cooling ducts (10) .

5. The drive unit as claimed in claim 1, characterized in that the actuating rod (13) is displaceable by means of a servomotor (14).

6. The drive unit as claimed in one of claims 1 to 5, characterized in that the hollow shaft (3) can be coupled and uncoupled on the end face to and from a coupling element (16) and/or a sleeve (19).

7. The drive unit as claimed in claim 6, characterized in that the coupling element (16) is displaceable by means of the actuating rod (13).

8. The drive unit as claimed in one of the preceding claims, characterized in that the drive unit (1) can be used both as a driving motor and as a driven motor during transmission testing.

9. The drive unit as claimed in one of the preceding claims, characterized in that the drive unit (1) can be fastened to a carrying structure (34, 34a, 34b), in particular to a gantry, for transmission testing.

10. The drive unit as claimed in one of the preceding claims, characterized in that the drive unit (1) can be fastened to a handling appliance (35), in particular a bending arm robot.

11. The drive unit as claimed in one of the preceding claims, characterized in that the drive unit (1) comprises a lifting arrangement (20) , via which the drive unit (1) can be displaced with respect to the carrying structure (34, 34a, 34b; 2) or to the handling appliance (35, 35a) in the direction of the longitudinal axis of the hollow shaft (3).

12. A device for testing transmissions, characterized by the combination of the drive unit (1) as claimed in one of claims 1 to 8 with a gantry-like carrying structure (34) or with a handling appliance (35), in particular a bending arm robot.