TEST BENCH

Description

[0001] The invention relates to a test stand with a base frame on which a test stand drive with a test shaft rotatably driven about a rotary axis is arranged, wherein the test shaft can be connected coaxially to a bearing shaft of a bearing unit rotatably mounted about the rotary axis, wherein the bearing unit is detachably arranged in a recess coaxial to the rotary axis of a bearing housing fixedly connected to the base frame, and the bearing shaft has a fastening element at its end facing away from the test stand drive and protruding from the bearing housing for detachably fastening a test specimen.

[0002] Such test benches are used, among other things, to perform acoustic, vibration, torque, and functional tests on the rotating test specimen. Test specimens can be, for example, electric motors and gearboxes, particularly for electric vehicle drives.

[0003] These tests place high loads on the bearing unit, causing it to wear out quickly and require replacement. Because the axis of rotation of the test bench drive and the bearing shaft must be coaxial with high precision to prevent any distortion of the measurement results, replacing the bearing unit necessitates a time-consuming and labor-intensive realignment of the test bench drive to the bearing shaft.

[0004] A test bench of the type mentioned above is known from DE 10 2016 224 142 A1.

[0005] From DE 509 315 C, an adjustable roller bearing is known in which an inner race is arranged on a working spindle, on which the rollers of the bearing are arranged. The outer race of the bearing consists of an axially wound spring band, the outer contour of which is conically ground and mounted in a sleeve with the same counter-cone. The sleeve with its outer contour is inserted into a bore of a bearing body. The spring band can be wound more tightly by twisting it. Furthermore, the sleeve is displaceable relative to the spring band.

[0006] A needle bearing mounted on a shaft is known from US 2,670,235 A and DE 871,856 C. The outer ring of the needle bearing is designed as a longitudinally slotted sleeve with a conical outer surface and is supported by a correspondingly conical inner surface of a sleeve-like outer ring. The outer ring of the needle bearing can be axially retensioned by means of a clamping nut.

[0007] The object of the invention is to create a test rig of the type mentioned above, whose bearing unit can be mounted quickly and with precise positioning despite its simple design.

[0008] This problem is solved according to the invention in that the coaxial recess in the bearing housing is a conical section-shaped recess symmetrical to the axis of rotation, in which a bearing sleeve of the bearing unit is arranged in a rotationally fixed manner, the bearing sleeve having an outer conical wall which, with its outer contour being at least partially the same as the contour of the wall of the conical section-shaped recess, is in contact with the wall of the conical section-shaped recess, wherein the bearing sleeve has a through bearing bore coaxial to the axis of rotation in which the bearing shaft is rotatably mounted via one or more bearings.

[0009] The test bench drive is preferably an electric motor.

[0010] The design according to the invention forms the bearing unit consisting of bearing sleeve, bearing and bearing shaft into a component that can be easily pre-assembled.

[0011] During installation, this component is precisely aligned coaxially with the rotational axis of the test bench drive, with its outer conical wall fitting into the conical-section-shaped recess without play and with very high positional accuracy, so that no further alignment is required. This allows for quick replacement of the bearing unit.

[0012] The load transfer from the bearing shaft takes place in the area of ​​the bearings via the bearing sleeve directly into the bearing housing and the base frame.

[0013] If the end with the smaller diameter of the cone-shaped recess faces the test bench drive, there is largely unimpeded access to the cone-shaped recess.

[0014] The cone angle of the cone-shaped recess can be between 1° and 5°. Preferably, the cone angle is between 1° and 3°, particularly 2°. This ensures not only precise coaxial alignment of the bearing unit but also efficient force transmission of the bearing forces into the bearing housing.

[0015] To ensure a secure fit of the outer conical wall of the bearing sleeve against the conical-section-shaped recess, the outer conical wall of the bearing sleeve can be formed by conical wall sections in the two end regions of the bearing sleeve, between which the bearing sleeve is formed with a radially circumferential ring recess.

[0016] The bearing shaft can be rotatably mounted in the bearing bore by means of rolling bearings and / or sliding bearings arranged in the two end regions of the bearing bore.

[0017] In order to absorb vibrations effectively during testing and thus largely avoid distortions of the test data, the bearing sleeve and / or the base frame and / or the bearing housing can be designed as a vibration-damping component with high inherent damping.

[0018] Preferably, the bearing housing is formed as a single unit with the base frame.

[0019] The bearing housing can also be a compact component with a large mass and, in particular, a large wall thickness.

[0020] In order to be able to quickly disassemble or assemble the bearing unit, the bearing sleeve can have a radially circumferential annular shoulder at its larger diameter end, on the side of which facing away from the smaller diameter end of the bearing sleeve a locking element is axially in contact, which can be detachably attached to the bearing housing.

[0021] For this purpose, the locking element can simply be a clamping ring that can be inserted into a coaxial annular groove of the bearing housing.

[0022] The fastening element for the end of the bearing shaft protruding from the bearing housing can be a fastening flange.

[0023] An embodiment of the invention is shown in the drawing and is described in more detail below. The drawing shows: Figure 1: A perspective view of a test bench setup. Figure 2: A side view of the test bench setup. Figure 1 Figure 3 shows an enlarged section "X" of the test bench of the test bench arrangement according to Figure 2 .

[0024] The test bench arrangement according to the Figure 1 and 2 Figure 1 shows a test stand 1, which has a base frame 2 on which an electric motor 3 and a bearing housing 4 are fixedly arranged as a test stand drive.

[0025] Base frame 2 and bearing housing 4 are formed as a single unit and exhibit vibration-damping properties. This can be achieved by the fact that base frame 2 and bearing housing 4 consist of a housing filled with concrete.

[0026] The electric motor 3 has a test shaft 6 which can be rotatably driven by it about a rotary axis 7, which is designed as a drive train 8 leading coaxially to the rotary axis 7 to the bearing housing 4, on which a torque measuring device (not shown) and other measuring devices can be arranged.

[0027] The bearing housing 4 has a cone-section-shaped recess 5 that is coaxial and symmetrical to the axis of rotation and has a cone angle of 2°, the end of which, with a smaller diameter, faces the electric motor 3.

[0028] A bearing sleeve 10 of a bearing unit 9 is inserted into the conical recess 5, the bearing sleeve 10 having an outer conical wall corresponding to the conical recess 5. The outer conical wall of the bearing sleeve 10 is formed by conical wall sections 11 in the two end regions of the bearing sleeve 10. An annular recess 12 is formed between the two conical wall sections 11, so that the bearing sleeve 10 is in contact with the wall of the conical recess 5 only with its conical wall sections 11.

[0029] According to another embodiment, not shown in the figures, no ring recess 12 is provided.

[0030] The bearing sleeve 10 is inserted into the recess 5 from the left side, extending 360° circumferentially to the surface of the conical-section-shaped recess 5, and secured in the installed position by a clamping ring 13. The clamping ring 13 is inserted into an annular groove 14 of the bearing housing 4.

[0031] A gap is left so that the ring 13 can press the bearing sleeve 10 precisely into the conical seat 11. The axial position of the bearing sleeve 10 is ensured by the precisely manufactured diameter cone of both components.

[0032] The bearing sleeve 10 is secured against rotation by a pin 16, which is firmly inserted into a corresponding radial bore 17 in the bearing sleeve 10 and projects radially out of this bore into a slot 18 of the same width as the pin 16. The slot 18 formed in the bearing housing 4 is open towards the end face of the bearing housing 4 facing away from the electric motor 3.

[0033] The bearing sleeve 10 has a bearing bore 19 extending coaxially to the axis of rotation 7, in the axial end regions of which rolling bearings 20, 20' are inserted with their outer rings. The inner rings of the rolling bearings 20, 20' are arranged on a bearing shaft 21. Plain bearings 20, 20' could also be used instead of rolling bearings 20, 20'.

[0034] The bearing shaft 21 is detachably connected to the drive train 8 at its right end, while the left end of the bearing shaft 21, which protrudes from the bearing sleeve 10, is provided with a mounting flange 22.

[0035] A rotatable test specimen (not shown) can be arranged in a receiving housing 23. The test specimen can be, for example, an electric drive, particularly for a vehicle, or a transmission module. A shaft of the test specimen is connected coaxially to the axis of rotation 7 in a rotationally fixed manner to the mounting flange 22, and the receiving housing 23 is connected in a rotationally fixed manner to the bearing housing 4 (or alternatively to a substructure (not shown) below the test specimen). The connection of the test specimen's shaft can be direct or indirect, via a coupling or drive shaft. Reference sign

[0036] 1 Test stand 2 Base frame 3 Electric motor 4 Bearing housing 5 Recess 6 Test shaft 7 Rotary axis 8 Drive train 9 Bearing unit 10 Bearing sleeve 11 Conical wall areas 12 Ring recess 13 Clamping ring 14 Ring groove 15 Ring shoulder 16 Pin 17 Radial bore 18 Slot 19 Bearing bore 20 Rolling bearing or plain bearing 20' Rolling bearing or plain bearing 21 Bearing shaft 22 Mounting flange 23 Mounting housing

Claims

1. Test bench (1) with a base frame (2) on which a test bench drive is arranged, having a test shaft (6) that can be driven rotationally about an axis of rotation (7), wherein the test shaft (6) can be connected coaxially to a bearing shaft (21) of a bearing unit (9) that is mounted rotatably about the axis of rotation (7), wherein the bearing unit (9) is releasably arranged in a recess (5), coaxial with the axis of rotation (7), of a bearing housing (4) that is fixedly connected to the base frame (2), and the bearing shaft (21) has, at its end projecting from the bearing housing (4) and facing away from the test bench drive, a fastening element for the releasable attachment of a test specimen, characterized in that the coaxial recess (5) in the bearing housing (4) is a conical-section-shaped recess (5) symmetrical to the axis of rotation (7), in which a bearing sleeve (10) of the bearing unit (9) is non-rotatably and releasably arranged, said bearing sleeve having an outer conical wall which, with its at least partially matching outer contour, conforms to the contour of the wall of the conical-section-shaped recess (5) and is in contact with the wall of the conical-section-shaped recess (5), wherein the bearing sleeve (10) also has a through-bearing bore (19) coaxial with the axis of rotation (7), in which the bearing shaft (21) is rotatably supported via one or multiple bearings.

2. Test bench according to Claim 1, characterized in that the smaller-diameter end of the conical-section-shaped recess (5) faces the test bench drive.

3. Test bench according to any one of the preceding claims, characterized in that the cone angle of the conical-section-shaped recess (5) is between 1° and 5°.

4. Test bench according to any one of the preceding claims, characterized in that the outer conical wall of the bearing sleeve (10) is formed by conical wall sections (11) in the two end regions of the bearing sleeve (10), between which the bearing sleeve (10) is formed with a radially circumferential annular recess (12).

5. Test bench according to any one of the preceding claims, characterized in that the bearing shaft (21) is rotatably supported in the bearing bore (19) via rolling bearings (20, 20') and / or plain bearings positioned at both axial end regions of the bearing bore (19).

6. Test bench according to any one of the preceding claims, characterized in that the bearing sleeve (10) and / or the base frame (2) and / or the bearing housing (4) is designed as a vibration-damping body with high inherent damping properties.

7. Test bench according to any one of the preceding claims, characterized in that the larger-diameter end of the bearing sleeve (10) has a circumferential shoulder (15) at its larger-diameter end, on the side of which, facing away from the smaller-diameter end of the bearing sleeve (10), a securing element is axially positioned in contact and can be releasably fastened to the bearing housing (4).

8. Test bench according to Claim 6, characterized in that the securing element is a clamping ring (13) that can be inserted into a coaxial groove (14) of the bearing housing (4).

9. Test bench according to any one of the preceding claims, characterized in that the fastening element on the end of the bearing shaft (21) projecting from the bearing housing (4) is a fastening flange (22).