Revolving drum arrangement for a tyre test stand and device for grinding the outer circumferential surface of the revolving drum

Abstract

The invention relates to a revolving drum arrangement for a tyre test stand, having a revolving drum (20) that can be rotatably driven about a revolving drum axis (4) by the output shaft (2) or a revolving drum shaft (3) of a rotary drive which can be rotatably driven by the output shaft (2). A stationary bearing journal (6) that surrounds the output shaft (2) or the revolving drum shaft (3) is arranged coaxially with respect to the revolving drum axis (4), on which bearing journal a hub (10) is rotatably mounted by means of at least one hydrostatic bearing (11), the hub being connected to the output shaft (2) or the revolving drum shaft (3) for conjoint rotation therewith, and having a receptacle for the coaxial fastening of the revolving drum (20) surrounding the hub (10).

Description

[0001] ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03

[0002] Drum assembly for a tire test stand and device for grinding the

[0003] Outer circumferential surface of the drum

[0004] The invention relates to a drum assembly for a tire test stand with a drum rotatably driven about a drum axis from the output shaft or a drum shaft of a rotary drive.

[0005] Furthermore, the invention relates to a device for grinding the outer circumferential surface of the running drum.

[0006] In such a running drum arrangement for a tire test stand, it is known to arrange the running drum on a running drum shaft which can be connected to the output shaft of the rotary drive via a coupling, wherein the running drum shaft is rotatably mounted in bearings on both sides of the running drum.

[0007] If a road surface is permanently attached to the drum and measurements are to be taken on different road surfaces, the entire drum must be replaced. To avoid having to remove the bearings, the bearings and bearing housings remain on the drum. Electrical connections of the sensors on the bearing housings must be disconnected and reconnected during the drum replacement. The alignment of the drums to the measuring hub may need to be checked and corrected. The coupling between the output shaft of the rotary drive and the drum shaft must be removed. This may require axially shifting the rotary drive. This increases the time required and therefore the cost of replacing the drum.

[0008] The object of the invention is therefore to provide a drum assembly for a tire test stand of the type mentioned above, as well as a device for grinding the outer circumferential surface of the drum, which eliminates these disadvantages and, with a simple design, enables cost-effective drum replacement with backlash-free centering of the drum to the drum axis. ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03

[0009] This problem is solved according to the invention by arranging a stationary bearing journal coaxially to the drum axis, enclosing the output shaft or the drum shaft, on which a hub is rotatably mounted by means of at least one hydrostatic bearing, which is non-rotatably connected to the output shaft or the drum shaft and which has a receptacle for coaxial fastening of the drum enclosing the hub.

[0010] This design according to the invention eliminates the need for bearings and bearing housings for the drum shaft and separate sensors for each drum.

[0011] Changing the running drum without manually aligning the running drum is quick and easy.

[0012] The hydrostatic bearing with a relatively large diameter allows for high radial forces.

[0013] Angular compensation of the drum bearing is not required, as the two bearing components are each housed in a separate part (bearing journal and hub). The bearing journal is sufficiently rigid, so no deflection needs to be taken into account.

[0014] For simple, backlash-free and quick-mounting centering of the running drum, the hub can have a radially outwardly projecting hub ring with which a radially inwardly projecting roller ring of the running drum can be connected coaxially to the running drum axis.

[0015] The hub ring and roller ring can be arranged parallel to each other and connected by means of an interlocking form connection, through which the roller ring can be aligned coaxially to the running drum axis.

[0016] If the hub ring has a coaxial, radially outwardly directed, radially circumferential first conical ring surface and the roller ring or a separate component has a coaxial, radially inwardly directed, radially circumferential corresponding second conical ring surface ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03, wherein the second conical ring surface encloses the first conical ring surface and the hub ring and roller ring can be axially connected to each other in a centered manner, then the drum is automatically centered during assembly.

[0017] In a simple way, the hub ring and roller ring can be axially connected to each other in a centered manner by means of a screw connection.

[0018] A backlash-free centering of the running drum can be achieved by having the first conical ring surface and / or the second conical ring surface have an excess.

[0019] Before the bolted joint is tightened, an axial gap remains in the joint's interface due to the excess material on the first and / or second conical ring surface. When the bolted joint is tightened, the preload force of the bolts closes this axial gap as the cones expand elastically.

[0020] The second conical surface of the roller ring is difficult to access with a machining tool. To make this second conical surface easier to manufacture (i.e., grind), a centering ring with the second conical surface, which can be manufactured separately, can be arranged coaxially between the hub ring and the roller ring.

[0021] To transmit the rotary motion of the output shaft to the hub, the output shaft or the drum shaft can be connected to the hub via a coaxial transmission piece.

[0022] If a coupling is arranged between the output shaft or drum shaft and the transmission piece, this results in easy assembly and disassembly of the drum. ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03

[0023] A device for grinding the outer circumferential surface of the running drum of the type described above can have a rotatably driven shaft and a radially outwardly projecting hub ring with which a radially inwardly projecting roller ring of the running drum can be connected coaxially to the running drum axis.

[0024] Grinding the outer circumferential surface of the running drum is therefore quick and easy to perform without manually aligning the running drum.

[0025] For simple, backlash-free and quick-mounting centering of the drum, the shaft can have a radially outwardly projecting hub ring with which a radially inwardly projecting roller ring of the drum can be connected coaxially to the drum axis.

[0026] The hub ring and roller ring can be arranged parallel to each other and connected by means of an interlocking form connection, through which the roller ring can be aligned coaxially to the shaft axis.

[0027] If the hub ring has a coaxial, radially outwardly directed, radially circumferential first conical ring surface and the roller ring or a separate component has a coaxial, radially inwardly directed, radially circumferential corresponding second conical ring surface, wherein the second conical ring surface encloses the first conical ring surface and the hub ring and roller ring can be axially connected to each other in a centered manner, then the centering of the running drum is automatically carried out during assembly.

[0028] In a simple way, the hub ring and roller ring can be axially connected to each other in a centered manner by means of a screw connection.

[0029] A backlash-free centering of the running drum can be achieved by having the first conical ring surface and / or the second conical ring surface have an excess.

[0030] Before the bolted joint is tightened, an axial gap remains in the joint's separation plane due to the excess material of the first conical ring surface and / or the second conical ring surface. When the bolted joint is tightened, the axial gap closes due to the preload force of the bolts, as the cones expand elastically. (ZF Friedrichshafen AG File 304943, Friedrichshafen, 2024-09-03)

[0031] The second conical surface of the roller ring is difficult to access with a machining tool. To make this second conical surface easier to manufacture (i.e., grind), a centering ring with the second conical surface, which can be manufactured separately, can be arranged coaxially between the hub ring and the roller ring.

[0032] An embodiment of the invention is shown in the drawing and is described in more detail below. The drawing shows:

[0033] Figure 1 shows a side view in longitudinal section of a tire test stand with a running drum.

[0034] Figure 2 shows a section of the tire test stand with a running drum according to Figure 1.

[0035] Figure 3 shows a section of a device for grinding the outer circumferential surface of a running drum.

[0036] The tire test stand of Figures 1 and 2 has an electric motor 1 as a rotary drive in a test stand housing 5, the output shaft 2 of which rotatably drives a coaxial drum shaft 3 about a drum axis 4 via a first coupling 8.

[0037] A tubular bearing journal 6, coaxial to the drum axis 4, is fixedly arranged on the test stand housing 5, through which the drum shaft 3 is guided and at its end protruding from the bearing journal 6 can be coupled to a coaxial transmission piece 9 via a second coupling 7.

[0038] The transmission piece 9 is in turn rotationally fixed to a hub 10, which is rotatably mounted on the bearing journal 6 by hydrostatic bearings 11 via two axially spaced lubricant pockets 13. ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03

[0039] Lubricant is continuously supplied to the hydrostatic bearings 11 via a pressure line 12 from a pump (not shown).

[0040] The transmission element 9 is rotatably mounted on a bearing sleeve 15, which surrounds the drum shaft 3 at a radial distance, above a pair of rolling bearings 14. The bearing sleeve 15 is supported on the side facing the electric motor by a support sleeve 16, which surrounds the drum shaft at a radial distance, against a stop 17 fixedly arranged on the drum shaft 3.

[0041] The hub 10 has in its central area a flange-like hub ring 18 projecting radially outwards, parallel to which a flange-like roller ring 19 of a running drum 20 enclosing the hub 10 is directed radially inwards.

[0042] The hub ring 18 and roller ring 19 are clamped against each other by axial screws 21.

[0043] The hub ring 18 has an outwardly facing, radially circumferential first conical ring surface 22, onto which a coaxially opposite, radially inwardly facing, radially circumferential second conical ring surface 24 of a centering ring 23 is partially pushed. The conical ring connection between the first conical ring surface 22 and the second conical ring surface 24 has an interference fit. The screws 21, via the roller ring 19, press the centering ring 23 with its second conical ring surface 24 axially onto the first conical ring surface 22 with preload, thereby centering the running drum 20 coaxially with the running drum axis 4.

[0044] To mount the running drum 20, it simply needs to be slid axially onto the hub 10 and connected to the hub ring 18 via the centering ring 23 and its roller ring 19 using the screws 21. The running drum 20 can be disassembled in the reverse manner, without the need to remove any further components.

[0045] Figure 3 shows a section of a device for grinding the outer circumferential surface of a running drum 20. A rotatably driven shaft 25, as shown in Figures 1 and 2, has a radially outwardly projecting hub ring 18' (ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03) to which the radially inwardly projecting roller ring 19 of the running drum 20 can be connected.

[0046] According to Figures 1 and 2, the hub ring 18' is provided with a first conical ring surface 22' which can be connected to the second conical ring surface 24 of the running drum 20 via the centering ring 23 and thus centered.

[0047] ZF Friedrichshafen AG File 304943

[0048] Friedrichshafen 2024-09-03

[0049] Reference mark

[0050] 1 electric motor

[0051] 2 Output shaft

[0052] 3. Running drum shaft

[0053] 4. Running drum axle

[0054] 5 test bench housings

[0055] 6 bearing journals

[0056] 7 second clutch

[0057] 8 first clutch

[0058] 9 Transfer piece

[0059] 10 hub

[0060] 11 hydrostatic bearings

[0061] 12 Pressure line

[0062] 13 Schmiermitteltaschen

[0063] 14 rolling bearings

[0064] 15 Bearing sleeve

[0065] 16 Support sleeve

[0066] 17 attacks

[0067] 18 hub ring

[0068] 18' hub ring

[0069] 19 roller ring

[0070] 20 running drum

[0071] 21 screws

[0072] 22 first cone surface

[0073] 22' first cone face

[0074] 23 Centering ring

[0075] 24 second cone surface

[0076] 25 wave

Claims

ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03 Patent claims 1. Drum assembly for a tire test stand with a drum assembly (20) rotatably driven about a drum assembly axis (4) from the output shaft (2) or a drum assembly shaft (3) of a rotary drive, characterized in that a fixed bearing journal (6) enclosing the output shaft (2) or the drum assembly shaft (3) is arranged coaxially to the drum assembly axis (4), on which a hub (10) is rotatably mounted by means of at least one hydrostatic bearing (11), which is non-rotatably connected to the output shaft (2) or the drum assembly shaft (3) and which has a receptacle for coaxial fastening of the drum assembly (20) enclosing the hub (10).

2. Drum assembly according to claim 1, characterized in that the hub (10) has a radially outwardly projecting hub ring (18) with which a radially inwardly projecting roller ring (19) of the drum (20) can be connected coaxially to the drum axis (4).

3. Running drum arrangement according to claim 1, characterized in that hub ring (18) and roller ring (19) are arranged parallel to each other and can be connected by means of an interlocking form connection, by which the roller ring (19) can be aligned coaxially to the running drum axis (4).

4. Drum assembly according to one of the preceding claims, characterized in that the hub ring (18) has a coaxial radially outwardly directed, radially circumferential first conical ring surface (22) and the roller ring (19) or a separate component has a coaxial radially inwardly directed, radially circumferential corresponding second conical ring surface (24), wherein the second conical ring surface (24) surrounds the first conical ring surface (22) and the hub ring (18) and roller ring (19) are axially connectable to each other in a centered manner.

5. Drum assembly according to claim 4, characterized in that hub ring (18) and roller ring (19) can be axially connected to each other in a centered manner by a screw connection (21). ZF Friedrichshafen AG File 304943 Friedrichshafen 2024-09-03 6. Drum assembly according to claim 4, characterized in that the first conical ring surface (22) and / or the second conical ring surface (24) have an oversize.

7. Drum assembly according to one of claims 4 to 6, characterized in that a centering ring (23) is arranged coaxially between the hub ring (18) and the roller ring (19), which has the second conical ring surface (24).

8. Drum assembly according to one of the preceding claims, characterized in that the output shaft (2) or the drum shaft (3) is connected to the hub (10) via a coaxial transmission piece (9).

9. Drum assembly according to claim 8, characterized in that a coupling (7) is arranged between the output shaft (2) or the drum shaft (3) and the transmission piece (9).

10. Device for grinding the outer circumferential surface of the running drum according to one of the preceding claims, characterized in that a rotatably driven shaft (25) has a radially outwardly projecting hub ring (18') with which a radially inwardly projecting roller ring (19) of the running drum (20) can be connected coaxially to the running drum axis (4).

Images