GB2266123A

GB2266123A - Dynamic monitoring apparatus for rail vehicle bearings

Info

Publication number: GB2266123A
Application number: GB9208393A
Authority: GB
Inventors: Keith Ebbrell
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-04-16
Filing date: 1992-04-16
Publication date: 1993-10-20
Also published as: GB9208393D0

Abstract

Apparatus for testing rail vehicle bearings comprises a rolling rail arrangement (20) by which a single axle wheel set, which consists of an axle (12) carrying a pair of rail wheels (14a, 14b) disposed inboard of respective bearings (10a, 10b) and which is dismounted from an associated rail vehicle, can be supported and rotated in its normal horizontal operational attitude. A first loading means (30a, 30b) enables a vertical load to be applied to the axle bearings (10a, 10b) when the wheel set is thus supported. Means (40) can also be included for applying a variable lateral load to the wheels (14a, 14b) of the wheel set under test. <IMAGE>

Description

DESCRIPTION DYNAMIC MONITORING APPARATUS FOR RAIL VEHICLE BEARINGS The present invention is concerned with an apparatus for use in the dynamic monitoring of rail vehicle wheel bearings and with a method of bearing monitoring using this apparatus.

Conventional rail vehicles, such as rail trucks, carriages, tankers and the like, have a plurality of pairs of solid metal wheels mounted rigidly on respective metal axles. A respective bearing is mounted at each end of the axle, outboard of the wheels and, when assembled in the rail vehicle, the vehicle load is transmitted to the axle and wheels via the bearings. Thus, these bearings are subjected to very heavy loads during use which, in time, can lead to bearing overheating and eventual bearing failure.

Such bearing failure can be catastrophic, leading in severe cases to major derailment incidents. The conventional means of testing rail vehicle is to position the whole vehicle on a "rolling road/rail" type of test apparatus. However, the latter type of apparatus is extremely expensive in view of the size of the vehicles involved and only publicly owned rail operations can usually afford same. Thus, the problem of bearing monitoring is particularly acute for private owners of rail vehicles who may not have the expensive facilities currently necessary for major servicing of their vehicles.

It is an object of the present invention to provide an apparatus and monitoring technique by which the condition of rail vehicle bearings can be checked relatively easily.

In accordance with a first aspect of the present invention, there is provided an apparatus for testing rail vehicle bearings, comprising rolling rail means by which a single axle wheel set, which consists of an axle carrying a pair of rail wheels disposed inboard of respective bearings and which is dismounted from an associated rail vehicle, can be supported and rotated in its normal horizontal operational attitude and a first loading means by which a vertical load can be applied to the axle bearings when the wheel set is thus supported.

Preferably, the vertical load is arranged to be established by means of one or more hydraulic or pneumatic cylinders disposed above said bearings when the wheel set is supported on said rolling rail means.

Advantageously, the apparatus includes a frame having a base portion carrying the rolling rail means, side portions, and an upper portion which connects the side portions, said one or more cylinders being supported by said upper portion of the frame.

Preferably, the rolling rail means comprises two pairs of drive wheels, each pair being adapted to rotatably support a respective one of the wheels of a wheel set under test. The four drive wheels are preferably carried by two parallel drive shafts journalled horizontally at the same height and coupled together for rotation at the same speed, for example by one or more toothed belts and pulleys. The drive shafts are coupled to a suitable rotary power source whereby the drive wheels, and hence a wheel set supported thereon, can be rotated at a selected speed.

In a further embodiment, means can also be included by applying a variable lateral load to the wheels of the wheel set under test. Preferably, this is accomplished using respective rollers which can be brought into forced rolling engagement with the outboard lateral side surfaces of the wheels. The load can again be generated by suitable power sources, such as hydraulic or pneumatic cylinders.

According to a second aspect of the invention, a technique for testing bearings using the above described apparatus comprises the steps of: (a) applying a light vertical load to the bearings of a wheel set under test which is supported rotatably on said rolling rail means; (b) rotating the axle up to a predetermined speed; (c) applying additional vertical loading to both bearings simultaneously; and (d) monitoring and logging the condition of the wheel bearings, for example by monitoring and logging shock pulse signals in said bearings.

In one embodiment, while maintaining the vertical loading, lateral loading is applied to the wheels in turn and shock pulse signals in the wheel bearings are again monitored and logged.

Monitoring of the wheel bearing shock pulse signals can be by any suitable means, for example a conventional shock pulse monitor.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings, in which: Fig.1 is a front elevation of one embodiment of a test apparatus in accordance with the present invention, with an axle and bearing assembly disposed therein for testing; and Fig.2 is a partial end elevation of the apparatus of Fig.1, again with the axle and bearing assembly disposed therein.

Unlike the known test apparatus, the present apparatus tests the bearings of each wheel set with the associated axle removed from the vehicle. The drawing shows a test being made on bearings 10a,10b of an axle 12 which has a pair of wheels 14a,14b disposed inboard of the bearings.

The test apparatus illustrated in the drawings comprises a support frame 16 in which there is mounted a drive assembly consisting of a pair of parallel, horizontal drive shafts 18a,18b, each of which carries a pair of bevelled drive wheels 20, the drive shafts being supported on the frame 16 by means of pairs of drive shaft support blocks 22 and bearing assemblies 24 disposed on each side of each drive wheel 20, respectively. The two drive shafts 18a,18b are connected together by drive pulleys 26a,26b and toothed belts 28a,28b so that they rotate together.

One of the drive shafts 18 is coupled to a means (not shown) for imparting rotation to these shafts from a rotary power source, for example a belt drive, hydraulic drive, power take off (PTO) or the like.

The longitudinal spacing of the drive wheels 20 on the drive shafts 18 is such that the wheels 14a, 14b of an axle to be tested rest on and are supported by the drive wheels, as shown in Figs. 1 and 2. The use of a pair of drive wheels 20 for each of the axle wheels 14 ensures that the axle set is supported in a stable manner, even when under rotation.

Attached to an upper part of the frame 16 are two double-acting hydraulic (or pneumatic) cylinders 30a, 30b whose pistons 32a, 32b extend downwardly and carry respective location pads 34a, 34b which are adapted to engage the housing of the two bearings 10a,10b in a manner such as to impart a downward load onto the bearings. Gauges 36 indicate the hydraulic pressures in the cylinders 30 and hence the bearing load which is applied. The downward load applied to the bearings 10 by way of the cylinders 30 can therefore be varied by adjusting the cylinder pressures. Obviously, when introducing or removing the axle from the test apparatus, the pistons 32a, 32b are withdrawn upwardly to lie well clear of the bearings 10.

In addition to the above described means for applying selected vertical loads to the axle bearings, the apparatus can include means for selectively applying lateral side pressures to the wheels. In the illustrated embodiment, the latter means comprises a pair of rollers 38a, 38b which are adapted to be displaced horizontally by respective hydraulic or pneumatic cylinders 40a, 40b so as to engage with the outer side surfaces 42a, 42b of the wheels.

As evident from the drawings, the rollers 38a, 38b contact the respective parts of the wheels 14a, 14b with a rolling engagement therebetween when they are applied to the wheels and the wheels are being rotated with the axle 12 by the power source (not shown) and drive shafts 18.

A dynamic test on the bearings 10a,10b using the above described apparatus is conducted as follows.

The single axle wheel set 10a, 10b,12,14a,14b is first removed from the associated vehicle and uplifted onto the drive wheels 20 (the latter wheels 20 can be selectively displaced on the shafts 18 to accommodate any variation in the sizes of wheel gauge encountered in practice). The vertical pressure pistons 32a, 32b are then lowered by the cylinders 30a, 30b so as to bring the location pads 34a, 34b into light engagement with the bearing boxes 10a,10b. Rotation of the wheel set is then initiated by rotation of the drive shafts 18 from the power source (not shown). On reaching a desired wheel speed (r.p.m.), the pistons 32a, 32b are lowered further so as slowly and evenly to apply an increasing vertical load to the bearings 10a,10b up to a predetermined test loading. The operational condition of the bearings is now monitored and logged using suitable apparatus (not shown).The basic test made on the bearings is to monitor the shock pulses emitted by the bearing. Standard devices are known for this purpose. However, the present invention is not limited to the use of such test equipment and any suitable bearing monitoring equipment may be employed.

If a lateral test is also to be made (optional) then, keeping the vertical loading on the wheels, the other rollers 38a, 38b are moved against the wheels 14a,14b so as to apply a predetermined lateral test loading. One wheel 14 is loaded first, and the bearings 10 are monitored and the readings and logged.

The side loading on the one wheel is then removed and the opposite wheel loaded to the same loading, for example using a hydraulic converter. The bearings are again monitored and logged.

The side loading on the wheels is then removed and the drive system disengaged. The vertical loading can remain during this stage in order to assist in braking the wheel set to a halt. Finally, the vertical loading is removed and the wheel set retrieved from the frame to complete the test cycle.

The above described test equipment enables rail bearings to be tested under realistic loaded conditions with the wheels sets removed from the vehicle itself. Thus, the test equipment does not have to accommodate the weight of the vehicle itself, which can be substantial. For example, a typical vehicle axle weight may be up to twentyfour tons. A corresponding vertical loading can easily be applied by way of the cylinders 30 to simulate full operational loading.

Claims

1. An apparatus for testing rail vehicle bearings, comprising rolling rail means by which a single axle wheel set, which consists of an axle carrying a pair of rail wheels disposed inboard of respective bearings and which is dismounted from an associated rail vehicle, can be supported and rotated in its normal horizontal operational attitude and a first loading means by which a vertical load can be applied to the axle bearings when the wheel set is thus supported.

2. An apparatus as claimed in claim 1, including one or more hydraulic or pneumatic cylinders disposed above said bearings, when the wheel set is supported on said rolling rail means, for establishing said vertical load.

3. An apparatus as claimed in claim 2, which includes a frame having a base portion carrying the rolling rail means, side portions, and an upper portion which connects the side portions, said one or more cylinders being supported by said upper portion of the frame.

4. An apparatus as claimed in claim 1, 2 or 3, wherein the rolling rail means comprises two pairs of drive wheels, each pair being adapted to rotatably support a respective one of the wheels of a wheel set under test.

5. An apparatus as claimed in claim 4, wherein the four drive wheels are carried by two parallel drive shafts journalled horizontally at the same height and coupled together for rotation at the same speed.

6. An apparatus as claimed in claim 5, wherein the two parallel drive shafts are coupled together by one or more toothed belts and pulleys.

7. An apparatus as claimed in claim 5 or 6, wherein the drive shafts are coupled to a rotary power source whereby the drive wheels, and hence a wheel set supported thereon, can be rotated at a selected speed.

8. An apparatus as claimed in any of claims 1 to 7, including means for applying a variable lateral load to the wheels of the wheel set under test.

9. An apparatus as claimed in claim 8, wherein said variable lateral loading is achieved by the provision of respective rollers which can be brought into forced rolling engagement with the outboard lateral side surfaces of the wheels.

10. An apparatus as claimed in claim 9, wherein said variable lateral load is generated by a hydraulic or pneumatic cylinder.

11. A method for testing bearing using the apparatus of claim 1, comprising the steps of: (a) applying a light vertical load to the bearings of a wheel set under test which is supported rotatably on said rolling rail means; (b) rotating the axle up to a predetermined speed; (c) applying additional vertical loading to both bearings simultaneously; and (d) monitoring and logging the condition of the wheel bearings such as by monitoring and logging shock pulse signals in said bearings.

12. A method as claimed in claim 11, wherein the monitoring and logging step comprises monitoring and logging shock pulse signals in said bearings.

13. A method as claimed in claim 12, wherein, while maintaining the vertical loading, lateral loading is applied to the wheels in turn and shock pulse signals in the wheel bearings are again monitored and logged.

14. A method as claimed in claim 13, wherein monitoring of the wheel bearing shock pulse signals is effected using a conventional shock pulse monitor.

15. An apparatus for testing rail vehicle bearings, substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.

16. A method for testing rail vehicle bearings, substantially as hereinbefore described with reference to the accompanying drawings.