GB2399872A

GB2399872A - Roller with recesses to drain liquid from bearing

Info

Publication number: GB2399872A
Application number: GB0405887A
Authority: GB
Inventors: Manfred Brandenstein; Wolfgang Hublein
Original assignee: SKF AB
Current assignee: SKF AB
Priority date: 2003-03-26
Filing date: 2004-03-16
Publication date: 2004-09-29
Anticipated expiration: 2024-03-16
Also published as: GB0405887D0; GB2399872B; FR2852888B1; ITTO20040081A1; DE20304991U1; FR2852888A1

Abstract

A roller has recesses in an axial end of the roll, which are connected to a free space adjacent the bearing. This arrangement allows liquid to drain from the vicinity of the bearing. The roll can be used in a washing installation having at least one washing device movable on a rail, because it is desirable to allow soap solution or water to drain away from the bearing. The recesses may be uniformly spaced, and may be in the form of bores.

Description

ROLLER

The invention relates to a roller having a rolling circumference and having a bearing for the rotatable mounting of the rolling circumference relative to an axle.

Rollers have manifold uses and are known in a plurality of different designs. As a rule, a roller has a peripheral roller circumference or shell, having a cylindrical surface, which is mounted rotatably relative to an axis by means of a bearing. A roller of this type is known, for example, from US 4,668,209. In the known roller the rolling circumference is made from plastics material using an injection-moulding process. The axial end faces of the rolling circumference have a series of recesses which, for reasons associated with injection technology, are separated from one another by webs of different thickness in a peripheral direction.

EP 0 928 276 B1 further discloses an idler roller whose rolling circumference has an outer rim which is connected via radially extending ribs to a hub arranged radially inside the outer rim. In one example of embodiment, the ribs have the special feature that they are provided with a respective central recess which extends in an axial direction. The recesses are intended to ensure symmetrical deformation of the ribs in the event of radial compression of the outer rim.

In view of the multiple application sectors of rollers, it also happens that the bearing of the bearing of the roller is exposed externally to liquid. In applications of this type a seal is provided to protect the bearing, which 2 - seals the interior of the bearing from the environment and thus also from the liquid to which the bearing is exposed.

However, it has been found that sometimes, despite the seal, liquid penetrates into the bearing and causes damage thereto.

The invention is based on the object of reducing the ingress of liquid into the bearing or bearings of a roller.

This object is achieved by the feature combination of Claim 1.

The roller according to the invention is provided with a rolling circumference and a bearing for the rotatable mounting of the rolling circumference relative to an axle.

The rolling circumference has a plurality of recesses which are open to the environment and which are arranged uniformly in peripheral direction. A special feature of the roller according to the invention is that the recesses are connected to a free space adjacent the bearing so that any liquid to which the bearing is exposed externally can drain via the recesses.

The invention has the advantage that the accumulation of a large amount of liquid, to which the bearing is exposed from the outside, is effectively prevented and thereby the danger of the ingress of liquid into the bearing can be considerably reduced.

The recesses are preferably open in axial direction towards the environment. In this way the draining of liquid away from the bearing can take place reliably. In a - 3 - preferred example of embodiment the recesses are designed so that they overlap radially and/or axially with the free space. This has the advantage that, without additional measures and solely as a result of the overlapping, a connection is already provided between the recesses and the free space, or a such a connection can be provided at a little additional cost. Liquid can drain away from a region adjacent the bearing through the connections (i.e. the connections act as passages). In particular, the recesses can take the form of bores.

As a rule, the bearing is sealed from the environment by at least one seal. The bearing may take the form of a rolling bearing, in particular a two-row ball bearing.

It is especially advantageous if the rolling circumference serves as a transducer ring for a sensor device. In this case the recesses can serve as marks which are detected by the sensor device. A transducer ring integrated into the rolling circumference in this way has the advantage that it is very robust and is very well protected from damage by external influences.

The rolling circumference can be designed so that it has a peripheral radial groove on its outer circumferential surface. In this way be a guide can provided for the roller by means of a rail.

The roller according to the invention is intended, for example, for use in a washing installation with at least one washing device movable on rails. It is advantageous that the possibility of draining water via the recesses is assured - 4 even during the frequently occurring rest phases of the roller.

The invention further relates to a system comprising a roller and a sensor device disposed adjacent the roller. The roller is provided with a rolling circumference and a bearing for the rotatable mounting of the rolling circumference relative to an axle. The system according to the invention is distinguished in that the rolling circumference has a plurality of recesses open towards the environment, which are arranged uniformly in peripheral direction and serve as marks which can be detected by the sensor device.

The invention will be described in more detail with reference to the exemplified embodiment illustrated in the drawings, wherein: Figure 1 shows an exemplified embodiment of the system according to the invention, comprising a roller and a sensor device disposed adjacent to the roller, in a sectional view, and Figure 2 shows the exemplified embodiment of Figure 1 in a side view.

Figure 1 shows an exemplified embodiment of the system according to the invention, comprising a roller 1 and a sensor device 2 disposed adjacent the roller 1. An associated side view is illustrated in Figure 2. The roller 1 has a rolling circumferences and a two-row ball bearing 4 having a first inner ring 5, a second inner ring 6 axially adjacent the first inner ring 5, a common outer ring 7, as - 5 - well as a first set 8 and a second set 9 of balls. The balls 8 and 9 are guided by a first cage 10 and a second cage 11.

The ball bearing 4 is sealed in its axial end zones by a first seal 12 and a second seal 13.

The rolling circumference 3 is as a rule made from metal and is preferably hardened. In applications in which the roller 1 is only loaded to a very small extent, the rolling circumference 3 may also be made from a plastics material. On its outer circumferential surface the rolling circumferences has a peripheral radial groove 4, in which a rail 15 engages. One of the axial end faces of the rolling circumferences is provided with bores 16 which extend in an axial direction and are arranged at equal distances apart in the peripheral direction of the rolling circumferences. The centres of the bores 16 are disposed on the same radius as the centre of the sensor device 2. On the axial side of the roller 1, on which the bores 16 are arranged, an annular free space 17 axially adjoins the ball bearing 4 and it overlaps the bores 16 in axial direction and in radial direction so that a respective communication 18 is formed between the free space 17 and the bores 16.

The inner rings 5 and 6 are pressed on to a stepped axle 19 so that the first inner ring abuts axially against a shoulder 20 of the axle 19. The second inner ring 6 is located axially by a spacer sleeve 21. The outer ring 7 is pressed into the rolling circumferences and is secured axially by a shoulder 22 of the rolling circumferences and an adjusting spring 23. The axle 19 is screwed by means of two nuts 24 to a mounting 25, to which the sensor device 2 is also screwed by means of a further nut 26. 6 -

By means of the arrangement described above it is possible, for example, to move along the rail 15 a washing device of a washing installation, which is secured to the mounting 25 but is not shown in the drawings. For this purpose, a plurality of the roller assemblies illustrated in Figures 1 and 2 are mounted on the washing device and in addition there is provided a plurality of parallel extending rails 15. Flanges on either side of the cylindrical surface retain the rolling circumference 3 to the rail 15. During the movement of the washing device the rolling circumference 3 rotates relative to the rigid axle 19 so that the bores 16 move past the sensor device 2 and so that the bores 16 act as marks which can be detected by the sensor device 2. The sensor device 2 can detect the movement of the roller 1 and thus the movement and position of the washing device by way of this movement of the bores 16.

During the washing operation the cleaning or rinsing liquid used, for example soap solution or water, can enter the region of the free space 17 and the first seal 12 of the ball bearing 4 is exposed thereto from the outside. In this event it is especially important for the invention that the liquid does not remain in the free space 17 but can drain via the communications 18 into the bores 16 and from there to the environment. This is particularly important when the roller 1 is at a standstill since, otherwise, the liquid would be trapped in the lower region of the free space 17 and the adjacent peripheral zone of the first seal 12 would thus be permanently exposed thereto. Despite a very low leakage rate of the first seal 12, in the course of time this would result in an ingress of liquid into the interior of the ball bearing 4 and cause corresponding damage.

However, because of the communications 18 precisely in this lower region of the free space 17 it is ensured that any liquid present can drain via the bores 16 to the environment. Even if the leakage rate of the first seal 12 in the new condition is negligible, in the course of time it would be increased by permanent exposure to the liquid and ultimately would result in a perceptible leak. - 8 -

Claims

1. A roller with a rolling circumference and a bearing for the rotatable mounting of the rolling circumference relative to an axle, wherein the rolling circumference has a plurality of recesses which are open to the environment, and wherein the recesses are connected to a free space adjacent the bearing so that liquid to which the bearing is exposed can drain via the recesses.

2. A roller according to claim 1, wherein the recesses are arranged uniformly about the rolling circumference.

3. A roller according to claim 1 or 2, wherein the recesses are open in an axial direction towards the environment.

4. A roller according to any one of the preceding claims, wherein the recesses overlap radially and/or axially with the free space.

5. A roller according to any one of the preceding claims, wherein the recesses are in the form of bores.

6. A roller according to any one of the preceding claims, wherein the bearing is sealed from the environment by at least one seal.

7. A roller according to any one of the preceding claims, wherein the bearing is in the form of a rolling bearing, in particular a two-row ball bearing. - 9

8. A roller according to any one of the preceding claims, comprising a sensor device operable to detect, via the recesses, rotation of the rolling circumference.

9. A roller according to any one of the preceding claims, wherein the rolling circumference has a peripheral radial groove on its outer circumferential surface.

10. A roller according to any one of the preceding claims, wherein the rolling circumference is made from metal and is preferably hardened.

11. A roller according to any one of the preceding claims, comprising an axle.

12. A washing installation having at least one washing device moveable on a rail, comprising a roller according to any one of the preceding claims.

13. A roller as hereinbefore described and/or with reference to the Figure.

A washing installation as hereinbefore described.