TOOL AND METHOD FOR EXTRACTING A SENSOR UNIT FROM A BEARING RING

Abstract

The invention provides a tool and a method for extracting a sensor body clipped to a first ring of a bearing. The sensor body includes engaging portions provided on a first radial edge thereof, and a second radial edge opposite to the first radial edge. The sensor body is configured to be mounted such that a circular gap is formed between the second radial edge and a component configured to be in relation with the first ring. The tool includes a plurality of hooks configured to be inserted into the gap and to reach under the second radial edge.

Claims

1. A tool for extracting a sensor body clipped to a first ring of a bearing, the sensor body including engaging portions disposed on a first radial edge thereof, and a second radial edge opposite to the first radial edge, the sensor body being configured to be mounted such that a circular gap is formed between the second radial edge and a component configured to be in relation with the first ring, the tool comprising: a plurality of hooks configured to be inserted into the gap and to reach under the second radial edge.

2. The tool according to claim 1, wherein the hooks are configured to be deflected in a radial direction away from the second radial edge while being inserted and to snap under the second radial edge upon reaching a predetermined axial position.

3. The tool according to claim 2, wherein the predetermined axial position is set such that it is reached before or at the axial position where a stop portion of a tool body of the tool comes into axial stop against the first ring.

4. The tool according to claim 2, wherein the hooks are provided with inclined axial end surfaces configured to radially deflect the hooks when the axial end surfaces come in contact with the sensor body upon inserting the tool into the gap.

5. The tool according to claim 2, wherein the hooks are made of flexible material.

6. The tool according to claim 5, wherein end portions of the hooks configured to reach under the edge are provided with reinforcing metal inserts.

7. The tool according to claim 2, wherein the hooks are pivotally mounted on the tool body and loaded with a spring radial direction toward the second radial edge.

8. The tool according to claim 1, further comprising: a. a tool body having a stop portion configured to come into axial stop against the first ring of the bearing; and b. a centering portion configured to center the tool body relative to the component configured to rotate in relation to the first ring.

9. The tool according to claim 1, further comprising means for manually releasing the hooks from the second radial edge.

10. The tool according to claim 1, wherein the component configured to rotate in relation to the first ring is a shaft, and wherein the first ring is an outer ring of the bearing.

11. The tool according to claim 9, wherein an inner ring of the bearing is mounted in the shaft.

12. The tool according to claim 1, further comprising providing an attachment portion on an axial side opposite to the stop portion, wherein the attachment portion is configured to be attached to a bearing extractor.

13. A method for extracting a sensor body clipped to a first ring of a bearing, the sensor body including a plurality of clips disposed on a first radial edge thereof, and a second radial edge opposite to the first radial edge, the sensor body configured to be mounted such that a circular gap is formed between the second radial edge and a component configured to rotate in relation to the first ring, wherein the method comprises: providing a tool having a plurality of hooks configured to be inserted into the gap and to reach under the second radial edge, inserting the hooks into the gap until the hooks engage with the second radial edge, and extracting the sensor body by pulling the tool in a direction opposite to the insertion direction.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0026] FIG. 1 illustrates a sensor body clipped to a first ring of a bearing;

[0027] FIG. 2 is a perspective view of a tool according to the invention;

[0028] FIG. 3 is a sectional view of the tool according to FIG. 1;

[0029] FIG. 4 illustrates a configuration where the tool is inserted halfway into a gap;

[0030] FIG. 5 illustrates a configuration where the tool is fully inserted into the gap;

[0031] FIG. 6 is a second embodiment of the invention where the hooks are made of flexible material and formed as one piece with the tool body;

[0032] FIG. 7 illustrates a third embodiment of the invention wherein end portions of the hooks configured to reach under the edge are provided with reinforcing metal inserts; and

[0033] FIGS. 8a and 8c illustrate a method for clipping a new sensor body using a tool according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] FIG. 1 illustrates a sensor body 10 clipped to a first ring 12 formed as an outer ring of a bearing. The sensor body 10 includes a plurality of clips 14 provided on a first radial edge 18a thereof. The clips 14 are axial protrusions of a cover member 38 of the sensor body 10. The cover member 38 is a stamped sheet-metal piece. The clips 14 engage with a circular groove 16 or recess with undercut in the outer ring 12 of the bearing. A second radial edge 20 of the sensor body 10 opposite to the first radial edge 18 includes a cylindrical inner surface 20a. When the bearing equipped with the sensor body 10 is mounted on a shaft 22 of an electric motor or generator as shown in FIG. 1, the cylindrical inner surface 209 on the second radial edge 20 forms a circular gap is formed between the second radial edge 20 and the shaft 22.

[0035] The outer ring 12 of the bearing is fitted into a motor housing 26 and fixed therein by suitable means. An inner ring 28 of the bearing is fitted over the shaft 22.

[0036] A magnetic encoder ring 30 is attached to the inner ring 28 of the bearing and the sensor body 10 includes Hall cells or other magnetic sensors (not shown) detecting an oscillating magnetic field generated by the passing magnetic poles of the encoder ring 30 when the shaft 22 is rotating.

[0037] FIG. 2 is a perspective view of a tool 32 according to the invention and FIG. 3 is a sectional view thereof.

[0038] The tool 32 includes a main body 34 and plurality of hooks 36 protruding from a radially inner edge of a lower axial surface 37 of the main body 34. The hooks 36 are configured to be inserted into the gap 24 between the shaft 22 and the sensor body 10 and are long enough to reach under the second radial edge 20 of the sensor body 10, more specifically under the axially lower edge of the cylindrical inner surface 20a of the cover member 38 of the sensor unit 10.

[0039] Optionally, the tool 32 may include means for manually releasing the hooks 36 from the sensor body 10, for example rods guided in radial bores as shown in dashed lines in FIG. 3.

[0040] FIG. 4 illustrates a configuration where the tool 32 is inserted halfway into the gap 24 between the shaft 22 and the sensor body 10. The upper edge of the cylindrical inner surface 20a of the sensor body 10 is rounded such that the hooks 36 are deflected radially inward in a radial direction away from the second radial edge 20 while being inserted. In alternative embodiments, the hooks 36 might be provided with inclined axial end surfaces configured to radially deflect the hooks 36 when the axial end surfaces come in contact with the sensor body 10 upon inserting the tool into the gap 24.

[0041] A radially inner surface of the tool body 34 fits precisely over the shaft 22 and therefore serves as a centering portion that is configured to center the tool body 34 relative to the shaft.

[0042] FIG. 5 illustrates a configuration where the tool 32 is fully inserted into the gap 24 between the shaft 22 and the sensor body 10 such that the hooks 36 snap under the second radial edge 20. At the same time, a stop portion of the tool body 34 formed as a set of protruding supports 40 comes into axial stop against the first ring 12.

[0043] The tool body 34 includes an attachment portion 42 on an axial side opposite to the stop portion 40, i.e. on the upper surface in FIGS. 4 and 5, wherein the attachment portion 42 has an undercut configured to be attached to a bearing extractor (not illustrated). The dimensions of the undercut recess correspond to those of standard bearings such that a standard bearing extractor can be used.

[0044] Thanks to the attachment portion 42, the tool according to the invention can be combined with any existing bearing extractor. This tooling removes the sensor body 10 without damaging the bearing and the impulse ring 30. The extraction effort is below 100N such that it can be applied trough the bearing ball set.

[0045] In the embodiment of FIGS. 4 and 5, the hooks 36 are pivotably mounted on the tool body 34 and loaded with a spring in a radial direction toward the second radial edge 20.

[0046] FIG. 6 is a second embodiment of the toll 32 according to the invention where the hooks 36 are made of flexible material and formed as one piece with the tool body 34.

[0047] FIG. 7 illustrates a third embodiment of the invention wherein end portions of the hooks 36 configured to reach under the second radial edge 18 are provided with reinforcing metal inserts 44.

[0048] When the failed sensor body 10 is removed, the new one can be clipped. The force requires for clipping is between 500 and 1000N. Consequently this force cannot through the ball set. The force has to come from the motor flange, or can be applied manually.

[0049] A method for clipping a new sensor body using a tool according to the invention is illustrated in FIGS. 8a-8b. The sensor body 10 is centered on its inner diameter in the tool 32 (cf. FIG. 8a). Then the tool 32 is centered on the rotor shaft 22 (FIG. 8b). The tool 32 is provided with five sector-shaped supports as stop portions 40, providing the accurate axial placement of the sensor body 10 (FIG. 8c). The tool 32 is then released by a suitable mechanism deflecting the hooks 36 radially inward.

[0050] The sequence of FIGS. 4 and 5 illustrates a method for extracting a sensor body 10 clipped to the outer ring 12 of a bearing as described above.

[0051] The method includes using a tool 32 as described above, wherein the hooks 36 are inserted into the gap 24 until the hooks engage with the second radial edge 20, and extracting the sensor body 10 by pulling the tool 32 in a direction opposite to the insertion direction.