Abrasion-resistant and hydrolysis-resistant encoder, bearing unit with encoder and method for producing the encoder

Abstract

Encoder for bearing units are disclosed, as well as methods of making the encoders. In one example, an encoder includes a magnet part including a material which comprises polyketone and at least one magnetic filler. In an example method, an insert part is introduced into a mold, wherein the insert part is a support part, a metal foil or a metal-coated foil. The mold is closed and a melt is injected into the closed mold, wherein the melt includes a material which comprises polyketone and at least one magnetic filler. The melt may then be cooled, wherein the insert part joins with the melt to form the encoder.

Claims

1. An encoder for bearing unit, comprising: an encoder including a magnet part including a material which comprises polyketone and at least one magnetic filler.

2. The encoder as claimed in claim 1, wherein the at least one magnetic filler comprises hard ferrites, iron, iron-containing compounds, or rare earth elements, or a combination of these fillers.

3. The encoder as claimed in claim 1, wherein a fraction of the filler is 70 to 95 wt % of the material.

4. The encoder as claimed in claim 1, wherein a metal foil, a metal-coated foil, or a metal coating is disposed or applied on the magnet part or an adhesion promoter is disposed between the metal foil, the metal-coated foil or the metal coating and the magnet part.

5. The encoder as claimed in claim 1, wherein the encoder comprises a support part, wherein the magnet part is applied on the support part or wherein an adhesion promoter is disposed between the support part and the magnet part.

6. A bearing unit comprising an encoder as claimed in claim 1.

7. A method for producing an encoder for bearing units, comprising the following steps: introducing an insert part into a mold, wherein the insert part is a support part, a metal foil or a metal-coated foil, closing the mold, injecting a melt into the closed mold, wherein the melt includes a material which comprises polyketone and at least one magnetic filler, and cooling the melt, wherein the insert part joins with the melt to form the encoder.

8-10. (canceled)

11. The method of claim 7, wherein the insert part is a support part and the support part is pretreated mechanically or by phosphating.

12. The method of claim 7, wherein the insert part is a support part and an adhesion promoter is provided on the support part.

13. An encoder for bearing unit, comprising: a magnet part including a material which comprises polyketone and at least one magnetic filler; and a support part; wherein the magnet part is applied on the support part or wherein an adhesion promoter is disposed between the support part and the magnet part.

14. The encoder as claimed in claim 13, wherein the at least one magnetic filler comprises hard ferrites, iron, iron-containing compounds, or rare earth elements, or a combination of these fillers.

15. The encoder as claimed in claim 13, wherein a fraction of the filler is 70 to 95 wt % of the material.

16. The encoder as claimed in claim 13, wherein a metal foil, a metal-coated foil, or a metal coating is disposed or applied on the magnet part or an adhesion promoter is disposed between the metal foil, the metal-coated foil or the metal coating and the magnet part.

17. A bearing unit comprising an encoder as claimed in claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The disclosure is now illustrated by way of example using figures, wherein:

[0055] FIG. 1 to FIG. 7 show example encoders of the disclosure,

[0056] FIG. 8 shows a bearing unit with an example encoder,

[0057] FIG. 9 shows an alternative bearing unit with an example encoder,

[0058] FIG. 10a to 10e show an example production method for an example encoder,

[0059] FIG. 11a to 11d show an alternative production method for an example encoder,

[0060] FIG. 12a to 12d show an alternative production method for an example encoder, and

[0061] FIG. 13a to 13e show a further alternative production method for an example encoder.

DETAILED DESCRIPTION

[0062] FIG. 1 to FIG. 7 show example embodiments. The disclosure is not confined to these embodiments. The encoder 1 shown in FIG. 1 to FIG. 7 comprises a magnet part 3. The magnet part 3 includes a material which comprises polyketone and at least one magnetic filler. The filler contains ferrite, iron, iron-containing compounds, or elements of the rare earths, or a combination of these fillers. The fraction of the filler is in the range from 70 to 95 wt % of the material. The encoder is annular in form.

[0063] In FIG. 1 the encoder 1 comprises a support part 2, a magnet part 3, and an adhesion promoter 7. The adhesion promoter 7 is disposed between the support part 2 and the magnet part 3. The support part 2 has an L-shaped cross section. The adhesion promoter 7 is a primer and in particular may also be an adhesion promoter foil. The support part 2, the magnet part 3 and/or the adhesion promoter 7 may be applied in a two-component injection molding process.

[0064] In FIG. 2 the encoder 1 has a support part 2 and a magnet part 3. The magnet part 3 bears flat against one side of the support part 2. The support part 2 has an L-shaped cross section. The support part 2 and/or the magnet part 3 may be applied in a two-component injection molding process.

[0065] In FIG. 3 the encoder 1 has a magnet part 3 and a metal foil 4. The metal foil 4 bears flatly against one side of the magnet part 3. The magnet part 3 has an L-shaped cross section.

[0066] In FIG. 4, the encoder 1 has a magnet part 3, a metal foil 4, and an adhesion promoter 7. The adhesion promoter 7 is disposed between the metal foil 4 and the magnet part 3. The magnet part 3 has an L-shaped cross section.

[0067] In FIG. 5 the encoder 1 has a magnet part 3 and a metal coating 6. The metal coating 6 bears flatly against one side of the magnet part 3. The magnet part 3 has an L-shaped cross section.

[0068] In FIG. 6 the encoder 1 comprises a magnet part 3, an adhesion promoter 7, and a metal-coated foil 5. The metal-coated foil 5 lies between the adhesion promoter 7 and the magnet part 3. The magnet part 3 has an L-shaped cross section.

[0069] In FIG. 7 the encoder 1 comprises a magnet part 3, an adhesion promoter 7, and a metal-coated foil 5. The adhesion promoter 7 lies between the metal-coated foil 5 and the magnet part 3. The magnet part 3 has an L-shaped cross section.

[0070] In addition to the encoders shown in FIG. 1 to FIG. 7, further dispositions of the individual components are also conceivable.

[0071] FIG. 8 shows the bearing unit 10. The bearing unit 10 comprises two bearing rings 11, 12, disposed radially one above the other, and rolling elements 13 revolving between them. Additionally, the bearing unit 10 has an encoder 1, which is formed of a support part 2 and a magnet part 3. The encoder 1 is disposed between the bearing rings 11, 12.

[0072] FIG. 9 shows an alternative bearing unit 10. The bearing unit 10 comprises two bearing rings 11, 12, disposed radially one above the other, and rolling elements 13 revolving between them. Additionally, the bearing unit 10 has an encoder 1, which is formed of a magnet part 3 and an adhesion promoter 7. The encoder 1 is adhered on a first bearing ring 11, e.g., the outer ring, without provision of a metal support sheet.

[0073] Alternatively, the encoder may also be injection-molded onto the first bearing ring 11. Application to the bearing ring 11 by injection molding may take place with or without adhesion promoter.

[0074] FIG. 10a to FIG. 13e show example embodiments. The disclosure is not confined to these embodiments. The encoders produced by the methods all comprise a magnet part including a material which comprises polyketone and at least one magnetic filler.

[0075] FIG. 10a to 10e show a first production method for an example encoder 1. The production method is a one-component injection molding process.

[0076] The first method for producing the encoder 1 for bearing units 15 comprises the following steps: [0077] introducing an insert part into a mold 20, where the insert part is a support part 2, [0078] injecting a melt 30 into the closed mold 20, where the melt 30 includes a material which comprises polyketone and at least one magnetic filler, and [0079] cooling the melt 30, where the support part 2 joins with the melt 30 to form the encoder 1.

[0080] The support part 2 here may have been pretreated mechanically or by phosphating. Furthermore, an adhesion promoter may also be provided on the support part 2. The melt 30 is injected under the action of pressure. After cooling has taken place, the encoder 1 can be ejected or removed from the mold 20. The mold 20 in this case is part of an injection molding machine.

[0081] FIG. 11a to 11d show a second production method for an inventive encoder 1. The production method is a two-component injection molding process.

[0082] The second method for producing the encoder 1 for bearing units 15 comprises the following steps: [0083] introducing an insert part into a mold 20, where the insert part is a support part 2, [0084] injecting a first component 25 into the mold 20, where the first component 25 is an adhesion promoter, [0085] cooling the first component 25, where the first component 25 joins with the support part 2, [0086] injecting a second component 26 into the mold 20, where the second component 26 includes a material which comprises polyketone and at least one magnetic filler, and [0087] cooling the second component 26, where the second component 26 joins with the first component 25 and in this way the encoder 1 is formed.

[0088] The support part 2 here may have been pretreated mechanically or by phosphating. The first component 25 and the second component 26 are injected under the action of pressure. Both components are flowable, and preferably are melts. After cooling has taken place, the encoder 1 can be ejected or removed from the mold 20. The mold 20, the first device 21, and the second device 22 here are parts of an injection molding machine.

[0089] FIG. 12a to 12d show a third production method for an inventive encoder 1. The production method is an in-mold foil coating process.

[0090] The third method for producing the encoder 1 for bearing units 15 comprises the following steps: [0091] introducing an insert part into a mold 20, where the insert part is a metal foil 4, [0092] injecting a melt 30 into the mold 20, where the melt 30 includes a material which comprises polyketone and at least one magnetic filler, and [0093] compressing the melt 30, where the melt 30 joins with the metal foil 4 to form the encoder 1 on cooling of the melt 30.

[0094] Furthermore, there may also be an adhesion promoter provided on the metal foil 4. When the mold 20 is pressed together, the metal foil 4 inserted into the mold 20 is embossed in correspondence with the shape of the mold 20. The melt 30 is injected under the action of pressure. After cooling has taken place, the encoder 1 can be ejected or removed from the mold 20. The mold 20, the first device 21, and the second device 22 here are parts of an injection molding machine.

[0095] FIG. 13a to 13e show a fourth production method for an inventive encoder 1. The production method is an injection-compression molding process.

[0096] The fourth method for producing the encoder 1 for bearing units 15 comprises the following steps: [0097] introducing an insert part into a mold 20, where the insert part is a support part 2, [0098] injecting a melt 30 into a mold 20 by a first device 21, where the melt 30 includes a material which comprises polyketone and at least one magnetic filler, and [0099] compressing the melt 30, where the melt 30 joins with the support part 2 to form the encoder 1 on cooling of the melt 30.

[0100] The support part 2 here may have been pretreated mechanically or by phosphating. Furthermore, there may also be an adhesion promoter provided on the support part 2. When the melt 30 is injected into the mold 20, the mold 20 is not completely closed, and so an embossing gap 24 is able to form in the mold 20. As a consequence of action of pressure, 23, on the mold 20, the melt 30 is compressed in the mold 20. As soon as the mold 20 is closed, the embossing gap 24 no longer exists. After cooling has taken place, the encoder 1 can be ejected or removed from the mold 20. The mold 20, the first device 21, and the second device 22 here are parts of an injection machine.

[0101] A fifth production method, though not shown, is a fluidized sintering process.

[0102] The fifth method for producing the encoder 1 for bearing units 15 comprises the following steps: [0103] heating a support part, [0104] introducing the support part into a bath of plastics powder, where the plastics powder comprises polyketone and at least one magnetic filler, more particularly magnetic particles, and where the plastics powder is fluidized by an airstream, and [0105] impinging the magnetic particles onto the support part, with the plastics powder remaining adhering on the support part.

[0106] Furthermore, there are also additional methods envisaged for producing an encoder for bearing units. Methods include the following: [0107] PVD methods (physical vapor deposition methods), [0108] CVD methods (chemical vapor deposition methods), [0109] electroplating or vapor deposition (e.g., electron beam, sputtering, etc.).

[0110] The provision of the methods highlights different possibilities for producing an encoder for bearing units.

TABLE-US-00002 List of reference numerals 1 encoder 2 support part 3 magnet part 4 metal foil 5 metal-coated foil 6 metal coating 7 adhesion promoter (=primer) 10 bearing unit 11 bearing ring 12 bearing ring 13 rolling element 20 mold 21 device 22 device 23 action of pressure 24 embossing gap 25 component 26 component 30 melt