Bearing arrangement and method for producing same

Abstract

A bearing assembly includes a thermosetting plastic bearing carrier having a receptacle for holding a bearing ring of the bearing and an injection molded connector between an inner circumference of the receptacle and an outer circumference of the bearing ring made from a thermoplastic plastic. The connector may include axial end portions that radially overlap portions of the bearing carrier. Also a method for forming a bearing assembly.

Claims

1. A bearing assembly comprising: a bearing and a bearing carrier for holding the bearing, wherein the bearing carrier includes a receptacle that is defined by an inner surface of the bearing carrier for a bearing ring of the bearing, the bearing being located in the receptacle of the bearing carrier, wherein the bearing carrier comprises a thermosetting plastic, wherein a connection between the bearing carrier and the bearing ring is produced at least partly by at least one molded part made from a thermoplastic plastic, and wherein the at least one molded part is positioned along the inner surface of the bearing carrier so as not to be embedded therein.

2. The bearing assembly according to claim 1, wherein the thermoplastic plastic is injected in at least one free space that is present between an inner circumference of the receptacle and an outer circumference of the bearing ring.

3. The bearing assembly according to claim 1 wherein the molded part forms a radial projection at least in one axial end region that radially projects over the bearing carrier and/or the bearing ring.

4. The bearing assembly according to claim 1, wherein the bearing carrier includes at least one through-bore for receiving an attachment means and/or wherein the bearing carrier includes at least one blind bore for the entry of the attachment means.

5. The bearing assembly according to claim 1, wherein an axial extension of the molded part is between 20% and 500% of an axial extension of the bearing ring.

6. The bearing assembly according to claim 1, wherein a maximum radial extension (s.sub.1max) of the molded part in a region between the receptacle and the bearing ring, in millimeters, is:
s.sub.1max=1.7613.Math.ln(D.sub.0)1.8079 for 3 mm<D.sub.0<50 mm
and
s.sub.1max=1.0811.Math.ln(D.sub.0)+0.8021 for D.sub.050 mm where D.sub.0 a bearing outer diameter in mm.

7. The bearing assembly according to claim 6, wherein a minimum radial extension (s.sub.1min) of the molded part in a region between the receptacle and the bearing ring is 0.1 mm.

8. The bearing assembly according to claim 1, wherein the bearing carrier projects radially inward over the bearing ring in an axial end region so that the bearing ring is disposed with axial undercut in the bearing carrier.

9. The bearing assembly according to claim 8, wherein the molded part extends in an axial gap between the radially inwardly projecting region of the bearing carrier and the bearing ring of the bearing.

10. The bearing assembly according to claim 1, wherein the bearing ring includes a radially outwardly extending flange in an axial end region.

11. The bearing assembly according to claim 10, wherein the molded part extends in an axial gap between the flange and the bearing carrier.

12. The bearing assembly according to claim 10 wherein the flange and the bearing carrier end axially flush.

13. The bearing assembly according to claim 1, wherein the bearing ring extends radially into a groove-shaped recess in the bearing carrier so that the bearing ring is disposed with two-sided axial undercut in the bearing carrier and wherein the bearing carrier is comprised of at least two parts that are axially joined and together from the groove-shaped recess.

14. The bearing assembly according to claim 1, wherein the bearing ring includes a radially outwardly extending flange section that extends into a groove-shaped opening in the bearing carrier so that the flange section is disposed with two-sided axial undercut in the bearing carrier and wherein the bearing carrier is comprised of at least two parts that are axially joined and together form the groove-shaped recess.

15. The bearing assembly according to claim 1, wherein the bearing is a rolling-element bearing.

16. The bearing assembly according to claim 1, wherein the bearing carrier is part of an electric motor, or a fan, or a transmission.

17. A method for manufacturing a bearing assembly according to claim 1, comprising: a) placing the bearing ring in the receptacle of the bearing carrier; b) aligning the bearing ring relative to the bearing carrier in a desired position; c) injecting molten thermoplastic plastic in a ring gap between an inner circumference of the receptacle and an outer circumference of the bearing ring to produce the molded part; and d) allowing the injected thermoplastic plastic to cure.

18. The bearing assembly according to claim 1, wherein the maximum radial thickness (s.sub.1max) of the connector, in millimeters, is:
s.sub.1max=1.7613.Math.ln(D.sub.0)1.8079 for 3 mm<D.sub.0<50 mm
and
s.sub.1max=1.0811.Math.ln(D.sub.0)+0.8021 for D.sub.050 mm where D.sub.0 is a bearing outer diameter in mm.

19. A bearing assembly comprising a bearing carrier for holding at least one bearing, wherein the bearing carrier includes a receptacle for a bearing ring of the bearing, wherein the bearing carrier comprises a thermosetting plastic, wherein a connection between the bearing carrier and the bearing ring when the bearing ring is located in the receptacle is produced at least partly by at least one molded part made from a thermoplastic plastic, and wherein the bearing ring includes a circumferential bearing ring groove into which a snap ring is inserted, wherein the snap ring extends radially into a bearing carrier groove in the bearing carrier and is coated in the bearing carrier groove by a material of the molded part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the invention are depicted in the drawings.

(2) FIG. 1 shows the front view of a bearing carrier that holds a bearing,

(3) FIG. 2 shows a cross-sectional view of the bearing carrier as taken along lines II-II of FIG. 1,

(4) FIG. 3 shows a first alternative solution in the depiction according to FIG. 2,

(5) FIG. 4 shows a second alternative solution in the depiction according to FIG. 2, and

(6) FIG. 5 shows a third alternative solution in the depiction according to FIG. 2,

(7) FIG. 6 shows a fourth alternative solution in the depiction according to FIG. 2,

(8) FIG. 7 shows a fifth alternative solution in the depiction according to FIG. 2,

(9) FIG. 8 shows a sixth alternative solution in the depiction according to FIG. 2,

(10) FIG. 9 shows a seventh alternative solution in the depiction according to FIG. 2,

(11) FIG. 10 shows an eighth alternative solution in the depiction according to FIG. 2, and

(12) FIG. 11 shows a ninth alternative solution in the depiction according to FIG. 2.

DETAILED DESCRIPTION

(13) In FIGS. 1 and 2 a bearing assembly 1 can be seen, which in the present case forms a cover element for an electric machine. The bearing assembly 1 includes a bearing carrier 2 that carries a rolling-element bearing 3. A not-depicted shaft is supported by the bearing 3.

(14) The bearing carrier 2 is comprised of a thermoset and is designed essentially annular. In the radially inner-lying end region the bearing carrier 2 includes a cylindrical receptacle 4 into which the bearing 3 and in particular its outer ring is inserted, wherein after the inserting of the bearing 3 into the receptacle 4 a ring gap arises.

(15) This ring gap is filled with thermoplastic plastic material that has been introduced in the context of an injection-molding process. The thermoplastic material forms a molded part 5 that produces the connection between the bearing outer ring of the bearing 3 and the bearing carrier 2.

(16) As can be seen in FIG. 2 the molded part 5 is embodied from thermoplastic plastic here such that radial projections 6, 7, 8, and 9 arise in the two axial end regions of the molded part 5, which radial projections 6, 7, 8, and 9 each form an undercut in axial direction a and thus ensure that the bearing outer ring is non-relocatably fixed axially relative to the bearing carrier 2. Here the projections 6, 7, 8, and 9 extend annularly around the entire circumference.

(17) For fixing the bearing carrier 2 or cover on thenot depictedmachine element, through-bores 10 are provided in the bearing carrier 2, which through-bores are configured for passage of an attachment screw.

(18) The size of the molded part 5 made from thermoplastic material is small in relation to the size of the bearing carrier 2 made from thermoset material. This results from the incorporated radial extension s.sub.1 of the molded part 5 on the one hand and the radial extension s.sub.2 of the bearing carrier 2 on the other hand. The extension s.sub.1 is, for example, at most 15% of the extension s.sub.2. In the exemplary embodiment mentioned a circular outer circumference is provided here for the bearing carrier 2. If no circular shape is present, the mentioned percentages refer to the respective maximum or minimum distance of the circumference of the bearing carrier 2 from the axis of rotation of the bearing.

(19) Alternatives to the solution according to FIG. 2 are depicted in FIGS. 3 to 10.

(20) In FIG. 3 it is provided that the molded part 5 has a generally hollow-cylindrical shape. However, a groove 11 is incorporated in the central region in the outer ring of the bearing 3. This has the consequence that with injecting of the thermoplastic material of the molded part 5 this thermoplastic material forms an undercut in axial direction a, so that an interference-fit axial connection is provided between the bearing carrier 2 and the bearing 3, althoughin contrast to FIG. 2the axial end regions of the molded part 5 end (optionally) flush with the outer ring of the bearing 3 or the bearing carrier 2.

(21) Of course such a groove 11 can generally also be located in the bearing carrier 2; then in addition to a material bond there is also an interference fit in the axial direction between the bearing carrier 2 and the molded part 5.

(22) The opposite design is also conceivable, according to which the outer ring of the bearing 3 (and possibly also the bearing ring 2) includes a radial elevation in the axial center region, over which the material of the shaped part 5 lies.

(23) As can be seen in FIG. 3 the molded part 5 does not project axially over the sides of the outer ring of the bearing 2 or the bearing carrier 2. This projection is thus zero or the molded part 5 is even axially recessed with respect to the bearing ring or the bearing carrier.

(24) The shape of the groove 11 or of a corresponding radial projection here can be designed in any manner: for example, groove-shaped, almond-shaped, step-shaped, or diagonal protrusions or recesses can be provided. These designs can be provided either on the bearing outer ring or on the bearing carrier or on both elements.

(25) FIG. 4 shows another solution. Here the bearing carrier 2 is provided with a T-shaped structure in radial section in the contact region with the molded part 5. The result is that after the injection-molding of the molded part 5 a both material-bonded and interference-fit connection between the bearing carrier 2 and the molded part 5 results. Of course, such a connection is generally also conceivable for the connection between the outer ring of the bearing 3 and the molded part 5.

(26) Another differently designed connection between the outer ring of the bearing 3 and the bearing carrier 2 emerges from FIG. 5.

(27) Here the bearing carrier includes a number of openings 12 (e.g., bores) extending in radial direction a, through which the molten material of the molded part 5 can flow during injection-molding; it flows uniformly in the ring gap between the outer ring of the bearing 3 and the bearing carrier 2.

(28) In the right and left axial end region the material of the molded part 5 flows together and forms the radial projections depicted, in an analogous manner to those according to FIG. 2 (see there the reference numbers 6, 7, 8, and 9).

(29) The openingsconfigured, for example, as opening or borethus allow that the thermoplastic material can flow during injection-molding of the molded part 5 from one end side (e.g., from a sprue side) to the other end side. Thus an improved material distribution can be achieved with injection of the thermoplastic; furthermore an improved interference fit arises between thermoset and thermoplastic.

(30) Thus a firm connection is given between the outer ring of the bearing 3 and the bearing carrier 2.

(31) FIGS. 6 to 10 show further variants of the proposed solution.

(32) In FIG. 6 it is provided that the bearing carrier 2 projects radially inward over the outer ring of the bearing 3 in a, namely in the axial end region. Thus the bearing outer ring of the bearing 3 is disposed with an axial undercut in the bearing carrier 2. In this case the molded part 5 extends in an axial gap 13 between the radially inwardly projecting region of the bearing carrier 2 and the bearing ring of the bearing 3.

(33) According to FIG. 7 the outer ring of the bearing 3 includes a circumferential groove 14. A snap ring 15 is inserted into this groove 14. In the installed state the circumferential groove 14 is deeper than the snap ring 15 so that installability is provided (the snap ring is divided at a circumferential point and is pressed together and is held together until reaching the base of the circumferential groove 14 in order to be able to push the bearing 3 axially into the bearing carrier 2). In the installed state the snap ring 15 extendsas depicted in FIG. 7radially into a groove 16 in the bearing carrier 2. The material of the molded part 5 has been injected in this location so that it coats the snap ring.

(34) In the solution according to FIG. 8 it is provided that the bearing ring of the bearing 3 includes a radially outwardly extending flange 17 in an axial end region (namely in the right axial end region). In this case the thermoplastic molded part 5 generated by injection-molding extends in an axial gap 18 between the flange 17 and the bearing carrier 2. In the exemplary embodiment the flange 17 and the bearing carrier 2 end axially flush.

(35) As can be seen in the exemplary embodiments according to FIG. 9 and FIG. 10, the bearing carrier 2 can also be configured two-part (or multi-part). It is comprised of the parts 2 and 2, which are axially joined and connected. Due to correspondingly configured recesses in the parts 2, 2, the bearing carrier 2 forms a groove-shaped recess 19 in its interior, which groove-shaped recess 19 serves to receive the bearing outer ring or a part thereof such that there is a two-sided axial undercut for the bearing carrier 2, so that an axial fixing of the bearing 3 relative to the bearing carrier 2 is given.

(36) In the design according to FIG. 9 it is provided that the outer ring of the bearing 3 extends radially into said groove-shaped recess 19 in the bearing carrier 2 so that the mentioned two-sided axial undercut is present.

(37) Meanwhile according to FIG. 10 it is provided that the outer ring of the bearing 3 has a radially outwardly extending flange section 20. This extends into the groove-shaped recess 19 in the bearing carrier. In turn a two-sided axial undercut is thus present. After placement in the two joined parts 2, 2 of the bearing carrier 2, the flange section 20 is fixed in the bearing carrier 2 by the injected molded part 5.

(38) Finally, the embodiment according to FIG. 11 represents in this respect an alternative or additional solution to the extent that no through-bores 10 are provided here, rather blind bores 21. The blind bores 21 allow the screwing-in of a screw in order to attach the bearing carrier 2 to a fixture. In general the blind bore 21 can be introduced directly into the material of the bearing carrier 2 and a thread can be cut in. Howeveraccording to the depicted exemplary embodimentan insert element 22 is preferred that is introduced into the injection mold during injection-molding of the bearing carrier 2 so that the insert element 22 is completely surrounded by material of the bearing carrier and is thus fixed in situ in the bearing carrier 2.

(39) As is to be recognized in the exemplary embodiment according to FIG. 11, the insert element 22 can include for this purpose in an axial end region a flange-type widening that ensures a stable fixing of the insert element 22 in the bearing carrier 2. With the fixing of the bearing carrier 2 a screw can then be screwed-in into the thread 23 of the insert element 22.

(40) Of course through-bores 10 and blind bores 21 can also be used in combination.

REFERENCE NUMBER LIST

(41) 1 Bearing assembly

(42) 2 Bearing carrier made from thermoset plastic

(43) 2 Part of the bearing carrier

(44) 2 Part of the bearing carrier

(45) 3 Bearing

(46) 4 Receptacle

(47) 5 Molded part made from thermoplastic plastic

(48) 6 Radial projection

(49) 7 Radial projection

(50) 8 Radial projection

(51) 9 Radial projection

(52) 10 Through-bore

(53) 11 Groove

(54) 12 Opening

(55) 13 Axial gap

(56) 14 Circumferential groove

(57) 15 Snap ring

(58) 16 Groove in bearing carrier

(59) 17 Flange

(60) 18 Axial gap

(61) 19 Groove-shaped recess in bearing carrier

(62) 20 Flange section

(63) 21 Blind bore

(64) 22 Insert element

(65) 23 Thread

(66) a Axial direction

(67) r Radial direction

(68) s.sub.1 Radial extension of the molded part

(69) s.sub.1min Minimum radial extension of the molded part

(70) s.sub.1max Maximum radial extension of the molded part

(71) s.sub.2 Radial extension of the bearing carrier

(72) D.sub.0 Bearing outer diameter