HEAD BEARING ASSEMBLY FOR A DENTAL OR SURGICAL HANDPIECE AND DENTAL OR SURGICAL HANDPIECE COMPRISING SUCH A HEAD BEARING ASSEMBLY

Abstract

The disclosure relates to a head bearing assembly for a dental or surgical handpiece, comprising an outer sleeve, in which at least four radial bearings are arranged, which enclose an axis of rotation and each have their own bearing outer ring or a common bearing outer rings, wherein the bearing outer rings are surrounded radially on the outside by the outer sleeve in the circumferential direction about the axis of rotation, and each radial bearing has at least one or exactly one rolling element row with rolling elements which are arranged one behind the other in the circumferential direction and rolling in the respective bearing outer ring.

The head bearing assembly according to the disclosure is characterized in that the at least four radial bearings have a common, integral bearing inner ring on which the rolling elements are arranged in rolling contact.

Claims

1. Head bearing assembly for a dental or surgical handpiece, comprising an outer sleeve, in which at least four radial bearings are arranged, which enclose an axis of rotation and each have their own bearing outer ring or a common bearing outer rings, wherein the bearing outer rings are surrounded radially on the outside by the outer sleeve in the circumferential direction about the axis of rotation, and each radial bearing has at least one or exactly one rolling element row with rolling elements which are arranged one behind the other in the circumferential direction and rolling in the respective bearing outer ring; wherein the at least four radial bearings have a common, integral bearing inner ring on which the rolling elements are arranged in rolling contact.

2. Head bearing assembly according to claim 1, wherein the head bearing assembly forms a pre-assembled, inherently stable, functional unit.

3. Head bearing assembly according to claim 1, wherein the bearing outer rings are axially spring-loaded against each other and/or against the outer sleeve in the direction of the axis of rotation.

4. Head bearing assembly according to claim 1, wherein the bearing inner ring encloses a receiving space for a tool shaft of a dental or surgical tool.

5. Head bearing assembly according to one of claim 1, comprising a tool shaft for a dental or surgical tool, wherein a surface of the tool shaft forms the bearing inner ring.

6. Head bearing assembly according to one of claim 1, wherein the bearing outer rings are mounted in the outer sleeve so as to be axially displaceable in the direction of the axis of rotation, in particular against the spring pretension.

7. Head bearing assembly according to claim 6, wherein the outer sleeve has at least one axial stop which faces one of the bearing outer rings in the direction of the axis of rotation in such a way that the bearing outer ring abuts against the axial stop in the event of a displacement.

8. Head bearing assembly according to claim 7, wherein the outer sleeve has at least two axial stops facing each other, in particular axially outside the two axially outer bearing outer rings.

9. Head bearing assembly according to claim 1, wherein between at least two bearing outer rings positioned next to each other, in particular between two axially inner bearing outer rings, a spacer is arranged, against which the two bearing outer rings rest or against which the two bearing outer rings are spring-loaded.

10. Head bearing assembly according to claim 1, wherein the outer sleeve is composed of a plurality of parts connected to each other in a materially bonded and/or force-locking and/or form-fitting manner, comprising at least one or more of the following components: a cover part at a first axial end of the outer sleeve; an integral or multi-part center part which directly surrounds the bearing outer rings; a ring part at a second axial end of the outer sleeve, which is inserted in particular into an axial end of the center part.

11. Head bearing assembly according to claim 1, wherein the radial bearings are arranged in pairs in the region of the axial ends of the outer sleeve with an axial spacing of the pairs and each form an X alignment.

12. Head bearing assembly according to claim 1, wherein the bearing inner ring is of stepped design along a radially inner surface.

13. Dental or surgical handpiece having a housing, having a head bearing assembly mounted in the housing according to claim 1, and having a tool shaft supported in the outer sleeve by the radial bearings.

14. Dental medical or surgical handpiece according to claim 13, wherein the tool shaft is stepped at a radially outer surface facing the radially inner surface of the bearing inner ring.

15. Dental or surgical handpiece according to claim 13, wherein at least one or more damping ring(s), in particular in the form of an O-ring in each case, is/are introduced between the radially outer surface of the tool shaft and the radially inner surface of the bearing inner ring, wherein at least one damping ring is arranged in particular in the region of each axial end of the bearing inner ring.

16. Head bearing assembly according to claim 2, wherein the bearing outer rings are axially spring-loaded against each other and/or against the outer sleeve in the direction of the axis of rotation.

17. Head bearing assembly according to claim 2, wherein the bearing inner ring encloses a receiving space for a tool shaft of a dental or surgical tool.

18. Head bearing assembly according to claim 3, wherein the bearing inner ring encloses a receiving space for a tool shaft of a dental or surgical tool.

19. Head bearing assembly according to claim 2, comprising a tool shaft for a dental or surgical tool, wherein a surface of the tool shaft forms the bearing inner ring.

20. Head bearing assembly according to claim 3, comprising a tool shaft for a dental or surgical tool, wherein a surface of the tool shaft forms the bearing inner ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The disclosure will be described below in an exemplary manner by way of exemplary embodiments and the figures, wherein:

[0039] FIG. 1 shows a schematic representation of a head bearing assembly according to the disclosure;

[0040] FIG. 2 shows an alternative embodiment of a head bearing assembly.

DETAILED DESCRIPTION

[0041] FIG. 1 shows an example of a head bearing assembly 13 of a dental or surgical handpiece in an axial section, wherein only one side of the head bearing assembly 13 is shown in relation to the axis of rotation 6. The head bearing assembly 13 is received in a housing 14 of the handpiece, wherein the housing 14 is also shown only very schematically. In addition to the head bearing assembly 13, a drive for the tool shaft 8 carrying a dental or surgical tool 9 is generally arranged in the housing 14, as well as a clamping device which absorbs axial forces of the tool shaft 8 in order to hold the tool 8 in the housing 14. The clamping device could also be part of the head bearing assembly 13, but is preferably provided separately therefrom.

[0042] The head bearing assembly 13 has an outer sleeve 1, which in the exemplary embodiment shown in FIG. 1 is in three parts, comprising a cover part 1.1, a hollow cylindrical center part 1.2 and a ring part 1.3 inserted at the second axial end of the center part 1.2. The cover part 1.1 and the ring part 1.3 form axial support surfaces for the axially outer spring elements 16, via which the axially outer bearing outer rings 3 of the axially outer radial bearings 2.1, 2.4 are resiliently supported on the outer sleeve 1.

[0043] In total, the head bearing assembly 13 has four radial bearings 2.1, 2.2, 2.3 and 2.4 positioned axially adjacent to one another, wherein two radial bearings 2.1, 2.2 and 2.3, 2.4 are arranged in each case in pairs at one axial end of the outer sleeve 1 and the central part 1.2 respectively. The bearing outer rings 3 of each pair of radial bearings 2.1, 2.2 and 2.3, 2.4 are preferably supported directly against each other in the axial direction. They could also each be of integral (single-piece) design. Between the bearing outer rings 3 of the two axially inner radial bearings 2.2, 2.3 there is preferably a spacer 12 which is supported axially on both sides against the two bearing outer rings 3 of the radial bearings 2.2, 2.3 by a spring element 16 in each case.

[0044] In the exemplary embodiment shown, all spring elements 16 are designed as wave springs. However, this is not mandatory.

[0045] To prevent an undesirably wide deflection of the axially outer spring elements 16, the outer sleeve 1 has axial stops 10, 11, each of which faces one of the two bearing outer rings 3 of the axially outer radial bearings 2.1, 2.4.

[0046] The bearing inner ring 5 of all radial bearings 2.1, 2.2, 2.3, 2.4 is designed as an integral (single-piece) sleeve in which the tool shaft 8 is accommodated. Accordingly, the bearing inner ring 5 encloses a receiving space 7 for the tool shaft 8.

[0047] In the exemplary embodiment shown, but not necessarily, damping rings 15 are provided between the tool shaft 8 and the bearing inner ring 5, preferably one damping ring 15 at each axial end of the bearing inner ring 5. Due to a stepped design of the radially inner surface of the bearing inner ring 5 and a diametrically oppositely stepped radially outer surface of the tool shaft 8, the insertion of the tool shaft 8 against the frictional force of the damping rings 15 is facilitated, since correspondingly the axial section with the comparatively smaller diameter of the tool shaft 8 does not have to slide along the damping ring 15 arranged on the correspondingly larger inner diameter of the bearing inner ring 5 when the tool shaft 8 is inserted.

[0048] The radial bearings 2.1, 2.2, 2.3, 2.4 are designed as deep groove ball bearings in the shown exemplary embodiment, but this is not mandatory. The rolling elements 4, which roll on the common bearing inner ring 5 and the separate bearing outer rings 3, are designed as balls.

[0049] As indicated by the force lines, each pair of immediately adjacent radial layers 2.1, 2.2 and 2.3, 2.4 forms an X alignment.

[0050] In the exemplary embodiment shown, the spacer 12 is also mounted in the outer sleeve 1 via damping rings 15. This reduces vibrations. However, this is also not mandatory.

[0051] In the three-part outer sleeve 1 according to FIG. 1, the cover part 1.1 is preferably inserted into the center part 1.2 with an interference fit and/or is connected to it by a material bond. The ring part 1.3 can also be inserted into the center part 1.2 with an interference fit and/or be connected to it by a material bond.

[0052] In the exemplary embodiment according to FIG. 2, the head bearing assembly 13 has a simplified design and requires a comparatively smaller radial installation space. For example, the cover part 1.1 is of integral (single-piece) design with the center part 1.2 and can be manufactured integrally therewith. The spacer 12 and the bearing outer rings 3 are inserted in direct contact in the outer sleeve 1 and the axial stops 10, 11 have been dispensed with.

[0053] Reference is made further to the description of FIG. 1.

LIST OF REFERENCE SIGNS

[0054] 1 Outer sleeve [0055] 1.1 Cover part [0056] 1.2 Center part [0057] 1.3 Ring part [0058] 2.1 Radial bearing [0059] 2.2 Radial bearing [0060] 2.3 Radial bearing [0061] 2.4 Radial bearing [0062] 3 Bearing outer ring [0063] 4 Rolling element [0064] 5 Bearing inner ring [0065] 6 Axis of rotation [0066] 7 Receiving space [0067] 8 Tool shaft [0068] 9 Tool [0069] 10 Axial stop [0070] 11 Axial stop [0071] 12 Spacer [0072] 13 Head bearing assembly [0073] 14 Housing [0074] 15 Damping ring [0075] 16 Spring element