Angular-position measuring device

Patent metadata

Field	Value
Publication number	US-9404769-B2
Application number	US-201414278748-A
Country	US
Kind code	B2
Filing date	May 15, 2014
Priority date	May 16, 2013
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

An angular-position measuring device includes a shaft rotatable relative to a body about an axis extending in a z-direction. A measuring standard having an end face is fastened on the shaft in rotatably fixed manner. The body includes a scanning device for scanning the measuring standard. Both the roller bearing and a sealing unit are provided on the side of the measuring standard facing the end face relative to the z-direction, The sealing unit includes rings that are rotatable relative to each other and are separated from each other by a gap, the gap being filled at least partially with a fluid.

First claim

What is claimed is:

1. An angular-position measuring device, comprising:
a body;
a roller bearing;
a shaft rotatable relative to the body, via the roller bearing, about an axis extending in a z-direction; and
a measuring standard, having an end face, fastened on the shaft in rotatably fixed manner;
wherein the body includes a scanning device adapted to scan the measuring standard;
wherein both the roller bearing and a sealing unit are arranged on a side of the measuring standard that faces the end face relative to the z-direction; and
wherein the sealing unit includes rings rotatable relative to each other and separated from each other by a gap, the gap being at least partially filled with a fluid.

2. The angular-position measuring device according to claim 1 , wherein the sealing unit includes a ring mounted on the shaft and a ring mounted on the body, a maximum diameter of the ring mounted on the shaft being greater than a minimum diameter of the ring mounted on the body.

3. The angular-position measuring device according to claim 2 , wherein the ring mounted on the shaft includes a radially-projecting extension in contact with the fluid.

4. The angular-position measuring device according to claim 2 , wherein the ring mounted on the shaft includes a radially-projecting extension that extends into a circumferential groove of the ring mounted on the body.

5. The angular-position measuring device according to claim 1 , wherein at least one of the rings is arranged as a multi-part component.

6. The angular-position measuring device according to claim 1 , wherein the angular-position measuring device includes two roller bearings.

7. The angular-position measuring device according to claim 6 , wherein the sealing unit includes a ring mounted on the shaft and a ring mounted on the body, the rings being arranged between the roller bearings.

8. The angular-position measuring device according to claim 7 , wherein at least one of the rings is preloaded in the z-direction.

9. The angular-position measuring device according to claim 7 , wherein the ring mounted on the body is preloaded in the z-direction.

10. The angular-position measuring device according to claim 1 , wherein the ring mounted on the shaft includes a reservoir for the fluid.

11. The angular-position measuring device according to claim 10 , wherein the ring mounted on the shaft includes a radially-extending projection including at least one recess forming the reservoir.

12. The angular-position measuring device according to claim 10 , wherein the ring mounted on the shaft includes a radially-extending projection including a plurality of recesses forming the reservoir.

13. The angular-position measuring device according to claim 1 , wherein the fluid includes an oil.

14. The angular-position measuring device according to claim 1 , wherein a radially-inner ring of the sealing unit and a radially-outer ring of the sealing unit do not contact each other.

15. The angular-position measuring device according to claim 1 , wherein the fluid in the sealing unit is adapted to prevent air flow through the roller bearing.

Assignees

• Heidenhain Gmbh Dr Johannes

Inventors

• Meyer Hermann

Classifications

• F16C33/761

  specifically for bearings with purely axial load · CPC title

• G01D3/028 Primary

  mitigating undesired influences, e.g. temperature, pressure · CPC title

• F16C2361/65

  Gear shifting, change speed gear, gear box · CPC title

• F16C33/745

  by capillary action · CPC title

• F16C19/00

  Bearings with rolling contact, for exclusively rotary movement (adjustable bearings F16C23/00, F16C25/00 {; electrically insulating bearings H02K5/173}) · CPC title