LINEAR ENCODER

• US 20170199060A1
• Filed: 01/03/2017
• Published: 07/13/2017
• Est. Priority Date: 01/07/2016
• Status: Active Grant

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Shimoda, Daisuke, Motoyuki, Katsumi, Watanabe, Yoshio
• Granted Patent: US 10,209,103 B2
• Time in Patent Office: Days
• CPC Class Codes: G01D 11/10 Elements for damping the movement of parts
• CPC Class Codes: G01D 5/34761 Protection devices, e.g. caps; Blowing devices

Abstract

A linear encoder includes a scale disposed within a housing and a scanning unit that is displaceable in a measuring direction relative to the scale. The scanning unit includes a scanning head disposed inside of the housing opposite to the scale such that the scale is scannable by the scanning head, as well as a mount to which the scanning head is fastened, and a driving component, via which the mount is coupled to a mounting base disposed outside of the housing. A vibration damper suppresses vibrations transversely to the measuring direction. The vibration damper is disposed on the mount or on the scanning head, and includes a damping mass and an elastic element. The damping mass is fastened by the elastic element to an attachment surface of the mount or of the scanning head.

Claims

1. A linear encoder, comprising:

a scale disposed within a housing;

a scanning unit that is displaceable in a measuring direction relative to the scale, the scanning unit comprising;

a scanning head disposed inside of the housing opposite to the scale such that the scale is scannable by the scanning head,

a mount to which the scanning head is fastened, and

a driving component, via which the mount is coupled to a mounting base disposed outside of the housing; and

a vibration damper which suppresses vibrations transversely to the measuring direction, the vibration damper being disposed on the mount or on the scanning head, the vibration damper including a damping mass and an elastic element, the damping mass being fastened by the elastic element to an attachment surface of the mount or of the scanning head.

2. The linear encoder as recited in claim 1, wherein the vibration damper is disposed inside of the housing.

3. The linear encoder as recited in claim 1, wherein the scanning head does not contact the scale and is fastened to the driving component without any compensating coupling.

4. The linear encoder as recited in claim 1, wherein the driving component is sword-shaped and flexurally stiff in the measuring direction, and, in a second direction that is orthogonal to the measuring direction, is relatively thin, and wherein the elastic element is configured to allow the damping mass to move in the second direction.

5. The linear encoder as recited in claim 4, wherein the attachment surface is a plane that is defined by the measuring direction and the second direction.

6. The linear encoder as recited in claim 1, wherein the elastic element is an adhesive layer between the mount and the damping mass.

7. The linear encoder as recited in claim 6, wherein the adhesive is acrylic-based and affixed by its own adhesive strength to the attachment surface.

8. The linear encoder as recited in claim 1, wherein the vibration damper is disposed at a location on the mount that is longitudinally aligned with the scanning head in the measuring direction.