Multiturn encoder

• US 20030112157A1
• Filed: 09/30/2002
• Published: 06/19/2003
• Est. Priority Date: 12/06/2000
• Status: Active Grant

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Strasser, Erich
• Granted Patent: US 6,683,545 B2
• Time in Patent Office: Days
• US Class Current: 341/2
• CPC Class Codes: G01D 5/04 using levers; using cams; using gearing
• CPC Class Codes: G01D 5/3473 Circular or rotary encoders

Abstract

In a multiturn rotary encoder, a first code disk is arranged with an input shaft for detecting the angular position of the input shaft within one rotation. To detect the number of rotations of the input shaft, a multiturn part is provided with further code disks in the form of magnet bodies which are driven geared down. A printed circuit board having detector devices for scanning the first code disk and the magnet bodies is positioned between the first code disk and the multiturn part. The detector devices of the first code disk and of the magnet bodies are mounted on one common side of a printed circuit board which is opposite the first code disk.

Claims

1. A multiturn rotary encoder comprising

a first code carrier (3) that is connected to an input shaft (2) and is able to be scanned by a detector device (8) for detecting the angular position of the input shaft (2);

a plurality of further code carriers (10, 11, 12) for measuring the number of rotations of the input shaft (2), each further code carrier (10, 11, 12) being driven geared down via a step-down gear (20) relative to the respective preceding code carrier (3, 10, 11), and a detector device (30) being provided for scanning each further code carrier (10, 11, 12);

the further code carriers (10, 11, 12) are arranged within the peripheral region of the first code carrier (3),

wherein

the detector device (8) of the first code carrier (3) and the detector devices (30) of the further code carriers (10) are disposed on a shared side (40) of a printed circuit board (4).

2. The multiturn rotary encoder as recited in claim 1, wherein the printed circuit board (4) is arranged spatially between the first code carrier (3) and the further code carriers (10, 11, 12).

3. The multiturn rotary encoder as recited in claim 1, wherein the first code carrier (3) is arranged spatially between the printed circuit board (4) and the further code carriers (10, 11, 12).

4. The multiturn rotary encoder as recited in one of claims 1 through 3, wherein the further code carriers (10, 11, 12) are magnet bodies (10, 11, 12) which are mounted in a manner allowing them to rotate about rotation axes (D10, D11, D12) running parallel to the input shaft (2), the magnet bodies being magnetized differently in alternation in the direction of rotation and each of them being assigned a detector device (30) sensitive to magnetic fields.

5. The multiturn rotary encoder as recited in claims 2 and 4, wherein the first code carrier (3) is arranged opposite the side (40) of the printed circuit board (4) on which the detector devices (8, 30) are located, and the further code carriers (10, 11, 12) are arranged facing the opposite side (41) of the printed circuit board (4).

6. The multiturn rotary encoder as recited in claim 5, wherein the printed circuit board (4) has openings or blind-end bores (50) in the region of the detector devices (30) sensitive to magnetic fields.

7. The multiturn rotary encoder as recited in claim 6, wherein the magnet bodies (10, 11, 12) extend into the openings or blind-end bores (50).

8. The multiturn rotary encoder as recited in claim 2, wherein the further code carriers (10, 11, 12) are arranged opposite the side (40) of the printed circuit board (4) on which the detector devices (8, 30) are located, and the first code carrier (3) is arranged facing the other side (41) of the printed circuit board (4).

9. The multiturn rotary encoder as recited in claim 8, wherein the printed circuit board (4) has an opening (60) in the region of the detector device (8) of the first code carrier (3).

10. The multiturn rotary encoder as recited in one of the preceding claims,

wherein the first code carrier is a code disk (3) that is able to be scanned photoelectrically and that is assigned a photoelectric detector device (8) on the printed circuit board (4).