Angle position transmitter having a static magnetic field sensor and a magnet on the transmitter shaft for detecting a full revolution of the transmitter shaft

• US 5,072,181 A
• Filed: 12/15/1987
• Issued: 12/10/1991
• Est. Priority Date: 12/22/1986
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Burger, Wilheim
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): EDMONDS, WARREN
• Application Number:
  US07/132,391
• Time in Patent Office: 1,456 Days
• Field of Search: 324/207, 324/208, 324/226, 324/227, 324/234, 324/235, 324/236, 324/239, 324/251, 324/252, 324/260-262, 324/165, 324/166, 324/167, 324/173, 324/174, 324/175, 324/178 , 324/179, 73/862.33, 73/862.31, 73/862.34, 73/862.35
• US Class Current: 324/207.25
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00
• CPC Class Codes: G01D 2205/26 Details of encoders or position sensors specially adapted to detect rotation beyond a full turn of 360°, e.g. multi-rotation
• CPC Class Codes: G01D 5/34738 Axles; Driving or coupling means

Abstract

In an angle position transmitter with a photoelectrically scannable transmitter disc and doubly supported transmitted shaft, the angle position transmitter determines the angle position of a rotary machine element so as to indicate absolute position with less than a full revolution. The measuring range is increased several times without adversely affecting the compact design of the angle position transmitter which is already limited by the need for a double support of the transmitter shaft. A magnet revolving with the transmitter shaft signals full revolutions of the transmitter shaft at a stationary magnetic field sensor. The full rotations are counted in a revolution counter. A sign is determined by the direction of motion. The magnet rotates in the dead space between two antifriction bearings of a transmitter shaft. The angle position transmitter is particularly well suited for use in machine tools, robots and motor vehicles.

Claims

1. An angle position transmitter for determining a position angle for a rotatable machine, comprising:

a transmitter shaft for transmitting rotary motion from the machine part;

a photoelectrically scannable transmitter disc mounted on said transmitter shaft, for detecting the angle position of the shaft within one revolution;

at least two anti-friction bearings positioned along said transmitter shaft supporting said shaft;

at least one magnet arranged on said transmitter shaft between said bearings so as to rotate with said transmitter shaft and make full rotations; and

at least one stationary magnetic field sensor for detecting a full revolution of said magnet and indicating the direction of the rotation of said transmitter shaft.

2. An angle position transmitter as claimed in claim 1, wherein said stationary magnetic field sensor is chosen from the group consisting of a Wiegand sensor, a pulse wire or a reed contact.

3. An angle position transmitter as claimed in claim 1 further comprising a bearing housing enclosing said bearings, said bearing housing including a chamber receiving said magnetic field sensor.

4. An angle position transmitter as claimed in claim 1, further comprising:

outer bearing rings for said bearings; and

a thin stationary tensioning sleeve positioned between said outer bearing rings and between said magnet and said stationary magnetic field sensor, said tensioning sleeve being magnetically permeable and positioned such that said magnet rotates at the smallest practical distance from an inside wall of said tensioning sleeve.

5. An angle position transmitter as claimed in claim 1, further comprising a setting magnet for said stationary magnetic-field sensor that rotates with said transmitter shaft, having a polarity which is opposite to said magnet arranged on said transmitter shaft.

6. An angle position transmitter as claimed in claim 1, further comprising a bidirectional revolution counter that is connected to said stationary magnetic field sensor to count the full rotations of the magnet and generate an output signal in response thereto, said output signal being indicative of the direction of said rotation.