Servo motor with a built-in drive circuit
AssigneeTamagawa Seiki Kabushiki Kaisha
InventorsHiromasa Miura, Toshiyuki Noda
Life of this patent
Estimating the term…
Abstract
A servo motor with a built-in drive circuit is provided in which, when power is off, positional data including multiple-rotation counting values is stored in a nonvolatile memory to thereby eliminate battery back-up, and in which the CPU of a drive control circuit portion is in charge of the multiple-rotation counting itself to thereby eliminate the circuit for multiple-rotation counting. Due to a reduction in the number of lines involved and an elimination of battery back-up, a reduction in size is achieved. The servo motor with a built-in drive circuit includes an absolute encoder for detecting rotation of a servo motor portion and an electromagnetic mechanical brake, in which, when the power is off, the positional data at that time is stored in a nonvolatile memory.
Claims4
A servo motor with a built-in drive circuit in which a servo motor portion provided in a cylindrical case and composed of a stator and a rotor is servo-driven by a sensor circuit portion, a drive control circuit portion, and a motor drive circuit portion,
- said servo motor comprising:
- an absolute encoder operable to detect rotation of said servo motor portion;
- a sensor circuit board;
- a motor drive board;
- cooling fins operable to dissipate heat from said servo motor;
- and
- an electromagnetic mechanical brake which is released when said servo motor portion is being driven,
- wherein said electromagnetic mechanical brake is engaged by an action of a spring when said servo motor portion is not to be driven,
- wherein said electromagnetic mechanical brake comprises:
- a stationary brake plate;
- and
- a movable brake plate;
- wherein, when said servo motor portion is not to be driven, said movable brake plate is pressed against said stationary brake plate by the action of said spring;
- wherein said drive control circuit portion is coupled to said sensor circuit board;
- wherein said motor drive circuit portion and a power device are coupled to said motor drive board;
- wherein said drive control circuit portion is operable to control said electromagnetic mechanical brake and said motor drive circuit portion;
- and
- wherein, when power is off, positional data at that time is stored in a nonvolatile memory.
Dependencies are inferred from the claim text.