US 4,656,409 A · Electromagnetic servo unit

Abstract

An electromagnetic servo unit is constituted with an outer casing (1), a first shaft (4) and a second shaft (5) both rotatably supported by the casing, an electric motor (2) built in the casing coaxially with the second shaft, a torque detecting mechanism (4b, 29, 27, 41, 42, 34, 35) for detecting torque applied to either of the first and second shafts, a control mechanism (34, 35, 41, 42) for receiving a detection signal from the torque detecting mechanism and controlling operation of the electric motor, and a transmission mechanism (8; 280) for transmitting an output of the electric motor. The torque detecting mechanism is arranged inside the casing, and the first and second shafts are mutually actuatably connected to each other within the casing through the torque detecting mechanism. Preferably, the first and second shafts are coaxially supported by the casing, and have a relative angular displacement therebetween made use of for, when it is developed exceeding a predetermined angle range, closing an operation control circuit (C; D) of the electric motor.

Claims12

Dependent claims

An electromagnetic servo unit comprising:

an outer casing;
a first shaft and a second shaft both rotatably supported by said casing;
an electric motor having an armature coaxially and rotatably arranged around said second shaft and a field arranged inside said casing;
torque detecting means for detecting torque applied to either of said first shaft and said second shaft;
control means arranged inside said casing, for receiving a detection signal from said torque detecting means, and for controlling operation of said electric motor in accordance therewith;
and
a transmission mechanism for transmitting rotary force of said armature of said electric motor,
wherein:
said torque detecting means is arranged inside said casing;
and
said first shaft and said second shaft are mutually actuatably connected to each other within said casing through said torque detecting means.

8 more elements

An electromagnetic servo unit, comprising:

an outer casing;
a first shaft and a second shaft both rotatably and coaxially supported in said casing;
an electric motor having an armature coaxially and rotatably arranged around said second shaft and a field arranged inside said casing;
torque detecting means arranged inside said casing, for detecting torque applied to either of said first shaft and said second shaft, said first shaft and said second shaft being mutually actuatably connected to each other within said casing through said torque detecting means, said torque detecting means including:
a part of said first shaft within said casing;
a part of said second shaft within said casing;
elastic means interposed between said part of said first shaft and said part of said second shaft;
an electrical resistance assembly fixed on either of said first shaft and said second shaft;
and
a brush means secured to the other of said first shaft and said second shaft and adapted to be forced into contact with said electrical resistance assembly;
and
a transmission mechanism for transmitting rotary force of said armature of said electric motor;
wherein said electrical resistance assembly and said brush means of said torque detecting means are adapted to close an operation control circuit of said electric motor when a relative angular displacement between said first shaft and said second shaft is developed exceeding a predetermined angle range.

10 more elements

Dependencies are inferred from the claim text.

Electromagnetic servo unit

Life of this patent

Electromagnetic servo unit

Life of this patent

Abstract

Claims12