US 5,705,908 AGranted

Drive unit and a motor drive control method

AssigneeNEC Corporation

InventorHideo Kashimura

Life of this patent

Estimating the term…

Loading patent…

Abstract

A drive unit capable of maintaining the stability of driving speed with respect to the driven part in which the motor is not used at a low drive efficiency. Said drive unit comprises the first and second stepping motors 12 and 14 transmitting power to the driven part at a rated driving output corresponding to the load torque of said driven part, the first and second motor drive control units 15 and 16 supplying electric power to these first and second stepping motors 12 and 14 and controlling their drive, a temperature detection circuit 7 detecting the temperature of the heat generated by these first and second motor drive control units 15 and 16 and outputting temperature detection signals, and a system control circuit 3 switching the allocation of the main drive unit or the auxiliary drive unit based on the temperature detection signals outputted from the allocation and temperature detection circuit 7 allocating one of the first or second stepping motors 12 or 14 to serve as the main drive unit or the auxiliary drive unit when the detected temperature has exceeded the previously set reference temperature.

Claims10

Dependent claims

A drive unit operable to drive a driven part comprising:

a first and a second stepping motor for transmitting power corresponding to a load torque of the driven part to the driven part;
a first and a second motor control unit for respectively supplying electric power to said first and second stepping motors and for respectively controlling a driving operation of said first and second stepping motors;
a speed detection circuit for detecting a driving speed of the driven part and for outputting speed detection signals;
a temperature detection section for detecting a temperature generated by each of said first and second motor control units and for outputting temperature detection signals;
and
a system control circuit for determining a driving output of said first and second motor control units based on the speed detection signals output by said speed detection circuit for allocating one of said first and second stepping motors as a main drive unit and the other of said first and second stepping motors as an auxiliary drive unit, wherein a driving output of said auxiliary drive unit is modified according to said speed detection signals, and for switching an allocation of said first and second stepping motors as said main drive unit and said auxiliary drive unit based on the temperature detection signals output from said temperature detection section when the temperature of one of said first and second motor drive control units exceeds a reference temperature.

3 more elements

Dependencies are inferred from the claim text.