US Patent No. 9,224,546

BRAKE DRIVE CONTROLLING DEVICE FOR PROMPTLY SWITCHING STATE OF BRAKE FROM RELEASED STATE TO FASTENED STATE


Patent No. 9,224,546
Issue Date December 29, 2015
Title Brake Drive Controlling Device For Promptly Switching State Of Brake From Released State To Fastened State
Inventorship Yasuyuki Matsumoto, Yamanashi (JP)
Naoyuki Suzuki, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 9,224,546

1. A brake drive controlling device that controls drive of a brake by electric power stored in a DC link unit connected to
an AC power supply via a converter, for switching the brake from a released state to a fastened state by stopping a brake
drive current flowing in the brake that brakes a driven body driven in a gravity axis direction by a motor, the brake drive
controlling device comprising:
a first switching device that is connected to one end of the brake wherein a switch command is input to the first switching
device so that a state of the first switching device is switched from an off-state to an on-state to cause a brake drive current
to flow in the brake;

a second switching device that is connected to the other end of the brake wherein the switch command is input to the second
switching device so that a state of the second switching device is switched from an off-state to an on-state to cause a brake
drive current to flow in the brake;

a first rectifying device, one end being connected to the other end of the brake, and the other end being connected to one
end of the DC link unit; and

a second rectifying device, one end being connected to the other end of the DC link unit, and the other end being connected
to the one end of the brake; and

a third device that prevents a flow of energy between the brake and at least one different brake that are connected in parallel
with each other, wherein the flow is caused by a difference in counter electromotive force between the brake and the at least
one different brake,

wherein when the first switching device and the second switching device are in the off-states, at least either the first rectifying
device or the second rectifying device returns, to the DC link unit, energy that is stored in the brake when at least either
the first switching device or the second switching device is in the on-state.