US 11,735,991 B2
Actuator
Katsuya Fukushima, Tokyo (JP); Masashi Ishii, Tokyo (JP); Hiroki Niwa, Tokyo (JP); Akira Suzuki, Tokyo (JP); Kazuto Oga, Tokyo (JP); Shogo Wakuta, Tokyo (JP); Satoshi Hara, Tokyo (JP); Tomofumi Mizuno, Tokyo (JP); and Shigeki Hayashi, Kawasaki (JP)
Assigned to THK CO., LTD., Tokyo (JP)
Appl. No. 17/284,932
Filed by THK CO., LTD., Tokyo (JP)
PCT Filed Oct. 8, 2019, PCT No. PCT/JP2019/039633
§ 371(c)(1), (2) Date Apr. 13, 2021,
PCT Pub. No. WO2020/080181, PCT Pub. Date Apr. 23, 2020.
Claims priority of application No. 2018-197700 (JP), filed on Oct. 19, 2018.
Prior Publication US 2021/0379760 A1, Dec. 9, 2021
Int. Cl. H02P 25/06 (2016.01); H02K 41/03 (2006.01)
CPC H02K 41/031 (2013.01) [H02P 25/06 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An actuator comprising:
a shaft;
a linear motion motor including a stator and a mover, wherein movement of the mover in parallel with a central axis of the shaft relative to the stator of the linear motion motor causes the shaft to move in a direction of the central axis;
a connecting member that is at least a part of a member connecting the mover of the linear motion motor and the shaft;
a force sensor provided in the connecting member, an output of the force sensor being according to a force applied to the connecting member;
an amplifier that amplifies the output of the force sensor;
a low-pass filter that reduces components of frequencies higher than a cut-off frequency, among components of frequencies included in an output from the amplifier; and
a control device that detects a load applied to the shaft, based on the output from the amplifier, until the shaft or a member associated with the shaft comes in contact with an other member, and that detects the load applied to the shaft, based on an output from the low-pass filter, after the shaft or the member associated with the shaft comes in contact with the other member.