US 12,410,581 B2
Electric cylinder and work machine
Hideshi Iitani, Tokyo (JP); and Shouta Akazaki, Tokyo (JP)
Assigned to KOMATSU LTD., Tokyo (JP)
Appl. No. 18/730,372
Filed by Komatsu Ltd., Tokyo (JP)
PCT Filed Nov. 17, 2022, PCT No. PCT/JP2022/042709
§ 371(c)(1), (2) Date Jul. 19, 2024,
PCT Pub. No. WO2023/139906, PCT Pub. Date Jul. 27, 2023.
Claims priority of application No. 2022-007049 (JP), filed on Jan. 20, 2022.
Prior Publication US 2025/0101707 A1, Mar. 27, 2025
Int. Cl. E02F 3/42 (2006.01); E02F 3/32 (2006.01); F16H 25/20 (2006.01); F16H 25/24 (2006.01)
CPC E02F 3/425 (2013.01) [E02F 3/32 (2013.01); F16H 25/24 (2013.01); F16H 2025/2081 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An electric cylinder comprising:
a motor that is a driving source;
an output shaft configured to rotate in response to driving of the motor;
a sun gear coupled to the output shaft and configured to rotate in response to rotation of the output shaft;
a tubular holder disposed adjacent to an axial end surface of the motor and including a fluid accommodation portion that allows a magnetic fluid to be accommodated between the holder and an outer periphery of the sun gear;
a pair of magnetic pole pieces provided on an inner peripheral surface of the holder; and
a magnet disposed between the pair of magnetic pole pieces and configured to hold the magnetic fluid in the fluid accommodation portion by using an action of a magnetic field.