Abstract: When it is determined that the number of times that motor rotation-indicative quantity has been detected has exceeded a measurement interval, a feedback speed value is calculated from a motor rotation-indicative quantity detected immediately before, a motor rotation-indicative quantity detected immediately before the last time a measurement interval determination means determined that the number of times had exceeded the measurement interval, and time that has elapsed since the last time the measurement interval determination means determined that the number of times had exceeded the measurement interval, and the measurement interval having a length calculated from a greater one between the calculated feedback speed value and a speed command value is set for the measurement interval determination means to refer to.

Abstract: The present invention is to provide an electro hydrostatic actuator excellent in a snubbing characteristic including a cylinder type actuator main body 1, a piston 2 having a piston rod, the piston slidingly moving in a cylinder of the actuator main body, a motor 18, a pump 19 for supplying fluid according to the rotation of the motor, a mechanism for adjusting a running amount of the fluid into and from the cylinder according to the motion of the piston, and a reservoir 8 for adjusting the supply of the fluid corresponding to a volume difference generated according to the motion of the piston, and a controller 17 which controls the number of revolutions of the motor according to the calculated load torque, and a snubbing control method used for this. An electro hydrostatic actuator of realizing a snubbing mechanism capable of increasing energy efficiency, when used for a landing gear retraction/extension device of an airplane, can be provided.

Abstract: When it is determined that the number of times that motor rotation-indicative quantity has been detected has exceeded a measurement interval, a feedback speed value is calculated from a motor rotation-indicative quantity detected immediately before, a motor rotation-indicative quantity detected immediately before the last time a measurement interval determination means determined that the number of times had exceeded the measurement interval, and time that has elapsed since the last time the measurement interval determination means determined that the number of times had exceeded the measurement interval, and the measurement interval having a length calculated from a greater one between the calculated feedback speed value and a speed command value is set for the measurement interval determination means to refer to.

Abstract: The present invention is to provide an electro hydrostatic actuator excellent in a snubbing characteristic including a cylinder type actuator main body 1, a piston 2 having a piston rod, the piston slidingly moving in a cylinder of the actuator main body, a motor 18, a pump 19 for supplying fluid according to the rotation of the motor, a mechanism for adjusting a running amount of the fluid into and from the cylinder according to the motion of the piston, and a reservoir 8 for adjusting the supply of the fluid corresponding to a volume difference generated according to the motion of the piston, and a controller 17 which controls the number of revolutions of the motor according to the calculated load torque, and a snubbing control method used for this. An electro hydrostatic actuator of realizing a snubbing mechanism capable of increasing energy efficiency, when used for a landing gear retraction/extension device of an airplane, can be provided.