Actuator system for articulated mechanism
An actuator system for articulated mechanism may have a fluid actuator having a displaceable member operating an output configured to apply an output force to the articulated mechanism. A fluid system may be in fluid communication with the fluid actuator to supply the fluid actuator with motive fluid to contribute to the output force. The fluid system may include a pressure reservoir configured for storing fluid, a pumping device for controlling a pressure of the fluid in the reservoir, and a circuit for directing the fluid from the reservoir to the fluid actuator. An actuator device may be operatively connected to the fluid actuator to apply a variable force to the displaceable member to contribute to the output force.
1 . An actuator system comprising:
a fluid actuator having a displaceable member operating an output configured to apply an output force;
a fluid system in fluid communication with the fluid actuator to supply the fluid actuator with motive fluid to contribute to the output force, the fluid system including
a reservoir configured for storing fluid under pressure,
a pressurizing device for increasing a pressure of the fluid in the reservoir, and
a circuit for directing the fluid from the reservoir to the fluid actuator; and
an actuator device operatively connected to the fluid actuator to apply a variable force to the displaceable member to contribute to the output force.
2 . The actuator system according to claim 1 , wherein the fluid actuator is a hydraulic cylinder and the displaceable member is a piston, the actuator device being an electric motor connected to the piston by a piston rod.
3 . The actuator system according to claim 2 , wherein the electric motor and the piston rod form an electro-mechanical actuator device.
4 . The actuator system according to claim 3 , wherein the electro-mechanical actuator device is a ball screw device.
5 . The actuator system according to claim 1 , wherein the fluid actuator is a rotary actuator.
6 . The actuator system according to claim 5 , wherein the actuator device is an electric motor connected to a vane of the rotary actuator.
7 . The actuator system according to claim 1 , wherein the pressure reservoir is part of a spring-loaded cylinder.
8 . The actuator system according to claim 1 , wherein the pressure reservoir is part of a diaphragm reservoir.
9 . The actuator system according to claim 1 , further including a secondary reservoir, the pressurizing device directing fluid from the secondary reservoir to the pressure reservoir.
10 . The actuator system according to claim 1 , wherein the pressurizing device includes a pump.
11 . The actuator system according to claim 1 , wherein the circuit includes a valve between the reservoir and the fluid actuator to selectively control a supply of the motive hydraulic fluid.
12 . The actuator system according to claim 1 , further including a hydrostatic transmission formed by the fluid actuator and at least one slave actuator for transmission of the output force.
13 . The actuator system according to claim 12 , including a plurality of the slave actuator for a single one of the fluid actuator.
14 . The actuator system according to claim 12 , wherein the slave actuator is a slave rotary actuator.
15 . The actuator system according to claim 12 , wherein the slave actuator is a slave cylinder.
16 . The actuator system according to claim 1 , further including a controller unit operatively controlling the pressurizing device and the actuator device.
17 . The actuator system according to claim 16 , wherein the controller unit operatively controls the pressurizing device for the reservoir to provide the motive fluid to the fluid actuator to oppose against a constant load.
18 . A system comprising:
an articulated mechanism having links interconnected by at least one joint; and
an actuator system according to claim 1 to apply an output force between the links to move the links relative to one another about the at least one joint.
19 . An actuator system comprising:
a fluid actuator having a displaceable member operating an output configured to apply an output force;
a fluid system in fluid communication with the fluid actuator to supply the fluid actuator with motive fluid to contribute to the output force, the fluid system including
a reservoir configured for storing fluid under pressure,
a pressurizing device for increasing a pressure of the fluid in the reservoir, and
a circuit for directing the fluid from the reservoir to the fluid actuator, whereby the motive fluid is supplied by the reservoir directly to the fluid actuator; and
an actuator device operatively connected to the fluid actuator to apply a variable force to the displaceable member to contribute to the output force.
20 . An actuator system comprising:
a fluid actuator having a displaceable member operating an output configured to apply an output force;
a fluid system including
a reservoir configured for storing fluid under pressure,
a pressurizing device for increasing a pressure of the fluid in the reservoir, and
a circuit for directing the fluid from the reservoir to the fluid actuator; and
an actuator device operatively connected to the fluid actuator to apply a variable force to the displaceable member to contribute to the output force;
wherein the reservoir of the fluid system is in fluid communication with the fluid actuator, whereby the reservoir supplies the fluid actuator with motive fluid to contribute to the output force, such that the output force is a combination of a pressure from the reservoir and of the variable force from the actuator device.