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US 10,890,197 B2Granted
Hydraulic actuator with a frequency dependent relative pressure ratio
AssigneeClearMotion, Inc.
InventorsJoseph Thomas Belter, Graham A. Dowie, Marco Giovanardi, Brian Alexander Selden
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Abstract
Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.
Claims23
A hydraulic actuator comprising:
- a hydraulic cylinder that includes an extension chamber and a compression chamber;
- a hydraulic pump, with a first port and a second port, capable of generating a pressure differential between the compression chamber and the extension chamber;
- a hydraulic circuit including an extension-side and a compression-side, wherein the extension-side of the circuit includes the extension chamber and a first fluid flow path fluidically connecting the first port to the extension chamber, and wherein the compression-side of the circuit includes the compression chamber and a second fluid flow path fluidically connecting the second port to the compression chamber;
- wherein the hydraulic actuator exhibits a first relative compliance factor when exposed to a first oscillating input, and a second relative compliance factor when exposed to a second oscillating input, wherein:
- the frequency of the first oscillating input is less than the frequency of the second oscillating input, and
- the first relative compliance factor is greater than the second relative compliance factor.
3 more elements
A hydraulic actuator comprising:
- a hydraulic cylinder that includes an extension chamber and a compression chamber;
- a hydraulic pump, with a first port and a second port, capable of generating a pressure differential between the compression chamber the extension chamber;
- a first compliance element;
- a second compliance element;
- a first fluid flow path fluidically connecting the first port to the first compliance element;
- a second fluid flow path fluidically connecting the first port to the extension chamber;
- a third fluid flow path fluidically connecting the second port to the second compliance element;
- a fourth fluid flow path fluidically connecting the second port to the compression chamber;
- wherein the hydraulic actuator exhibits a first relative compliance factor when exposed to a first oscillating input, and a second relative compliance factor when exposed to a second oscillating input, wherein:
- the frequency of the first oscillating input is less than the frequency of the second oscillating input, and
- the first relative compliance factor is greater than the second relative compliance factor.
8 more elements
A hydraulic actuator comprising:
- a hydraulic cylinder that includes an extension chamber and a compression chamber;
- a hydraulic pump, with a first port and a second port, arranged to generate a pressure differential between the compression chamber the extension chamber;
- a first gas charged accumulator;
- a second gas charged accumulator;
- a first fluid flow path fluidically connecting the first port to the first gas charged accumulator;
- a second fluid flow path fluidically connecting the first port to the extension chamber;
- a third fluid flow path fluidically connecting the second port to the second gas charged accumulator;
- a fourth fluid low path fluidically connecting the second port to the compression chamber;
- wherein the hydraulic actuator exhibits a first relative pressure factor in response to a first oscillating input, and a second relative pressure factor in response to a second oscillating input, and wherein:
- the frequency of the first oscillating input is below the frequency of the second oscillating input;
- and
- the first relative pressure factor is less than the second relative pressure factor.
9 more elements
A method of operating a hydraulic actuator having a hydraulic cylinder with a piston slidably received in the hydraulic cylinder and dividing the hydraulic cylinder into an extension chamber and a compression chamber, the method comprising:
- applying a first oscillating input to the actuator, wherein the first oscillating input generates a first pressure wave in the extension chamber and a second pressure wave in the compression chamber, wherein a ratio of an amplitude of the first pressure wave to an amplitude of the second pressure wave is a first relative pressure factor;
- and
- applying a second oscillating input to the actuator, wherein the second oscillating input generates a third pressure wave in the extension chamber and a fourth pressure wave in the compression chamber, wherein a ratio of an amplitude of the third pressure wave to an amplitude of the fourth pressure wave is a second relative pressure factor;
- wherein a frequency of the second oscillating input is greater than a frequency of the first oscillating input;
- and wherein the second relative pressure factor is greater than the first relative pressure factor.
2 more elements
Dependencies are inferred from the claim text.