Piston position measuring device
AssigneeRosemount Inc.
InventorsDavid E. Wiklund, Terrance F. Krouth, Richard J. Habegger, Richard R. Hineman
Life of this patent
Estimating the term…
Abstract
A measuring device is provided for determining a position of a piston contained within a hydraulic actuator as a function of a hydraulic fluid flow. The measuring device includes a bi-directional flow sensor positioned inline with the hydraulic fluid flow and a piston position module. The flow sensor is configured to produce a flow rate signal that is indicative flow rate of the hydraulic fluid flow into and out of a first cavity. The piston position module is configured to receive the flow rate signal from the flow sensor and produce a piston position signal that is indicative of the position of the piston within the hydraulic actuator as a function of the flow rate signal.
Claims21
A device for measuring a position of a piston slidably contained within a hydraulic cylinder of a hydraulic actuator, the piston and the hydraulic cylinder define a first cavity that receives a hydraulic fluid flow, the device comprising:
- a bi-directional flow sensor positioned inline with the hydraulic fluid flow and having a flow rate signal output that is indicative of a flow rate of the hydraulic fluid into and out of the first cavity and is based on differential pressure;
- and
- a piston position module adapted to receive the flow rate signal output and responsively provide a piston position signal output related to the piston position within the hydraulic cylinder as a function of the flow rate signal output.
A hydraulic actuator, comprising:
- a hydraulic cylinder having first and second ports formed therein for receiving first and second hydraulic fluid flows therethrough, respectively;
- a piston slidably received in the hydraulic cylinder, wherein the piston and the hydraulic cylinder define first and second cavities fluidically coupled to the first and second hydraulic fluid flows through the first and second ports respectively;
- a first flow sensor positioned inline with the first hydraulic fluid flow and having a first flow rate signal output that is indicative of a flow rate of the first hydraulic fluid flow into and out of the first cavity and is based upon differential pressure;
- and
- a piston position module adapted to receive the first flow rate signal and having a first piston position signal output, produced as function of the first flow rate signal, that is related to a first position of the piston within the hydraulic cylinder.
A method of measuring a position of a piston slidably contained within a hydraulic cylinder of a hydraulic actuator, the piston and the hydraulic cylinder define a first cavity, the method comprising:
- measuring a differential pressure in a flow of hydraulic fluid into and out of the first cavity;
- determining a flow rate of hydraulic fluid into the first cavity as a function of the differential pressure;
- and
- calculating the position of the piston within the hydraulic cylinder as a function of the fluid flow rate.
Dependencies are inferred from the claim text.