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US 2014/0193230 A1Published application
Hydraulic fluid warm-up
AssigneeDeere & Company
InventorErik W. McWethy
Life of this patent
Estimating the term…
Abstract
A work vehicle including a hydraulic circuit having a cooled return line with a cooler, a bypass return line that bypasses the cooler on the cooled return line, and a controller that electronically controls the flow of hydraulic fluid between the cooled return line and the bypass return line.
Claims21
A work vehicle including:
- a chassis;
- at least one traction device supporting the chassis;
- at least one hydraulic actuator coupled to the chassis;
- a hydraulic circuit configured to operate the at least one hydraulic actuator, the hydraulic circuit including:
- a source of hydraulic fluid;
- a delivery device in fluid communication with the source and the at least one hydraulic actuator to deliver the hydraulic fluid to the at least one hydraulic actuator;
- a first return line from the delivery device to the source, the first return line including a first flow control device and a cooler, the first flow control device allowing the hydraulic fluid to travel along the first return line when a pressure in the hydraulic circuit exceeds a first passage pressure of the first flow control device;
- a second return line from the delivery device to the source that bypasses the cooler on the first return line, the second return line including a second flow control device, the second flow control device allowing the hydraulic fluid to travel along the second return line when the pressure in the hydraulic circuit exceeds a second passage pressure of the second flow control device;
- and
- a controller in communication with at least one of the first and second flow control devices to adjust at least one of the first and second passage pressures.
7 more elements
A work vehicle including:
- a chassis;
- at least one traction device supporting the chassis;
- at least one hydraulic actuator coupled to the chassis;
- a hydraulic circuit configured to operate the at least one hydraulic actuator, the hydraulic circuit including:
- a source of hydraulic fluid;
- a delivery device in fluid communication with the source and the at least one hydraulic actuator to deliver the hydraulic fluid to the at least one hydraulic actuator;
- a first return line from the delivery device to the source, the first return line including a cooler;
- a second return line from the delivery device to the source;
- and
- a controller that electronically adjusts the hydraulic circuit between:
- a first cooling mode, wherein the second return line is restricted more than the first return line to direct the hydraulic fluid through the cooler on the first return line;
- and a second bypass mode, wherein the first return line is restricted more than the second return line to direct the hydraulic fluid through the second return line while bypassing the cooler on the first return line.
9 more elements
A method of operating a work vehicle, the work vehicle including a chassis and at least one hydraulic actuator coupled to the chassis, the method including the steps of:
- directing hydraulic fluid from a source to the at least one hydraulic actuator;
- returning the hydraulic fluid from the at least one hydraulic actuator to the source via at least one of:
- a first return line that includes a cooler;
- and
- a second return line;
- and
- electrically restricting the first return line relative to the second return line to direct the hydraulic fluid through the second return line while bypassing the cooler on the first return line.
4 more elements
Dependencies are inferred from the claim text.