# US 2014/0193230 A1 · Hydraulic fluid warm-up > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0193230 A1 - Document ID: US20140193230A1 - Status: Published application - Kind: A1 - Application number: 13/793,795 - Filed: 2013-03-11 - Published: 2014-07-10 - Earliest claimed: 2013-01-08 - Assignees: Deere & Company - Applicants: Deere & Company - Inventors: Erik W. McWethy - Web page: https://patentgrep.com/patent/US20140193230A1 ## CPC - E02F 3/435: {for dipper-arms, backhoes or the like} - E02F 9/226: {Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating} - F15B 21/0427: Heating - F01P 3/20: Cooling circuits not specific to a single part of engine or machine (F01P3/22 takes precedence) - F01P 7/165: {characterised by systems with two or more loops} - F01P 2060/02: Intercooler - F01P 2060/04: Lubricant cooler - F01P 2060/08: Cabin heater - F15B 21/0423: Cooling - F15B 2211/30505: Non-return valves, i.e. check valves - F15B 2211/41563: being connected to a pressure source and a return line - F15B 2211/611: Diverting circuits, e.g. for cooling or filtering - F15B 2211/62: Cooling or heating means - F15B 2211/6343: representing a temperature - F15B 2211/851: during starting - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - F01P: COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES (arrangements in connection with cooling of propulsion units in vehicles B60K11/00; heat-transfer, heat-exchange or heat-storage materials C09K5/00; {cooling of gas-turbine engines F02C7/12}; heat exchange in general, radiators F28) ## 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. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The work vehicle of claim 1, wherein the controller is in electrical communication with at least one of the first and second flow control devices. ### Claim 3 (depends on 1) The work vehicle of claim 1, wherein the controller adjusts at least one of the first and second passage pressures based on at least one of: a temperature input; a time input; and a manual input from an operator of the work vehicle. ### Claim 4 (depends on 3) The work vehicle of claim 3, wherein the controller adjusts at least one of the first and second passage pressures to: direct the hydraulic fluid along the first return line when the temperature input indicates that the hydraulic fluid is at or above a predetermined temperature; and direct the hydraulic fluid along the second return line when the temperature input indicates that the hydraulic fluid is below the predetermined temperature. ### Claim 5 (depends on 4) The work vehicle of claim 4, wherein the predetermined temperature is about 40° C. or more. ### Claim 6 (depends on 1) The work vehicle of claim 1, wherein the first flow control device includes a first check valve having a first cracking pressure, and the second flow control device includes a second check valve having a second cracking pressure. ### Claim 7 (depends on 6) The work vehicle of claim 6, further including a regulating valve in communication with the controller and the first check valve, the regulating valve having: a first, neutral position that allows pressure to escape from the first check valve; and a second position that directs pressure into the first check valve to increase the first cracking pressure of the first check valve. ### Claim 8 (depends on 7) The work vehicle of claim 7, wherein the regulating valve is a proportional valve that is adjustable to at least one intermediate position between the first and second positions. ### Claim 9 (depends on 1) The work vehicle of claim 1, wherein the second passage pressure of the second flow control device normally exceeds the first passage pressure of the first flow control device, such that hydraulic fluid normally travels through the first flow control device and the cooler on the first return line. ### Claim 10 (depends on 9) The work vehicle of claim 9, wherein, during initial operation of the work vehicle, the controller at least one of: increases the first passage pressure of the first flow control device above the second passage pressure of the second flow control device; and decreases the second passage pressure of the second flow control device below the first passage pressure of the first flow control device; wherein the hydraulic fluid travels through the second flow control device on the second return line while bypassing the cooler on the first return line. ### Claim 11 (depends on 1) The work vehicle of claim 1, wherein: the first flow control device includes at least one of a check valve, a pressure relief valve, and an orifice; and the second flow control device includes at least one of a check valve, a pressure relief valve, and an orifice. ### Claim 12 (depends on 1) The work vehicle of claim 1, wherein the controller comprises an on-off switch. ### Claim 13 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. ### Claim 14 (depends on 13) The work vehicle of claim 13, wherein the controller adjusts the hydraulic circuit based on at least one of: a temperature input; a time input; and a manual input from an operator of the work vehicle. ### Claim 15 (depends on 13) The work vehicle of claim 13, wherein the controller is in electrical communication with a regulating valve, and the regulating valve directs a pilot signal to a flow control device to adjust the hydraulic circuit between the first cooling mode and the second bypass mode. ### Claim 16 (depends on 13) The work vehicle of claim 13, wherein the controller operates the hydraulic circuit in the first cooling mode when the hydraulic fluid is at or above a predetermined temperature, and in the second bypass mode when the hydraulic fluid is below the predetermined temperature. ### Claim 17 (depends on 13) The work vehicle of claim 13, wherein the controller comprises an on-off switch. ### Claim 18 (depends on 13) The work vehicle of claim 13, wherein the at least one hydraulic actuator operates a work tool that is movably coupled to the chassis of the work vehicle. ### Claim 19 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. ### Claim 20 (depends on 19) The method of claim 19, wherein the second return line is normally restricted relative to the first return line to direct the hydraulic fluid through the cooler on the first return line. ### Claim 21 (depends on 19) The method of claim 19, wherein restricting the first return line relative to the second return line includes at least one of: restricting the first return line; and opening the second return line.