Hydraulic systems for mobile machines and associated methods
A mobile machine including: a frame; at least left and right propulsion devices on left and right sides of the mobile machine; and a hydraulic system including: a left hydraulic cylinder configured to adjust a distance between the frame and the left propulsion device, and having a rod end and a blind end; a right hydraulic cylinder configured to adjust a distance between the frame and the right propulsion device, and having a rod end and a blind end; a first valve set movable between positions permitting and preventing flow of hydraulic fluid between the rod ends of the left and hydraulic cylinders; and a second valve set movable between positions permitting and preventing the flow of the hydraulic fluid between the blind ends of the left and right hydraulic cylinders.
1 . A mobile machine, comprising:
a frame;
a plurality of propulsion devices supported by the frame, the plurality of propulsion devices including at least a left propulsion device on a left side of the mobile machine, and a right propulsion device on a right side of the mobile machine; and
a hydraulic system, comprising:
a left hydraulic cylinder configured to adjust a distance between the frame and the left propulsion device, the left hydraulic cylinder comprising a rod end and a blind end;
a right hydraulic cylinder configured to adjust a distance between the frame and the right propulsion device, the right hydraulic cylinder comprising a rod end and a blind end;
a first valve set movable between positions permitting and preventing flow of hydraulic fluid between the rod end of the left hydraulic cylinder and the rod end of the right hydraulic cylinder; and
a second valve set movable between positions permitting and preventing the flow of the hydraulic fluid between the blind end of the left hydraulic cylinder and the blind end of the right hydraulic cylinder,
wherein positioning the first and second valve sets in the positions preventing flow prevents fluid from flowing between the left and right hydraulic cylinders.
2 . The mobile machine of claim 1 , further comprising:
a rotor assembly supported by the frame, wherein the rotor assembly is selectively deployable to pulverize a layer of a ground surface under the mobile machine.
3 . The mobile machine of claim 1 , wherein the hydraulic system further comprises:
a tank supported by the frame, the tank configured to retain the hydraulic fluid and to supply the hydraulic fluid; and
a pump supported by the frame, the pump configured to receive the hydraulic fluid from the tank, to pressurize the received hydraulic fluid, and to flow the pressurized hydraulic fluid to the left hydraulic cylinder and the right hydraulic cylinder.
4 . The mobile machine of claim 1 , wherein the left propulsion device comprises a left rear propulsion device on a left rear portion of the mobile machine,
wherein the right propulsion device comprises a right rear propulsion device on a right rear portion of the mobile machine,
wherein the left hydraulic cylinder comprises a left rear hydraulic cylinder on the left rear portion of the mobile machine,
wherein the right hydraulic cylinder comprises a right rear hydraulic cylinder on the right rear portion of the mobile machine.
5 . The mobile machine of claim 4 , wherein the plurality of propulsion devices includes a left front propulsion device on a left front portion of the mobile machine, and a right front propulsion device on a right front portion of the mobile machine,
wherein the hydraulic system further comprises:
a left front hydraulic cylinder configured to adjust a distance between the frame and the left front propulsion device; and
a right front hydraulic cylinder configured to adjust a distance between the frame and the right front propulsion device.
6 . The mobile machine of claim 4 , wherein the hydraulic system further comprises a controller configured to operate the first valve set and the second valve set in a first mode and a second mode, such that:
in the first mode, the controller positions the first valve set to prevent the flow of the hydraulic fluid between the rod end of the left rear hydraulic cylinder and the rod end of the right rear hydraulic cylinder, and positions the second valve set to prevent the flow of the hydraulic fluid between the blind end of the left rear hydraulic cylinder and the blind end of the right rear hydraulic cylinder, and
in the second mode, the controller positions the first valve set to permit the flow of the hydraulic fluid between the rod end of the left rear hydraulic cylinder and the rod end of the right rear hydraulic cylinder, and positions the second valve set to permit the flow of the hydraulic fluid between the blind end of the left rear hydraulic cylinder and the blind end of the right rear hydraulic cylinder.
7 . The mobile machine of claim 1 , wherein the hydraulic system further comprises a controller configured to operate the first valve set and the second valve set in a first mode and a second mode, such that in the first mode the controller positions the first valve set to prevent the flow of the hydraulic fluid between the rod end of the left hydraulic cylinder and the rod end of the right hydraulic cylinder, and positions the second valve set to prevent the flow of the hydraulic fluid between the blind end of the left hydraulic cylinder and the blind end of the right hydraulic cylinder, and such that in the second mode the controller positions the first valve set to permit the flow of the hydraulic fluid between the rod end of the left hydraulic cylinder and the rod end of the right hydraulic cylinder, and positions the second valve set to permit the flow of the hydraulic fluid between the blind end of the left hydraulic cylinder and the blind end of the right hydraulic cylinder.
8 . The mobile machine of claim 7 , wherein the controller is configured to operate the first valve set and the second valve set in the first mode or the second mode based on at least one of a speed of the mobile machine, a distance the mobile machine has traveled, a slope of the mobile machine, or an elapsed travel time of the mobile machine.
9 . The mobile machine of claim 1 , wherein each of the left propulsion device and the right propulsion device are on a same end of the mobile machine,
wherein each of the left hydraulic cylinder and the right hydraulic cylinder are on the same end of the mobile machine as the left propulsion device and the right propulsion device.
10 . A hydraulic system for a road reclaimer, the hydraulic system comprising:
a left hydraulic cylinder configured to adjust a position of a left propulsion device of the road reclaimer, the left hydraulic cylinder comprising a rod end and a blind end;
a right hydraulic cylinder configured to adjust a position of a right propulsion device of the road reclaimer, the right hydraulic cylinder comprising a rod end and a blind end;
a first valve set positionable to permit and prevent flow of hydraulic fluid between the rod end of the left hydraulic cylinder and the rod end of the right hydraulic cylinder; and
a second valve set positionable to permit and prevent the flow of the hydraulic fluid between the blind end of the left hydraulic cylinder and the blind end of the right hydraulic cylinder,
wherein the rod end of the right hydraulic cylinder is not fluidly connected to the blind end of the left hydraulic cylinder.
11 . The hydraulic system of claim 10 , further comprising:
a tank configured to retain the hydraulic fluid and to supply the hydraulic fluid; and
a pump configured to receive the hydraulic fluid from the tank, to pressurize the received hydraulic fluid, and to flow the pressurized hydraulic fluid to the left hydraulic cylinder and the right hydraulic cylinder.
12 . The hydraulic system of claim 10 , wherein the left hydraulic cylinder comprises a left rear hydraulic cylinder configured to be installed on a left rear portion of the road reclaimer,
wherein the right hydraulic cylinder comprises a right rear hydraulic cylinder configured to be installed on a right rear portion of the road reclaimer.
13 . The hydraulic system of claim 12 , wherein the hydraulic system further comprises:
a left front hydraulic cylinder configured to adjust a position of a left front propulsion device of the road reclaimer; and
a right front hydraulic cylinder configured to adjust a position of a right front propulsion device of the road reclaimer.
14 . The hydraulic system of claim 12 , wherein the hydraulic system further comprises a controller configured to operate the first valve set and the second valve set in a first mode and a second mode, such that in the first mode the controller positions the first valve set to prevent the flow of the hydraulic fluid between the rod end of the left rear hydraulic cylinder and the rod end of the right rear hydraulic cylinder, and positions the second valve set to prevent the flow of the hydraulic fluid between the blind end of the left rear hydraulic cylinder and the blind end of the right rear hydraulic cylinder, and such that in the second mode the controller positions the first valve set to permit the flow of the hydraulic fluid between the rod end of the left rear hydraulic cylinder and the rod end of the right rear hydraulic cylinder, and positions the second valve set to permit the flow of the hydraulic fluid between the blind end of the left rear hydraulic cylinder and the blind end of the right rear hydraulic cylinder.
15 . The hydraulic system of claim 10 , wherein the hydraulic system further comprises a controller configured to operate the first valve set and the second valve set in a first mode and a second mode, such that in the first mode the controller positions the first valve set to prevent the flow of the hydraulic fluid between the rod end of the left hydraulic cylinder and the rod end of the right hydraulic cylinder, and positions the second valve set to prevent the flow of the hydraulic fluid between the blind end of the left hydraulic cylinder and the blind end of the right hydraulic cylinder, and such that in the second mode the controller positions the first valve set to permit the flow of the hydraulic fluid between the rod end of the left hydraulic cylinder and the rod end of the right hydraulic cylinder, and positions the second valve set to permit the flow of the hydraulic fluid between the blind end of the left hydraulic cylinder and the blind end of the right hydraulic cylinder.
16 . The hydraulic system of claim 15 , wherein the controller is configured to operate the first valve set and the second valve set in the first mode or the second mode based on at least one of a speed of the road reclaimer, a distance the road reclaimer has traveled, a slope of the road reclaimer, or an elapsed travel time of the road reclaimer.
17 . The hydraulic system of claim 10 , further comprising a controller, wherein the controller is configured to control the first valve set and the second valve set to open together, and to control the first valve set and the second valve set to close together.
18 . A method of operating a mobile machine including a left rear propulsion device on a left side of the mobile machine, a right rear propulsion device on a right side of the mobile machine, and a hydraulic system including a left rear hydraulic cylinder having a rod end and a blind end and configured to adjust a height of the left rear propulsion device, a right rear hydraulic cylinder having a rod end and a blind end and configured to adjust a height of the right rear propulsion device, a first valve set between the rod end of the left rear hydraulic cylinder and the rod end of the right rear hydraulic cylinder, and a second valve set between the blind end of the left rear hydraulic cylinder and the blind end of the right rear hydraulic cylinder, the method comprising:
with a controller of the mobile machine:
positioning the first valve set and the second valve set to prevent flow of hydraulic fluid between the left rear hydraulic cylinder and the right rear hydraulic cylinder when at least one of a slope of the machine is above a first predetermined slope or a travel time of the machine is below a predetermined travel time; and
positioning the first valve set and the second valve set to permit the flow of the hydraulic fluid between the left rear hydraulic cylinder and right rear hydraulic cylinder when at least one of the slope of the machine is below a second predetermined slope or the travel time of the machine is above the predetermined travel time.
19 . The method of claim 18 , wherein positioning the first valve set and the second valve set to permit flow comprises:
positioning the first valve set to permit the flow of the hydraulic fluid between the blind ends of the left rear hydraulic cylinder and the right rear hydraulic cylinder, and
positioning the second valve set to permit the flow of the hydraulic fluid between the rod ends of the left rear hydraulic cylinder and the right rear hydraulic cylinder.
20 . The method of claim 18 , wherein positioning the first valve set and the second valve set to prevent flow comprises:
positioning the first valve set to prevent the flow of the hydraulic fluid between the blind ends of the left rear hydraulic cylinder and the right rear hydraulic cylinder, and positioning the second valve set to prevent the flow of the hydraulic fluid between the rod ends of the left rear hydraulic cylinder and the right rear hydraulic cylinder.