US20150158669A1

US20150158669A1 - Hydraulic tank fill system

Info

Publication number: US20150158669A1
Application number: US14/624,615
Authority: US
Inventors: Edward W. Mate; Kevin D. Kolonsky
Original assignee: Caterpillar Global Mining LLC
Current assignee: Caterpillar Global Mining LLC
Priority date: 2015-02-18
Filing date: 2015-02-18
Publication date: 2015-06-11
Also published as: CN205371116U

Abstract

A hydraulic tank fill system for a machine includes a tank, a valve operatively coupled to the tank, and a supply line in communication with the valve and the tank. The supply line supplies a fluid into the tank from a fluid source. A breather device installed on a top portion of the tank exerts a pressure on the fluid in the tank for controlling at least one of an operating pressure associated with the tank. A vent line in communication with the valve and the top portion of the tank to receive an excess quantity of the fluid based on the exertion of pressure on the fluid in the tank. An orifice disposed in the vent line exerts a back pressure on the excess quantity of the fluid received into the vent line.

Description

TECHNICAL FIELD

The present disclosure relates to a hydraulic tank fill system for a machine, and more particularly to a system for controlling fluid fill parameters of the hydraulic tank.

BACKGROUND

Machines such as, miners, dozers, loaders, excavators, motor graders, and other types of heavy machinery use one or more hydraulic actuators to accomplish a variety of tasks. These actuators are fluidly connected to a tank on the machine and, using pumps, provide pressurized fluid to chambers within the actuators. Valve arrangements are fluidly connected between the tank and the actuators to control a flow rate and direction of pressurized fluid flow to and from the chambers of the actuators. Thus, the fluid from the tank is continuously provided to the actuators, and the fluid follows a closed hydraulic circuit and is fed back to the tank. With time and use or due to leakage in the hydraulic circuit, the fluid in the tank requires refilling.
Conventionally, a mining machine employs a venturi type apparatus to fill the tank. The venturi type design does not include any automatic stop system associated with the filling of the tank, due to which, the tank may be overfilled. This may further result in the fluid exiting through breathers installed on the tank, and additionally causing clogging of the breathers in some situations. Oil saturated breathers may not operate efficiently and are prone to further clogging from fluid particles. Overfilling the tank leads to wastage of the fluid from a filling source, the filling source meant for refilling the tank. Further, overfilling of the tank reduces space available for expansion of the fluid during high temperature conditions.
U.S. Pat. No. 7,299,820, hereinafter referred to as the '820 patent, relates to an anti-overflow partition provided in a hydraulic reservoir. In order to prevent hydraulic fluid infiltrating out from a hydraulic fluid tank when a vehicle is in operation, the tank is compartmentalized by the anti-overflow partition. In the '820 patent, the anti-overflow partition includes a wall like structure provided in the hydraulic reservoir which maintains the fluid at different levels and further holding air captive to avoid reaching of the fluid to the feed orifice during a leaning operation of the reservoir. However, such system does not function as an automatic system incorporating state of the art components for filling the reservoir and simultaneously preventing overfilling from the reservoir.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a hydraulic tank fill system for a machine is disclosed. The hydraulic tank fill system includes a tank configured to store a fluid. The hydraulic tank system further includes a valve operatively coupled to the tank. The hydraulic tank system also includes a supply line in communication with the valve and the tank. The supply line is configured to supply the fluid into the tank from a fluid source. The hydraulic tank system also includes a breather device installed on a top portion of the tank. The breather device is configured to exert a pressure on the fluid in the tank for controlling at least one of an operating pressure associated with the tank. The hydraulic tank system further includes a vent line in communication with the valve and the top portion of the tank. The vent line is configured to receive an excess quantity of the fluid based on the exertion of pressure on the fluid in the tank. The hydraulic tank system also includes an orifice disposed in the vent line. The orifice being sized such that the orifice is configured to exert a back pressure on the excess quantity of the fluid received into the vent line.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective top view of an exemplary machine, according to one embodiment of the present disclosure;

FIG. 2 is a schematic diagram of a hydraulic tank fill system associated with the machine of FIG. 1, according to one embodiment of the present disclosure; and

FIG. 3 is schematic diagram of a hydraulic tank fill system associated with the machine of FIG. 1, according to another embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to specific aspects or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.
FIG. 1 illustrates an exemplary machine 100. The machine 100 is a continuous miner Alternatively, the machine 100 may be a fixed or mobile machine that performs operations associated with an industry such as mining, construction, farming, or any other industry known in the art. For example, the machine 100 may be an earth moving machine such as a miner, dozer, a loader, a backhoe, an excavator, a motor grader, a dump truck, or any other earth moving machine. The machine 100 may also embody a generator set, a pump, a marine vessel, or any other suitable machine.
The machine 100 includes a frame 102, at least one implement 104, and at least one hydraulic actuator 106 between the implement 104 and the frame 102. The implement 104 is embodied as a mining tooth. Alternatively, the implement 104 may include any other worktool used for the performance of a task by the respective machine. For example, the implement 104 may include a blade, a bucket, a shovel, a ripper, a dump bed, a propelling device, or any other task-performing device known in the art. The implement 104 rotates and moves relative to the frame 102. The frame 102 includes a structural unit that supports movement of the machine 100.
The frame 102 is a stationary base frame connecting a power source (not shown) of the machine 100 to a traction device 108, a movable frame member of a linkage system, or any other frame known in the art. The hydraulic actuator 106 present on the machine 100 is a hydraulically operated component, and is operable on provision of a hydraulic fluid under pressure. Such hydraulic fluid is provided to the hydraulic actuator 106 via a tank 202 (see FIG. 2) present on the machine 100. In an example, the tank 202 is positioned proximate to a portion 110 as labelled on the machine 100 in the accompanying figures.
FIG. 2 illustrates a hydraulic tank fill system 200 associated with the machine 100. The hydraulic tank fill system 200 includes the tank 202. The tank 202 is configured to store a fluid 204. The tank 202 may be a cuboidal shaped structure having a base portion 206, a top portion 210, and one or more walls 208 extending perpendicularly between the base portion 206 and the top portion 210. In alternative embodiments, the tank 202 may include any geometrical shape. The fluid 204 stored in the tank 202 is configured to be transferred to the hydraulic actuator 106 for operation of the hydraulic actuator 106. The fluid 204 may be transferred to the hydraulic actuator 106 via a hydraulic pump 203. The hydraulic pump 203 may be any type of known positive displacement pump. Alternatively, the hydraulic pump 203 may be any other component serving the purpose of supplying the fluid 204 from the tank 202 to different components of the machine 100. In an example, the hydraulic pump 203 may be a 30 GPM flow pump.
As the hydraulic pump 203 operates, the fluid 204 from the tank 202 is continuously supplied to the hydraulic actuator 106, and the fluid 204 is again fed back to the tank 202 following a closed loop cycle. The hydraulic tank fill system 200 further includes a valve 212 operatively coupled to the tank 202. In an embodiment, the valve 212 is a manually activated dual valve configured to be operated by an operator of the machine 100. The valve 212 is a 2 position, 4 way valve. Alternatively, the valve 212 disclosed herein may be any type of a known 4-way, 2-position valve. In one example, the valve 212 may be a 4-way, 2-positon ball valve. Alternatively, the valve 212 may be a 4-way, 3-position valve. Alternatively, the valve 212 may be any semi-automatic or automatic shut-off valve known in the art. The valve 212 is a directional control valve and is configured to turn on or off the flow of the fluid 204 into and from the hydraulic tank fill system 200 on being operated by the operator of the machine 100. In operation, the operator of the machine 100 may operate an activation switch (not shown) disposed either on an exterior or interior of the machine 100 for activating or deactivating the valve 212.
The hydraulic tank fill system 200 further includes a supply line including a first supply line 213 and a second supply line 214. The second supply line 214 is in communication with the valve 212 and the tank 202, and the first supply line 213 is in communication with the valve 212 and the hydraulic pump 203. Further, a venturi or jet pump 215 is provided on the second supply line 214. The venturi or jet pump 215 is configured to regulate flow of the fluid 204 in the hydraulic tank fill system 200 on activation of the valve 212. The fluid source 216, in communication with the venturi or jet pump 215, may be any mobile or immobile source for supplying the fluid 204. The venturi or jet pump 215 is configured to create a siphon effect in the second supply line 214 which acts as a driving source and is configured to transfer the fluid 204 from the fluid source 216 into the tank 202. The first and second supply lines 213, 214 may be embodied as a hose or fluid conduit. Generally the second supply line 214 is connected to a bottom portion of the tank 202. The first and second supply lines 213, 214 are configured to supply the fluid 204 into the tank 202 on activation of the valve 212. Although not explicitly shown, the hydraulic tank fill system 200 may include other hydraulic components disposed on the second supply line 214 such as, a relief valve configured to regulate line pressure, a return filter having specifications corresponding to the machine 100, etc.
With use and time, or due to leakage of the fluid 204 from the hydraulic tank fill system 200, a level of the fluid 204 may decrease within the tank 202, and thereby requiring refilling or replenishment. In an example, a desired fluid height “H” of the fluid 204 needs to be maintained in the tank 202 for optimum operation of the machine 100. In an embodiment, the fluid 204 is refilled into the tank 202 by mechanically coupling the fluid source 216 to the tank 202, in order to increase the level of the fluid 204 in the tank 202. The fluid source 216 may be coupled to the tank 202 via the first and second supply lines 213, 214, on operation of the valve 212, and will be explained in detail later in this section.
The hydraulic tank fill system 200 further includes a breather device 218 installed at the top portion 210 of the tank 202. The breather device 218 may be any state of the art air breathing equipment known in the art. The breather device 218 is configured to exert a pressure on a top level of the fluid 204 in the tank 202. The pressure exerted on the top level of the fluid 204 is denoted by arrows with a label “P”. The specifications of the breather device 218 are selected corresponding to the hydraulic pump 203. In an example, the breather device 218 may be a 10 Psig breather device. The breather device 218 is configured to maintain an air pocket above the fluid 204 within the tank 202. The air pocket exerts the pressure “P” on the top level of the fluid 204. Further, the air pocket is maintained in the tank 202 for exerting the pressure “P” on the top level of the fluid 204 in order to control an operating pressure of the fluid 204, a flow rate of the fluid 204 exiting the tank 202, or both associated with the tank 202. The pressure “P” has an impact on the siphon effect through the second supply line 214 because of the pressure exerted on the discharge of the venturi or jet pump 215.
A partition wall 220 is provided inside the tank 202. The partition wall 220 extends perpendicularly from the top portion 210 of the tank 202. In an embodiment, the air pocket is maintained between a first wall of the one or more walls 208 and the partition wall 220 to exert the pressure “P” on the fluid 204. A partition chamber 222 is formed between the partition wall 220, the top portion 210, and a second wall of the one or more walls 208 of the tank.
The hydraulic tank fill system 200 further includes a vent line having a first vent line 223 and a second vent line 224. The second vent line 224 is in communication with the partition chamber 222. The first and second vent lines 223, 224 are fluidly connected with the valve 212. The second vent line 224 is positioned at the top portion 210 of the tank 202. In an embodiment, the second vent line 224 is configured to receive an excess quantity of the fluid 204 based on the exertion of the pressure “P” on the fluid 204 in the tank 202 and in the second supply line 213. The excess quantity of the fluid 204 may be defined as quantity of the fluid 204 exceeding the desired fluid height “H” in the tank 202 while performing the fill operation.
In operation, as the level of the fluid 204 recedes below the desired fluid height “H”, the operator operates the valve 212 to an active state. The valve 212 being a dual valve, fluidly connects the first supply line 213 with the second supply line 214, and the first vent line 223 with the second vent line 224 of the hydraulic tank fill system 200 in the active state (connections denoted as “L”). Further, the fluid 204 is transferred from the fluid source 216 to the tank 202 based on the siphon effect mentioned earlier. As described earlier, the air pocket is maintained in the tank 202, by the breather device 218, for exerting the pressure “P” on the fluid 204. During the fill operation, as the fluid 204 reaches the desired fluid height “H” within the tank 202, the air pocket exerts the pressure “P” on the fluid 204. This pressure “P” causes pushing of excess quantity of the fluid 204 that is more than the desired fluid height “H”, towards the partition chamber 222. The excess quantity of the fluid 204 that reaches the partition chamber 222 is received by the second vent line 224.
The hydraulic tank fill system 200 further includes an orifice 226 disposed in the second vent line 224. In an embodiment, the orifice 226 is sized such that it is configured to exert a back pressure on the excess quantity of the fluid 204 received into the second vent line 224. The exerted back pressure will restrict flow of the fluid 204 through the second vent line 224. The sizing of the orifice 226 is dependent on the specifications of the venturi or jet pump 215, and other hydraulic components, such as, the breather device 218. In an example, the back pressure exerted by the orifice 226 may be in the range of 8-10 Psig. Thus, under the combined effect of the pressure “P” exerted on the fluid 204 within the tank 202, and the back pressure exerted on the excess fluid 204 within the second vent line 224, the desired fluid height “H” is maintained within the hydraulic tank fill system 200. Additionally, loss of the fluid 204 may be contained within the hydraulic tank fill system 200 in view of the back pressure.
Although not shown, the hydraulic tank fill system 200 may include one or more indication devices, such as, any audio or video device configured to alert and inform the operator about reaching or exceeding the desired fluid height “H” and flow of the fluid 204 into the second vent line 224. Accordingly the operator may deactivate the valve 212 to shut both the first and second supply lines 213, 214 and the first and second vent lines 223, 224, thereby disconnecting the connection “L”. The first vent line 223 further includes a breather 228 for keeping external contaminants out of the hydraulic tank fill system 200 and the tank 202. Alternatively, the breather 228 may be replaced with a check valve or the like apparatus.
FIG. 3 illustrates a hydraulic tank fill system 300 associated with the machine 100, according to another embodiment of the present disclosure. The hydraulic tank fill system 300 includes similar components with inherent functionality corresponding to the hydraulic tank fill system 200, except for a second tank 302 which replaces the tank 202 of the prior explained embodiment. The second tank 302 does not include the partition chamber 222, in view of absence of the partition wall 220. Absence of the partition wall 220 in the second tank 302 will provide more space to the air pocket for exerting the pressure “P” on the fluid 204. The second tank 302 further includes a vent extension 304 disposed at the top portion 210 of the second tank 302. The vent extension 304 extends from the top portion 210 within the second tank 302. The vent extension 304 is in communication with the second vent line 224, and is configured to receive the excess quantity of the fluid 204 on exertion of the pressure “P”, and further transfer the excess quantity of the fluid 204 to the second vent line 224. The working of the hydraulic tank fill system 300 is similar to that of the hydraulic tank fill system 200 as described earlier.

INDUSTRIAL APPLICABILITY

The industrial applicability of the hydraulic tank fill system 200, 300 described herein will be readily appreciated from the foregoing discussion. As described earlier, the hydraulic tank fill system 200, 300 includes the breather device 218 configured to maintain the air pocket in the tanks 202, 302. The air pocket exerts the pressure “P” on the fluid 204 as the fluid 204 attains the desired fluid height “H”, and further pushes out the excess fluid 204 into the second vent line 224.
The orifice 226 provided in the second vent line 224 is sized to exert the back pressure on the excess fluid 204, as received into the second vent line 224. The simultaneous pressure “P” exerted on the fluid 204 on achieving the desired fluid height “H”, and the back pressure exerted on the excess fluid 204 received into the second vent line 224, acts as an automatic shut-off system for the hydraulic tank fill system 200, 300 that maintains the desired fluid height “H’ and also prevents the excess fluid 204 from overflowing from the tank 202, 302. It should be noted that the hydraulic tank fill system 200, 300 may cause a reduction in overfill of the tanks 202, 302. The presence of the air pocket also prevents the fluid 204 from reaching the breather device 218, thereby preventing clogging. The hydraulic tank fill system 200, 300 employs state of the art components that can be easily and cost effectively retrofitted with conventional hydraulic systems on equipment similar to the machine 100.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

Claims

What is claimed is:

1. A hydraulic tank fill system for a machine, the hydraulic tank fill system comprising:

a tank configured to store a fluid;

a valve operatively coupled to the tank;

a supply line in communication with the valve and the tank, the supply line configured to supply the fluid into the tank from a fluid source;

a breather device installed on a top portion of the tank, the breather device configured to exert a pressure on the fluid in the tank for controlling at least one of an operating pressure associated with the tank;

a vent line in communication with the valve and the top portion of the tank, the vent line configured to receive an excess quantity of the fluid based on the exertion of pressure on the fluid in the tank; and

an orifice disposed in the vent line, the orifice being sized such that the orifice is configured to exert a back pressure on the excess quantity of the fluid received into the vent line.