WO2013086885A1

WO2013086885A1 - Driving system of engineering machinery and closed hydraulic circuit thereof

Info

Publication number: WO2013086885A1
Application number: PCT/CN2012/082182
Authority: WO
Inventors: 詹纯新; 刘权; 张建军; 李义; 李英智; 宋院归; 王启涛
Original assignee: 中联重科股份有限公司; 湖南中联重科专用车有限责任公司
Priority date: 2011-12-15
Filing date: 2012-09-27
Publication date: 2013-06-20
Also published as: CN102555793B; CN102555793A

Abstract

Disclosed is a closed hydraulic circuit. A first switch valve is connected between the first interface of a closed oil pump and the first interface of a motor via a pipeline, and a second switch valve is connected between the second interface of the closed oil pump and the second interface of the motor via a pipeline. The oil output of an oil-compensation pump is divided into a first branch, a second branch and a third branch, wherein the first branch is connected to the pipe between the first switch valve and the first interface of the closed oil pump via a first oil-compensation valve; the second branch is connected to the pipe between the second switch valve and the second interface of the closed oil pump via a second oil-compensation valve; and the third branch divides into two branches after connecting to a one-way lock valve, wherein one branch is connected to the pipe between the first switch valve and the first interface of the motor via a first safety valve, the other branch is connected to the pipe between the second switch valve and the second interface of the motor via a second safety valve. An accumulator is connected to the pipeline between the one-way lock valve and each of the safety valves.

Description

Construction machinery drive system and closed hydraulic circuit

Technical field

The present invention relates to a drive system, and more particularly to a drive system for a construction machine and a closed hydraulic circuit therefor. Background technique

Hydraulic transmission is a liquid working medium, which realizes energy conversion, transmission and control through various hydraulic components. It has been widely used in various mechanical equipments as one of the key basic technologies of modern transmission and control. In many construction machinery, such as excavators, cranes, bulldozers, hydraulic transmission and full hydraulic drive are commonly used.

The hydraulic circuit of the hydraulic transmission can be divided into an open hydraulic circuit and a closed hydraulic circuit according to the circulation mode of the working medium. The closed hydraulic circuit has low energy consumption, compact structure and easy to realize stepless speed change, and has been widely used in engineering machinery walking systems.

Referring to Figure 1, a closed hydraulic circuit of an existing application engineering machine includes a closed oil pump 11, a charge pump 12, a replenishing oil 13, a replenishing overflow 14, a motor 15 and a fuel tank 16. The closed oil pump 11 and the motor 15 are directly connected through a pipe, and the shifting and commutation of the motor 15 are realized by changing the variable of the closed oil pump 11 to change the flow rate and direction of the hydraulic oil in the main oil passage. The charge pump 12 is connected to the motor on the two sides of the motor 15 through the oil supply line 13 to compensate for the leakage of the system. The charge pump 12 and the oil overflow overflow 14 and the fuel tank 16 form a circuit. The charge pump 12 draws oil from the oil tank 16 and some oil is used to compensate the leakage flow of the system. Most of the oil is recirculated through the oil overflow overflow 14 Fuel tank 16.

When the construction machinery is in the state of standing slope, the anti-torque and rotation tendency of the axle will drive the motor to move from the static to the rotating direction, causing the motor to be pressed. However, the existing closed hydraulic circuit cannot withstand the motor rolling, and the motor is easy to rotate, thereby driving the axle to rotate, and the phenomenon of rolling occurs. This does not apply to the drive system of construction machinery. Summary of the invention

The present invention provides a closed hydraulic circuit that is suitable for use in a drive system of a construction machine. Further, the present invention provides a drive system for a construction machine having the above closed hydraulic circuit. In order to achieve the above advantages, the present invention provides a closed hydraulic circuit including a closed oil pump, a motor, a charge pump, a first oil fill and a second oil fill, the closed oil pump including a first interface and a second interface The motor includes a first interface and a second interface, and the closed hydraulic circuit further includes a first switching width, a second switching width, a one-way locking width, an energy storage component, a first safety width, and a second safety width The first switching width is connected between the first interface of the closed oil pump and the first interface of the motor through a pipeline, and the second switching width is connected to the second interface of the closed oil pump and the motor by a pipeline. Between the two interfaces; the oil output of the charge pump is divided into a first branch, a second branch and a third branch, wherein the first branch is connected to the first switched wide and closed oil pump through the first supplemental oil On the pipe between the first interface, the second branch is connected to the pipe between the second interface of the second switching wide and closed oil pump through the second oil filling, and the third branch is connected to the one-way locking After splitting into two branches, one of which passes through the a safety wide connection to the conduit between the first switching width and the first interface of the motor, and the other branch being connected to the conduit between the second switching width and the second interface of the motor via the second safety wide, The energy storage component is connected to the line between the one-way lock width and each safety gap.

In an embodiment of the present invention, the first interface of the closed oil pump is connected to the first switching width through a first pipe, and the first switching width is connected to the first interface of the motor through a second pipe. The second port of the closed oil pump is connected to the second switch width through a third pipe, and the second switch is connected to the second port of the motor through a fourth pipe.

In an embodiment of the invention, the closed oil pump and the charge pump are dual working pumps. In an embodiment of the invention, the closed oil pump and the charge pump are coupled to different drive devices.

In an embodiment of the invention, the closed hydraulic circuit further includes a fuel tank and a replenishing overflow. The charge overflow overflow is connected between the charge pump and the oil tank.

In an embodiment of the invention, the energy storage component is an accumulator or an accumulator cylinder.

The invention also provides a driving system for a construction machine, comprising an engine, an axle reducer and an axle, the drive system further comprising the closed hydraulic circuit, the engine and the closed oil pump and the charge pump Drive connection, the motor is drivingly connected to the axle reducer, and the axle reducer is drivingly connected to the axle.

Compared with the prior art, when the vehicle is stopped, the first switching mode and the second switching mode are closed, the oil source at both ends of the motor is completely cut off, and the oil source at both ends of the motor is in the first and second safety. The wide set pressure is relatively closed so that it can withstand the pressure. Even when the motor leaks due to volumetric efficiency problems, the oil of the energy storage component can compensate the low pressure chamber in time, thus avoiding the vehicle standing on the slope, the engine stalling and not making A slowdown caused a safety accident.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

detailed description

Referring to Figures 2 and 3, the drive system 1000 of the construction machine of the present invention includes a closed hydraulic circuit 200, an engine 300, an axle reducer 400, an axle 500, and a tire 600 mounted on the axle 500.

The closed hydraulic circuit 200 includes a main circuit 70 and an oil replenishing device 30. The main circuit 70 includes a closed oil pump 20, a first switching width 75, a motor 40, and a second switching width 76. The closed oil pump 20 includes a first interface 22 and a second interface 24. Motor 40 includes a first interface 42 and a second interface 44. Closed oil The first interface 22 of the pump 20 is connected to the first switching width 75 via a first conduit 71, and the first switching width 75 is connected to the first interface 42 of the motor 40 via a second conduit 72. The second switching width 76 is connected to the second interface 24 of the closed oil pump 20 via a third conduit 73, and the second interface 44 of the motor 40 is connected to the second switching width 76 by a fourth conduit 74. When the first switching width 75 and the second switching width 76 are simultaneously closed, the oil of the pipe 71 and the pipe 72 is completely blocked by the first switching width 75, and the oil of the pipe 73 and the pipe 74 is widened by the second switching. 76 completely blocked.

The oil replenishing device 30 includes a fuel tank 60, a charge pump 31, a first oil replenishing width 32a, a second oil replenishing width 32b, an oil filling overflow width 33, a one-way locking width 35, an energy storage member 36, and a first safety wide 37. And the second safety is 38. In this embodiment, the energy storage component is an accumulator or an accumulator cylinder. The charge pump 31 draws oil from the oil tank 60, and the oil of the charge pump 31 is divided into three branch outputs, and the first branch is connected to the first interface of the first switch width 75 and the closed oil pump 20 through the first charge width 32a. 22 on the pipe 71. The second branch is connected to the conduit 73 between the second switching width 76 and the second port 24 of the closed oil pump 20 via the second oil filling line 32b. The third branch is connected to the one-way lock width 35 and then divided into two branches, one of which is connected to the duct 72 between the first switch width 75 and the first interface 42 of the motor 40 through the first safety barrier 37. The other branch is connected to the conduit 74 between the second switching width 76 and the second interface 44 of the motor 40 via a second safety flange 38; the charge overflow manifold 33 is connected between the charge pump 31 and the fuel tank 60, The excess oil of the charge pump 31 is returned to the tank 60. The energy storage component 36 is connected to the line between the one-way lock width 35 and each of the safety widths 37/38. The one-way lock width 35 is provided so that the oil can only flow from the charge pump 31 into the energy storage component 36. However, the charge pump 31 cannot be flown from the accumulator member 36.

The first switching width 75 and the second switching width 76 are used to open or cut off the oil source at both ends of the motor 40. The first oil filling width 32a and the second oil filling width 32b are used for the oil filling of the closed oil pump 20 and the system pressure setting during the normal operation of the driving system; the first safety width 37 and the second safety width 38 are used for the motor 40 to be stationary. The system pressure setting when the oil is replenished and the drive system is at rest; the oil filling overflow width 33 is mainly used for the charge pressure setting of the low pressure chamber when the hydraulic system is working. When the vehicle is running under normal driving, the third branch outputted by the charge pump 31 only charges the energy storage component 36 and does not perform oil replenishment work on the system. It is carried out by the first and second branches.

The engine 300 is drivingly coupled to the closed oil pump 20 and the charge pump 31, the motor 40 is drivingly coupled to the axle reducer 400, and the axle reducer 400 is drivingly coupled to the axle 500. By changing the rotational speed of the engine 300 to change the output flow of the closed oil pump 20 and the input amount of the motor 40, the mechanical energy is converted into hydraulic energy to drive the motor 40 to drive the vehicle. The engine 300 can drive the oil of the closed oil pump 20 to flow in both directions, so that the motor 40 can move in both directions to push the engineering machine forward or backward.

The oil can flow from the first port 22 of the closed oil pump 20, through the first switching width 75, the motor 40 and the second switching width 76, and return to the closed oil pump 20. At this time, the first ports 42 of the pipes 71, 72 and the motor 40 are the high pressure side, and the pipes 73, 74 and the second port 44 of the motor 40 are the low pressure side. When the drive system is in operation, the oil of the charge pump 31 is compensated for the pipe 73 through the second charge width 32b. When the drive system is at rest, the oil of the energy storage component 36 is compensated for by the second safety flange 38.

The oil may also flow from the second port 24 of the closed oil pump 20, through the second switching block 76, the motor 40 and the first switching width 75, and return to the closed oil pump 20. At this time, the second ports 44 of the pipes 73, 74 and the motor 40 are the high pressure side, and the pipes 71, 72 and the first port 42 of the motor 40 are the low pressure side. When the drive system is in operation, the oil of the charge pump 31 compensates the pipe 71 through the first charge width 32a. When the drive system is stationary, the oil of the energy storage component 36 is compensated by the first safety barrier 37.

In the present embodiment, the charge pump 31 and the closed oil pump 20 are duplex working pumps, and are all connected to the engine 300. However, it will be appreciated by those skilled in the art that the charge pump 31 and the closed oil pump 20 can also be driven by respective drive means, rather than the duplex type of the same drive unit.

When the vehicle is driving, the power oil source is output from the closed oil pump 20, and the charge pump 31 realizes the low pressure chamber replenishment and the accumulating member 36 is stamped. At this time, the first switching width 75 and the second switching width 76 are opened, and the oil source is Directly driving the motor 40 to rotate, the bidirectional rotation of the motor 40 can be realized, that is, the vehicle Forward and reverse functions. When the vehicle is on the slope, the engine is turned off and there is no braking, the anti-torque and the turning tendency of the axle 500 will drive the motor 40 to move from the stationary to the rotating direction to cause the motor 40 to be pressed; but since the engine 300 is stopped, the first The switching width 75 and the second switching width 76 are closed, the oil source at both ends of the motor 40 is completely cut off, and the oil source at both ends of the motor 40 is relatively closed under the pressure set by the first and second safety widths 37 and 38, so that the pressure can be withstood. Even when the motor 40 leaks due to volumetric efficiency problems, the oil of the accumulator component 36 can compensate the low pressure chamber in time, thereby preventing the vehicle from slipping and causing a safety accident when the vehicle is parked, the engine is turned off, and there is no braking.

The above is only the embodiment of the present invention, and is not intended to limit the scope of the present invention. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. The equivalents of the technical solutions disclosed above may be modified or modified to equivalent variations without departing from the technical scope of the present invention, without departing from the technical scope of the present invention. Any simple modifications, equivalent changes and modifications made by the embodiments are still within the scope of the technical solutions of the present invention.

Claims

Rights request

A closed hydraulic circuit comprising a closed oil pump, a motor, a charge pump, a first oil fill and a second oil fill, the closed oil pump comprising a first interface and a second interface, the motor comprising An interface and a second interface, wherein: the closed hydraulic circuit further comprises a first switching width, a second switching width, a one-way locking width, an energy storage component, a first safety wide and a second safety wide. The first switching width is connected between the first interface of the closed oil pump and the first interface of the motor through a pipeline, and the second switching width is connected through the pipeline to the second interface of the closed oil pump and the second interface of the motor The oil output of the charge pump is divided into a first branch, a second branch and a third branch, wherein the first branch is connected to the first switching wide and closed oil pump through the first oil filling On the pipe between the interfaces, the second branch is connected to the pipe between the second interface of the second switching wide and closed oil pump through the second oil filling, and the third branch is connected to the one-way locking and is divided into Two branches, one of which passes through the first safe wide Connected to the pipe between the first switching width and the first interface of the motor, and the other branch is connected to the pipe between the second switching width and the second interface of the motor through the second safety wide, the energy storage component Connect to the line between the one-way lock and each safety fence.

2 . The closed hydraulic circuit according to claim 1 , wherein: the first interface of the closed oil pump is connected to the first switching width through a first pipe, and the first switching width and the motor are An interface is connected between the second pipe through a second pipe, and the second port of the closed oil pump is connected to the second switch width through a third pipe, and the second switch is connected to the second interface of the motor through the fourth pipe connection.

The closed hydraulic circuit according to claim 1, wherein the closed oil pump and the charge pump are double working pumps.

4. The closed hydraulic circuit of claim 1 wherein: said closed oil pump and said The charge pump is connected to different drive units.

5. The closed hydraulic circuit of claim 1 wherein: said closed hydraulic circuit further comprises a fuel tank and a charge overflow overflow, said charge overflow overflow being connected to said charge pump and said Between the fuel tanks.

The closed hydraulic circuit according to claim 1, wherein the energy storage member is an accumulator or an accumulator cylinder.

7. A drive system for a construction machine, comprising an engine, an axle reducer and an axle, characterized in that: the drive system further comprises a closed hydraulic circuit according to any one of claims 1 to 6, The engine is drivingly coupled to the closed oil pump and the charge pump, the motor is drivingly coupled to the axle reducer, and the axle reducer is drivingly coupled to the axle.