Hydrostatic transmission system of loading machine

Abstract

The hydrostatic transmission system comprises an engine, a closed walking pump, a hydraulic oil tank, an oil supplementing pump, a walking motor set, a transfer case proportional electromagnetic valve, a transfer case and a drive axle. The engine is in transmission connection with the closed walking pump; the closed walking pump and the walking motor group form a closed system with a circulating oil path; the closed walking pump is also used for supplementing oil from the hydraulic oil tank through an oil supplementing pump, and a T port of the closed walking pump is communicated with the hydraulic oil tank; the walking motor set is in transmission connection with the transfer case. The transfer case proportional electromagnetic valve is communicated with the transfer case and is used for controlling the transfer case; the transfer case is in transmission connection with the drive axle; the hydrostatic transmission system is utilized, and the hydraulic efficiency is high, so that the fuel efficiency can be improved, and better performance improvement is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of loaders, in particular to a static hydraulic transmission system of a loader. Background Art

[0002] Loaders are earthwork machines widely used in construction projects such as highways, railways, buildings, hydropower, ports, and mines. Traditional loaders use traditional torque converters and gearboxes to achieve kinetic energy transmission, but they have the following defects: 1. The travel noise is high; 2. The mechanical transmission efficiency is low and the fuel consumption is high; 3. The forward and reverse gear shifting has a large impact, which has a large impact on the structural parts and low driving comfort; 4. The maintenance cost of the entire life cycle is high, and the overrunning clutch is easily damaged; 5. The operating comfort is poor, and the gears need to be shifted back and forth by hand. Utility Model Content

[0003] The utility model aims to provide a hydrostatic transmission system for a loader, which can improve fuel efficiency and achieve better performance improvement.

[0004] In order to achieve the above purpose, the solution of the utility model is:

[0005] A hydrostatic transmission system of a loader includes an engine, a closed travel pump, a hydraulic oil tank, a supplementary oil pump, a travel motor group, a transfer case proportional solenoid valve, a transfer case and a drive axle;

[0006] The engine is drivingly connected to the closed travel pump;

[0007] The closed travel pump and the travel motor group form a closed system with a circulating oil circuit; the closed travel pump is also replenished with oil from the hydraulic oil tank through an oil replenishment pump, and the T port of the closed travel pump is connected to the hydraulic oil tank;

[0008] The travel motor group is connected to the transfer case in a transmission manner; the transfer case proportional solenoid valve is connected to the transfer case for controlling the transfer case; the transfer case is connected to the drive axle in a transmission manner;

[0009] The travel motor group includes a first travel motor and a second travel motor;

[0010] The S port of the closed travel pump is connected to the A port of the first travel motor and the B port of the second travel motor through the oil collecting block, and the P port of the closed travel pump is connected to the B port of the first travel motor and the A port of the second travel motor through the oil collecting block;

[0011] The T1 port of the first travel motor is connected to the T2 port of the second travel motor, and the T1 port of the second travel motor is connected to the U port of the closed travel pump.

[0012] Furthermore, the first power take-off port of the engine is provided with a coupling, and is transmission-connected to the closed travel pump via the coupling.

[0013] Furthermore, the oil replenishment pump is installed at the second power take-off port of the engine.

[0014] Furthermore, the input end of the oil replenishment pump is communicated with the hydraulic oil tank, and an oil suction filter is provided between the input end and the hydraulic oil tank; the output end of the oil replenishment pump is communicated with the F port of the closed travel pump.

[0015] Furthermore, a pressure oil filter is installed at the output end of the oil replenishment pump, and the output of the pressure oil filter is divided into two paths, the first path is connected to the F port of the closed travel pump, and the second path is provided with a three-way piece so that the second path is connected to the U port of the first travel motor and the U port of the second travel motor respectively.

[0016] Furthermore, a pressure oil filter is installed at the output end of the oil replenishment pump, and the output of the pressure oil filter is divided into two paths, the first path is connected to the F port of the closed travel pump, and the second path is provided with a four-way piece so that the second path is respectively connected to the U port of the first travel motor, the U port of the second travel motor and the oil supply port of the transfer case proportional solenoid valve.

[0017] Furthermore, T2 of the first travel motor is also connected to a cooling system, and the cooling system is connected to the hydraulic oil tank via an oil return filter.

[0018] Furthermore, a one-way valve is provided between the T-port of the closed travel pump and the hydraulic oil tank, the one-way valve being connected toward the hydraulic oil tank.

[0019] After adopting the above technical solution, the closed travel pump is directly driven by the engine, and then the closed travel pump drives the travel motor group through hydraulics, and then the transfer case is hydraulically driven by the electronic control system through the transfer case proportional solenoid valve. That is, by utilizing the hydrostatic transmission system, due to the high hydraulic efficiency, fuel efficiency can be improved to achieve better performance improvement.

[0020] The whole vehicle is driven to move by changing the flow rate. Compared with the traditional structure, the entire hydrostatic transmission system of the utility model has no gears and can achieve stepless speed regulation. The engine speed and machine speed can change smoothly and continuously, so that the engine can maximize its efficiency within a more effective range and reduce the heat load generated by the transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A connection block diagram of an embodiment of the utility model;

[0022] Figure 2 This is a system principle diagram of an embodiment of the utility model.

[0023] Explanation of reference numerals: engine 1, first power take-off port 11, second power take-off port 12, closed travel pump 2, oil supply line 21, oil return line 22, hydraulic oil tank 3, oil replenishment pump 4, oil suction filter element 41, oil pressure filter 42, first line 421, second line 422, travel motor group 5, first travel motor 51, second travel motor 52, transfer case proportional solenoid valve 6, transfer case 7, drive axle 8, cooling system 9, return oil filter element 91, check valve 10. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] like Figure 1 and Figure 2 As shown, a hydrostatic transmission system of a loader includes an engine 1, a closed travel pump 2, a hydraulic oil tank 3, an oil replenishment pump 4, a travel motor group 5, a transfer case proportional solenoid valve 6, a transfer case 7 and a drive axle 8.

[0026] The engine 1 is drivingly connected to the closed travel pump 2 for driving the closed travel pump 2 to rotate.

[0027] The closed travel pump 2 and the travel motor group 5 form a closed system with a circulating oil circuit; the closed travel pump 2 is also replenished with oil from the hydraulic oil tank 3 through the oil replenishment pump 4, and the T port (return oil port) of the closed travel pump 2 is connected to the hydraulic oil tank 3 for returning oil to maintain the needs of the closed system.

[0028] The travel motor group 5 is transmission-connected to the transfer case 7 , and the travel motor group 7 is mounted on the power take-off port of the transfer case 7 .

[0029] The transfer case proportional solenoid valve 6 is connected to the transfer case 7 and is used to control the transfer case 7. This is a prior art and the specific working principle will not be described in detail.

[0030] The transfer case 7 is in driving connection with the drive axle 8 for distributing power to the drive axle to drive the loader to move.

[0031] By this, the hydrostatic transmission system of the loader of the utility model directly drives the closed travel pump 2 by the engine 1, and then the closed travel pump 2 drives the travel motor group 5 by hydraulic pressure. Due to the high hydraulic efficiency, the fuel efficiency can be improved; and the transfer case 7 is hydraulically driven by the transfer case proportional solenoid valve 6 through the electronic control system (existing technology, not shown in the figure). By using the hydrostatic transmission system, better performance improvement can be achieved.

[0032] The vehicle is driven to move by changing the flow rate. The entire hydrostatic transmission system has no gears and can achieve stepless speed regulation. The engine 1 speed and the machine speed can change smoothly and continuously, so that the engine 1 can maximize its efficiency within a more effective range and reduce the heat load generated by the transmission system.

[0033] In this embodiment, the first power take-off port 11 of the engine 1 is provided with a coupling (not shown), and is transmission-connected to the closed travel pump 2 through the coupling. The closed travel pump 2 of this embodiment takes the model HPV165 as an example.

[0034] The second power take-off port 12 of the engine 1 is equipped with the oil replenishment pump 4, which is used to drive the oil replenishment pump 4 to rotate so as to replenish oil to the closed system. The input end of the oil replenishment pump 4 is connected to the hydraulic oil tank 3, and an oil suction filter 41 may be provided between the input end and the hydraulic oil tank 3; the output end of the oil replenishment pump 4 is connected to the F port (oil replenishment port) of the closed travel pump 2, which is used to replenish oil to the closed travel pump 2.

[0035] The travel motor group 5 includes a first travel motor 51 and a second travel motor 52. The first travel motor 51 and the second travel motor 52 of this embodiment have different powers and can respectively adopt CMV170 and CMV215 hydraulic motors.

[0036] The S port (oil outlet) of the closed travel pump 2 is connected to the A port (oil inlet) of the first travel motor 51 and the B port (oil inlet) of the second travel motor 52 through an oil collecting block (not shown in the figure), and the P port (oil outlet) of the closed travel pump 2 is connected to the B port (oil inlet) of the first travel motor 51 and the A port (oil inlet) of the second travel motor 52 through an oil collecting block, thereby forming an oil supply circuit 21 of the closed travel pump 2 to the travel motor group 5, that is, a working oil circuit. The hydraulic oil output by the closed travel pump 2 can be distributed to the A port and the B port of the first travel motor 51, and the A port and the B port of the second travel motor 52 through the S port and the P port, respectively, to drive the travel motor group 5 to operate.

[0037] The T1 port (return oil port) of the first travel motor 51 is connected to the T2 port (return oil port) of the second travel motor 52, and the T1 port (return oil port) of the second travel motor 52 is connected to the U port (unloading oil port) of the closed travel pump 2, thereby forming the return oil circuit 22 of the travel motor group 5 to the closed travel pump 2, so that the hydraulic oil can flow back to the closed travel pump 2 to form the closed system. And the return oil circuit 22 is a series structure, which can facilitate pipeline connection and save pipelines.

[0038] Since the travel motor group 5 has high requirements for cleanliness, in this embodiment, a pressure oil filter 42 can be installed at the output end of the oil replenishment pump 4, and the output of the pressure oil filter 42 is divided into two paths. The first path 421 is connected to the F port of the closed travel pump 2, and the second path 422 is provided with a three-way piece so that the second path 422 can be connected to the U port (flushing port) of the first travel motor 51 and the U port (flushing port) of the second travel motor 52 respectively. The second path 422 is used to flush and clean the travel motor group 5, which can improve the working efficiency of the motor.

[0039] In this embodiment, T2 (return oil port) of the first travel motor 51 can also be connected to the cooling system 9, and the cooling system 9 can be connected to the hydraulic oil tank 3 through the return oil filter 91, so as to dissipate heat and return oil to the hydraulic oil. In the above-mentioned closed system, if the return oil cannot dissipate heat in time, a large amount of heat will accumulate and there will be nowhere to discharge it. Therefore, by connecting T2 of the first travel motor 51 to the cooling system 9, heat can be dissipated in time to ensure that the closed system will not be overheated.

[0040] In this embodiment, the second path 422 can also provide an oil source for the transfer case proportional solenoid valve 6. Specifically, the three-way piece of the second path 422 can be replaced with a four-way piece, so that the second path 422 can be connected to the oil supply port pipeline of the transfer case proportional solenoid valve 6 at the same time to supply oil. The transfer case proportional solenoid valve 6 is controlled by the overall electronic control system to control the operation of the transfer case 7. The oil return port of the transfer case proportional solenoid valve 6 is also connected to the hydraulic oil tank 3 for oil return.

[0041] In this embodiment, a one-way valve 10 may be provided between the T-port of the closed travel pump 2 and the hydraulic oil tank 3 , the one-way valve 10 being connected toward the hydraulic oil tank 3 .

[0042] In summary, the hydrostatic transmission system of a loader of the utility model realizes power transmission of the transmission system in a hydraulic manner by setting up a closed system in coordination with the engine 1, and setting up a hydraulically controlled transfer case proportional solenoid valve 6 in coordination with the transfer case 7, thereby effectively improving the performance of the transmission system.

[0043] After actual installation test, this hydrostatic transmission system has at least the following advantages:

[0044] 1. Compared with the existing transmission torque converter and gearbox structure, the fuel consumption of this hydrostatic transmission system is reduced by more than 30%. The traction force is continuously output without interruption during gear shifting, and the throttle is reduced to slow down. There is almost no need to brake during operation. The engine 1 works in a low fuel consumption area, with fast acceleration and high efficiency.

[0045] 2. Compared with the existing transmission torque converter and gearbox structure, the overall efficiency of the machine using this hydrostatic transmission system is increased by 20%.

[0046] 3. The hydraulic transmission eliminates the need for a shift mechanism, which reduces noise in the cab and improves comfort.

[0047] 4. Makes vehicle operation more convenient by eliminating the left-hand shift lever. Both hands will not leave the steering wheel at the same time during operation, which is safer and faster.

[0048] 5. The traction force is only related to the system pressure and has nothing to do with the speed of the engine 1. There is no need to step on the accelerator hard, which effectively reduces the power demand and keeps the whole machine in the low fuel consumption area for a long time.

[0049] The above is only a preferred embodiment of the utility model, and the protection scope of the utility model is not limited to the above embodiments. All technical solutions under the idea of ​​the utility model belong to the protection scope of the utility model. It should be pointed out that for ordinary technicians in this technical field, equivalent changes and modifications without departing from the principle of the utility model should still fall within the protection scope of the utility model.

[0050] In the description of the embodiments of the present application, it should be understood that the indicated orientation or position relationship is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when in use, or is the orientation or position relationship commonly understood by technical personnel in this field. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0051] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" and "several" is two or more, unless otherwise clearly and specifically defined.

[0052] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

Claims

1. A hydrostatic transmission system for a loader, characterized in that: It includes engine, closed travel pump, hydraulic oil tank, oil replenishment pump, travel motor group, transfer case proportional solenoid valve, transfer case and drive axle; The engine is drivingly connected to the closed travel pump; The closed travel pump and the travel motor group form a closed system with a circulating oil circuit; the closed travel pump is also replenished with oil from the hydraulic oil tank through an oil replenishment pump, and the T port of the closed travel pump is connected to the hydraulic oil tank; The travel motor group is connected to the transfer case in a transmission manner; the transfer case proportional solenoid valve is connected to the transfer case for controlling the transfer case; the transfer case is connected to the drive axle in a transmission manner; The travel motor group includes a first travel motor and a second travel motor; The S port of the closed travel pump is connected to the A port of the first travel motor and the B port of the second travel motor through the oil collecting block, and the P port of the closed travel pump is connected to the B port of the first travel motor and the A port of the second travel motor through the oil collecting block; The T1 port of the first travel motor is connected to the T2 port of the second travel motor, and the T1 port of the second travel motor is connected to the U port of the closed travel pump.

2. A hydrostatic transmission system for a loader according to claim 1, characterized in that: The first power take-off port of the engine is provided with a coupling, and is transmission-connected to the closed travel pump via the coupling.

3. The hydrostatic transmission system of a loader according to claim 1, characterized in that: The oil replenishment pump is installed at the second power take-off port of the engine.

4. A hydrostatic transmission system for a loader according to claim 1 or 3, characterized in that: The input end of the oil replenishment pump is communicated with the hydraulic oil tank, and an oil suction filter is provided between the input end and the hydraulic oil tank; the output end of the oil replenishment pump is communicated with the F port of the closed travel pump.

5. The hydrostatic transmission system of a loader according to claim 1 or 3, characterized in that: An oil pressure filter is installed at the output end of the oil replenishment pump, and the output of the oil pressure filter is divided into two paths, the first path is connected to the F port of the closed travel pump, and the second path is provided with a tee piece so that the second path is connected to the U port of the first travel motor and the U port of the second travel motor respectively.

6. A hydrostatic transmission system for a loader according to claim 1 or 3, characterized in that: An oil pressure filter is installed at the output end of the oil replenishment pump, and the output of the oil pressure filter is divided into two paths, the first path is connected to the F port of the closed travel pump, and the second path is provided with a four-way piece so that the second path is respectively connected to the U port of the first travel motor, the U port of the second travel motor and the oil supply port of the transfer case proportional solenoid valve.

7. The hydrostatic transmission system of a loader according to claim 1, characterized in that: The T2 of the first travel motor is also connected to a cooling system, and the cooling system is connected to the hydraulic oil tank via an oil return filter.

8. The hydrostatic transmission system of a loader according to claim 1, characterized in that: A one-way valve is provided between the T port of the closed travel pump and the hydraulic oil tank, which is connected toward the hydraulic oil tank.

Images