Digital hydrostatic transmission loop

Abstract

The utility model discloses a digital hydrostatic transmission loop which comprises a hydraulic oil tank, a filter, a metering pump, an overflow valve, a high-speed switch valve, an energy accumulator, an electromagnetic directional valve, a variable displacement motor and a cooler. An oil inlet of the filter is connected with the hydraulic oil tank through a pipeline, an oil suction port of the metering pump is connected with an oil outlet of the filter through a pipeline, a pump port is connected with the high-speed switch valve groups through a pipeline, and a working oil port of the first high-speed switch valve group is connected with an oil inlet of the electromagnetic reversing valve through a pipeline. A working oil port of the second high-speed switch valve group is connected with the variable displacement motor adjusting oil cylinder through a pipeline, and a working oil port of the electromagnetic reversing valve is connected with the variable displacement motor through a pipeline. According to the utility model, the digital hydraulic technology is applied to accelerate the response speed of the system; the system efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a hydrostatic transmission system, and more particularly to a digital hydrostatic transmission circuit. Background Art

[0002] Some existing non-road mobile equipment uses a closed hydrostatic transmission circuit to drive the machinery. In this closed hydrostatic transmission circuit, the hydraulic pump's inlet and outlet are connected to the hydraulic motor's inlet and outlet via pipes, forming a closed loop. The motor's speed is controlled by adjusting the hydraulic pump.

[0003] In a closed hydrostatic transmission circuit, the structure of the variable hydraulic pump that constitutes the pump control system is far more complex and expensive than the flow valve of the valve control system. The volume, mass, and related inertia and friction of the regulating components in the variable plunger pump are much larger than those of the regulating valve core in the valve control system, so the response speed is slower and the power demand for the regulating device itself is larger. Utility Model Content

[0004] The utility model addresses the shortcomings of existing closed hydrostatic transmission circuits and provides a digital hydrostatic transmission circuit. The circuit utilizes digital hydraulic technology to accelerate system response speed and improve system efficiency.

[0005] The technical solution for achieving the objectives of the present invention is as follows: a digital hydrostatic travel transmission circuit is designed, characterized by a hydraulic oil tank 1, a filter 2, a metering pump 3, a first relief valve 4, a first high-speed switching valve group 5, an accumulator 6, an electromagnetic reversing valve 7, a second relief valve group 8, a variable motor 9, a variable motor regulating cylinder 10, a second high-speed switching valve group 11, a cooler 12, and an oil return filter 13. The oil inlet of the filter 2 is connected to the hydraulic oil tank 1 via a pipeline, the oil suction port of the metering pump 3 is connected to the oil outlet of the filter 2 via a pipeline, and the pump port is connected to the high-speed switching valve group via a pipeline. The working oil port of the first high-speed switching valve group 5 is connected to the oil inlet of the electromagnetic reversing valve 7 via a pipeline, the working oil port of the second high-speed switching valve group 11 is connected to the variable motor regulating cylinder 8 via a pipeline, and the working oil port of the electromagnetic reversing valve 7 is connected to the hydraulic motor 9 via a pipeline.

[0006] In the digital hydrostatic transmission circuit of the present invention, the oil outlet of the electromagnetic reversing valve 7 is connected to the cooler 12 via a pipeline, and the cooler 12 is connected to the oil return filter 13 via a pipeline.

[0007] In the digital hydrostatic transmission circuit of the present invention, the oil port of the variable motor regulating cylinder is connected to a second high-speed on-off valve group via a pipeline. The two high-speed on-off valves that deliver oil to the variable motor regulating cylinder 10 are connected to the oil outlet of the metering pump 3 via pipelines. The two high-speed on-off valves that deliver oil to the variable motor regulating cylinder 10 are also connected to the cooler 12 via pipelines.

[0008] In the digital hydrostatic transmission circuit of the present invention, the variable motor regulating cylinder 10 is a double-acting cylinder. When the oil inlet high-speed switching valve connected to the rodless chamber of the variable motor regulating cylinder 10 is opened, the oil discharge high-speed switching valve connected to the rod chamber of the variable motor regulating cylinder 10 is opened together, and the oil in the rodless chamber drives the piston movement to achieve the adjustment of the displacement of the variable motor 9, and the oil in the rod chamber returns to the hydraulic oil tank 1 through the high-speed switching valve, the cooler 12, and the return oil filter 13; conversely, the oil in the rod chamber drives the piston movement to achieve reverse adjustment of the displacement of the variable motor 9, and torque control is achieved by adjusting the displacement of the variable motor 9.

[0009] In the digital hydrostatic transmission circuit of the present invention, the oil outlet of the metering pump 3 is connected to the oil inlet of the first high-speed switching valve group 5 through a pipeline. The pipeline connecting the oil outlet of the first high-speed switching valve group 5 and the oil inlet of the electromagnetic reversing valve 7 is provided with an accumulator 6. A second overflow valve group 8 is provided between the two pipelines connecting the working oil port of the electromagnetic reversing valve 7 and the variable motor 9.

[0010] In the digital hydrostatic transmission circuit of the present invention, the first high-speed switching valve group 5 realizes flow control by regular on-off switching, thereby adjusting the speed of the variable motor 9. The electromagnetic reversing valve 7 realizes the direction control of the variable motor 9. The accumulator 6 absorbs the pressure pulsation caused by the high-speed switching valve. The second overflow valve group ensures the safety of the high-pressure oil circuit and relieves pressure to the low-pressure oil circuit.

[0011] In the digital hydrostatic transmission circuit of the present invention, a first relief valve 4 is provided between the oil outlet of the metering pump 3 and the oil inlet of the high-speed switching valve group to prevent the entire system from being overloaded.

[0012] The high-speed on-off valve in this digital hydrostatic transmission circuit is a typical digital hydraulic valve. It converts a series of input pulses into a fast and accurate on-off state, controlled directly by digital signals without the need for digital-to-analog conversion. It offers advantages such as a simple structure, high reliability, low throttling losses, and fast response. The use of digital hydraulic technology improves the efficiency of the hydrostatic transmission system and accelerates system response. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model relates to a digital hydrostatic transmission circuit.

[0014] Parts names and serial numbers in the figure:

[0015] 1-Hydraulic oil tank; 2-Filter; 3-Dosing pump; 4-First overflow valve; 5-First high-speed switching valve group; 6-Accumulator; 7-Solenoid reversing valve; 8-Second overflow valve group; 9-Variable motor; 10-Variable motor regulating cylinder; 11-Second high-speed switching valve group; 12-Cooler; 13-Return oil filter. DETAILED DESCRIPTION

[0016] The specific implementation scheme is described below with reference to the accompanying drawings.

[0017] Figure 1 The figure shows the principle diagram of the digital hydrostatic transmission circuit of the present invention. The digital hydrostatic transmission circuit includes a hydraulic oil tank 1, a filter 2, a metering pump 3, a first relief valve 4, a first high-speed on-off valve group 5, an accumulator 6, a solenoid reversing valve 7, a second relief valve group 8, a variable motor 9, a variable motor regulating cylinder 10, a second high-speed on-off valve group 11, a cooler 12, and an oil return filter 13.

[0018] The oil inlet of the filter 2 is connected to the hydraulic oil tank 1 through a pipeline, the oil suction port of the metering pump 3 is connected to the oil outlet of the filter 2 through a pipeline, the pump port is connected to the high-speed switching valve group through a pipeline, the working oil port of the first high-speed switching valve group 5 is connected to the oil inlet of the electromagnetic reversing valve 7 through a pipeline, the working oil port of the second high-speed switching valve group 11 is connected to the variable motor regulating cylinder 10 through a pipeline, and the working oil port of the electromagnetic reversing valve 7 is connected to the hydraulic motor 9 through a pipeline.

[0019] The oil outlet of the electromagnetic reversing valve 7 is connected to the cooler 12 via a pipeline, and the cooler 12 is connected to the return oil filter 13 via a pipeline.

[0020] The oil port of the variable motor regulating cylinder 10 is connected to the second high-speed on-off valve group 11 via a pipeline. The two high-speed on-off valves that deliver oil to the variable motor regulating cylinder 10 are connected to the oil outlet of the metering pump via pipelines, and the two high-speed on-off valves that realize the oil output function of the variable motor regulating cylinder are connected to the cooler via pipelines.

[0021] The oil outlet of the metering pump 3 is connected to the oil inlet of the first high-speed switching valve group 5 through a pipeline. The pipeline connecting the oil outlet of the first high-speed switching valve group 2 and the oil inlet of the electromagnetic reversing valve 7 is provided with an accumulator 6. A second overflow valve group 8 is provided between the two pipelines connecting the working oil port of the electromagnetic reversing valve 7 and the variable motor 9.

[0022] A first relief valve 4 is provided between the oil outlet of the metering pump 3 and the oil inlet of the high-speed switching valve group to ensure that the pressure of the entire system will not be overloaded.

[0023] In the present invention, the first relief valve 4 ensures that the system pressure does not exceed the limit value, and the metering pump 3 delivers the high-pressure oil to the oil inlet of the high-speed switching valve group.

[0024] Several high-speed switch valves in the first high-speed switch valve group 5 are connected in parallel. Each high-speed switch valve can be directly controlled by a computer. Through regular on-off switching, stepless flow regulation can be achieved, thereby controlling the speed of the variable motor.

[0025] The second high-speed switching valve 11 group includes four high-speed switching valves, two of which are connected to the metering pump 3 through a pipeline, and the other two are connected to the cooler 12 through a pipeline to allow the oil to flow back to the hydraulic oil tank 1. When the oil inlet high-speed switching valve connected to the rodless cavity of the variable motor regulating cylinder 10 is opened, the oil discharge high-speed switching valve connected to the rod cavity of the variable motor regulating cylinder 10 is opened together, and the rodless cavity oil pushes the piston to achieve the adjustment of the displacement of the variable motor 9, and the rod cavity oil returns to the hydraulic oil tank 1 through the high-speed switching valve, the cooler 12, and the return oil filter 13; conversely, the rod cavity oil pushes the piston to achieve reverse adjustment of the displacement of the variable motor 9, and torque control is achieved by adjusting the displacement of the variable motor 9.

[0026] The electromagnetic reversing valve 7 controls the direction of the variable motor 9.

[0027] The present invention only provides a digital hydrostatic transmission circuit, and the control method is not limited to the above control form. For example, the above-mentioned variable motor displacement is changed to achieve torque control, and changing the displacement can also achieve speed regulation.

[0028] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A digital hydrostatic transmission circuit, comprising a hydraulic oil tank (1), a filter (2), a metering pump (3), a first relief valve (4), a first high-speed switching valve group (5), an accumulator (6), an electromagnetic reversing valve (7), a second relief valve group (8), a variable motor (9), a variable motor regulating cylinder (10), a second high-speed switching valve group (11), a cooler (12), and an oil return filter (13), characterized in that: The metering pump (3) outputs a constant flow rate and realizes flow change by adjusting the first high-speed switch valve group (5) to control the speed of the variable motor (9). The oil outlet of the metering pump (3) is connected to the oil inlet of each high-speed switch valve in the first high-speed switch valve group (5) through a pipeline. The oil inlet of the filter (2) is connected to the hydraulic oil tank (1) through a pipeline. The oil suction port of the metering pump (3) is connected to the oil outlet of the filter (2) through a pipeline. The working oil port of the first high-speed switch valve group (5) is connected to the oil inlet of the electromagnetic reversing valve (7) through a pipeline. The working oil port of the second high-speed switch valve group (11) is connected to the variable motor regulating cylinder (10) through a pipeline. The working oil port of the electromagnetic reversing valve (7) is connected to the variable motor (9) through a pipeline. The oil outlet of the electromagnetic reversing valve (7) is connected to the cooler (12) through a pipeline. The cooler (12) is connected to the return oil through a pipeline. The oil port of the variable motor regulating oil cylinder (10) is connected to the second high-speed switch valve group (11) through a pipeline, wherein the two high-speed switch valves for delivering oil to the variable motor regulating oil cylinder are connected to the oil outlet of the metering pump (3) through a pipeline, and the two high-speed switch valves for realizing the oil output function of the variable motor regulating oil cylinder (10) are connected to the cooler (12) through a pipeline, the oil outlet of the metering pump (3) is connected to the oil inlet of the first high-speed switch valve group (5) through a pipeline, and the pipeline connecting the oil outlet of the first high-speed switch valve group 5 and the oil inlet of the electromagnetic reversing valve (7) is provided with an accumulator (6), a second overflow valve group (8) is provided between the two pipelines connecting the working oil port of the electromagnetic reversing valve (7) and the variable motor (9), and a first overflow valve (4) is provided between the oil outlet of the metering pump (3) and the oil inlet of the high-speed switch valve group to ensure that the pressure of the entire system will not be overloaded.

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