阅读说明：本技术 静液压传动及其换挡系统 (Hydrostatic transmission and gear shifting system thereof ) 是由 安晓波 赵遵平 孙常盛 付贤杰 于 2021-09-08 设计创作，主要内容包括：本发明提供了一种静液压传动及其换挡系统,包括电磁换向阀组、两档液控变速箱、闭式变量泵、两点变量马达、油箱、控制器和压力传感器,所述电磁换向阀组通讯连接所述控制器,并在所述控制器控制下分别控制高低速和驻车制动,所述两档液控变速箱提供两个速比,所述闭式变量泵通讯连接所述控制器,通过比例电流进行控制,所述两点变量马达通讯连接所述控制器,并在所述控制器控制下在满排量与半排量两种状态下进行切换,所述控制器通讯连接所述压力传感器,所述压力传感器测量传动系统的压力,所述闭式变量泵从所述油箱中吸油,并向所述两点变量马达和所述两档液控变速箱供油。本发明可以在不增加太多成本的基础上增大整车行驶速度范围。(The invention provides a hydrostatic transmission and a gear shifting system thereof, which comprises an electromagnetic directional valve bank, a two-gear hydraulic control gearbox, a closed variable pump, a two-point variable motor, an oil tank, a controller and a pressure sensor, wherein the electromagnetic directional valve bank is in communication connection with the controller, and respectively controlling high and low speed and parking brake under the control of the controller, wherein the two-gear hydraulically-controlled gearbox provides two speed ratios, the closed variable displacement pump is in communication connection with the controller, the two-point variable motor is communicated with the controller and is switched between a full displacement state and a half displacement state under the control of the controller, the controller is in communication connection with the pressure sensor, the pressure sensor measures the pressure of the transmission system, and the closed variable pump absorbs oil from the oil tank and supplies oil to the two-point variable motor and the two-gear hydraulically-controlled transmission. The invention can enlarge the running speed range of the whole vehicle on the basis of not increasing too much cost.)

1. A hydrostatic transmission and a gear shifting system thereof are characterized by comprising an electromagnetic directional valve bank, a two-gear hydraulic control gearbox, a closed variable pump, a two-point variable motor, an oil tank, a controller and a pressure sensor, wherein the electromagnetic directional valve bank is in communication connection with the controller, and respectively controlling high and low speed and parking brake under the control of the controller, wherein the two-gear hydraulically-controlled gearbox provides two speed ratios, the closed variable displacement pump is in communication connection with the controller, the two-point variable motor is communicated with the controller and is switched between a full displacement state and a half displacement state under the control of the controller, the controller is in communication connection with the pressure sensor, the pressure sensor measures the pressure of the transmission system, and the closed variable pump absorbs oil from the oil tank and supplies oil to the two-point variable motor and the two-gear hydraulically-controlled transmission.

2. The hydrostatic transmission and shifting system of claim 1, wherein the electromagnetic directional valve set comprises a transmission high-low gear switching solenoid valve and a parking brake solenoid valve, and the transmission high-low gear switching solenoid valve and the parking brake solenoid valve control high-low speed and parking brake respectively.

3. The hydrostatic transmission and shifting system of claim 1, wherein the two-speed hydraulically controlled transmission provides two speed ratios through high and low speed control ports.

4. The hydrostatic transmission and shifting system of claim 1, wherein said closed variable displacement pump is continuously variable regulated by a proportional solenoid valve.

5. The hydrostatic transmission and shifting system of claim 1, wherein said two point variable displacement motor controls the displacement of the pump via a two point displacement control solenoid to switch between full displacement and half displacement under control of said controller.

6. The hydrostatic transmission and shifting system as recited in claims 1-5, further comprising an oil suction strainer disposed at an inlet of the system oil path.

7. The hydrostatic transmission and shifting system as recited in claims 1-5, further comprising a high pressure filter disposed at an outlet of the system oil path.

8. The hydrostatic transmission and shifting system thereof of any one of claims 1-5, wherein said system further comprises a parking brake, said parking brake being in communication with said oil reservoir through said solenoid directional valve bank.

9. The hydrostatic transmission and shifting system thereof according to any one of claims 1 to 5, wherein the system is applied to mining machinery.

Technical Field

The invention relates to the field of engineering machinery in general, and particularly relates to a hydrostatic transmission and a gear shifting system thereof.

Background

In mining machinery, hydrostatic transmission is an important chassis transmission mode, and has the advantages of simple and convenient arrangement, high reliability, large transmission torque, stepless speed change and the like. The common hydrostatic transmission system is used on engineering machinery such as a forklift and a trolley, and the speed of the engineering machinery is generally low.

Disclosure of Invention

The present invention has a primary object to overcome at least one of the above-mentioned drawbacks of the prior art, and to provide a hydrostatic transmission and a shifting system thereof, which can increase the driving speed range of the whole vehicle without increasing too much cost, and is easy and safe to operate.

In order to achieve the purpose, the invention adopts the following technical scheme:

according to one aspect of the invention, a hydrostatic transmission and a gear shifting system thereof are provided, which comprises an electromagnetic directional valve bank, a two-gear hydraulic control gearbox, a closed variable pump, a two-point variable motor, an oil tank, a controller and a pressure sensor, wherein the electromagnetic directional valve bank is in communication connection with the controller, and respectively controlling high and low speed and parking brake under the control of the controller, wherein the two-gear hydraulically-controlled gearbox provides two speed ratios, the closed variable displacement pump is in communication connection with the controller, the two-point variable motor is communicated with the controller and is switched between a full displacement state and a half displacement state under the control of the controller, the controller is in communication connection with the pressure sensor, the pressure sensor measures the pressure of the transmission system, and the closed variable pump absorbs oil from the oil tank and supplies oil to the two-point variable motor and the two-gear hydraulically-controlled transmission.

According to an embodiment of the invention, the electromagnetic directional valve set comprises a gearbox high-low gear switching electromagnetic valve and a parking brake electromagnetic valve, and the gearbox high-low gear switching electromagnetic valve and the parking brake electromagnetic valve respectively control high-low speed and parking brake.

According to one embodiment of the invention, the two-gear hydraulically-controlled gearbox provides two speed ratios through the high-low speed control oil port.

According to one embodiment of the invention, the closed variable displacement pump is steplessly adjustable by means of a proportional solenoid valve.

According to an embodiment of the present invention, the two-point variable displacement motor controls the displacement of the pump by a two-point displacement control solenoid valve to switch between a full displacement state and a half displacement state under the control of the controller.

According to an embodiment of the present invention, the system further includes an oil suction filter disposed at the system oil inlet.

According to an embodiment of the present invention, the system further includes a high pressure filter disposed at an outlet of the system oil path.

According to an embodiment of the invention, the system further comprises a parking brake, and the parking brake is communicated with the oil tank through the electromagnetic reversing valve group.

According to an embodiment of the invention, the system is applied to a mining machine.

According to the technical scheme, the hydrostatic transmission and the gear shifting system thereof have the advantages and positive effects that:

1) compared with the common scheme of the mining machinery, namely 'closed pump + two-point variable motor + transfer case', the transmission system of the invention greatly enlarges the stepless speed change range of the system and enhances the adaptability of the system on the basis of not increasing too much cost. The underground low-speed large-torque demand (0-10km/h) can be met, and the high-speed small-torque demand (0-30km/h) of the pavement can be met.

2) The gear shifting system is simple and convenient to operate and has safety. The first gear and the second gear are advanced, the first gear and the second gear are retreated, the neutral gear is controlled by a gear shifting combination switch, and the operation is convenient; the high-low speed of two grades of hydraulically controlled gearboxes is because of switching at ordinary times rarely (generally use low-speed in the pit, the road surface uses high-speed, and must park and shift gears), uses wane switch control, and the manipulation is simple and convenient and can effectively avoid the maloperation.

3) The controller can receive a load signal of the engine and measure the consumed power of the hydrostatic transmission system, and when the load of the hydrostatic transmission system exceeds a set value (such as 70% of the total power of the engine), the controller can reduce the power of the whole vehicle by automatically reducing the displacement of the closed pump, protect the engine and prevent flameout.

Drawings

Various objects, features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, when considered in conjunction with the accompanying drawings. The drawings are merely exemplary of the invention and are not necessarily drawn to scale. In the drawings, like reference characters designate the same or similar parts throughout the different views. Wherein:

FIG. 1 is a schematic representation of the hydrostatic transmission of the present invention and its shifting system shown in an exemplary embodiment.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

In the following description of various examples of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example structures, systems, and steps in which aspects of the invention may be practiced. It is to be understood that other specific arrangements of parts, structures, example devices, systems, and steps may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Moreover, although the terms "top," "bottom," "front," "back," "side," and the like may be used in this specification to describe various example features and elements of the invention, these terms are used herein for convenience only, e.g., in accordance with the orientation of the examples described in the figures. Nothing in this specification should be construed as requiring a specific three dimensional orientation of structures in order to fall within the scope of the invention.

FIG. 1 is a schematic representation of the hydrostatic transmission of the present invention and its shifting system shown in an exemplary embodiment. As shown in fig. 1, the hydrostatic transmission and the shifting system thereof in the present embodiment includes an electromagnetic directional valve bank 1, a two-gear hydraulically controlled transmission 2, a closed variable pump 3, a two-point variable motor 4, an oil tank 7, a controller 8, and a pressure sensor 9.

The electromagnetic directional valve set 1 is in communication connection with the controller 8 and respectively controls high and low speed and parking brake under the control of the controller 8. The two-gear hydraulic control gearbox 2 provides two speed ratios, and the closed variable displacement pump 3 is in communication connection with the controller 8 and is controlled through proportional current. The two-point variable displacement motor 4 is connected with the controller 8 in a communication way and is switched between a full displacement state and a half displacement state under the control of the controller 8. The controller 8 is in communication connection with the pressure sensor 9, the pressure sensor 9 measures the pressure of the transmission system, the closed variable pump 3 sucks oil from the oil tank 7 and supplies oil to the two-point variable motor 4 and the two-gear hydraulically-controlled gearbox 2.

In this embodiment, the electromagnetic directional valve set 1 includes a transmission high-low gear switching electromagnetic valve 1.1 and a parking brake electromagnetic valve 1.2, and the transmission high-low gear switching electromagnetic valve 1.1 and the parking brake electromagnetic valve 1.2 control high-low speed and parking brake respectively.

In this embodiment, the two-gear hydraulically-controlled transmission 2 provides two speed ratios through the high-low speed control oil port. In this embodiment, the closed variable displacement pump 3 realizes stepless regulation by a proportional solenoid valve 3.1. In this embodiment, the two-point variable displacement motor 4 controls the displacement of the pump by a two-point displacement control solenoid valve 4.1 to switch between a full displacement state and a half displacement state under the control of the controller 8.

In this embodiment, the system further comprises an oil suction filter 5 disposed at the inlet of the system oil path. In this embodiment, the system further includes a high pressure filter 6 disposed at the system oil path outlet. In the embodiment, the system further comprises a parking brake, and the parking brake is communicated with the oil tank 7 through an electromagnetic reversing valve group.

In this embodiment, the system is applied to a mining machine. In this embodiment, the controller 8 controls the operation of the hydrostatic system via electrical signals. It receives the signals of each operating device to convert, and then outputs signals to control the operation of other elements. The pressure sensor 9 measures the pressure of the transmission system and feeds the pressure back to the controller 8, and when the power of the transmission system exceeds the set pressure of the system, the controller 8 controls the closed variable displacement pump 3 to reduce the flow, so that the engine is prevented from being flamed out, and the engine is protected.

In this embodiment:

1. the whole vehicle can be started (controlled by a controller) only when the vehicle is parked. Before engaging gear, the parking brake electromagnetic valve 1.2 is electrified, and the pilot oil of the closed variable displacement pump 3 enters from the port P of the electromagnetic directional valve 1 and flows out from the port B to release the parking brake.

2. High-low speed switching: when the high-low gear switching electromagnetic valve 1.1 of the gearbox is not electrified, pilot oil of the closed variable displacement pump 3 passes through a port P of the electromagnetic directional valve 1 and a port A1 to reach a low-speed control port of the two-gear hydraulically-controlled gearbox 2, so that the two-gear hydraulically-controlled gearbox is in a low-speed gear state; on the contrary, when the high-low gear switching electromagnetic valve 1.1 of the gearbox is electrified, the pilot oil of the closed variable displacement pump 3 passes through the port P of the electromagnetic directional valve 1 and then reaches the high-speed control port of the two-gear hydraulically-controlled gearbox 2 through the port B1, so that the two-gear hydraulically-controlled gearbox is in a high-speed gear state.

3. Switching between the first gear and the second gear: when the electromagnetic directional valve 4.1 of the two-point variable motor 4 is not powered on, the two-point variable motor 4 is in a full displacement state, and the first gear is adopted at the moment; when the electromagnetic directional valve 4.1 is electrified, the two-point variable displacement motor 4 is in a half displacement state, and the second gear is adopted.

4. Forward, backward stepless speed change and neutral gear: when the proportional solenoid valve 3.1 of the closed variable pump 3 is not electrified, the discharge capacity of the closed variable pump 3 is zero and the closed variable pump is in a neutral gear; when a coil of the port A of the proportional electromagnetic valve 3.1 obtains a proportional current, the port A of the closed variable pump 3 starts to produce oil, the flow rate is in direct proportion to the current, hydraulic oil flows to the port A of the two-point variable motor 4 to push the port A to rotate forwards, the whole vehicle starts to advance at the moment, and the current controls the vehicle speed; on the contrary, when the coil of the port B of the proportional electromagnetic valve 3.1 obtains a proportional current, the port B of the closed variable pump 3 starts to discharge oil, the flow rate is in direct proportion to the current, the hydraulic oil flows to the port B of the two-point variable motor 4 to push the port B to rotate reversely, the whole vehicle starts to retreat at the moment, and the current controls the vehicle speed.

5. The gear-shifting combination switch is adopted for control, and the operation is convenient. The high-low speed gear shifting is controlled by a rocker switch, so that misoperation can be effectively avoided.

According to the technical scheme, the hydrostatic transmission and the gear shifting system thereof have the advantages and positive effects that:

1) compared with the common scheme of the mining machinery, namely 'closed pump + two-point variable motor + transfer case', the transmission system of the invention greatly enlarges the stepless speed change range of the system and enhances the adaptability of the system on the basis of not increasing too much cost. The underground low-speed large-torque demand (0-10km/h) can be met, and the high-speed small-torque demand (0-30km/h) of the pavement can be met.

2) The gear shifting system is simple and convenient to operate and has safety. The first gear and the second gear are advanced, the first gear and the second gear are retreated, the neutral gear is controlled by a gear shifting combination switch, and the operation is convenient; the high-low speed of two grades of hydraulically controlled gearboxes is because of switching at ordinary times rarely (generally use low-speed in the pit, the road surface uses high-speed, and must park and shift gears), uses wane switch control, and the manipulation is simple and convenient and can effectively avoid the maloperation.

3) The controller may receive a load signal from the engine, and when the load of the hydrostatic transmission system exceeds a set value (e.g., 70% of the total engine power), the controller may reduce the overall vehicle power by automatically reducing the displacement of the closed pump, protecting the engine from stalling.

It should be understood by those of ordinary skill in the art that the specific constructions and processes illustrated in the foregoing detailed description are exemplary only, and are not limiting. Furthermore, the various features shown above can be combined in various possible ways to form new solutions, or other modifications, by a person skilled in the art, all falling within the scope of the present invention.