Closed hydrostatic driving system of loading machine

Abstract

The utility model discloses a closed hydrostatic driving system of a loader, which relates to the technical field of loaders and comprises a driving hydraulic pump, a first oil port of the driving hydraulic pump is connected with a control valve A and is respectively connected with first oil ports of a first driving motor and a second driving motor through the control valve A; a second oil port of the driving hydraulic pump is connected with a control valve B, and is respectively connected with second oil ports of the first driving motor and the second driving motor through the control valve B; the first driving motor and the second driving motor are respectively used for driving front axle wheels and rear axle wheels; the driving hydraulic pump, the two control valves and the two driving motors are used for controlling the movement of the front axle and the movement of the rear axle respectively, a gearbox, a transmission shaft and the like are omitted in a transmission part, the transmission efficiency can be improved, the failure rate of the whole machine is reduced, the transmission process is more stable, and noise is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of loader, concretely relates to a closed hydrostatic drive system of loader. BACKGROUND

[0002] At present, the loader in the industry has developed mechanical drive, hydrostatic drive, electric drive and various driving modes, wherein the hydrostatic drive is a driving mode relying on hydraulic pressure energy to transfer power. The current technical route of the hydrostatic drive loader is that the walking hydraulic pump is driven by the engine, one or two walking motors installed on the transfer case are driven by the walking hydraulic pump, the output end of the transfer case is connected with the front and rear drive axle through the transmission shaft, and then the driving wheel is driven to rotate.

[0003] The existing hydrostatic transmission scheme cancels the hydraulic torque converter of the mechanical transmission scheme, increases the hydraulic transmission, and has the defects of low transmission efficiency, large transmission impact, large noise and single vehicle driving mode. UTILITY MODEL CONTENT

[0004] In view of the deficiencies of the prior art, the utility model provides a closed hydrostatic drive system of loader, which uses hydraulic transmission to replace the hydraulic torque converter, gearbox and transmission shaft of the original mechanical transmission scheme, improves the transmission efficiency compared with the traditional technology, has small noise and low failure rate, and can realize various driving modes.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0006] A closed hydrostatic drive system of loader, comprising a driving hydraulic pump, a first oil port of the driving hydraulic pump is connected with a control valve A, and the first oil port of the control valve A is connected with the first oil port of a first driving motor and a second driving motor respectively; a second oil port of the driving hydraulic pump is connected with a control valve B, and the second oil port of the control valve B is connected with the second oil port of the first driving motor and the second driving motor respectively; the first driving motor and the second driving motor are used for driving front axle wheels and rear axle wheels respectively.

[0007] As a further implementation mode, the control valve A and the control valve B both adopt three-position three-way electromagnetic valves, which are used for controlling the on-off of the oil port of the driving hydraulic pump connected with the first driving motor and the second driving motor, so that the driving motor is in a working state or a shutdown state; when the first oil port and the second oil port of the driving hydraulic pump are connected with the first oil port and the second oil port of the driving motor, the driving motor is in the working state; when the two oil ports of the driving motor are not connected with the two oil ports of the driving hydraulic pump, the driving motor is in the shutdown passive rotation state.

[0008] As a further implementation, the first drive motor is provided with a control valve C on the oil path between the control valve A and the control valve B, the control valve C is a two-position four-way electromagnetic valve, and when the first drive motor is passively rotated in a stop state, the control valve C connects two oil ports of the first drive motor to form a hydraulic oil self-circulation path and prevent pressure build-up.

[0009] As a further implementation, the second drive motor is provided with a control valve D on the oil path between the control valve A and the control valve B.

[0010] As a further implementation, the output end of the first drive motor is connected to the input end of the front drive axle to drive the front axle to rotate.

[0011] As a further implementation, the output end of the second drive motor is connected to the input end of the rear drive axle to drive the rear axle to rotate.

[0012] As a further implementation, when the first oil port of the hydraulic drive pump is connected to the first oil ports of the first drive motor and the second drive motor, and the second oil port of the hydraulic drive pump is connected to the second oil ports of the first drive motor and the second drive motor, the vehicle is driven to travel by the front axle and the rear axle at the same time.

[0013] As a further implementation, when the first oil port of the drive hydraulic pump is connected to the first oil port of the first drive motor, the second oil port of the drive hydraulic pump is connected to the second oil port of the first drive motor, and the first oil port and the second oil port of the second drive motor are connected, the drive hydraulic pump drives the vehicle to travel by driving the first drive motor, and the vehicle is driven by the front axle only.

[0014] As a further implementation, when the first oil port of the drive hydraulic pump is connected to the first oil port of the second drive motor, the second oil port of the drive hydraulic pump is connected to the second oil port of the second drive motor, and the first oil port and the second oil port of the first drive motor are connected, the drive hydraulic pump drives the vehicle to travel by driving the second drive motor, and the vehicle is driven by the rear axle only.

[0015] As a further implementation, the drive hydraulic pump is driven by the engine through a shaft coupling.

[0016] With the above technical scheme, the utility model has the following beneficial effects:

[0017] 1. The utility model drives the front axle and the rear axle by the drive hydraulic pump, two control valves and two drive motors, cancels the setting of the transmission part such as the gearbox and the transmission shaft, provides transmission efficiency, reduces the whole machine failure rate, and the transmission process is more stable, and noise is greatly reduced.

[0018] 2、The utility model has multiple drive mode optional, can realize single front axle drive, single rear axle drive and front and rear axle drive simultaneously, can select the best drive mode according to different working conditions, reaches the purpose of energy saving and consumption reduction.

[0019] 3、The utility model compares to the drive mechanical drive scheme, the structure is simpler, has reduced the failure rate and maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings constituting a part of the utility model are used to provide further understanding of the utility model, and the illustrative embodiment of the utility model and the explanation thereof are used to explain the utility model, and do not constitute improper limitation to the utility model.

[0021] Figure 1 It is system arrangement schematic drawing in the utility model embodiment;

[0022] Figure 2 It is control valve schematic drawing in the utility model embodiment;

[0023] Figure 3 It is front and rear axle drive simultaneously schematic drawing in the utility model embodiment;

[0024] Figure 4 It is only front axle drive schematic drawing in the utility model embodiment;

[0025] Figure 5 It is only rear axle drive schematic drawing in the utility model embodiment;

[0026] Figure 6 It is vehicle fault when being trailer state schematic drawing in the utility model embodiment.

[0027] In the drawing: 1, front drive axle;2, first drive motor;3, control valve C;4, control valve A;5, drive hydraulic pump;6, control valve B;7, control valve D;8, second drive motor;9, rear drive axle. DETAILED DESCRIPTION

[0028] It should be pointed out that the following detailed description is all exemplary, aims at providing further explanation to the utility model. Unless otherwise indicated, all technical and scientific terms used in the utility model have the same meaning as that understood by ordinary skilled person in the technical field to which the utility model belongs.

[0029] It should be noted that the terminology used herein is for descriptive purposes only and is not intended to limit the exemplary embodiments according to this invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0030] Example 1

[0031] In one typical embodiment of this application, a closed-loop hydrostatic drive system for a loader is provided, such as... Figures 1-6 As shown, the system includes a drive hydraulic pump 5. The first port of the drive hydraulic pump is connected to a control valve A4, which in turn connects to the first ports of a first drive motor 2 and a second drive motor 3. The second port of the drive hydraulic pump 5 is connected to a control valve B6, which in turn connects to the second ports of the first drive motor 2 and the second drive motor 3. The first drive motor and the second drive motor are used to drive the front axle wheels and the rear axle wheels, respectively.

[0032] Specifically, such as Figure 1 As shown, in the closed hydrostatic drive system of this embodiment, the drive hydraulic pump 5 is driven by the engine. The drive hydraulic pump is directly connected to the engine through a coupling. The drive hydraulic pump and the drive motor are connected through hydraulic oil pipes to form a closed pipeline.

[0033] like Figure 1 As shown, the hydraulic pump 5 has two ports, a and b. Port a of the hydraulic pump 5 branches into two hydraulic circuits via control valve A4. One circuit connects to port a of the first drive motor 2 via control valve C3, and the other circuit connects to port a of the second drive motor 3 via control valve D7. Port b of the hydraulic pump 5 branches into two hydraulic circuits via control valve B6. One circuit connects to port b of the first drive motor 2 via control valve C3, and the other circuit connects to port b of the second drive motor 3 via control valve D7.

[0034] In this embodiment, the output end of the first drive motor 2 is connected to the input end of the front drive axle 1, which can drive the front axle wheels to rotate.

[0035] Specifically, when multiple control valves are in combination, and the oil port a of the hydraulic pump 5 is connected to the oil port a of the first drive motor 2, and the oil port b of the first drive motor 2 is connected to the oil port b of the hydraulic drive pump 5, the first drive motor 2 starts, thereby turning the front axle wheels.

[0036] In this embodiment, the output end of the second drive motor 3 is connected with the input end of the rear drive axle 9, and the rear axle wheels can be driven to rotate.

[0037] When the oil port a of the hydraulic drive pump 5 is communicated with the oil port a of the second drive motor 3, and the oil port b of the second drive motor 3 is communicated with the oil port b of the hydraulic drive pump 5 in the combined state of the multiple control valves, the second drive motor 3 is started to realize the rotation of the rear axle wheels.

[0038] When the oil ports a of the first drive motor 2 and the second drive motor 3 are simultaneously supplied with oil, and the oil ports b are simultaneously returned to oil, the front drive axle 1 and the rear drive axle 9 are simultaneously driven, and the rotation directions of the front axle wheels and the rear axle wheels are consistent.

[0039] Specifically, to realize the above control, in this embodiment, as shown in Figure 2 , the control valve A and the control valve B adopt the same three-position three-way electromagnetic valve to switch the oil circuit. Taking the role of the control valve A 4 in the system as an example, when the control valve A 4 works at A1 position, the oil port a of the hydraulic drive pump is only communicated with the oil port a of the second drive motor 3; when the control valve A 4 works at A2 position, the oil port a of the hydraulic drive pump is only communicated with the oil port a of the first drive motor 2; when the control valve A 4 works at A3 position, the oil port a of the hydraulic drive pump is simultaneously communicated with the oil ports a of the first drive motor 2 and the second drive motor 3.

[0040] In this embodiment, the control valve C 3 is located on the oil circuit between the first drive motor 2 and the control valve A 4 and the control valve B 6, and is used to control the start-stop state of the first drive motor 2. The control valve D 7 is located on the oil circuit between the second drive motor 3 and the control valve A 4 and the control valve B 6, and is used to control the start-stop state of the second drive motor 3. As shown in Figure 2 , the control valve C and the control valve D adopt the same two-position four-way electromagnetic valve. Taking the role of the control valve C 3 in the system as an example, when the control valve C 3 works at C1 position, the oil port a of the first drive motor 2 is directly communicated with the oil port b, and at this time, the first drive motor 2 is in the shutdown state. When the control valve C 3 works at C2 position, the oil port a of the first drive motor 2 is communicated with the output end of the control valve A 4, and the oil port b of the first drive motor 2 is communicated with the output end of the control valve B 6. When the control valve A 4 works at A2 position or A3 position, and the control valve B 6 works at B2 position or B1 position, the first drive motor 2 is in the working state; otherwise, the first drive motor 2 is in the shutdown state.

[0041] The hydrostatic drive system of this embodiment can realize multiple drive modes, which are respectively:

[0042] Mode one, the front axle and the rear axle are simultaneously driven:

[0043] As shown in Figure 3As shown, in this working state, control valve A4 operates at position A3, control valve B6 operates at position B1, control valve C3 operates at position C2, and control valve D7 operates at position D1.

[0044] The oil port a of the driving hydraulic pump 5 is connected to the oil ports a of the first driving motor 2 and the second driving motor 3 respectively, and the oil port b of the driving hydraulic pump 5 is connected to the oil ports b of the first driving motor 2 and the second driving motor 3 respectively. At this time, the vehicle is driven by the front drive axle and the rear drive axle at the same time.

[0045] Specifically, when the hydraulic pump is driven to output oil from port a and return oil from port b, the vehicle moves in one direction; when the hydraulic pump is driven to output oil from port b and return oil from port a, the vehicle moves in the opposite direction.

[0046] Mode 2: Front axle driven only, rear axle not working.

[0047] like Figure 4 As shown, in this working state, control valve A4 is in position A2, control valve B6 is in position B2, control valve C3 is in position C2, and control valve D7 is in position D2.

[0048] The oil port a of the driving hydraulic pump 5 is connected to the oil port a of the first driving motor 2, the oil port b of the driving hydraulic pump 5 is connected to the oil port b of the first driving motor 2, and the oil port a of the second driving motor 3 is connected to the oil port b. At this time, the driving hydraulic pump drives the first driving motor 2 to realize the vehicle movement. The vehicle is only driven by the front drive axle. The displacement of the second driving motor 3 is adjusted to the minimum and is passively rotated by the rear axle wheels.

[0049] Mode 3: Rear axle driven only, front axle not driven.

[0050] like Figure 5 As shown, in this working state, control valve A4 operates at position A1, control valve B6 operates at position B3, control valve C3 operates at position C1, and control valve D7 operates at position D1.

[0051] The oil port a of the driving hydraulic pump 5 is connected to the oil port a of the second driving motor 3, the oil port b of the driving hydraulic pump 5 is connected to the oil port b of the second driving motor 3, and the oil port a of the first driving motor 2 is connected to the oil port b. At this time, the driving hydraulic pump drives the second driving motor 3 to realize the vehicle movement. The vehicle is only driven by the rear drive axle. The displacement of the first driving motor 2 is adjusted to the minimum and is passively rotated by the front axle wheels.

[0052] In addition to the driving modes described above for normal vehicle operation, this embodiment can also achieve:

[0053] Mode 4, when the vehicle is broken down and being towed:

[0054] like Figure 6As shown, when the engine is stopped and the vehicle cannot move, other vehicles need to tow the faulty vehicle to move, at this time the control valve C3 works in the C1 position, and the control valve D7 works in the D2 position, so the faulty vehicle can be towed to move.

[0055] It should be noted that, in order to facilitate the description of the working state of the utility model, four control valves are designed separately in the embodiment, and in the actual use process, the control valves can be combined according to the requirements, and the control valve C and the control valve D can be integrated in the driving motor.

[0056] In addition, the above embodiments are only used to illustrate the technical solutions of the utility model, rather than limit them, and those skilled in the art should understand that the utility model can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A closed center hydrostatic drive system for a loader, comprising: The hydraulic drive pump is connected with a control valve A through a first oil port, and the control valve A is connected with a first oil port of a first drive motor and a second drive motor respectively; the hydraulic drive pump is connected with a control valve B through a second oil port, and the control valve B is connected with a second oil port of the first drive motor and the second drive motor respectively; the first drive motor and the second drive motor are used for driving front axle wheels and rear axle wheels respectively.

2. A closed center hydrostatic drive system for a loader as set forth in claim 1, characterized in that, The control valve A and the control valve B are both three-position three-way electromagnetic valves.

3. A closed center hydrostatic drive system for a loader as set forth in claim 1, wherein, A control valve C is arranged on an oil path between the first drive motor and the control valve A and the control valve B, and the control valve C is a two-position four-way electromagnetic valve.

4. A closed center hydrostatic drive system for a loader as set forth in claim 3, wherein, A control valve D is arranged on an oil path between the second drive motor and the control valve A and the control valve B.

5. A closed center hydrostatic drive system for a loader as set forth in claim 1, wherein, An output end of the first drive motor is connected with an input end of a front drive axle.

6. A closed center hydrostatic drive system for a loader as set forth in claim 5, wherein, An output end of the second drive motor is connected with an input end of a rear drive axle.

7. A closed center hydrostatic drive system for a loader as set forth in claim 1, wherein, When the first oil port of the hydraulic drive pump is communicated with the first oil ports of the first drive motor and the second drive motor respectively, and the second oil port of the hydraulic drive pump is communicated with the second oil ports of the first drive motor and the second drive motor respectively, the vehicle is driven to move by the front drive axle and the rear drive axle simultaneously.

8. A closed center hydrostatic drive system for a loader as set forth in claim 1, wherein, When the first oil port of the hydraulic drive pump is communicated with the first oil port of the first drive motor, the second oil port of the hydraulic drive pump is communicated with the second oil port of the first drive motor, and the first oil port and the second oil port of the second drive motor are communicated, the hydraulic drive pump drives the vehicle to move by driving the first drive motor, and the vehicle is driven by the front drive axle only.

9. A closed center hydrostatic drive system for a loader as set forth in claim 1, wherein, When the first oil port of the hydraulic drive pump is communicated with the first oil port of the second drive motor, the second oil port of the hydraulic drive pump is communicated with the second oil port of the second drive motor, and the first oil port and the second oil port of the first drive motor are communicated, the hydraulic drive pump drives the vehicle to move by driving the second drive motor, and the vehicle is driven by the rear drive axle only.

10. A closed center hydrostatic drive system for a loader as set forth in claim 1, wherein, The hydraulic drive pump is driven by an engine through a shaft coupling.

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