Electro-hydraulic high-precision bidirectional servo pump

Abstract

The utility model belongs to servo pump technical field, concretely relates to a kind of electro-hydraulic high-precision bidirectional servo pump, comprising: pump base, control group, protection valve group, the pump base includes transmission shaft, rotor assembly, variable group, pump cover, the control group includes control valve, sensor and controller, the variable group includes swash plate and the swing mechanism of driving swash plate, swing mechanism is located at the side of swash plate, the driving piece action of swing mechanism is controlled by control valve, control valve is driven by controller.The utility model can be modified setting value at will according to user demand by additionally setting control group and variable group, is a kind of electric control servo pump suitable for the change of working condition load is violent and frequent, equipment is widely used in working condition range, precision is high, and function is more, can greatly simplify the complexity of hydraulic system.

Description

TECHNICAL FIELD

[0001] The utility model belongs to servo pump technical field, concretely relates to a kind of electro-hydraulic high-precision bidirectional servo pump. BACKGROUND

[0002] Constant-pressure oil source is often needed in hydraulic system, and two similar constant-pressure oil sources are available, one is pump fixed displacement operation, and overflow valve control system pressure is in output circuit, and the other is constant-pressure pump;The existing constant-pressure pump is all pressure cut-off type, i.e.full displacement operation before pressure reaches set value, and zero displacement after set pressure value, and this constant-pressure pump is suitable for constant-pressure fixed flow and load change is not drastic and not frequent working condition, and for complex load change working condition, overflow valve control system constant pressure is often used.

[0003] Constant-pressure pump is generally set by setting mechanical spring or electromagnet signal to set constant pressure value, and it is usually set at factory, and it cannot be changed or changed complexly thereafter, and constant pressure value cannot be changed frequently according to load demand or modified randomly according to user demand. INVENTION CONTENTS

[0004] The utility model aims at providing a kind of electro-hydraulic high-precision bidirectional servo pump to solve the problems raised in the above background.

[0005] To achieve the above object, the utility model provides the following technical scheme: a kind of electro-hydraulic high-precision bidirectional servo pump, comprising: pump base, control valve, pressure sensor, position sensor, protection valve group, the side of swash plate in the pump base is equipped with swing mechanism for swinging, the swing mechanism includes first end cover, second end cover and variable piston, one end of the swash plate is installed in the middle of variable piston side, the moving area for the transverse movement of variable piston is formed between the first end cover and the second end cover, the first end cover, the second end cover and the variable piston jointly constitute the driving member for the hydraulic drive of variable piston, and the driving member and the swash plate jointly constitute the variable group, and the control valve, the pressure sensor, the position sensor and the controller jointly constitute the control group.

[0006] Preferably, the side opposite to the first end cover and the second end cover is provided with oil pressure cavity, the moving area is formed between the two oil pressure cavities, and the two oil pressure cavities are connected by hydraulic flow channel between the control valve, the variable group is symmetrical structure, and the left and right sides correspond to positive and negative directions with symmetry center as boundary.

[0007] Preferably, the controller in the control group can output instruction according to given real-time signal according to control protocol, and the instruction output is to the control valve, and the control valve is high-frequency response proportional servo valve, can control flow direction first end cover or second end cover, make the oil pressure cavity of corresponding end cover side increase, drive variable piston to move, to change the actual displacement of pump.

[0008] Preferably, the upper part of the variable piston middle part is further provided with a position sensor for position positioning, and the top of the variable piston middle part is further provided with an inclined surface for position detection, the position defined by the center symmetry of the variable piston is the zero position on the inclined surface, and the positions above and below the zero position correspond to displacement negative and displacement positive respectively, and the position sensor feeds back signals to the controller according to the definition.

[0009] Preferably, the pump base is provided with a protection valve group for protecting the pump, so as to ensure the safety of the system in abnormal state.

[0010] Preferably, the oil outlet of the pump base is provided with two pressure sensors, the pressure sensors detect the pressure of the pump output flow and feed back to the controller, as long as one of the two pressure sensors works normally, the normal operation of the servo pump can be ensured, and the fault tolerance of the servo pump is greatly improved.

[0011] Preferably, the pump base is provided with a protection valve group for protecting the pump, the protection valve group has two flow channels connected to the oil inlet and the oil outlet of the pump respectively, when the pump works normally, the pressure of the oil outlet is higher than that of the oil inlet, the protection valve group is normally closed, and when an abnormal state occurs, for example, when the pressure of the oil outlet is lower than that of the oil inlet, the protection valve group is opened.

[0012] Preferably, the controller in the control group has two closed-loop controls, which are position closed-loop control and pressure closed-loop control, the position closed-loop control has a relatively higher level and is preferentially executed, the position sensor participates in the position closed-loop control and is used for feeding back the real-time position of the variable piston, so as to ensure that the position of the variable piston is always in the instruction corresponding displacement positive and negative interval, and the pressure sensor participates in the pressure closed-loop control and is used for feeding back the real-time pressure of the pump output, so as to ensure that the output pressure of the variable piston is always in the instruction corresponding pressure range.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] (1) The utility model discloses a control group and variable group are added, and the set value can be modified at will according to user's demand, is a kind of electric control servo pump suitable for load change violent and frequent, equipment is widely used in working condition range, precision is high, and it has many functions, can greatly simplify the complexity of hydraulic system.

[0015] (2) The utility model discloses a sensor and controller are added, provide a new pump control type, improve the system fault tolerance while improving pump control precision, and can have the function of feedback pump state to monitoring system, greatly provide safety. DRAWINGS

[0016] Figure 1 It is the side view of the utility model;

[0017] Figure 2This is a top view of the present invention;

[0018] Figure 3 This is a schematic diagram showing the fit between the variable piston, the first end cap, and the second end cap of this utility model.

[0019] Figure 4 This is a schematic diagram of the electro-hydraulic principle of this utility model;

[0020] In the diagram: 1. Pump base; 2. Protective valve assembly; 3. Pressure sensor; 4. Position sensor; 5. Connecting valve body; 6. Control valve; 7. Drive shaft; 8. Controller; 9. Swashplate; 10. Variable piston; 11. First end cover; 12. Second end cover; 13. Rotor assembly; 14. Hydraulic chamber; 15. Hydraulic flow channel; 16. Pump cover; 17. Rotary shaft; 18. Angle line. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] refer to Figures 1-4 As shown, the present invention provides an electro-hydraulic high-precision bidirectional servo pump, comprising: a pump base 1, a control valve 6, a pressure sensor 3, a position sensor 4, and a protection valve group 2. The pump base 1 includes a drive shaft 7, a rotor assembly 13, a variable assembly, and a pump cover. The variable assembly includes a first end cover 11, a second end cover 12, and a variable piston 10.

[0023] Combination Figure 3 As shown, each of the first end cap 11 and the second end cap 12 has a hydraulic chamber 14 on its opposite side. The moving area is formed between the two hydraulic chambers 14. The two hydraulic chambers 14 are connected to the control valve 6 by a hydraulic oil circuit 15.

[0024] The swash plate 9 and the swing mechanism are designed as a structure capable of swinging left and right, the swing angle direction and angle of the swash plate 9 are controlled by the position of the variable piston 10, the left and right sides of the variable piston 10 are provided with a first end cover 11 and a second end cover 12, the variable piston 10, the first end cover 11 and the second end cover 12 form a cavity, the cavity is filled with hydraulic oil, the variable piston 10 is pushed to move by controlling the flow of the hydraulic oil, the principle is similar to that of a hydraulic cylinder, the swash plate 9 is defined as zero position when in the middle position, at this time, the left and right direction displacement of the variable piston 10 corresponds to the positive and negative signals of the position sensor 4, and the displacement value and the signal value have a unique corresponding relationship. The control valve 6 controls the flow direction of the pressure oil, thereby controlling the moving direction of the variable piston 10.

[0025] As shown in Figure 2 The pump base 1 is provided with a protection valve group 2 for protecting the pump, the protection valve group 2 has two flow channels, which are connected to the oil inlet and the oil outlet of the pump respectively, when the pump normally works, the pressure of the oil outlet is higher than that of the oil inlet, the protection valve group 2 is normally closed, when an abnormal state occurs, for example, when the pressure of the oil outlet of the pump is lower than that of the oil inlet, the protection valve group 2 is opened, thereby ensuring the safety of the whole system under the abnormal state.

[0026] As shown in Figure 4As shown, the controller 8 receives the instruction signal from the user, the instruction signal is defined in the controller 8, the signal information contains the two information of the left and right swing direction of the swash plate 9 and the set output pressure value, after the instruction signal is calculated, it is judged whether the value comparison with the feedback of the pressure sensor 3 or the position sensor 4 is needed, if the signal is not in the specified interval, the invalid instruction is executed, and if the signal is in the reasonable interval, the feedback comparison is carried out; there are two closed-loop controls in the controller 8, which are position closed-loop control and pressure closed-loop control, and the position closed-loop control has higher priority, if the position sensor 4 feedback is the same as the swing direction contained in the instruction signal, the comparison of the pressure sensor 3 is carried out; if the pressure feedback is less than the instruction value, the controller 8 outputs control to the control valve 6, so that the control variable piston 10 moves to a larger swash plate 9 angle until the maximum angle, if the pressure feedback is greater than the instruction value, the controller 8 outputs control to the control valve 6, so that the control variable piston 10 moves to a smaller swash plate 9 angle until the middle position; if the position sensor 4 feedback is different from the swing direction contained in the instruction signal, the controller 8 outputs control to the control valve 6, so that the control variable piston 10 moves to the swing direction corresponding to the instruction, and the swash plate 9 angle is continuously increased until the pressure sensor 3 feedback signal is consistent with the instruction signal; the invalid instruction is that the controller 8 outputs control to the control valve 6, so that the control variable piston 10 moves to the maximum angle of the swash plate 9, at this time, the pump is operated at full capacity. When the pump output pressure fluctuates with the load, the pressure sensor 3 feedbacks the output pressure value in real time, the controller 8 compares it with the instruction signal, and then outputs the control signal to the control valve 6 in real time, so as to control the angle of the swash plate 9 in real time, and the whole process is executed by two closed-loop feedback control levels.

[0027] Further, in order to facilitate the deflection of the swash plate 9 on the pump body 1, referring to Figure 2 As shown, the pump body 1 is provided with a rotating shaft 17, the rotating center of the swash plate 9 is installed on the rotating shaft 17, the pump body 1 is provided with an angle line 18, and the angle line 18 is arranged on the inner side of the end of the swash plate 9 away from the variable piston 10, and the one end of the swash plate 9 sequentially passes through each position of the angle line 18 based on the deflection. The swash plate 9 is rotatably installed on the pump body 1 through the rotating shaft 17, and the angle of the swash plate 9 can be determined through the angle line 18.

[0028] In the utility model, in combination Figures 1-2 As shown, the upper part of the middle part of the variable piston 10 of the embodiment is further provided with a position sensor 4 for position positioning, and the top of the middle part of the variable piston 10 is further provided with an inclined surface for position detection.

[0029] The above, in use the position sensor 4 provided by the utility model, the position of the variable piston 10 can be monitored in real time through the position sensor 4, and the identification accuracy of the position sensor 4 is improved through the inclined surface.

[0030] In the utility model, in combination Figures 1-2As shown, two same pressure sensors 3 are arranged on the pump base 1 of the embodiment, the pressure sensors 3 detect the outlet pressure in real time and feedback to the controller 8, as long as one of the two pressure sensors can work normally, the normal operation of the pump can be ensured, and the fault tolerance of the pump is greatly improved.

[0031] Although the embodiments of the present application have been shown and described, it should be understood by those ordinary skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An electro-hydraulic high-precision bidirectional servo pump, characterized in that, The utility model relates to a pump, comprising: Pump base (1), control valve (6), pressure sensor (3), position sensor (4), protection valve group (2), one side of swash plate (9) in pump base (1) is equipped with swing mechanism for swinging, the swing mechanism includes first end cover (11), second end cover (12) and variable piston (10), one end of swash plate (9) is installed in the middle of one side of variable piston (10), and the moving area for the transverse movement of variable piston (10) is formed between first end cover (11) and second end cover (12), and first end cover (11), second end cover (12) and variable piston (10) jointly constitute the driving member for the hydraulic drive of variable piston (10), and the driving member and swash plate (9) jointly constitute the variable group, and control valve (6), pressure sensor (3), position sensor (4) and controller (8) jointly constitute the control group.

2. The electro-hydraulic high-precision bidirectional servo pump according to claim 1, characterized in that: The opposite side of first end cover (11) and second end cover (12) is provided with oil pressure cavity (14), the moving area is formed between the two oil pressure cavities (14), and the two oil pressure cavities (14) are connected with control valve (6) by hydraulic flow channel (15), and the variable group is a symmetrical structure, and the left and right sides correspond to the positive and negative directions with the symmetry center as the boundary.

3. The electro-hydraulic high-precision bidirectional servo pump according to claim 1, characterized in that: The controller (8) in the control group can make instruction output according to the given real-time signal according to the control protocol, and the instruction output is to control valve (6), and control valve (6) is a high-frequency response proportional servo valve, can control the flow direction to first end cover (11) or second end cover (12), makes the oil pressure cavity on the side of the corresponding end cover increase, drives variable piston (10) to move, thereby changes the actual displacement of the pump.

4. The electro-hydraulic high-precision bidirectional servo pump according to claim 3, characterized in that: The upper portion of the middle portion of variable piston (10) is further provided with position sensor (4) for position positioning, and the top of the middle portion of variable piston (10) is further provided with a bevel for position detection, and the position symmetrical to the center of variable piston (10) is defined as zero on the bevel, and the above and below of zero correspond to displacement negative and displacement positive respectively, and position sensor (4) feeds back signal to controller (8) according to the definition.

5. The electro-hydraulic high-precision bidirectional servo pump according to claim 1, characterized in that: The oil outlet of pump base (1) is provided with pressure sensor (3), and the number is two, and pressure sensor (3) detects the pressure of pump output flow and feeds back to controller (8), as long as one of the two pressure sensors (3) works normally, the normal operation of servo pump can be ensured, and the fault tolerance of servo pump is greatly improved.

6. The electro-hydraulic high-precision bidirectional servo pump according to claim 1, characterized in that: The pump base (1) is provided with protection valve group (2) for protecting the pump, and the protection valve group (2) has two flow channels, which are connected with the oil inlet and oil outlet of the pump respectively, when the pump works normally, the oil outlet pressure is higher than the oil inlet pressure, the protection valve group (2) is normally closed, when the abnormal state occurs, such as when the pump oil outlet pressure is lower than the oil inlet pressure, the protection valve group (2) is opened.

7. The electro-hydraulic high-precision bidirectional servo pump of any of claims 1, 2, 3, 4, 5, characterized in that: The controller (8) in the control group has two closed-loop controls, namely position closed-loop control and pressure closed-loop control, and the position closed-loop control is executed with relatively higher priority, the position sensor (4) participates in the position closed-loop control and is used for feeding back the real-time position of the variable piston, so that the position of the variable piston is always within the positive and negative displacement intervals corresponding to the instruction, and the pressure sensor (3) participates in the pressure closed-loop control and is used for feeding back the real-time pressure of the pump output, so that the output pressure of the variable piston is always within the pressure range corresponding to the instruction.

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