阅读说明：本技术 一种用于液压抽油机的液压系统 (Hydraulic system for hydraulic pumping unit ) 是由 曹健 于 2021-01-21 设计创作，主要内容包括：本发明涉及液压系统领域,尤其是一种用于液压抽油机的液压系统。通过变频电机带动柱塞泵为系统供油。油缸内活塞及推杆上升时,通过改变电机转速调节供油速度,从而调节油缸活塞的上升速度；油缸活塞下降时,充分利用油井泵挂产生的重力使活塞下降,通过比例调速阀控制排油速度,从而调节活塞下降速度。压力传感器、位移传感器8与计算机控制系统连接,计算机随时采集压力传感器6的压力数据和位移传感器8的位移数据,通过计算自动生成示功曲线,无需换向,液压系统结构简单,成本低廉,经久耐用,工作效率高,比传统抽油机节能10%以上。(The invention relates to the field of hydraulic systems, in particular to a hydraulic system for a hydraulic pumping unit. The variable frequency motor drives the plunger pump to supply oil for the system. When the piston and the push rod in the oil cylinder ascend, the oil supply speed is adjusted by changing the rotating speed of the motor, so that the ascending speed of the piston of the oil cylinder is adjusted; when the piston of the oil cylinder descends, the gravity generated by the pump hanger of the oil well is fully utilized to enable the piston to descend, and the oil discharge speed is controlled through the proportional speed regulating valve, so that the descending speed of the piston is regulated. Pressure sensor, displacement sensor 8 are connected with computer control system, and the computer gathers pressure sensor 6's pressure data and displacement sensor 8's displacement data at any time, through calculating automatic generation indicator curve, need not the switching-over, and hydraulic system simple structure, low cost, durable, work efficiency is high, and is more than 10% than traditional beam-pumping unit energy-conservation.)

1. The utility model provides a hydraulic system for hydraulic pumping unit, includes oil tank (1), motor (2), plunger pump (3), check valve (4), overflow valve (5), pressure sensor (6), air cleaner and muffler (7), displacement sensor (8), piston (9), hydro-cylinder (10), proportional speed control valve (11), electromagnetic switch valve (12), its characterized in that: the plunger pump (3) is connected with the motor (2), an oil suction port of the plunger pump (3) is connected with the oil tank (1) through an oil pipe, an oil outlet of the plunger pump (3) is connected with an oil inlet of the oil cylinder (10) through the oil pipe, a piston and a push rod (9) are arranged in the oil cylinder (10), the piston and the push rod (9) are connected with an oil pumping rod in an oil well, the oil pumping rod is connected with a downhole oil well pump, the oil cylinder piston and the push rod (9) move upwards to drive the piston of the oil pumping pump to ascend, a displacement sensor (8) is fixedly arranged at the middle position above the oil cylinder (10), the rotating speed of the motor (2) is adjusted through an electric signal fed back by the displacement sensor (8), the purpose of adjusting the ascending speed of the piston is achieved, the oil cylinder (10) is connected with the oil tank (1) through the oil pipe, a check valve, the oil pipe is provided with a proportional speed regulating valve (11) and an electromagnetic switch valve (12).

2. The hydraulic system of claim 1, wherein: an air filter and a silencer (7) are fixed on the outer side of the oil cylinder (10).

3. The use method of the hydraulic system for the hydraulic pumping unit is characterized in that: the motor (2) drives the pump to supply oil to the oil cylinder (10), the piston and the push rod (9) ascend, the displacement sensor controls the stroke of the piston, the switch and the proportional speed regulating valve are sequentially opened after the piston moves from the position I to the position II, the motor stops, the piston descends by means of gravity, the switch and the proportional speed regulating valve are closed after the piston moves to the position I, the motor is started, and the next cycle is started.

Technical Field

The invention relates to the field of hydraulic systems, in particular to a hydraulic system for a hydraulic pumping unit.

Background

The hydraulic system of the existing hydraulic pumping unit uses a common motor or a variable frequency motor to drive an oil pump to supply oil for the system, and uses an electromagnetic reversing valve to realize oil way reversing, and the hydraulic pumping unit requires high system pressure, large flow (over 10MPa of the pressure of the general system and over 100L/min of the flow), and frequent reversing (6-12 times/min), so that the hydraulic pumping unit generates large impact and noise during reversing, and the system has large resistance, thereby causing the problems of low service life of the reversing valve, oil leakage of the system, rising of the oil temperature and the like.

Disclosure of Invention

The invention provides a novel hydraulic system, which is used for solving the problems of system reversing, oil temperature rising, large system power consumption and the like in the prior art.

The technical scheme of the invention is as follows: a hydraulic system for a hydraulic pumping unit comprises an oil tank (1), a motor (2), a plunger pump (3), a one-way valve (4), an overflow valve (5), a pressure sensor (6), an air filter and silencer (7), a displacement sensor (8), a piston and push rod (9), an oil cylinder (10), a proportional speed control valve (11) and an electromagnetic switch valve (12), wherein the plunger pump (3) is connected with the motor (2), an oil suction port of the plunger pump (3) is connected with the oil tank (1) through an oil pipe, an oil outlet of the plunger pump (3) is connected with an oil inlet of the oil cylinder (10) through the oil pipe, the oil cylinder (10) is internally provided with the piston and the push rod (9), the piston and the push rod (9) are connected with an oil pumping rod in an oil well, the oil pumping rod is connected with an underground oil pumping pump, the oil cylinder piston and the push rod (9) move upwards to drive, the rotating speed of the motor (2) is adjusted through an electric signal fed back by the displacement sensor (8), the purpose of adjusting the rising speed of the piston is achieved, the oil cylinder (10) is connected with the oil tank (1) through an oil pipe, a one-way valve (4), a pressure sensor (6) and an overflow valve (5) are installed on the oil pipe, the oil cylinder (10) is further provided with an oil outlet, the oil outlet of the oil cylinder (10) is connected with the oil tank (1) through the oil pipe, and a proportional speed adjusting valve (11) and an electromagnetic switch valve (12) are installed. An air filter and a silencer (7) are fixed on the outer side of the oil cylinder (10).

The displacement sensor (8) feeds back electric signals to the electromagnetic switch valve (12), the proportional speed regulating valve (11) and the motor (2) to control the stroke and the direction change of the piston and the push rod (9).

Wherein the stroke is directly controlled by the displacement signal output by the displacement sensor (8), and the reversing is controlled by the electromagnetic switch valve

(12) The control, ascending and descending speed curves are preset according to the oil pumping process and are realized through a variable frequency motor (2) and a proportional speed regulating valve (11). When the system pressure is over-pressure, the overflow valve (5) is opened, and the automatic unloading is realized.

The motor (2) drives the plunger pump (3), the oil suction port of the plunger pump sucks oil from the oil tank (1), the oil is pressurized by the pump and then enters the oil cylinder (10), the piston and the push rod (9) are pushed to rise, the piston and the push rod (9) are connected with the oil pumping rod in an oil well, the oil pumping rod is connected with an underground oil well pump, the oil cylinder piston and the push rod move upwards to drive the piston of the oil well pump to rise, the electromagnetic switch valve (12) is opened after the piston rises to a set position, the speed regulating valve (11) is opened, the push rod of the oil cylinder piston descends by means of gravity, the oil.

The invention has the beneficial technical effects that: the oil way of the hydraulic system is a one-way circulating oil way, and the oil way does not need to be reversed, and the hydraulic system has the advantages of simple structure, low cost, durability and high working efficiency, and saves more than 10 percent of energy compared with the traditional oil pumping unit.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a flow chart of the present invention.

Fig. 3 is a state diagram of the piston of the present invention in position I.

Fig. 4 is a state diagram of the piston of the present invention in position II.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The working process shows that the motor 2 drives the pump to supply oil to the oil cylinder, the piston and the push rod 9 rise, the displacement sensor controls the stroke of the piston, the switch and the proportional speed control valve are sequentially opened after the position I reaches the position II, the motor stops, the piston descends by the gravity, the switch and the proportional speed control valve are closed after the position I reaches the position I, the motor is started, and the next cycle is started.

The variable frequency motor 2 drives the plunger pump 3 to supply oil for the system. When the piston and the push rod 9 in the oil cylinder 10 ascend, the oil supply speed is adjusted by changing the rotating speed of the motor, so that the ascending speed of the piston of the oil cylinder is adjusted; when the piston of the oil cylinder descends, the gravity generated by the pump hanger of the oil well is fully utilized to enable the piston to descend, and the oil discharge speed is controlled through the proportional speed regulating valve, so that the descending speed of the piston is regulated. The pressure sensor and the displacement sensor 8 are connected with a computer control system, and the computer collects pressure data of the pressure sensor 6 and displacement data of the displacement sensor 8 at any time and automatically generates a power indicating curve through calculation.

The application method comprises

1. And in the ascending stage of the piston 9, the motor 2 drives the plunger pump 3 to supply oil to the oil cylinder 10.

2. The motor works according to a set speed curve to drive the oil pump to supply oil to the oil cylinder, so that the piston rises at a set speed.

3. When the oil cylinder rises to a set stroke, the displacement sensor simultaneously feeds back signals to the motor, the proportional speed regulating valve 11 and the electromagnetic switch valve 12, the valve is opened, and the motor stops after time delay.

4. The piston of the oil cylinder begins to descend under the action of gravity, the one-way valve 4 of the oil inlet path is closed, and oil in the oil cylinder flows back to the oil tank 1 through the oil return path.

6. When the piston descends to a set position, the displacement sensor gives an electric signal, the hydraulic proportional speed regulating valve is closed, the electromagnetic switch valve is closed, the motor is started, and the plunger pump starts the next cycle from oil absorption of the oil tank.

5. The descending speed of the piston is regulated by a proportional speed regulating valve.

7. When the system pressure is over-pressure, the overflow valve 5 is opened, and the automatic unloading is realized.

9. When power failure or fault emergency stop occurs, the electromagnetic switch is closed. All oil paths are sealed, and the piston 9 stops moving.

10. The system collects pressure data of the pressure sensor 6 and displacement data of the displacement sensor 8 at any time, and a dynamometer curve is automatically generated through calculation.