CN103994042B - Piston type hydraulic pump with crank connecting rod structure - Google Patents

Abstract

The invention discloses a piston type hydraulic pump adopting a crank connecting rod structure, which includes two plungers, the plungers are arranged in a cavity, two cylinders are arranged along a straight line, a connecting rod connects the pistons of two driving mechanisms, and the connecting rod Two racks are arranged along its length direction, and two gears meshing with the racks are also arranged on the machine tool; the plunger is connected at the eccentric position of the gear through a hinge rod, and the hinge rod is hinged with the gears and the plunger. The present invention has the following advantages: (1) Only one symmetrical rack-pinion cylinder is used to realize the work of two plunger hydraulic pumps, with high working efficiency and good economy. (2) Driven by the cylinder, it does not pollute the environment. (3) The crank-link mechanism is a nonlinear mechanism. When the transmission angle and pressure angle are large, it is a stroke amplification mechanism. At this time, the hydraulic pump can output low-pressure and large-flow liquid; when the transmission angle and pressure angle are small, it is a force The amplifying mechanism can output high-pressure and small-flow liquid.

Description

Piston hydraulic pump with crank connecting rod structure

technical field

The invention belongs to the mechanical field and relates to a piston hydraulic pump adopting a crank connecting rod structure.

Background technique

At present, the throttling speed regulating system hydraulic speed regulating technology widely used in the industrial field mainly includes the throttling speed regulating system composed of a constant pump and a throttle valve and the pump speed regulating system driven by a variable pump. High-power hydraulic pumps with continuously adjustable flow and pressure are mainly swash plate axial piston pumps, but the structure of the swash plate axial piston pump is extremely complicated, especially the plunger has to withstand the radial force formed Torque, which makes its friction conditions deteriorate, service life and mechanical efficiency are reduced. In addition, the sliding shoe connected to the lower end of the plunger has a complex structure, extremely harsh friction conditions, and a complicated flow distribution system, etc., making the manufacturing process of the plunger pump extremely complicated. The traditional swash plate axial piston pump also has a fatal flaw that cannot be ignored, that is, the flow rate is unstable, resulting in the so-called pulsation rate. To reduce the flow rate pulsation rate, not only the number of plungers needs to be increased, but also the The number is a prime number, such as 3, 5, 7, 11, 13, 17, 19, 23 and so on. Therefore, an excessive number of plungers is actually a helpless choice, which not only makes the mechanism complicated, but also keeps the manufacturing cost high.

The hydraulic drive system of a hydraulic elevator is a typical hydraulic system that requires continuous speed regulation. In terms of energy saving and operating costs, it is ideal to use a servo variable axial piston pump for speed regulation. However, a servo variable axial piston pump The extremely expensive price and high failure rate limit its application in hydraulic elevators.

The Chinese patent with the authorized notification number CN 102207066 B also discloses a double-acting plunger pump driven by a symmetrical toggle lever, but this double-acting plunger pump only shows the last stage of mechanical transmission. With the drive motor, it will be found that the overall layout of the double-acting plunger pump is extremely asymmetrical. In addition, the toggle mechanism in the double-acting plunger pump is hinged on the eccentric pin shaft on the end face of the gear. The pin shaft is a cantilever beam, and the stress condition is extremely poor.

Contents of the invention

In order to solve the above problems, the present invention provides a piston type hydraulic pump with a simple structure and low cost, which can continuously adjust flow and pressure and adopts a crank-connecting rod structure.

The technical solution of the present invention is to provide a piston type hydraulic pump adopting a crank connecting rod structure, which includes two plungers, each of which is movably arranged in a cavity, and is characterized in that: it also includes Two piston-type driving mechanisms are set, a connecting rod connects the pistons of the two driving mechanisms, and two racks are arranged on the connecting rod along its length direction, and the two racks are respectively arranged on the connecting rod as the axis. the two sides of the connecting rod; the machine tool is also provided with two gears meshed with the rack, and the gears are symmetrically arranged on both sides of the connecting rod with the connecting rod as a symmetrical axis; the plunger The hinge rod is connected to the eccentric position of the gear, and the hinge rod is hinged to the gear and the plunger.

Preferably, the piston driving mechanism is an oil cylinder or an air cylinder.

Preferably, with the connecting rod as the axis of symmetry, two plungers are arranged symmetrically on both sides of the connecting rod, and the two plungers are arranged symmetrically with the axis of the connecting rod as the axis of symmetry, and the two are respectively connected to The gear meshed with the rack is arranged symmetrically with the axis of the connecting rod as the axis of symmetry.

Preferably, the ends of the cavity are provided with an oil inlet and an oil discharge; the oil inlet communicates with the oil tank through a one-way valve, and the oil discharge connects with an external hydraulic system through a one-way valve.

Preferably, the outlet of the one-way valve of the oil discharge circuit communicates with the pressure regulator, and the outlet of the pressure regulator leads to the hydraulic actuator system.

Preferably, a digital pressure switch is connected to the voltage regulator.

The piston hydraulic pump adopting the crank connecting rod structure of the present invention has the following advantages:

(1) Only one symmetrical rack-and-pinion cylinder is used to realize the work of two plunger hydraulic pumps, with high working efficiency and good economy.

(2) Driven by cylinders, it does not pollute the environment. Compared with hydraulic transmission technology, it has prominent green features and is in line with the development trend of green trends.

(3) The crank-link mechanism in the device is a nonlinear mechanism. When the transmission angle and pressure angle are large, the crank-link mechanism is a stroke amplification mechanism. At this time, the hydraulic pump can output low-pressure and large-flow liquid; When the pressure angle is small, the crank-link mechanism is a force amplification mechanism. At this time, the hydraulic pump can output high-pressure and small-flow liquid.

(4) The dual-station structure is adopted, and the force is balanced, which can effectively prolong the life of the structure.

Description of drawings

Fig. 1 is a structural schematic diagram of the best embodiment of the piston hydraulic pump adopting the crank connecting rod structure of the present invention.

detailed description

Specific embodiments of the present invention will be further described in detail below.

As shown in Figure 1, the piston hydraulic pump adopting the crank-connecting rod structure of the present invention includes two driving mechanisms 10, the driving mechanisms 10 can be oil cylinders or air cylinders, the cylinder is preferred to reduce the pollution caused by hydraulic oil. The two driving mechanisms 10 are arranged along a straight line, and a connecting rod 12 connects the pistons 14 of the two driving mechanisms 10 . A two-sided rack 16 is fixedly connected to the connecting rod 12, and a gear 18 and a gear 18' meshed with the rack 16 are respectively arranged on both sides. Of course, those of ordinary skill in the art can easily think of a rack 16 fixedly connected on the connecting rod 12 according to the thinking of the present invention, and several gears 18 and gears 18' are arranged on the same side of the rack 16; Two separate racks 16 are arranged on both sides, and a plurality of gears 18 and gears 18 ′ are arranged along the direction of the racks 16, so as to realize the function of a hydraulic pump. '

A left plunger 20 and a right plunger 20' are arranged on both sides of the connecting rod 12 respectively. The left plunger 20 and the right plunger 20' are fitly placed in their respective cavities; There is an oil inlet and outlet passage (not shown); the oil inlet passage (not shown) communicates with the fuel tank (not shown) through a one-way valve (not shown), and the oil outlet passage (not shown) passes through a one-way valve Interface with external hydraulic system (not shown). The outlet of the one-way valve (not shown) in the oil discharge circuit communicates with the voltage regulator (not shown), and the outlet of the voltage regulator leads to the hydraulic actuator system (not shown); a digital pressure switch is connected to the voltage regulator (not shown). The oil inlet and outlet passages, one-way valve, oil tank, voltage regulator, digital pressure switch and hydraulic actuator system are well-known and widely used structures in the industry, and are not the innovation points of the present invention.

The left plunger 20 and the right plunger 20' are hinged on the gear 18 and the gear 18' and the eccentric position of the gear 18 and the gear 18' through the hinge rod 22 and the hinge rod 22'.

The two cylinders 10 cooperatively drive the connecting rod 12 to move up or down, so that the rack 16 fixed on the connecting rod 12 will also move symmetrically accordingly.

When the rack 16 moves downward, it will drive the gears 18 and 18' on both sides and the gears 18 and 18' to move clockwise and counterclockwise respectively, and drive the crank connecting rod 22 and hinge rod 22' mechanism on both sides. Drive the left plunger 20 and the right plunger 20′ to move symmetrically inward at the same time. At this time, the volumes of the left and right cavities expand to form a negative pressure. To the valve, respectively into the cavity of the left plunger 20 and the right plunger 20'.

When the rack 16 moves upward, it will drive the gears 18 and 18' on both sides and the gears 18 and 18' to move counterclockwise and clockwise respectively, and drive the crank connecting rod 22 and hinge rod 22' mechanism on both sides to drive the left column The plug 20 and the right plunger 20' move symmetrically inwardly at the same time. At this time, the volume of the cavity corresponding to the left plunger 20 and the right plunger 20' shrinks, forming pressure on the oil, so that the lower check valve leading to the oil tank is closed, and the upper check valve is opened at the same time to realize the pressure oil output. .

The above embodiment is only one implementation mode of the present invention, and its description is relatively specific and detailed, but it should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (3)

1. a kind of piston type hydraulic pumps of employing brace and connecting rod framework, it includes two plungers, all activity settings of each described plunger In a cavity volume it is characterised in that：Also include arranging two-piston formula drive mechanism along a straight line, a connecting rod connects lives described in two The piston of plug drive mechanism, described connecting rod is provided with two tooth bars along its length, and tooth bar described in two is with described connection Bar is separately positioned on the both sides of described connecting rod for axle；Two and described tooth bar meshed gears, described tooth are also set up on lathe Wheel is symmetricly set on the both sides of described connecting rod with described connecting rod for symmetry axis, and described gear is provided with 13 wheels Tooth；Described plunger is connected at described gear eccentricity position by a toggle, and described toggle is all hinged with described gear and plunger；

Described piston type drive mechanism is oil cylinder or cylinder；

With described connecting rod as symmetry axis, the both sides of described connecting rod are symmetrically arranged with two described plungers, plunger described in two with The axis of described connecting rod is symmetrical arranged for symmetry axis, two respectively with described tooth bar meshed gears with the axis of described connecting rod It is symmetrical arranged for symmetry axis.

2. employing brace and connecting rod framework according to claim 1 piston type hydraulic pumps it is characterised in that：Described cavity volume End is equipped with in-line and oil extraction road；Described in-line is communicated with fuel tank by check valve, and check valve is passed through on described oil extraction road Connect with external hydraulic system.

3. employing brace and connecting rod framework according to claim 2 piston type hydraulic pumps it is characterised in that：Described oil extraction road The outlet of check valve communicate with voltage-stablizer, hydraulic executing system is led in the outlet of voltage-stablizer.