CN109654010B

CN109654010B - Plunger pump follow-up mechanism with self-cleaning function of current limiter

Info

Publication number: CN109654010B
Application number: CN201710942387.6A
Authority: CN
Inventors: 张艺宝; 李扬; 蒋文光; 武壮锋; 乔云; 冯茵
Original assignee: AECC Aero Engine Xian Power Control Technology Co Ltd
Current assignee: AECC Aero Engine Xian Power Control Technology Co Ltd
Priority date: 2017-10-11
Filing date: 2017-10-11
Publication date: 2020-04-03
Anticipated expiration: 2037-10-11
Also published as: CN109654010A

Abstract

The invention relates to a plunger pump, in particular to a plunger pump follow-up mechanism with a self-cleaning function of a current limiter. The servo mechanism comprises a piston rod (4), an adjusting piston (1), a current limiter (2), a cleaning needle (3) and a spring seat (6), the piston rod (4) is of a hollow structure, an oil duct which is communicated with a front cavity and a rear cavity of the adjusting piston (1) of the plunger pump is designed, the current limiter (2) is installed in the oil duct of the piston rod (4), one end of the cleaning needle (3) is fixed on the spring seat (6), and the other end of the cleaning needle is deep into a current limiting hole of the current limiter (2). The automatic cleaning of the follow-up mechanism current limiter in the working process is realized, and the pollution resistance and the use reliability of the product are improved.

Description

Plunger pump follow-up mechanism with self-cleaning function of current limiter

Technical Field

The invention relates to a plunger pump, in particular to a plunger pump follow-up mechanism with a self-cleaning function of a current limiter.

Background

The following mechanism is one of basic components of a swash plate type axial plunger pump, and has the function of changing the angle of a swash plate by adjusting the change of pressure difference force and spring force of front and rear cavities of a piston. In order to ensure that a certain pressure difference exists between the front cavity and the rear cavity of the adjusting piston, the inclined disc type axial plunger pump in the existing aviation product generally designs two oil ways which respectively enter the front cavity and the rear cavity of the adjusting piston, the front cavity is directly communicated with high-pressure of a plunger outlet, and the rear cavity is communicated with the pressure decompressed by a decompression valve or a flow-limiting oil nozzle.

Because the throttling oil nozzle is designed on the oil duct leading to the piston rear cavity, the diameter of the throttling oil nozzle is generally 0.8-1.5 mm. The size of the throttling area of the throttling oil nozzle influences the pressure difference of the front cavity and the rear cavity of the follow-up piston. The flow-limiting area is large, so that the transition process of the servo mechanism is influenced to be accelerated, the impact force borne by the swash plate is increased, if the flow-limiting area is small, the pressure of a rear cavity of the servo piston is small, the swash plate cannot be pushed to the maximum angle, the risk of blockage is also existed, and the pollution resistance is poor; in addition, the existing adjusting piston structure needs to design a special oil passage and a special mounting position for the throttling oil nozzle, so that the structural complexity and the processing difficulty are increased.

Disclosure of Invention

The purpose of the invention is as follows: the plunger pump follow-up mechanism with the self-cleaning function of the current limiter is provided, and the working reliability of the plunger pump follow-up mechanism is improved.

The technical scheme of the invention is as follows: a plunger pump follower having flow restrictor self-purging capability, characterized by: the follow-up mechanism comprises a piston rod 4, an adjusting piston 1, a current limiter 2, a cleaning needle 3 and a spring seat 6, wherein the piston rod 4 is of a hollow structure, an oil duct which is communicated with the front cavity and the rear cavity of the adjusting piston 1 of the plunger pump is designed, the current limiter 2 is installed in the oil duct of the piston rod 4, one end of the cleaning needle 3 is fixed on the spring seat 6, and the other end of the cleaning needle extends into a current limiting hole of the current limiter 2.

Preferably, the bottom of the spring seat 6 is provided with a hole, the bottom of the hole is a conical surface, and the cleaning needle 3 is arranged in the hole of the spring seat 6;

one end of the cleaning needle 3 is spherical, and the spherical surface is attached to the conical surface.

Preferably, the structure of the cleaning needle 3 in the working range of the flow restrictor 2 is a rod-shaped structure with a taper or a step.

Preferably, the inner wall of the oil passage of the piston rod 4 is provided with an annular groove, the annular groove can be provided with a cylinder with a central hole, and the cylinder is a flow limiter.

Preferably, the ratio of the orifice diameter of the flow restrictor within the flow restrictor to the diameter of the cleaning needle 3 is 1.2-1.4.

Preferably, the oil passage for communicating the front cavity and the rear cavity of the adjusting piston 1 of the plunger pump comprises an oil passage along the axis of the piston rod and an oil passage along the radial direction of the piston rod, the radial oil passage is a through hole, and an annular groove is formed in the radial oil passage on the outer circumferential surface of the piston rod.

The invention has the beneficial effects that: the automatic cleaning of the follow-up mechanism current limiter in the working process is realized, and the pollution resistance and the use reliability of the product are improved.

Drawings

FIG. 1 is a schematic diagram of a prior art plunger pump;

FIG. 2 is a schematic diagram of a cleaning structure of the present invention;

FIG. 3 is a schematic view of a cleaning structure according to the present invention.

Detailed Description

A plunger pump follow-up mechanism with a flow limiter self-cleaning function comprises a regulating piston 1, a flow limiter 2, a cleaning needle 3, a piston rod 4, a spring 5, a spring seat 6 and other components, and is shown in figure 3.

High-pressure oil pumped from the plunger pump enters the left cavity of the adjusting piston 1 through an oil passage hole, flows through two crossed oil passages on the piston rod 4 and reaches the current limiter 2, the high-pressure oil is decompressed by the current limiter 2 and then enters the rear cavity of the adjusting piston 1, and the position of the adjusting piston 1 is determined by the pressure difference force of the left cavity and the right cavity of the adjusting piston 1 and the elastic force of the spring 5. When the pressure of high-pressure oil pumped by the plunger pump changes, the adjusting piston 1 starts to move under the action of differential pressure, and the flow restrictor 2 is arranged in the piston rod 4 and moves together with the adjusting piston 1, so that the cleaning needle 3 arranged on the spring seat 6 automatically cleans the flow restrictor 2, and the flow restrictor 2 is prevented from being filthy and blocked. The area formed by the inner hole of the current limiter 2 and the outer circle of the cleaning needle 3 is the current limiting area, and current limiting combinations with different current limiting areas can be designed according to the requirements of the regulation rule of the product.

And one end of the piston rod 4 connected with the adjusting piston 1 is provided with two mutually perpendicular intersection oil way holes as oil through passages, and the intersection oil way holes are used for introducing oil in the left cavity of the adjusting piston into the right cavity of the piston. The radial hole is a through hole with the diameter phi of 2mm, and an annular groove is formed in the position of a radial oil way on the outer circumferential surface of the piston rod 4; the axial hole has a diameter phi of 2.5 mm.

The orifice of the axial hole is provided with a step hole and a clamping ring groove, the inner diameter of the step hole is matched with the outer diameter of the current limiter for use and is used for installing the current limiter 2, the clamping ring is arranged in the clamping ring groove and is used for fixing the current limiter 2, and the design has the function of modularizing the current limiter and is convenient for installation, inspection and replacement of the current limiter.

The adjusting piston 1 is a cylindrical metal piece machined with a central hole for mounting on the outer diameter of the piston rod 4. In order to improve the wear resistance of the adjusting

piston

1, 4 groups of annular grooves with the width of 1mm and the depth of 0.5mm are formed on the excircle of the piston, the excircle surface is plated with copper, and meanwhile, the excircle surface roughness Ra0.2 is ensured and polished.

The current limiter 2 is a cylinder with a central hole and is matched with the outer diameter of the cleaning needle for use; the restrictor 2 is sized in outer diameter to fit the mounting hole on the piston rod 4.

The cleaning needle 3 consists of a metal needle with the diameter phi of 1.2 mm-1.4 mm phi and a spherical ball, the spherical ball is provided with a central hole, the metal needle is welded in the central hole of the spherical ball by welding materials, and the non-concentricity of the welded metal needle and the spherical ball is not more than 0.15. In order to ensure flexible movement, the extending end of the metal needle and the excircle of the spherical ball are polished.

In order to optimize the flow limiting effect of the flow restrictor and the size and structure of parts and ensure a certain flow limiting area, the ratio of the aperture of the flow restrictor to the diameter of the cleaning needle 3 is 1.2-1.4. The structure of the cleaning needle 3 in the working range of the current limiter 2 is a rod-shaped structure with conicity or steps according to the adjustment requirements of different products, so that the required current limiting area is ensured.

The cleaning needle 3 is mounted in a spring seat 6. The bottom of the spring seat 6 is provided with a through hole with threads, the bottom of the hole is a conical surface, the spherical surface of the cleaning needle is attached to the conical surface of the spring seat, and when a plug screw with external threads is screwed into the threads of the spring seat and is locked by a punching point, the cleaning needle is compressed and is ensured to be concentric with the current limiter hole.

Claims

1. A plunger pump follower having flow restrictor self-purging capability, characterized by: the servo mechanism comprises a piston rod (4), an adjusting piston (1), a current limiter (2), a cleaning needle (3) and a spring seat (6), the piston rod (4) is of a hollow structure, an oil duct which is communicated with a front cavity and a rear cavity of the adjusting piston (1) of the plunger pump is designed, the current limiter (2) is installed in the oil duct of the piston rod (4), one end of the cleaning needle (3) is fixed on the spring seat (6), and the other end of the cleaning needle is deep into a current limiting hole of the current limiter (2).

2. A plunger pump follower with flow restrictor self-purging function as claimed in claim 1 wherein: the bottom of the spring seat (6) is provided with a hole, the bottom of the hole is a conical surface, and the cleaning needle (3) is arranged in the hole of the spring seat (6);

one end of the cleaning needle (3) is spherical, and the spherical surface is attached to the conical surface.

3. A plunger pump follower with flow restrictor self-purging function as claimed in claim 1 wherein: the structure of the cleaning needle (3) in the working range of the current limiter (2) is a rod-shaped structure with conicity or steps.

4. A plunger pump follower with flow restrictor self-purging function as claimed in claim 1 wherein: an annular groove is formed in the inner wall of the oil duct of the piston rod (4), a cylinder with a central hole can be installed in the annular groove, and the cylinder is a current limiter.

5. A plunger pump follower with flow restrictor self-purging function as claimed in claim 1 wherein: the ratio of the aperture of the flow restrictor in the flow restrictor to the diameter of the cleaning needle (3) is 1.2-1.4.

6. A plunger pump follower with flow restrictor self-purging function as claimed in claim 1 wherein: the oil duct communicated with the front cavity and the rear cavity of the adjusting piston (1) of the plunger pump comprises an oil path along the axis of the piston rod and an oil path along the radial direction of the piston rod, the radial oil path is a through hole, and an annular groove is formed in the radial oil path on the outer circumferential surface of the piston rod.