Double-loop control system with single hydraulic motor

Patent metadata

Field	Value
Publication number	US-10047768-B2
Application number	US-201415101399-A
Country	US
Kind code	B2
Filing date	Sep 24, 2014
Priority date	Feb 10, 2014
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

A double-loop control system with a single hydraulic motor relates to a technical field of hydraulic transmission control, including a hydraulic motor (1), a positive control loop (2), a negative control loop (3), a hydraulic pump (4), an accumulator (5), and an oil tank, wherein the hydraulic motor (1) adopts a unique thrust structure with four inlet/outlet ports; the positive control loop (2) and the negative control loop (3) independently control the hydraulic motor (1), wherein the positive control loop (2) and the negative control loop (3) drive together or only one drives; or braking kinetic energy and potential energy of loads are stored in the accumulator (5) for energy recovery. The present invention uses only one hydraulic motor for satisfying different work conditions and different load driving requirements with advantages such as simple structure, high system reliability and high energy efficiency.

First claim

What is claimed is:

1. A double-loop control system with a single hydraulic motor, comprising: a hydraulic motor ( 1 ), a positive control loop ( 2 ), a negative control loop ( 3 ), a hydraulic pump ( 4 ), an accumulator ( 5 ), and an oil tank (T), wherein a first oil port (A), a second oil port (B), a third oil port (C), and a fourth oil port (D) are provided on the hydraulic motor ( 1 );
wherein the positive control loop ( 2 ) comprises a first working oil port (E) and a second working oil port (F), which respectively suctions oil through a positive control loop inlet port (E′) and returns the oil through a positive control loop outlet port (F′); the first working oil port (E) of the positive control loop ( 2 ) connects with the first oil port (A) of the hydraulic motor ( 1 ), the second working oil port (F) of the positive control loop ( 2 ) connects with the second oil port (B) of the hydraulic motor ( 1 ), the positive control loop inlet port (E′) connects with an outlet port of the hydraulic pump ( 4 ), and the positive control loop outlet port (F′) connects with the oil tank (T) or an inlet port of the hydraulic pump ( 4 ); wherein the positive control loop ( 2 ) is an open loop with a separate meter-in and separate meter-out control system, or a closed loop controlled by the hydraulic pump ( 4 );
wherein the negative control loop ( 3 ) comprises a third working oil port (G) and a fourth working oil port (H), which respectively suctions the oil through the negative control loop inlet port (G′) and returns the oil through the negative control loop outlet port (H′); the third working oil port (G) of the negative control loop ( 3 ) connects with the third oil port (C) of the hydraulic motor ( 1 ), the fourth working oil port (H) of the negative control loop ( 3 ) connects with the fourth oil port (D) of the hydraulic motor ( 1 ), the negative control loop inlet port (G′) connects with the accumulator ( 5 ), and the negative control loop outlet port (H′) connects with the oil tank (T) or the accumulator ( 5 ); wherein the negative control loop ( 3 ) is an open loop with a separate meter-in and separate meter-out control system, or an open loop controlled by a proportional direction valve;
wherein the positive control loop ( 2 ) and the negative control loop ( 3 ) work independently and can be used interchangeably; when system needs higher driving force, the positive control loop ( 2 ) and the negative control loop ( 3 ) drive the hydraulic motor ( 1 ) together; when the system needs lower driving force, one of the positive control loop ( 2 ) or the negative control loop ( 3 ) individually drives the hydraulic motor ( 1 ), while the other one stops working; when the hydraulic motor ( 1 ) is in decelerating-braking or is dragged to move by load, the positive control loop ( 2 ) stops working, and the negative control loop ( 3 ) stores braking kinetic energy and potential energy of the load into the accumulator ( 5 ) for energy recovery.

2. The double-loop control system with the single hydraulic motor, as recited in claim 1 , wherein the hydraulic motor ( 1 ) is an axial piston hydraulic motor or a blade hydraulic motor; the hydraulic pump ( 4 ) is a constant hydraulic pump or a two-way displacement-variable pump.

3. The double-loop control system with the single hydraulic motor, as recited in claim 1 , wherein when the positive control loop ( 2 ) is the open loop with the separate meter-in and separate meter-out control system, the positive control loop ( 2 ) comprises a first pressure sensor ( 27 ), a second pressure sensor ( 28 ), a third pressure sensor ( 34 ), a first two-position two-way proportional throttle valve ( 29 ), a second two-position two-way proportional throttle valve ( 30 ), a third two-position two-way proportional throttle valve ( 32 ), a third two-position two-way proportional throttle valve ( 33 ), and a first relief valve ( 31 ); wherein an inlet port of the first two-position two-way proportional throttle valve ( 29 ) connects with the first working oil port (E) of the positive control loop ( 2 ), an outlet port of the first two-position two-way proportional throttle valve ( 29 ) connects with the positive control loop outlet port (F′); an inlet port of the second two-position two-way proportional throttle valve ( 30 ) connects with the second working oil port (F) of the positive control loop ( 2 ), an outlet port of the second two-position two-way proportional throttle valve ( 30 ) connects with the positive control loop outlet port (F′); an inlet port of the third two-position two-way proportional throttle valve ( 32 ) connects with the positive control loop inlet port (E′), an outlet port of the third two-position two-way proportional throttle valve ( 32 ) connects with the first working oil port (E) of the positive control loop ( 2 ); an inlet port of the fourth two-position two-way proportional throttle valve ( 33 ) connects with the positive control loop inlet port (E′), an outlet port of the fourth two-position two-way proportional throttle valve ( 33 ) connects with the second working oil port (F) of the positive control loop ( 2 );
wherein when the negative control loop ( 3 ) is the open loop controlled by the proportional direction valve, the negative control loop ( 3 ) comprises a first check valve ( 36 ), a second check valve ( 37 ) and an electromagnetic proportional direction valve ( 35 ); wherein an electromagnetic proportional direction valve inlet port (P), an electromagnetic proportional direction valve outlet port (O), a first electromagnetic proportional direction valve working oil port (M) and a second electromagnetic proportional direction valve working oil port (N) of the electromagnetic proportional direction valve ( 35 ) respectively connect with the negative control loop inlet port (G′), the negative control loop outlet port (H′), the third working oil port (G) of the negative control loop ( 3 ), and the fourth working oil port (H) of the negative control loop ( 3 ); an outlet port and an inlet port of the first check valve ( 36 ) respectively connect with the third working oil port (G) of the negative control loop ( 3 ) and the negative control loop outlet port (H′); an outlet port and an inlet port of the second check valve ( 37 ) respectively connect with the fourth working oil port (H) of the negative control loop ( 3 ) and the negative control loop outlet port (H′).

4. The double-loop control system with the single hydraulic motor, as recited in claim 1 , wherein when the positive control loop ( 2 ) is the closed loop controlled by the hydraulic pump ( 4 ), the positive control loop ( 2 ) comprises a first relief valve ( 31 ), a second relief valve ( 41 ), a third relief valve ( 42 ), a fourth check valve ( 36 ), a second check valve ( 37 ), a fifth two-position two-way proportional throttle valve ( 44 ), and a slippage pump ( 43 ); wherein an inlet port and an outlet port of the first check valve ( 36 ) respectively connect with an outlet port of the slippage pump ( 43 ) and the first working oil port (E) of the positive control loop ( 2 ); an inlet port and an outlet port of the second check valve ( 37 ) respectively connect with the outlet port of the slippage pump ( 43 ) and the second working oil port (F) of the positive control loop ( 2 ); an inlet port and an outlet port of the first relief valve ( 31 ) respectively connect with the outlet port of the slippage pump ( 43 ) and the oil tank (T); an inlet port and an outlet port of the second relief valve ( 41 ) respectively connect with the first working oil port (E) of the positive control loop ( 2 ) and the oil tank (T); an inlet port and an outlet port of the third relief valve ( 42 ) respectively connect with the second working oil port (F) of the positive control loop ( 2 ) and the oil tank (T); two oil ports of the fifth two-position two-way propo

Assignees

• Univ Taiyuan Technology

Inventors

• Quan Long
• Gao Youshan
• Hao Huimin
• Huang Jiahai
• Yang Jing

Classifications

• F15B2211/88

  Control measures for saving energy · CPC title

• F15B13/0401

  Valve members; Fluid interconnections therefor · CPC title

• F16H2061/0034

  Accumulators for fluid pressure supply; Control thereof · CPC title

• F15B2211/214

  the pressure sources being hydrotransformers · CPC title

• E02F9/2296

  Systems with a variable displacement pump · CPC title