What are the classifications of hydraulic systems? What are the components of a hydraulic system?

Open-loop hydraulic control and closed-loop hydraulic control are the two basic control methods of hydraulic control.

Among them, hydraulic closed-loop control systems often have multiple classification methods.

If there are any questions, welcome to discuss together, the first 139, the middle few numbers are 4008, and the last few numbers are 3280

1) Classification according to the tasks completed by the control system.

According to the type of tasks completed by the control system, the hydraulic control system can be divided into hydraulic servo control system (abbreviation, hydraulic servo system) and hydraulic regulation control system.

2) Classification according to the linearity of each component of the control system.

According to whether the control system contains nonlinear components, the hydraulic control system can be divided into linear system and nonlinear system.

3) Classification according to the continuity of the control signals in each component of the control system.

According to whether the control signals in the control system are all continuous signals, the hydraulic control system can be divided into continuous system and discrete system.

4) Classification according to the controlled physical quantity.

According to the different controlled physical quantities, the hydraulic feedback control system can be divided into position control system, speed control system, force control system and other physical quantity control system.

5) Classified according to hydraulic control components or control methods.

According to the type or control mode of hydraulic control components, the hydraulic feedback control system can be divided into valve control system (throttle control mode) and pump control system (volume control mode). Further according to the classification of hydraulic actuators, the valve control system can be divided into valve control hydraulic cylinder system and valve control hydraulic motor system; The pump control system can be divided into pump control hydraulic cylinder system and pump control hydraulic motor system.

6) Classification according to signal transmission medium.

According to the different control signal transmission media, the hydraulic control system can be divided into mechanical hydraulic control system (abbreviation, mechanical hydraulic servo system or mechanical hydraulic servo mechanism), electrical hydraulic control system, etc.

Classified according to the way of oil circulation: open system, closed system.

Classification by application: systems for stationary equipment, systems for mobile equipment.

Classification by working characteristics: hydraulic transmission system, hydraulic control system.

Classified according to actuator speed control mode: valve control system, pump displacement control system, pump speed control system, actuator control system.

According to the working state of the hydraulic pump when the main reversing valve is in the neutral position, it is classified as follows: open system, closed system.

It can be designed according to needs.

A complete, functioning hydraulic system should be composed of the following five main parts: 1Powerplant:

It is a device that supplies pressure oil to the hydraulic system and converts mechanical energy into hydraulic energy. The most common is a hydraulic pump. 2.

Actuator: It is a device that converts hydraulic energy into mechanical energy. Its form has a hydraulic cylinder for linear motion, and a hydraulic motor for rotary motion, and they are also called the actuators of the hydraulic system.

3.Control and regulation device: It is a device that controls or regulates the pressure, flow rate or flow direction in the system.

Such as relief valves, throttle valves, reversing valves, globe valves, etc. 4.Auxiliary devices:

Such as oil tanks, oil filters, oil pipes, etc. They are essential to keep the system working properly. 5.

Working medium: The fluid that transmits energy, i.e., hydraulic oil, etc. Since the end of the 18th century, when Britain made the world's first hydraulic press, hydraulic transmission technology has a history of two or three hundred years.

It was not until the 30s of the 20th century that it was more commonly used in cranes, machine tools and construction machinery. During the Second World War, due to the needs of the war, various military ** equipped with responsive and high-precision hydraulic control mechanisms appeared. After the end of World War II, hydraulic technology quickly shifted to civilian industry, and hydraulic technology was continuously applied to various automatic machines and automatic production lines.

Since the 60s of this century, hydraulic technology has developed rapidly with the development of atomic energy, space technology, and computer technology. Therefore, the real development of hydraulic transmission is only a matter of the last thirty or forty years. At present, hydraulic technology is developing towards rapid, high-pressure, high-power, high-efficiency, low-noise grip, durable, and highly integrated.

At the same time, computer-aided design (CAD), computer-aided testing (CAT), computer-aided control (CDC), mechatronics technology, reliability technology and other aspects of new hydraulic components and hydraulic systems are also the current development and research direction of hydraulic transmission and control technology. China's hydraulic technology was initially applied to machine tools and forging equipment, and later to tractors and construction machinery. With the introduction of some hydraulic components, production technology and self-design, China's hydraulic components have formed a series and have been widely used in various mechanical equipment.

The hydraulic system consists of five parts, namely power components, actuator components, control components, auxiliary components, and hydraulic oil.

1.Power components: hydraulic pump, hydraulic pump is a device that converts mechanical energy into hydraulic energy. Through the internal combustion engine or motor, the hydraulic pump is supplied with a certain speed and power, and then the pump outputs a certain flow and pressure of hydraulic oil.

2.Actuators: hydraulic cylinders and hydraulic motors, devices that convert hydraulic energy into mechanical energy. It is divided into hydraulic cylinders and hydraulic motors. By inputting a certain pressure and flow of hydraulic oil, the force (torque) of a certain speed ** speed is output.

3.Control Element: Hydraulic valve, a control element used to control oil pressure, flow direction and fluid velocity. According to the function, it is divided into pressure valve, flow valve and directional valve.

4.Auxiliary components: including oil tank, oil filter, oil pipe and pipe joint, sealing ring, pressure gauge, oil level oil thermometer, etc.

5.Hydraulic oil: Hydraulic oil is the working medium for transferring energy in the hydraulic system, and there are several categories such as various mineral oils, emulsions and synthetic hydraulic oils.

Power components, actuators, control components, auxiliary components and hydraulic fluids.

Abstract:Hydraulic components can be divided into three categories: power components, control components and actuators. Although they are all hydraulic components, their own functions and technical requirements for installation and installation are also different, which are introduced below for you.

What is the hydraulic system, what are the classifications of the hydraulic system.

1. What is a power element?

Power components refer to various hydraulic pumps.

1. There are two structural types: gear oil pump and tandem pump (including external meshing and internal meshing).

2. Vane oil pump (including single-stage pump, variable pump, double-stage pump, double-stage pump).

3. The piston oil pump is divided into axial piston oil pump and radial piston oil pump, and the axial piston pump has a quantitative pump, a variable pump, (the variable pump is divided into manual variable and pressure compensation variable, servo variable and so on) from the structure, it is divided into two oil distribution methods, end oil distribution and valve oil distribution oil, and the oil distribution type of radial piston pump is basically valve oil distribution.

2. What are the control elements?

All kinds of hydraulic valves belong to the control elements.

1. Pressure control valve.

1) Pressure control valves include: relief valves, electromagnetic relief valves, unloading relief valves, one-way relief valves and pressure reducing valves, one-way pressure reducing valves, sequence valves and one-way sequence valves.

2) The scope of the sequential valve is divided into seven types, such as direct control sequential valve, remote control sequential valve, unloading valve, direct control one-way sequential valve, remote control one-way sequential valve, direct control balance valve and remote control balance valve, as well as pressure relays, as well as various pressure control valves, which are used in various hydraulic storage stove systems according to different use conditions and characteristic requirements.

2. a directional control valve.

Directional control valves include check valves, hydraulic check valves, electromagnetic reversing valves, electromagnetic ball valves, electromagnetic reversing valves, manual reversing valves, and manual rotary valves.

3. Flow control valve.

Flow control valves include: throttle valves, one-way throttle valves, speed control valves, one-way speed control valves and stroke throttle valves, one-way stroke throttle valves, one-way stroke speed control valves, etc.

3. There are several kinds of actuators.

The actuators are hydraulic cylinders and hydraulic motors.

1. a hydraulic cylinder.

There are many types of vehicle cylinders, single-acting cylinders, hydraulic engine cylinders, swing cylinders, single-acting multistage cylinders (sleeve cylinders), double-acting multistage cylinders, and spring return cylinders.

2. Hydraulic motor.

Hydraulic motors, gear motors, vane motors, plunger motors, etc., that is to say, almost quantitative oil pumps can theoretically be used as motors.

3. Low-speed and high-torque hydraulic motor.

1) Internal meshing cycloidal motor.

2) Inner curve hydraulic motor, split shaft rotation and shell rotation two types of cavity dressing.

3) Double disc axial piston motor.

4) Radial piston type hydraulic motor.

5) Ball plug type low-speed high-torque hydraulic motor.

6) Static balance, low-speed, high-torque, low-hydraulic motor.

A complete hydraulic system consists of five parts, namely power components, actuators, control elements, auxiliary components (accessories) and hydraulic oil.

1. Power components.

The function of the power element is to convert the mechanical energy of the prime mover into the pressure energy of the liquid, which refers to the oil pump in the hydraulic system, which provides power to the entire hydraulic system. The structural forms of hydraulic pumps generally include gear pumps, vane pumps, piston pumps and screw pumps.

2. an actuator.

The role of actuators, such as hydraulic cylinders and hydraulic motors, is to convert the pressure energy of the liquid into mechanical energy to drive the load in a linear reciprocating or rotary motion.

3. a control element.

Control elements (i.e., various hydraulic valves) control and regulate the pressure, flow and direction of fluids in hydraulic systems. According to the different control functions, hydraulic valves can be divided into pressure control valves, flow control valves and directional control valves. Pressure control valves include relief valves (safety valves), pressure reducing valves, sequential valves, pressure relays, etc.

Flow control valves include throttle valves, adjusting valves, diverter collector valves, etc.; Directional control valves include check valves, hydraulic check valves, shuttle valves, reversing valves, etc. According to different control methods, hydraulic valves can be divided into on-off control valves, fixed-value control valves and proportional control valves.

4. Auxiliary components.

Auxiliary components include oil tank, oil filter, cooler, heater, slow track accumulator, oil pipe and pipe joint, sealing ring, quick change fitting, high-pressure ball valve, hose assembly, pressure measuring joint, pressure gauge, oil level gauge, oil temperature gauge, etc.

5. Hydraulic oil.

Hydraulic oil is the working medium for transferring energy in the hydraulic system, and there are several categories such as various mineral oils, emulsions and synthetic hydraulic oils.