Working principle of the excavator hydraulic pump system _CTP caterpillar, carter accessories,
Excavator hydraulic system is composed of some basic circuit and auxiliary circuit, they include working loop, pressure limiting circuit, unloading, buffer circuit, throttling control of motor speed and throttling speed loop, walking speed loop and the guide valve control circuit, etc.
Its components work mainly by the pump, oil pump, pilot control valve, distributing valve, safety valve, the big arm oil cylinder, lower oil cylinder, bucket cylinder, fuel tank and related piping, etc.
Excavator hydraulic system in the process of work, the hydraulic oil pump suction from the bottom of the tank through the oil filter is work, from the pump output has certain pressure of the hydraulic oil into a set of parallel distributing valve.
Through the handle - & rarr;
Pilot valve - & rarr;
Valve working group to implement the corresponding action, the system by the total on the total oil relief valve caps the total pressure of the system as a whole, each work oil relief valve respectively to overload protection and oil compensating effect to the corresponding oil.
The action of hydraulic excavator is complex, to institutions often start, brake, reversing, load change is big, shock and vibration frequency, and field operation, change of temperature and the geographical position, therefore according to the features of excavator and environmental characteristics, excavator hydraulic system should meet the following requirements: 1)
To ensure that the mining mechanical arm, arm and bucket can separate action, will be able to cooperate with each other to realize composite action.
The action of working device and rotary turntable can independently, and can make composite gesture, in order to improve the productivity of the excavator.
Left and right side of the crawler excavator crawler drive respectively, make walking excavator is convenient, flexible steering, and can be in situ, in order to improve the flexibility of excavator.
Ensure all excavator reversible, and stepless variable speed.
Guarantee the excavator work safe and reliable, and the executive components (
The hydraulic cylinder, hydraulic motor, etc. )
Good overload protection;
Slewing mechanism and walking device has reliable braking and speed limit;
To prevent the lower movable arm because of weight and fast and the machine speed sliding slope.
Mining mechanical arm loop excavator hydraulic system should be: 1)
With high transmission efficiency, to give full play to the engine power and fuel use economy.
Hydraulic system and hydraulic components in under the action of load change is big, sharp shock and vibration, with sufficient reliability.
Attune of portable cooler of resistance to vibration, reducing the system total calorific value, the host continue working when the hydraulic oil temperature is less than 80 degrees, or temperature rise of less than 45 degrees.
Because of excavator work site dust, more hydraulic oil are easy to be polluted, so better sealing performance of hydraulic system, hydraulic components of the oil pollution sensitivity was low, the entire hydraulic system to set up the oil filter and dust control device.
Adopts hydraulic or electro-hydraulic servo controlling device for excavator set automatic control system, and then improve the excavator technical performance and reduce the labor intensity of the driver.
At present the main pump of excavators mainly with plunger pump, the pump oil mechanism and syringe pump discharge liquid are exactly the same.
Mainly is the multiple plunger (
Is an odd number commonly, nine more, there are other number)
, into the cylinder (
Also called pump gallbladder)
Uniform distribution along axis and the plunger number in the same channel.
Then the sliding boots of the column plug is in plane and cylinder pressure have Angle of inclined plate.
The entire cylinder and the piston rotates, plunger rotation to the swash plate furthest from the cylinder block, piston and cylinder hole to squeeze in between a space, recently transferred to the inclined plate and cylinder, piston and cylinder hole between the minimum space.
Quite the same plunger in the channel with the matching between doing pulled into the reciprocating piston movement.
As long as the oil suction valve plate, port configuration to the inclined plate of the corresponding position, the distance from the cylinder oil discharge port configuration to the swash plate is apart from the recently in the corresponding position of the cylinder body, as long as the main pump rotates, can realize constant discharge of oil absorption.
Large arm and forearm not alone has big arm of hydraulic pump, forearm, they and other such as bucket, walk, such as rotary movements are made by one or two of the same (parallel or series pump
Some small drivers may turn with gear pump oil)
Its oil supply mechanism is that the oil from the main pump discharge to the control valve (
Multi-way valve, distributing valve, etc. , whatever, just name is different)
And then through the control valve valve core switch control (
May be the forerunner oil control, mechanical lever control, electromagnetic control, etc. )
, make the pressure oil into the large arm or lower oil cylinder of different cavity, to push the cylinder piston movement, so as to promote the forearm movement.
Such as pressure oil into the cylinder rod cavity (
Oil cylinder rod out of the end)
Oil cylinder rod recovery at this time, if is the forearm is to pull the forearm overhang (
Lower oil cylinder of the model on the top of the big arm, other heterogeneous machine)
If it is a big arm the show the big arm is reduced.
The same pressure oil into the rodless cavity (
The end of the oil cylinder cylinder)
, oil cylinder rod juts out, if it's forearm is characterized by lower recycling, is characterized by large arm arm can lift.