Structure And Principle Of Mining Loader

Structure And Principle Of Mining Loader

Date:Jan 24, 2018

The mining excavating loader is a mechanical equipment, mainly used for the construction and loading of gravel, soil and material collection for various mining, hydropower and tunnel projects, such as phosphate rock, iron ore, copper mine, gold mine, silver mine, lead zinc mine and coal mine roadway.

It is a combination of manipulator and conveyor, slag scraping and loading and unloading functions. It is characterized by safety, environmental protection, low energy consumption and high efficiency. It is a necessary advanced mining equipment for mine enterprises, and it is a substitute for artificial and other machinery.

The product carries out JB/T 5503 - 2004 "vertical claw excavating loader" and Q/DK01 - 2009 "coal mine loader" standard.

The use of environmental conditions for mining loaders of mine use:

1) the slope of the roadway is not more than 15 degrees.

2) tunnel environmental temperature of 5 to +40 DEG C, the maximum relative humidity is not more than 90% (the temperature is 25 degrees centigrade);

3) the necessary measures should be taken or special design should be taken in accordance with the circumstances when the use of the site is not more than 1000m, and the use of the plateau under the altitude of more than 1000m.

4) the maximum rock mass of the ore is not more than 400mm.

5) the voltage limit deviation is + 5%. The limit deviation of the frequency of AC frequency is 1%.

6) the coal dust and methane explosive gas in the surrounding of the loader should conform to the safety content stipulated in the safety regulations of the coal mine.

Structural features and working principles

Overall structure and working principle and performance

Mining loaders are mainly composed of driving, digging and transporting, and the two major systems of hydraulic and electrical.  Through the coordination and coordination of each part, the required action is realized by the hydraulic, electrical actuator and mechanical transmission mechanism, and the operation process is completed.

This machine sets four kinds of performance, such as hydraulic walking, collecting, transporting and loading. The hydraulic walking function through the hydraulic motor drive wheels, hydraulic motor with forward and backward, automatic braking performance of three; four wheel drive has a strong impetus to productivity, characteristics, mining acquisition function is completed by the manipulator, the manipulator has the mining boom, loading, unloading performance, the arm can rise and fall about the acquisition, rotary, control by hydraulic mining, by six joystick control, each handle two moves, twelve moves. Transport, loading performance by the conveyor system, the conveying frame controlled by the hydraulic cylinder lifting and conveying frame can be decreased when the front wheel bracket, and the conveying frame before contact with the material outlet of the ore surface more closely and work more stability and at the same time can be set for bulk material, flat ground.  The width of the conveyor belt is 650mm, and the transmission speed is about 5m/ seconds. The conveyor belt is driven by the hydraulic motor to make the conveyor more stable and the service life is longer.

The vehicle hydraulic system is driven by a 15kw motor to drive two high pressure gear pumps. The hydraulic oil is input into one multi way reversing valve through the gear pump, and the control of each hydraulic device is realized through the operation handle.

The whole vehicle electrical system adopts the mine flameproof electromagnetic starter, which can control the motor and ensure the safety of the body and equipment.

The power source is a power frequency 660 (380) V three-phase AC power introduced externally, the whole machine adopts a 15kw motor, and the driving roller is driven by hydraulic pressure. There is only one person in operation.

Walking mechanism

The machine is composed of chassis, front bridge, rear axle, tire, hydraulic motor, steering cylinder and so on.

Working principle: external three-phase V power supply, 660 (380) by the electric control push-button pump, handle multiple valve to control the hydraulic motor, the motor drives the transfer gear transfer case respectively drives a front and rear axle rotate so as to drive the tire of walking. The machine does not need independent brake stopping system, parking on a slope, just walking control valve is placed in position, the hydraulic system makes the front and rear wheels locked state is not backwards; when the stop for a long time, need to be brought before the notching spade to the parking.

Working institutions

The working mechanism of this machine is composed of large arm seat, large arm oil cylinder, large arm, small arm, dug bucket, large arm cylinder, small arm cylinder, and bucket oil cylinder.

The working principle is that the pump is operated by an oil pump, and a large number of handles, such as lifting, lowering, protrusion, retracting, turning, digging and so on, are operated by a multi-channel valve handle. The control of the expansion of the cylinder can make the arm spin, and the two ends of the rotary cylinder are equipped with a one-way throttle valve to control the speed of the revolving. Control large arm cylinder expansion can make the big arm move up and down, the big arm cylinder with one end of the rod cavity is equipped with a one-way throttle valve to control the speed of the drop of the arm. The control of a small arm cylinder can make the small arm move forward and backward. The control of the expansion of the bucket oil cylinder can make the bucket excavate. The bucket is equipped with a bucket tooth and can be replaced after wear.


The machine is composed of a front shovel, a driven roller, a roller, a roller and a conveyor belt.

Working principle: the external three-phase 660 (380) V power supply, starting by the flameproof electromagnetic starter, and using the multi-channel valve handle to operate the hydraulic motor to drive the drum, so as to realize the rotation of the conveyor belt and achieve the continuous transportation function.

Hydraulic system

The hydraulic system is composed of steel ball hydraulic motor, gear pump, priority valve, multi way reversing valve, hydraulic steering gear, hydraulic cylinder, hydraulic support hose, radiator, oil return filter, hydraulic oil tank and cable. When the hydraulic hose is used, it has the certificate of safety mark and is in the period of validity.

The working cycle of hydraulic system as shown in Figure six (black lines and arrows for the oil inlet pipe and the oil flow, the blue line and arrow to return pipe and oil return flow) by hydraulic oil, hydraulic oil tank, a hydraulic pump, is connected with a multi way reversing valve, and the hydraulic steering cylinder and valve with the bucket cylinder, boom cylinder and bucket rod cylinder, oil cylinder, hydraulic motor, transmission frame check valve and rotary cylinder are connected to a hydraulic oil pipe; steering gear and valve, a priority valve through the oil return branch pipe and the oil return pipe; the oil return pipe and hydraulic oil cooler, hydraulic oil filter, hydraulic tank series.

The hydraulic pump operates synchronously through the shaft and the motor. The gear pump starts working. The hydraulic oil from the fuel tank is pumped into the hydraulic oil, and the hydraulic oil pumped into the multi way reversing valve and the hydraulic steering gear, so as to prepare for the driving and operation.

When working, one valve pull to a working position, then cut off the valve neutral channel, and open the valve cavity two, hydraulic oil from the high pressure chamber into a chamber of the oil cylinder, push the piston to do a job, and a low pressure oil cavity of the cylinder through the valve cavity through a filter, hydraulic heat oil return tank, if the stem is pulled to the opposite position, reverse repeat the process.

The rated working pressure of the loader is 12Mpa. If the load is too high at work, the safety valve of the distributing valve will open automatically, and the high-pressure oil will be returned to the oil tank directly through the return pipe, so as to prevent damage to the hydraulic components, pipelines and components.

Working principle: external three-phase 660 (380) V power supply by the explosion-proof explosion-proof magnetic starter, explosion-proof motor control, lighting, electric work. This machine uses a dual magnetic starter, one controls the main oil pump, and a belt conveyer motor is controlled.

Installation and debugging


The installation of the loader must be installed by the professional personnel. According to the structural features of the whole machine, the installation is made according to the requirements of the drawings.  According to the chassis frame - the conveyer frame - the regulating frame - the excavating part - the hydraulic system - the order of the electrical system.


1, preparatory work before trial run: confirm that the circuit is connected and the cable is moderately tight; confirm that the fuel tank has been injected with hydraulic oil according to the regulations, and grease the place where the joint surfaces of the connection parts are rubbed together.

2, test run: first start the walking system to see whether the machine is normal, the steering system is flexible, and then start the operation of the transmission system is normal. Second, start the mining section to see if the extension arm is normal, and whether the extension arm is flexible.

Precautions for assembly

1. When assembling the connecting bolts, we should check whether the loose washer is complete and the degree of tightness conforms to the requirements.

2, the joint part of the hydraulic system must be cleaned and no dust and impurities are allowed to enter. At the same time check whether the sealing ring is complete or damaged, all pipelines should be straightened and fixed according to the original position.

3, after the complete installation of the whole machine should be carefully checked the parts of the fittings, auxiliary parts, etc., whether the installation is correct and stable.

4, the installation of electrical components should be held by a special person. The diameter of the cable entering the junction box should be in line with the pore size of the rubber pad. The bonding terminal should ensure that there is no gap between the rubber pad and the cable and rubber pad and the junction box, otherwise, the flameproof performance will be lost.

Use, operation

Check before homework:

1, check power system: cable, joint should be good, no breakage, connection line should be good, no burn, loose phenomenon.

2, check the hydraulic system: the connection between the components of the hydraulic system and its connection pipes should be tightened without obvious leakage phenomenon; the hydraulic oil level should comply with the regulations (oil volume accounts for about 4/5 of the total volume of the tank).

3, check the control system: the handle handle should be in the neutral position, the manipulation should be flexible, no stagnation.

4, check the conveying system: the conveyor belt should be perfect, the tensioning is suitable, the roller and the roller are flexible, and there is no abnormal sound.

5, when the brake needs to stop in the course of walking, the foot valve is placed in the middle, that is, the brake. If you stop for a long time, you need to press the head of the machine to the ground.

6. loader should start walking bell as warning signal when reversing or.

Specific operation process description

1. The operation of walking:

The three phase power supply is connected. When the starter is driven, the operation of the main oil pump is started, the main motor starts working, and the gear pump is driven to rotate. The hydraulic oil starts from the oil tank through the pump to the multi way reversing valve, and the oil return from the oil return pipe through the hydraulic oil filter and the hydraulic oil radiator to the fuel tank.

Push and pull the first handle of the left hand to the right or to the left, and carry the tank of the tank through the multiplex reversing valve to make the shovel rise or drop.

Push and pull the left hand second handles forward or backward, and drive the hydraulic motor to drive the wheels to rotate through the multi-directional valve, so that the whole machine moves forward or backward. At the same time, steering wheel is used to change the direction of the whole machine through the hydraulic steering gear and the directional cylinder.

2. During the mining operation:

Main operation methods: large arms, big arms, right arms, left arms, small arms and small arms. Use bucket, small arm and big arm to pick up debris and transport them to the side dump trucks or other mining equipments.

Matters needing attention

1, the user must be familiar with the instructions, in strict accordance with the instructions for operation, maintenance. Do not operate or use maintenance according to the requirements of this specification, causing car damage or personnel injury, and the user is responsible for it.

2, the car must be operated by a special person, and the non operator is not allowed to open and move. The dug bucket should be landed at non working time, and the suspension is strictly prohibited.

3, before the operation must check whether the three-phase power supply is balanced, each phase voltage should be indicated normal (380V), strictly prohibit phase starting motor.

4, the operation before the operation and no load operation, when the oil temperature is not less than 20 degrees can be done, if the oil temperature is higher than 80 C, the reason should be checked.

5, the operator should memorize the action of each handle, to control by hand, the line of sight should be concentrated on the bucket. When the handle is pulled, the action should be smooth, so as to avoid the hydraulic impact and damage the components and the structural parts.

In 6, operation or debugging, and strictly prohibited within the scope of the bucket, no contact rotating parts. Failure or abnormal murmurs should be stopped immediately and the total power should be cut off.

7, strictly prohibit the self adjustment of the pressure of the safety valve so as not to damage the hydraulic components or affect the performance, such as the private adjustment of the work pressure is a violation of the operation.

8. When the handle of the handle is stuck, it is not hard to operate. It should be checked and eliminated.

9, hydraulic system should use different types of hydraulic oil in different seasons. Hydraulic oil should be changed regularly for the first time in 200 hours, then replace it every 1000 hours.

10, the rear axle should replace the gear oil regularly, 50 hours for the first time, and then change every 500 hours later.

11, special attention should be paid to the fact that when the transport rack rises and people carry out maintenance operations under the transport rack, there must be reliable safety support under the transport rack, so as to prevent the transport rack suddenly falling down and hurting people.

12, the security requirements for power supply: power access, to prevent leakage of damage to people.

13, pay special attention: the position between the rear axle and the gearbox is connected with the fixed position of the axle sleeve. When the external force is needed to drive the machine, the coupling sleeve must be disconnected. When the machine is in operation, it must reset the coupling shaft sleeve and tighten the fastening screws to make it fixed.

14, the underground use should be equipped with a portable methane alarm.

15, in uphill (downhill) work (walking), the shift must be carried out in a static state, and the tire (or front) cushion can be skidding away for safety accidents.

Maintenance and maintenance

Disconnect the power supply, pull the handle and foot, so that the hydraulic system can be unloaded.

(1) the requirements for the maintenance of the class

1, check the cable and joint are not damaged, magnetic starter and other electrical appliances and their connection lines are burned, loose, and timely repair and replacement.

2, check the cardan shaft, bearing lubricating parts, should be timely and correctly (eachclass a) lubricating oil and calcium base grease.

3, check hydraulic oil tank oil surface height, when insufficient to refueling. Check the oil pump, oil cylinder, distribution valve, oil pipe and other connection places if there are leakage of oil.

4, check whether the tubing is bending and distorting and affect the smooth line of the pipeline, there is no leakage, and in time to eliminate.

5. Check the connecting parts. Whether the fasteners are loose and lost and fasten in time.

6, carry out the cleaning of the whole machine, especially the cleaning of the dust on the radiator.

(two) monthly maintenance requirements

1. Check the fixed bolts of the oil pump and tighten the loosening.

2, check the seals of the hydraulic components, especially if the "O" seal ring of the cylinder piston rod is damaged or not, if it should be replaced in time.

3. Cleaning hydraulic oil filter and radiator.

4, check hydraulic oil tank, clean oil pollution, remove impurities, add hydraulic working oil.

(three) quarterly maintenance requirements

1, cleaning the hydraulic system, sampling and checking whether the hydraulic working oil is deteriorating, otherwise the new oil should be replaced.

2. Check the pressure of the distributor safety valve to change.

3, check whether the pin shaft and shaft sleeve of each department are damaged.

4. Check the loosening of the installation bolts of the rotary mechanism and its parts.

5, replace the necessary vulnerable parts.

Transport, storage

1. The hoisting and transportation of the factory

The loader is transported by road, and the machine can be hoisted directly to the trailer with a crane or a crane. The front and back tires should be placed on the triangular sleepers. The tyres of the loader are fastened in the proper position of the trailer with rope. It must be placed and tied firmly.

2. Hoisting, transporting, downhole installation and notices of mine working face

According to the condition of the mine, the inclined shaft can enter the operation directly; the straight well must be disassembled and suspended into the mine. The machine according to the chassis, conveying frame, frame, adjusting mining department into four parts apart when disassemble according to a certain order mark, will open the hydraulic tubing joints wrapped into the dust in order to avoid. Most of the disassembled parts and parts are slowly hoisted into the downhole by winch, and then installed in the reverse order according to the dismantled sequence. We must ensure that the positions between the components are accurate and the connection is solid and reliable.

3, the loader should be stored in a place with rain proof and sunscreen facilities, and should be retreated for more than six months.

Previous: Structure Principle Of Loader - Transmission System

Next: Deep Analysis! Why Does The Engine Take White Smoke?