The complete small wheel loader machine mainly consists of power system, transmission system, working device, working hydraulic system, steering hydraulic system, frame, operating system, braking system, electrical system, cab, covering parts, air conditioning system, etc. The following is a detailed introduction to the working principles of the first five systems.

A brief analysis of the working principle of wheel loaders

The complete articulated wheel loader machine mainly consists of power system, transmission system, working device, working hydraulic system, steering hydraulic system, frame, operating system, braking system, electrical system, cab, covering parts, air conditioning system, etc. The following is a detailed introduction to the working principles of the first five systems.

1. Power system

The power system of the loader consists of the power source diesel engine and ancillary systems that ensure the normal operation of the diesel engine, including the diesel engine, fuel tank, throttle control assembly, cooling system, fuel pipeline, etc. The diesel engine completes the normal walking function through the dual-variable drive transmission system; drives the working hydraulic system to drive the working device to complete shoveling, lifting, dumping and other working actions; drives the steering hydraulic system to deflect the frame and complete the steering action.

2. Transmission system

The transmission system consists of a torque converter, gearbox, drive shaft, front and rear drive axles, and wheels. By automatically adjusting the output torque and speed of the transmission system, the loader can automatically change speed and pulling force according to road conditions and resistance to adapt to changing working conditions. After shifting into gear, the gear can be automatically and steplessly shifted from the starting point to the maximum speed of that gear, resulting in a smooth start and good acceleration performance. When encountering a slope or sudden road obstacle, it can automatically decelerate to increase traction without shifting gears and drive at any low speed to overcome obstacles. After the external resistance is reduced, the speed can be automatically increased quickly to improve the operating rate. When cutting materials, it can cut into the material pile at a high speed and automatically decelerate as the resistance increases to increase wheel traction to ensure cutting.

The power output from the engine is transmitted to the gearbox through the hydraulic torque converter. After the gearbox is changed, the specific speed is driven through the transmission shaft to drive the front and rear axles and the wheels to rotate at a certain speed to achieve the function of walking at a certain speed.

3. Working equipment

The working device of the loader consists of four major components: bucket, boom, rocker arm, and tie rod. The boom has a single-plate structure, the rear end is supported on the front frame, the front end is connected to the bucket, and the middle part is connected to the boom cylinder. When the boom cylinder expands and contracts, the boom rotates around its rear end pin to raise or lower the bucket. The rocker arm is a single rocker arm mechanism, and the middle part is connected to the boom. When the bucket cylinder expands and contracts, the rocker arm rotates around its middle supporting point, and the bucket rotates up or down through the pull rod.

Scope of application of wheel loaders

Years of production practice at home and abroad have proven that wheel loaders are suitable for the following tasks:

1. Used for various operations such as loading, pushing and dumping, lifting and pulling in the construction of open-pit mines, railway foundation building and road paving.

2. In small and medium-sized open-pit mines, it is used to replace excavators and automobiles as the main mining, loading and transportation equipment of the mine; it can be operated in conjunction with automobiles and can also be used to transport ore to the crushing station.

3. In some large-scale open-pit mines, cooperate with excavators to carry out mining and other auxiliary operations under complex conditions (such as selective mining, end of working face, explosion pile dispersion, trench excavation, etc.).

4. It can be used for joint mining, loading and transportation operations on working faces with large slopes to complete difficult mining work.

The two common front-loading machines, tire type and crawler type, each have their own characteristics. Although the crawler front loader has greater traction and shoveling force, and has better off-road and climbing performance, it is slow and inflexible, and sometimes requires a trailer to move the working location, resulting in higher construction costs. Therefore, crawler-type front loaders are rarely used in open-pit mines. The most common type of loaders used in mines around the world is tire loaders. Therefore, they are produced in large quantities and the manufacturing technology has also developed rapidly. The bucket capacity of the largest model has reached 40m3.

Advantages and Disadvantages of Wheel Loaders

In open-pit mines with suitable conditions, the use of wheeled transfer machines can highlight the advantages in the following aspects:

1. The tire-type front loader has fast traveling speed, short working cycle time and high loading efficiency. According to mine calibration data, a front-loading machine with a bucket capacity of 5 to 8 m3 can reach a speed of more than 35 km/h, which is 30 to 90 times faster than an electric shovel. Each working cycle only takes 40 to 45 seconds, and the average shift production capacity can reach 3,500. ~4000t, the average labor productivity can be increased by 50%~100%.

2. The tire-type front loader has a light weight, which is equivalent to 1/8~1/6 of the mass of an excavator with the same bucket capacity. It saves a lot of steel and the manufacturing cost is only 1/4~1/3 of the excavator. The price ratio is Excavators are cheap, which can reduce the investment in production equipment of the mine and reduce the proportion of fixed assets.

3. The tire-type front loader has strong climbing ability and good maneuverability. It can carry out loading operations on slope working surfaces that are not allowed by excavators. It can also work normally on newly built mining sites that lack electricity, thus speeding up the work. Mine development and construction and shortening the construction cycle.

4. The depreciation life of the tire-type front loader is only 1/4 to 1/8 of the excavator. It can be replaced with new more advanced equipment after 5 to 6 years of operation, which facilitates mine management and maintenance and is conducive to the upgrading of equipment. .

5. The tire-type front loader is easier to operate than an excavator, so it can shorten driver training time. At the same time, a loader only needs one driver to operate, which can save manpower, material resources and financial resources.

However, compared with excavators, front loaders also have some disadvantages in production:

(1) The tire-type front loader has a smaller excavation capacity than an excavator. When the blasting quality is poor and there are many large pieces, its working efficiency will be significantly reduced; for materials with strong viscosity, they need to be loosened before shoveling operations and other operations can be carried out. Auxiliary homework.

(2) Compared with excavators, the working mechanism of front loaders is smaller; due to safety conditions, it is not suitable to operate on working surfaces with high explosive piles, and the height of stope steps should generally not exceed 12m.

(3) The tires of loaders wear out quickly and have a shorter service life. In recent years, although measures such as installing protective chain rings or using padded track shoes have been adopted to reduce tire wear, the tire life is only about 1500 hours, and tire costs still account for a large proportion of production equipment costs (about 40 %~50%, even as high as 60%).