Classification and use of Loaders
The commonly used single bucket loaders are classified according to the power of the engine, the form of transmission, the structure of the walking system and the way of loading.
1. Engine power:
(1) the power is less than 74kw as a small loader.
The power is from 74 to 147kw as a medium loader
(3) power from 147 to 515kw as a large loader
4. Power more than 515kw is a special large loader
2. Transmission form:
(1) hydraulic mechanical transmission, small impact and vibration, long life of transmission parts, convenient operation, automatic adjustment between vehicle speed and load, generally used in medium and large loaders.
(2) hydraulic transmission: it can be stepless speed control and easy to operate, but its start-up is poor, and it is generally used only on small loaders.
Power transmission: stepless speed regulation, reliable work, simple maintenance, high cost, generally used in large loaders.
3. Walking structure:
Tyre type: light quality, fast speed, flexible maneuver, high efficiency, difficult to damage road surface, high ground ratio pressure, poor pass, but widely used.
2. Crawler type: small grounding ratio, good pass through, low center of gravity, good stability, strong adhesion, large traction force, big cutting force, low speed, poor flexibility, high cost, and easy to damage road surface when walking.
4. Loading and unloading methods:
First unload: simple structure, reliable work, good field of vision, suitable for various operating sites, a wide range of applications;
(2) rotary type: the working device is installed on the turntable with a turnable 360 degree. The side unloading does not need to turn around, the operation efficiency is high, but the structure is complex, the quality is large, the cost is high, and the side stability is poor, so it is suitable for the less competitive field.
Post unloading type: front end loading, rear end unloading, high efficiency and poor safety of operation.
Selection principle of loader model
1, model selection: mainly based on the situation and use of the selection and determination. Usually in the quarry and the soft base to carry out the operation, most of the use of tire loader with skid chain;
2, the choice of power: generally used diesel engines for construction machinery, especially in special areas, such as those above 3000m above sea level, special plateau diesel engines should be used.
3, the choice of transmission type: the general use of hydraulic - mechanical transmission. The key component is the choice of the torque converter. Two turbine and single phase two phase hydraulic torque converter are used in the loaders produced in China.
4, when the loader is selected, the braking performance of the loader should be fully considered, including three kinds of braking, parking brake and emergency braking. The brake has three kinds of hoofs, pliers and wet multiple pieces. The driving mechanism of the brake generally adopts the adding force device, and its power source has three kinds of compressed air, gas top oil and hydraulic type. The gas top oil brake system is commonly used, and the dual loop braking system is generally used in order to improve the safety of driving.