A grader is mainly composed of an engine, a transmission system, a travel system, a steering system, a braking system, a working device and a hydraulic control system, electrical equipment and a cab.
(1) Engine
Generally, an air-cooled or water-cooled multi-cylinder diesel engine is used. Most diesel engines use exhaust gas turbocharging technology.
(2) Transmission system
The transmission system generally consists of a main clutch, a torque converter, a gearbox, a rear axle transmission, a balance box series transmission device, etc. There are two configurations of transmissions in the transmission system, one is a manual transmission and the other is a power shift transmission.
(3) Travel system
The travel system includes a frame and wheels. The frame is a box-shaped integral type, which is a bow-shaped welded structure. The front end bow-shaped longitudinal beam is a single truss beam with a box-shaped section, and the working device and its operating mechanism are suspended or installed on this beam. The rear part of the frame consists of two longitudinal beams and a rear cross beam. The engine, transmission mechanism and cab are installed on the frame. The rear part of the frame is hinged to the rear axle housing through a guide plate and a bracket, and the front nose is supported on the front axle by a steel seat.
(4) Steering system
The steering system includes the front wheel steering system and the rear axle steering hydraulic system.
The steering system of the grader adopts a hydraulic steering system, which is mainly composed of a steering transmission mechanism, a steering hydraulic cylinder, a steering control valve, a steering hydraulic oil pump, etc.
In addition to the front wheel deflection steering system, other steering systems are also provided to expand the operating range, reduce the turning radius and reduce the lateral force. For example, there is a rear four-wheel deflection and a front wheel tilt.
The front frame deflection system can reduce the turning radius of the grader. It is especially suitable for places where oblique operations are required.
(5) Braking system
The braking system includes a foot brake and a hand brake.
The brake of the foot brake adopts a hydraulically opened, automatically boosted shoe brake. The brake transmission mechanism adopts a dual-line pneumatic hydraulic type (divided into two lines from the master brake cylinder, one to the middle and rear wheels respectively). The brake of the hand brake device is a cam-open, automatically amplified shoe brake, and the brake transmission mechanism adopts a mechanical type.
The gas-liquid integrated driving brake system consists of a gas-liquid drive mechanism and four wheel brakes. The wheel brakes are symmetrical self-amplified. The compressed air output by the air compressor enters the air reservoir after passing through the oil-water separator and the air pressure controller (the control system pressure is 0.5MPa). When the grader is braked, the compressed air pushes the piston in the booster through the control of the brake pedal and the brake valve, and the brake fluid in the brake master cylinder is pressed into the brake cylinders of the four wheel brakes respectively, pushing the brake shoes to produce a braking effect.
(6) Working device
The working device of the grader includes a scraper, a tiller and a bulldozer, among which the tiller and the bulldozer are auxiliary working devices.
① Scraper. The scraper device mainly consists of a scraper, a traction frame, a slewing circle, etc., as shown in Figure 2-29. The scraper consists of a blade and a blade. The front end of the traction frame is a ball joint, which is hinged to the front end of the frame, so the traction frame can rotate and swing in any direction around the ball joint. The slewing circle is supported on the traction frame and can rotate around the traction frame under the drive of the slewing drive device, thereby driving the scraper to rotate arbitrarily within 360°. There are two upper and lower slide rails on the back of the scraper supported on the slide grooves of the angle positioners on both sides, which can slide sideways under the push of the scraper side shift cylinder. The angle positioner is hinged to the lower end of the slewing circle ear plate and fixed with a nut at the upper end; when the nut is loosened, the shovel angle can be adjusted.
② Ripper. Rippers are mainly used to loosen hard soil, remove tree roots and stones in the soil, and renovate gravel and gravel roads. Rippers are installed on the back of the scraper and are mainly composed of rake teeth, rod shafts, safety springs, etc.
There are 6 rake teeth in total, which are installed on the rod shaft. When not in operation, the rake teeth are pointed upward and positioned by safety springs. When the tiller is required to work, remove the safety spring, pull out the shaft through the handle, and then place the rake teeth in the working position. After the rake teeth are lowered, push the shaft back. If the rake teeth need to be reduced, a spacer needs to be placed in the middle. When tilling, use the scraper lifting cylinder to make the tiller reach the appropriate depth of soil.
③ Bulldozer. The bulldozer is an auxiliary device of the grader. It is mainly used for large graders to assist in bulldozing operations.
(7) Hydraulic operating system
The hydraulic system is mainly composed of a fuel tank, a hydraulic pump, a multi-way valve, a hydraulic cylinder, a scraper rotary hydraulic motor, etc.
The hydraulic operating system of the grader drives the hydraulic devices of the entire vehicle, including the lifting of the scraper, the left and right tilting of the scraper, the left and right rotation of the scraper, the lifting of the tiller, the steering wheel deflection, and the braking of the brake. It is often composed of multiple oil circuits.
(8) Electrical equipment
The electrical equipment is composed of batteries, generators and regulators, starters, instruments and lighting devices, etc. The circuit adopts a single-wire system, with the negative pole grounded and the rated voltage is 24V.
