The key hints: the improvement measures of the loader braking force pump: the most of the force pumps of the inner wheel loader brake system are gas oil push loaders, and the XM-60 type adding pump used by most of the loaders at present in China is the drawback that the brake fluid in the oil cup will fluctuate greatly during the braking and the release of the brake.
Most of the force pumps of the inner wheel loader brake system are gas oil push loaders. Most of the XM-60 type loading pumps used in the domestic loaders at present have the disadvantage that the brake fluid in the oil cup will fluctuate greatly during the process of braking and relieving the brake.
When the cylinder piston rod drives the piston of the hydraulic cylinder forward, the brake fluid in the oil cup will flow down continuously to supplement the space formed after the piston moving forward. Conversely, when the piston of the hydraulic cylinder returns, the space in the rear of the cylinder is compressed rapidly, and the brake fluid that inflows into the cylinder is forced back into the oil cup, which will inevitably cause the fluctuation of the liquid surface of the brake fluid, thus producing bubbles. The more times we flip, the more bubbles we produce. That is, the longer the working time of the booster pump is, the more bubbles will be generated, so there will be a lot of gas in the brake fluid. With the increase of bubbles, the pressure of hydraulic system will decrease, and the reliability of braking will also decrease.
In order to eliminate the change of pressure caused by the change of air volume, the air volume on the upper part of the oil cup will change greatly. In order to eliminate the change of pressure caused by the change of air volume, the air blowhole is often left on the oil cup, which will also make the dust enter and cause the pollution of the brake fluid.
Therefore, after using the pump for a certain period of time, the air or brake fluid in the brake system must be eliminated in time, or the brake failure will be caused, and even the safety accidents will be caused.
Many afterburner manufacturers in China have improved the afterburner pump, with a more perfect structure.
There are two holes in the bottom of the oil cup, leading to the front end of the piston of the hydraulic cylinder and the middle oil cavity, so when the cylinder piston drives the piston to move forward, the two holes are all connected to the oil inlet cavity in the middle of the hydraulic cylinder, because the inlet cavity is full of the brake fluid before the start of the work, and there is no volume in the oil inlet cavity at work. Therefore, the movement of the cylinder piston outside the two hole will not cause the brake fluid to move up and down in the oil cup, so there will be no bubbles.
When the piston of a hydraulic cylinder moves between two holes, the volume of the oil chamber will change slightly, which will cause a slight fluctuation in the oil surface in the oil cup; at the same time, the oil cup is changed into a sealed structure to prevent the dust from the air into the oil, and the cleanliness of the brake fluid is maintained effectively. The installation test shows that the replacement period of the brake fluid is twice as much as that of the original afterburner pump.
Chongqing Hui Pu hydraulic power Manufacturing Co., Ltd. has made a further improvement on this basis, that is, the bottom of the oil cup is added to the bottom of the oil cup of the so-called optimized pump. When the cylinder piston drives the piston of the hydraulic cylinder forward, because the oil filling cavity and the working oil cavity are not connected, the whole process of the piston in the reciprocating movement will not cause the oil to turn over and down in the oil cup, so it will not produce bubbles. Later, the hydraulic cylinder piston seal form was changed from the static seal to the static seal, which further improved the reliability of the booster pump. The new optimized pump gas chamber is partly changed to diaphragm type (see Figure 4), which effectively eliminates the problem of cylinder piston and hydraulic cylinder piston with different axes caused by manufacturing errors. Bench test shows that the reliability of the booster pump is increased from 350 thousand to 650 thousand times.
Xugong Group Chongqing Construction Machinery Co., Ltd. has installed the optimized booster pump on the LW321F, LW521F and other host machines.
The improved afterburner pump can make the Xugong Group loader better adapt to the requirement of mountain braking frequency.
