Fault phenomenon, reason analysis and improvement method of hydraulic oil pump

Fault phenomenon, reason analysis and improvement method of hydraulic oil pump

I. Analysis of the failure phenomenon and cause of hydraulic oil pump

1. Check the inside leakage of the boom cylinder. The easiest way is to raise the boom to see if there is a clear and free fall. If the drop is obvious, remove the cylinder and check that the seal ring has been worn out and should be replaced;

2. Check the valve. First, clean the safety valve and check if the spool is worn out. Replace it if worn. After the safety valve is installed, if there is still no change, check the condition of the valve plug wear. The clearance limit is 0.06mm, and the wear should be replaced.

3. Measure the pressure of the hydraulic pump. If the pressure is low, then adjust, and the pressure can not be adjusted, then the hydraulic pump is seriously worn.

In general, the main reason that can cause hydraulic oil pump boom loading to fail is:

a. The hydraulic pump is heavily worn. When the pump is running at low speed, the leakage in the pump is serious. At high speed, the pump pressure slightly increases. However, due to the wear and internal leakage of the pump, the volumetric efficiency drops significantly and it is difficult to reach the rated pressure. The long time working of the hydraulic pump exacerbates the wear and increases the oil temperature. As a result, the hydraulic components are worn out, and the seals are aged and damaged. The seal capacity is lost, and the hydraulic oil deteriorates, eventually leading to failure.

b. The selection of hydraulic components is unreasonable. The boom cylinder specifications are 70/40 non-standard series, and the seals are also non-standard parts. The manufacturing cost is high and the seal replacement is inconvenient. The cylinder bore of the boom cylinder is bound to make the system set high pressure;

c. The design of the hydraulic oil pump system is unreasonable. As can be seen from Figure 1, the control valve and the hydraulic steering gear is a single pump in series, the safety valve set pressure is 16MPa, and the rated working pressure of the hydraulic pump is also 16MPa. Hydraulic pumps are often operated under full load or long-term overload (high pressure) conditions, and the system has hydraulic impact, long-term oil change, hydraulic oil contamination, exacerbated hydraulic pump wear, resulting in hydraulic pump casing burst (later discovered Such failures).

Second, the hydraulic pump improvement and effect

1. Improve hydraulic system design. After many arguments, the advanced priority valve and the load-sensing full-hydraulic steering gear were used. The new system was able to prioritize the distribution of flow according to the steering requirements. The amount of the load and the steering wheel rotation speed ensured that the fuel supply was adequate. All can be used to supply the working device circuit, thus eliminating the power loss caused by excessive oil supply to the steering circuit, improving the system efficiency and reducing the working pressure of the hydraulic pump;

2. Optimize the design of the boom cylinder and hydraulic pump to reduce the system working pressure. With optimized calculations, the boom cylinder uses the standard series 80/4. The displacement of the hydraulic oil pump was increased from 10 ml/r to 14 ml/r, and the system set pressure was 14 MPa, which satisfied the lifting force and speed requirements of the boom cylinder.

3. During use, attention should also be paid to the correct use and maintenance of the hydraulic pump of the loader. Add or replace the hydraulic oil regularly to maintain the cleanliness of the hydraulic oil and strengthen daily inspection and maintenance.

Sign Cnc Router


Sign Making Cnc Router, great option for sign, graphic, printing, displaying, advertising industry. Precision cutting aluminum, copper alloy trim, IT trim, acrylic, etc.


Acrylic Cutting Cnc Router's applicable scope:


  • Advertising industry: acrylic mini-word high-light cutting, MDF cutting, color plate engraving, all kinds of advertising plate, logo production.
  • Furniture industry: cabinet doors, wooden doors, solid wood, mahogany furniture, antique furniture all kinds of composite sheet cutting and engraving.
  • Panel processing industry: insulation, plastic chemical parts, PCB, anti-times special board, epoxy resin, ABS, PP, PE and other carbon compounds.
  • Crafts industry: can be mainly used for the artificial stone, PVC, wood, bamboo, marble, plexiglass, copper and aluminum, etc.
  • Decorative industry: screen, wave board, bamboo, marble, organic board, color plates and other materials on a variety of beautiful patterns and text carving.

Sign cnc router 1325

Mini acrylic word cnc cutting machine


Cnc Router for cutting mini acrylic word's Characteristics:


1. The bed is made of thick-walled steel pipe, which is treated by high temperature tempering to ensure machine body with high strength, and no deformation.
2. With breakpoint, continuation on break point function, with homing automatic error correction function, effectively guarantee the work of a long time in the processing accuracy.
3. Unique storage design, easy to store tools, tools.
4. Using high rack gear transmission to ensure machine with high precision, fast speed, maximum speed can up to 90m / min.
5. Featured circuit accessories, a variety of protection is complete, to ensure the safe operation of spare parts and machines to reduce the failure rate.
6. Equipment control system is simple, with user-friendly design, in line with human structure, to facilitate customer operation.
7.T-slot+Vacuum table, can be easily used for all kinds of materials.
8. Machine software`s compatibility is good, compatible with tyoe3 / Artcam / Castmate / Wentai and other CAD / CAM design software.
9. Precision tool auto-checking instrumen, save time and effort, a key to start, save resources.

10. High safety performance factor, a key operation and the host and line operation, while starting and stopping the limit, the wrong version of the alarm buzzer to improve the safety factor.

mini letter cutting machine's parts

acrylic cutting machine


Technical parameters:


  • Model AS-1325/1530/2030, optional
  • Controller: Multech P20
  • XYZ working size: 1300*2500*200mm
  • Running mode: Delta servo motor/Taiwan reducer
  • XYZ structure: XY1.5 helical tooth gear transmission+Z TBI ball screw+Taiwan HIWIN rail guide
  • Max traveling speed 90m/min
  • Cutter diameter: ï¿ 3.14.ï¿ 6.ï¿ 12.7ï¿ 12
  • Rail Guide brand: Taiwan HIWIN 25rail guide+25 Flange slider
  • Spindle power: Φ125mm-5.5KWwater cooling spindle
  • Working voltage(Optional): 380V 50hz
  • Inverter: 7.5KW 380V Sunfar inverter
  • Driver:  Delta servo driver
  • Switching power supply: MW power supply
  • Servo motor: Delta servo
  • Spindle revolving speed: 0-24000r/min
  • Table T-slot+Vacuum table
  • Compatible software: Windows2000/windows XP/windows7
  • Command code: Hpgl.G code.Uoo.Mmg.Plt

Sign Cnc Router

Sign Cnc Router,Sign Making Cnc Router,Cnc Router Sign Making Machine,Acrylic Sign Cnc Cutter

Shandong U-May CNC Technology Co., Ltd. , http://www.sesamecnc.com