Gear lubrication knowledge
A, the function of the wheel and types
Gear transmission is an important part of the machinery and equipment, has a transmission power, variable speed reverse function.
Gear type: according to the gear axis position can be divided into three categories - parallel axis transmission, intersecting axis and cross axis transmission.
Parallel to the axis of the transmission gear with spur gears, helical cylindrical gear, herringbone tooth cylindrical gear.
Intersecting axis transmission gear with spur bevel gears and helical bevel gears, spiral bevel gears.
Crisscross axis gear skew gear, worm gear drive gear, helical tooth cylindrical gear.
(2) the working characteristics of gear:
Different types of gears with different operating characteristics, such as: the spur gear transmission, the tooth contact line is a parallel to the axis of the straight line, the tooth meshing is along the tooth width of contact at the same time, or separately at the same time, so easy to cause shock and noise. In order to overcome this disadvantage, helical, worm gear, curved tooth, conic curve, hyperbola tooth transmission in order to achieve stable transmission, reduce the impact and noise, etc. These gears in meshing area at the same time, the contact line length than straight gear, and at the same time, there are several meshing tooth meshing part than straight teeth, and thus reduce pressure on the surface of the tooth, improves the carrying capacity of the gear transmission, increased service life.
(3) the gear working conditions
Special, with the rapid development of modern industry, the emergence of heavy, high speed, strong load equipment, gear transmission conditions of increasingly demanding, especially in the automotive industry, aviation industry, such as other general industrial gear reducer, the working conditions of the transmission case is relatively moderate. Anyhow gear under different operation conditions, the gear tooth surface meshing, the circumferential speed of the wheel pressure and oil temperature at work have bigger difference, the tooth surface meshing bearing pressure is 0.8 ~ 4 gpa, circumferential speed of the gear for 5 ~ 100 m/s, the oil temperature in the operation of work between 40 ~ 200 ℃.
Three, the condition of gear damage
(a)
In the form of gear damage
The form of gear damage can be divided into four types: adhesive wear, abrasive wear, fatigue wear, corrosion and wear. The above four types of wear performance under different working conditions (torque and speed, etc.)
(2)
The main reason for the damage
When the friction pair in the process of operation, one is a lubricating oil with low viscosity, low speed, the load is too big, can't build the oil film; Secondly, peripheral speed is too large, overload, produce sliding rolling, the quality of the lubricating oil level is poor, not appropriate, lack of oil viscosity caused by adhesive wear different level; A third is the lubrication system in external dust and other particles, and the internal chip, the impurities such as colloid particles caused by wear and tear; Fourthly, in the cycle again and again under the action of contact stress, make the gear produces fatigue wear and the surface material to produce pitting, flaking and fracture; Fifthly, in water in the lubricating system, metal particles, the chemistry of chemical pollutants, and lubricating oil and oxygen to participate in an inferior to cause corrosion and wear.