Reading volume:13 发表时间:2019/10/31 16:01:52
The gears in various mechanical transmission mechanisms can be divided into parallel shaft transmission, intersecting shaft transmission and cross shaft transmission according to the difference in the positional relationship between their axes.In each type of transmission, there are different transmission modes according to the different shapes of gears and teeth, such as parallel shaft transmission spur gears, helical cylindrical gears, herringbone cylindrical gears, and intersecting shaft transmissions include straight bevel gears and helical gears. Tooth bevel gears, spiral bevel gears, and cross-shaft transmissions include hyperbolic gears, worm gears, and spiral transmissions.
Transmission characteristics:
1. The gear transmission efficiency is high. Generally, the transmission efficiency of cylindrical gears can reach 98%. Compared with bearings, the equivalent curve radius of gears is small and the oil wedge conditions are poor.
2. The gear transmission tooth and the tooth are in line contact, so the contact area is small and the unit contact pressure is high
3. Gear transmission not only has limited contact, but also sliding contact, especially hyperbolic gears. The relative sliding speed between the gear teeth is relatively high, usually up to about 8, which will make the oil film thinner under high-speed and heavy-load conditions. Even partial rupture, resulting in increased friction and wear, leading to abrasions and seizures
4. The working temperature of gear oil is generally lower than that of internal combustion engine oil. When the vehicle speed is high, the relative sliding speed between the gear wheels will be very high, and the oil temperature will reach 160℃-100℃.