For the rack and pinion transmission with impact load, the following aspects should be paid attention to:
- It is better to design it as a modified gear, and it is a negative modified gear. Negative modification will help to improve the bending strength of the tooth root and the impact resistance of the gear.
- The heat treatment hardness of the tooth surface is not easy to be too hard. Hrc30 ~ HRC35 can be used. If the tooth surface is too hard, the tooth will crack under impact load.
- The quenching depth of the tooth surface is not easy to be too deep, which is generally 1 / 5m ~ 1 / 10m (M: modulus). It is necessary to maintain sufficient toughness of the core material to cushion the external impact load.
- On the premise that the structure allows, the modulus m should be slightly larger, which is particularly important for the starting transmission with impact load.
- The design speed is not easy to be too high.
- The structure shall have enough impact resistance and enough rigidity to ensure the operation of gear rack.
- For the selection of bearings, it is recommended to choose sliding bearings instead of rolling bearings. Sliding bearings can have good impact resistance, but they should be well lubricated.