Consequences of poor installation of offset press gears

The ideal installation of the gear on the offset press shaft shall be such that the centerline of the pitch circle of the gear coincides with the centerline of the shaft and the end face of the gear abuts the shoulder of the shaft. However, in practice, this requirement cannot be met due to various errors. The details are as follows:

(1) When the hole of the gear is not machined correctly or worn out due to prolonged use, once it is assembled with the shaft, the gear and the shaft will not fit tightly, and the phenomenon of left and right swinging will occur during operation.

(2) If the centerline of the gear is not coincident with the centerline of the shaft, there is an eccentricity, and radial runout occurs during operation, so that the center distance between the meshed gears is large and small, and changes once per revolution. There will be an impact sound during operation. When the eccentricity is large, seizure may also occur.

(3) If the gears are skewed on the shaft, there is a skew angle, and end surface runout occurs during operation. When the gear teeth mesh, the force is concentrated on the tooth surface, which makes the wear worse.

(4) If the gears are not in close contact with the shaft shoulder when the gears are installed, when the gear teeth are meshed, part of the tooth surfaces will be exposed without bearing the load, resulting in incorrect relative positioning of the two meshed gears in the axial direction. This not only affects the torque transmission of the two gears, but also easily damages the gear teeth.

Familiar with and understand the adverse symptoms and consequences caused by various defects in gear installation, help maintenance personnel and operators to correctly judge and prevent equipment failure in practice.