Types of gear transmission and troubleshooting methods

2023/01/09 09:31

 Gear transmission is one of the most widely used transmission forms in mechanical transmission. Its transmission is relatively accurate, high in efficiency, compact in structure, reliable in operation and long in service life.

How to deal with gear transmission failure?

【Faults caused by manufacturing errors】

When manufacturing gears, eccentricity usually occurs. Some typical errors, such as circumferential pitch error, base pitch error and tooth profile error. There are many reasons for these errors, such as machine tool movement, tool cutting, and tool errors. .Workpiece. Errors caused by improper installation and debugging of machine tool systems, fixture errors, gear deformation caused by heat treatment internal stress, etc. When the errors of the gears are large, the slow and fast micro-inertia of the gear transmission will interfere with the rotation, which will cause shock and vibration when the gear pairs mesh, and generate large noise.

[Faults caused by assembly errors]

Due to reasons such as assembly technology and assembly methods, assembly is usually caused when assembling gears. "One end contact. One end suspended" assembly error; straight line deviation of the gear shaft (concentricity. Neutral error) and gear unbalance. One-end contact or linear deviation of the gear shaft will cause uneven gear load, resulting in excessive load on a single gear, resulting in local early wear, and even gear breakage in severe cases. Unbalanced gears can cause shock vibration and noise.

【Faults during operation】

Fracture of gear teeth

During gear transmission, the active force of the driving gear and the reaction force of the driven gear act on the opposite gear respectively through the contact points. The dangerous situation is a moment when the contact point is at the top of the gear tooth; at this time, the gear tooth is like a cantilever beam, and the bending stress generated at the root of the tooth is large after being loaded. If due to sudden overload or impact overload, the tooth root is prone to overload fracture.

Tooth surface wear or scratches

During meshing transmission, the gear teeth slide relative to each other, coupled with poor lubrication. .The lubricating oil is not cleaned, the lubricating oil deteriorates, low speed and heavy load or poor heat treatment quality, etc., will lead to adhesive wear of the tooth surface. . Abrasive wear. Corrosive wear and scratches.

3. Tooth surface fatigue

The so-called tooth surface fatigue mainly includes pitting and peeling of the tooth surface. The main cause of pitting is the micro-fatigue cracks caused by the pulsating contact stress on the working surface of the gear teeth. When lubricating oil enters the surface crack area, the entrance is first closed and then squeezed during the engagement process. The lubricating oil in the micro-fatigue crack area expands the crack area on the tooth surface under high pressure, causing the metal particles on the surface to fall off the tooth surface, leaving small pits to form tooth surface pitting. When the fatigue cracks on the surface of the gear teeth extend deeper and farther, it will cause large areas or large areas of tooth surface spalling.

Tooth surface plastic deformation

When the gear material is soft and the transmission load is large, the plastic deformation of the tooth surface is easy to occur. When the friction force between the tooth surfaces is too large, the contact stress of the tooth surface will exceed the material’s anti-extrusion yield limit, and the tooth surface material will enter a plastic state, resulting in plastic flow of the tooth surface metal. This causes the drive gear to form grooves on the tooth surface near the pitch line, and form ribs on the tooth surface near the pitch line, thereby destroying the tooth shape.