Gear drive type

1. Cylindrical gear drive

For the transmission between parallel shafts, the general transmission ratio can be up to 8, the maximum 20, the two-stage can be up to 45, the maximum 60, the three-stage can be up to 200, the maximum 300. The transmission power can reach 100,000 kW, the speed can reach 100,000 RPM, and the circumference speed can reach 300 m/s. Single stage efficiency is 0.96 ~ 0.99. Spur gear transmission is suitable for medium and low speed transmission. Bevel gear drive runs smoothly, suitable for medium and high speed transmission. Herringbone gear transmission is suitable for transmission of high power and large torque. There are three kinds of meshing forms of cylindrical gear transmission: external meshing gear transmission, which is meshed by two external gears, and the steering of the two wheels is opposite; Internal gear transmission, by an internal gear and a small external gear mesh, the steering of the two wheels are the same; Pinion and rack drive, which can change the rotation of the gear into a straight line movement of the rack, or vice versa.

2. Bevel gear drive

Used for transmission between intersecting axes. The single-stage transmission ratio can be 6, the maximum is 8, and the transmission efficiency is generally 0.94 ~ 0.98. The transmission power of straight bevel gear can reach 370 kW, and the circumference speed is 5 m/s. Helical bevel gear drive runs smoothly and has high gear bearing capacity, but it is difficult to manufacture and less applied. Curvilinear bevel gear transmission runs smoothly, the transmission power can reach 3700 kilowatts, and the circular speed can reach more than 40 meters/second.

3. Hyperboloid gear drive

Used for transmission between staggered axes. The single-stage transmission ratio can reach 10, the maximum can reach 100, the transmission power can reach 750 kilowatts, the transmission efficiency is generally 0.9 ~ 0.98, and the circular speed can reach 30 meters/second. Due to the axis offset, pinion cantilever mounting can be avoided. It is widely used in the transmission of automobiles and tractors.

4. Spiral gear drive

For interleaved transmission, the transmission ratio can be up to 5, the carrying capacity is low, the wear is serious, and the application is few.

5. Worm drive

The main form of staggered shaft transmission, the axis staggered Angle is generally 90°. Worm drive can obtain a large transmission ratio, usually a single stage of 8 to 80, used to transfer movement up to 1500; Transmission power up to 4500 kW; The speed of the worm can reach 30,000 RPM; The circular velocity can reach 70 m/s. The worm drive works smoothly, the transmission ratio is accurate, and it can self-lock, but the transmission efficiency is less than 0.5 when self-locking. The sliding between the tooth surfaces of worm transmission is large, the heat is more, and the transmission efficiency is low, usually 0.45 ~ 0.97.

6. Arc gear drive

Gear transmission with convex and concave circular arc for tooth profile. The profile of the two teeth is point contact when the load is not loaded, and the contact point moves along the axis during the engagement process, and the longitudinal contact degree is greater than 1 to obtain continuous transmission. It is characterized by high contact strength and bearing capacity, easy to form oil film, no root cutting phenomenon, uniform tooth surface wear, good running performance; But the center distance, cutting depth and spiral Angle error sensitivity is very large, so the manufacturing and installation accuracy requirements are high.

7. Cycloidal gear drive

Gear drive with cycloidal tooth profile. The transmission tooth surface contact stress is small, good wear resistance, no root cutting phenomenon, but the manufacturing accuracy requirements are high, the center distance error is very sensitive. Only used in watches and instruments.

8. Planetary gear drive

A gear drive with a moving axis. There are many types of planetary gear transmission, and the performance of different types varies greatly, so it is very important to choose the type reasonably according to the working conditions. Commonly used by the sun wheel, planetary wheel, internal gear and planetary frame composed of ordinary planetary transmission, less tooth difference planetary gear transmission, cycloidal pin wheel drive and harmonic drive. Planetary gear transmission is generally composed of parallel shaft gears, with the characteristics of small size and light weight, the input shaft and output shaft can be in the same straight line.

Source: Network