The reducer is generally used for the transmission equipment with low speed and large torque. The motor, internal combustion engine or other high-speed running power can be decelerated by meshing the small number of teeth on the input shaft of the reducer with the large gear on the output shaft. The ratio of the number of teeth of the large and small gears is the transmission ratio.
The reducer is a relatively precise machine. The purpose of using it is to reduce the speed and increase the torque. There are many kinds of reducers with different models, and different types have different purposes.
According to the transmission type, it can be divided into gear reducer, worm reducer and planetary gear reducer; According to different transmission stages, it can be divided into single-stage and multi-stage reducers; According to the gear shape, it can be divided into cylindrical gear reducer, bevel gear reducer and bevel - cylindrical gear reducer; According to the layout of the transmission, it can be divided into deployable, split and coaxial reducers.
In order to facilitate the reasonable selection of gear reducers, the types, characteristics and applications of several common gear reducers are listed one by one for reference in type selection.
1. Single-stage cylindrical gear reducer
The single-stage cylindrical gear reducer is applicable to the reduction ratio of 3~5. The gear teeth can be straight teeth, helical teeth or herringbone teeth. The box is usually cast iron or welded with steel plates. Rolling bearings are commonly used in bearings, and sliding bearings are only used in heavy loads or ultra-high speeds.
2. Double-stage cylindrical gear reducer
Double-stage cylindrical gear reducers are divided into three types: expansion type, split type and coaxial type, applicable to reduction ratio of 8~40.
Deployable: high speed long tail helical gear, low speed can be straight or helical gear. Due to the asymmetric arrangement of the gear and the bearing, the shaft stiffness is required to be large, and the torque input and output ends should be kept away from the gear to reduce the uneven distribution of load along the tooth width caused by the bending deformation of the shaft. Simple structure, the most widely used.
Split type: generally, high-speed split is adopted. Because the gears are symmetrically arranged relative to the bearings, the forces on the gears and shafts are relatively uniform. In order to reduce the total axial force on the shaft, the helical direction of two pairs of gears should be opposite. The structure is relatively complex and is often used in places with high power and variable load.
Coaxial type: the axial size of the reducer is large, the intermediate shaft is long, and the rigidity is poor. When the immersion depth of two large gears is close, the bearing capacity of high-speed gear cannot be fully developed. It is often used in places where input and output shafts are coaxial.
3. Single-stage bevel gear reducer
The single-stage bevel gear reducer is applicable to the reduction ratio of 2~4. The transmission ratio should not be too large to reduce the size of bevel gears and facilitate machining. It is only used in transmission where two axes intersect vertically.
4. Bevel and cylindrical gear reducer
The bevel and cylindrical gear reducers are applicable to the reduction ratio of 8~15. The bevel gear shall be arranged at the high speed stage to reduce the size of the bevel gear. The bevel gear can be straight or curved. Cylindrical gears are mostly helical gears, which can offset part of the axial force of bevel gears.
5. Worm reducer
There are mainly cylindrical worm gear reducers, circular toroidal worm gear reducers, conical worm gear reducers and worm gear reducers, of which the cylindrical worm gear reducer is the most commonly used.
The worm gear reducer is applicable to the reduction ratio of 10~80. Compact structure, large transmission ratio, but low transmission efficiency, suitable for small power, clearance work occasions. When the worm circumferential speed V ≤ 4~5m/s, the worm is of the lower type, and the lubrication and cooling conditions are good; When V ≥ 4~5m/s, the stirring loss of oil is large, and the worm is generally of the upper type.
6. Planetary gear reducer
Due to structural reasons, the minimum single-stage reduction is 3, and the maximum is generally not more than 10. The common reduction ratio is 3/4/5/6/8/10. The number of stages of the reducer is generally not more than 3. However, some large reducers have 4-stage reduction compared with customized reducers.
Compared with other gear reducers, planetary gear reducers have the characteristics of high rigidity, high precision (single stage can achieve less than 1 point), high transmission efficiency (single stage can achieve 97% - 98%), high torque, volume ratio, and lifelong maintenance-free. Because of these characteristics, most planetary reducers are installed on stepper motors and servo motors to reduce speed, increase torque and match inertia.
WPWA120,WPWA135,WPWA155,WPWA175,WPWA200
