The reducer is generally used for the transmission equipment with low speed and high torque. The motor, internal combustion engine or other high-speed running power is meshed with the large gear on the output shaft through the gear with small number of teeth on the input shaft of the reducer to achieve the purpose of reduction. The ratio of the number of teeth of the large and small gears is the transmission ratio.
Reducer is a kind of relatively precise machinery. The purpose of using it is to reduce the speed and increase the torque. There are many types and models of reducers, 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 the 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, conical gear reducer and conical cylindrical gear reducer; According to the arrangement of transmission, it can be divided into expansion type, shunt type and coaxial type reducer.
In order to facilitate rational selection of reducers, the types, characteristics and applications of several common reducers are listed one by one for reference in selection.
1. Single stage cylindrical gear reducer
Single stage cylindrical gear reducer is suitable for reduction ratio of 3 ~ 5. The gear teeth can be straight teeth, oblique teeth or herringbone teeth. The box is usually cast with cast iron or welded with steel plates. Bearings are commonly used as rolling bearings. Sliding bearings are only used when heavy load or extra high speed.
2. Double stage cylindrical gear reducer
The two-stage cylindrical gear reducer can be divided into three types: expansion type, split type and coaxial type, and the applicable reduction ratio is 8 ~ 40.
Expansion type: high-speed stage long tail helical teeth, low-speed stage can be straight teeth or helical teeth. Due to the asymmetric arrangement of the gear with respect to the bearing, it is required that the rigidity of the shaft is large, and the torque input and output ends are kept away from the gear, so as to reduce the uneven distribution of the load along the tooth width caused by the bending deformation of the shaft. Simple structure and most widely used.
Shunt type: high speed shunt is generally adopted. Since the gear is symmetrically arranged with respect to the bearing, the bearing force of the gear and the bearing is relatively uniform. In order to reduce the total axial force on the shaft, the helix direction of the two pairs of gears should be opposite. The structure is complex, and it is often used in places with high power and variable load.
Coaxial type: the axial dimension of the reducer is large, the intermediate shaft is long, and the rigidity is poor. When the oil immersion depth of the two large gears is close, the bearing capacity of the high-speed gear cannot be fully developed. It is often used in places where the 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 the bevel gear and facilitate processing. It is only used in transmission where two axes intersect perpendicularly.
4. Conical and cylindrical gear reducer
Conical and cylindrical gear reducers are suitable for reduction ratio of 8 ~ 15. The bevel gear shall be arranged at the high speed stage to reduce the size of the bevel gear. Bevel gears may be straight teeth or curved teeth. Cylindrical gears are mostly helical teeth, which can offset part of the axial force of bevel gears.
5. Worm reducer
There are mainly cylindrical worm reducer, circular arc toroidal worm reducer, conical worm reducer and worm gear reducer, of which cylindrical worm reducer is the most commonly used.
Worm reducer is suitable for reduction ratio of 10 ~ 80. Compact structure, large transmission ratio, but low transmission efficiency, suitable for small power and clearance work. 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 agitation loss of oil is large. Generally, the worm is of upper type.
6. Planetary gear reducer
Because of the structure of planetary reducer, 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, and the number of reducer stages is generally not more than 3. However, some customized reducers with large reduction ratio have 4-stage reduction.
Compared with other reducers, planetary reducers are characterized by high rigidity, high accuracy (single stage can achieve less than 1 point), high transmission efficiency (single stage can reach 97% - 98%), high torque, volume ratio, and lifetime maintenance free. Because of these characteristics, most planetary reducers are installed on stepping motors and servo motors to reduce speed, increase torque and match inertia
WPWKS100,WPWKS120,WPWKS135,WPWKS155,WPWKS175
