The reducer is generally used for transmission equipment with low speed and high torque. The motor, internal combustion engine or other power running at high speed is decelerated by the gear with a small number of teeth on the input shaft of the reducer meshing with the large gear on the output shaft. The ratio of the number of teeth of the big and small gears is the transmission ratio. The reducer is a relatively precise machine. It can reduce the speed and increase the torque. There are many types of reducers, different models, and different types have different uses.
According to the transmission type, it can be divided into gear reducer, worm reducer and planetary gear reducer; according to the number of transmission stages, it can be divided into single-stage and multi-stage reducer; according to the gear shape, it can be divided into cylindrical gear reducer and bevel gear reducer And conical and cylindrical gear reducers; according to the arrangement of the transmission, it can be divided into unfolded, split and coaxial reducers. In order to facilitate the reasonable selection of reducers, the types, characteristics and applications of several common reducers are listed one by one for reference when selecting models.
- Single-stage cylindrical gear reducer.
It is suitable for a reduction ratio 3~5. The gear teeth can be straight, helical or herringbone. Its box is usually cast in cast iron, or it can be welded with steel plates. Rolling bearings are commonly used in bearings, and sliding bearings are only used for heavy loads or very high speeds.
- Double-stage cylindrical gear reducer
The double-stage cylindrical gear reducer is divided into three types: expansion type, split type and coaxial type, and the applicable reduction ratio is 8~40.
(1) Expanded
Its high-speed stage is a long tail helical tooth, and the low-speed stage can be straight or helical. Due to the asymmetric arrangement of the gear relative to the bearing, the rigidity of the shaft is required to be large, and the torque input and output ends are kept away from the gear to reduce the uneven distribution of the load along the tooth width caused by the bending deformation of the shaft. It has a simple structure and is the most widely used.
(2) Split flow
Generally, high-speed fractionation is used. Since the gears are arranged symmetrically with respect to the bearings, the gears and bearings are subjected to relatively uniform forces. In order to keep the total axial force on the shaft small, the helix directions of the two pairs of gears should be opposite. It has a complex structure and is often used in places with high power and variable loads.
(3) Coaxial
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 similar, the bearing capacity of the high-speed gear cannot be fully exerted. It is often used in places where the input and output shafts are coaxial.
3. Single-stage bevel gear reducer
Single-stage bevel gear reducer is suitable for reduction ratio 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 transmissions where the two axes intersect perpendicularly.
4. Conical and cylindrical gear reducer
It is suitable for reduction ratio of 8~15. The bevel gear should be arranged in the high speed stage to reduce the size of the bevel gear. Bevel gears can be straight or curved. Cylindrical gears are mostly helical teeth so that they can offset part of the axial force of the bevel gears.
5. Worm reducer
Worm reducer mainly includes cylindrical worm reducer, arc toroidal worm reducer, cone worm reducer and worm gear reducer. Cylindrical worm reducers are the most commonly used. The worm reducer is suitable for reduction ratio of 10~80. It has a compact structure and a large transmission ratio, but the transmission efficiency is low, and it is suitable for occasions with low power and clearance work. When the peripheral speed of the worm is V≤4~5m/s, the worm is under-mounted, and the lubrication and cooling conditions are better. When V ≥ 4~5m/s, the agitation loss of the oil is large, and the worm is generally an upper-mounted type.
6. Planetary gear reducer
Due to the structure of the planetary reducer, the minimum single-stage reduction is 3, and the maximum generally does not exceed 10. The common reduction ratio is 3/4/5/6/8/10, and the number of reducer stages generally does not exceed 3, but there are some reductions. There are 4 stages of reduction than the custom reducer. Compared with other reducers, planetary reducers have high rigidity, high precision (single-stage can achieve within 1 minute), high transmission efficiency (single-stage at 97%-98%), high torque, volume ratio, and lifetime maintenance-free. 75 – 2000 watt Planetary gear motor can reduce speed, increase torque, and match inertia.