As a power transmission mechanism, gear reducers are widely used and are usually produced in conjunction with micro motors. The main principle is to input the high output speed of the micro motor into the gear reducer, and the gear reducer drives the large gear through the small gear, achieving the effect of reducing speed and increasing torque. It is widely used in products that require low speed and high torque, such as robots, electronic locks, electric curtains, ATM machines, and so on. There are also many types and categories of gear reducers, each with its own advantages and disadvantages. Below, Tianfu Micro Motor will briefly explain the advantages and disadvantages of several common gear reducers.
1. Planetary gear reducer
It is tightly connected to the gearbox housing by an inner ring gear, with a driving gear at the center of the ring gear called the sun gear, surrounded by three planetary gears revolving around the sun gear, as shown in the figure.
The performance characteristics of planetary reducers are light weight, small size, wide transmission ratio range, high efficiency, and smooth transmission. Planetary reducers have a reduction ratio of less than 10, which is a first stage reduction, and a reduction ratio of more than 10, which is a second stage reduction. Generally, there are two types of gears: straight teeth and helical teeth. The disadvantage is that planetary gear reducers have high machining accuracy and complex structures.
2. RV gear reducer
The gear reducer uses planetary gears as the first stage of reduction, and an additional cycloidal pinwheel reducer as the second stage of reduction. Through a rigid disc and an output disc connected to the overall mechanism, the reduction output is ultimately achieved.
The main characteristics are high reduction ratio, high stiffness, strong impact resistance, compact structure, etc. The disadvantages are large volume, complex process, and multiple parts.
3. Harmonic gear reducer
It mainly consists of a generator, flexible gears, bearings, and rigid gears. The wave generator is equipped with flexible bearings to produce controllable elastic deformation of the flexible gears, which mesh with the rigid gears to transmit motion and power through gear transmission. The characteristics are high transmission ratio, high reduction ratio, small size, light weight, simple structure, few parts, high transmission efficiency, and long service life. The disadvantage is that the flexible wheel is prone to damage, has a high starting torque, and cannot be used for products with small transmission ratios.
4. Vector cycloidal reducer
This type of reducer does not use gears as transmission, but instead uses steel balls as transmission components to form a seamless cycloidal meshing with the cycloidal rolling path to replace the meshing of gears. It has the characteristics of compact structure, low noise, light weight, small volume, zero backlash, smooth transmission, and high output accuracy, with a transmission efficiency of about 95%.
