Advantages, disadvantages and application of harmonic gear reducer

Time:2020-07-09 11:18:26

Wave gear reducer is referred to as harmonic reducer. Because the structure of the harmonic gear reducer and the working principle of the harmonic gear reducer are very different from the ordinary gear reducer, it is determined that its application is different. The advantages of the harmonic reducer and the harmonic reduction are listed below. The shortcomings of the device and the application field of harmonic reducer.




Main advantage


(1) The transmission speed ratio is large. The single-stage harmonic gear transmission speed ratio ranges from 70 to 320, in some devices it can reach 1000, and the multi-stage transmission speed ratio can reach more than 30,000. It can be used not only for speed reduction, but also for speed increase occasions.


(2) High carrying capacity. This is because the number of teeth meshed at the same time in the harmonic gear transmission is large, and the number of teeth meshed at the same time in the double-wave transmission can reach more than 30% of the total number of teeth, and the flexible wheel uses high-strength materials, and the teeth are in surface contact with the teeth.


(3) High transmission accuracy. This is because the number of teeth meshed at the same time in the harmonic gear transmission is large, and the error is averaged, that is, multi-tooth meshing has a mutual compensation effect on the error, so the transmission accuracy is high. In the case of the same gear accuracy grade, the transmission error is only about 1/4 of that of ordinary cylindrical gear transmission. At the same time, the radius of the wave generator can be changed slightly to increase the deformation of the flexspline so that the backlash is small, and even the backlash-free meshing can be achieved. Therefore, the harmonic gear reducer has a small transmission idle distance and is suitable for reverse rotation.


(4) High transmission efficiency and smooth movement. Due to the uniform radial movement of the flexspline gear teeth during the transmission process, even if the input speed is high, the relative slip speed of the gear teeth is still extremely low (so it is one percent of the ordinary involute gear transmission) Therefore, the gear teeth are less worn and the efficiency is high (up to 69%-96%). Also, because both sides of the gear participate in the work when engaging in and out, there is no impact phenomenon and the movement is stable.


(5) Simple structure, few parts, and convenient installation. There are only three basic components, and the input and output shafts are coaxial, so the structure is simple and the installation is convenient.


(6) Small size and light weight. Compared with the general reducer, when the output torque is the same, the volume of the harmonic gear reducer can be reduced by 2/3, and the weight can be reduced by 1/2.


(7) Can transmit motion to confined space. Utilizing the flexibility of the flexspline, this valuable advantage of the wheel drive is unmatched by other existing drives.




Main disadvantage


(1) The flexspline is deformed periodically, thus generating alternating stress, making it prone to fatigue failure.


(2) The moment of inertia and starting torque are large, so it is not suitable for low-power tracking transmission.


(3) Cannot be used in occasions where the transmission ratio is less than 35.


(4) Harmonic transmission using roller wave generator (free deformation wave), its instantaneous transmission ratio is not constant.


(5) Poor heat dissipation conditions.




Application field


Harmonic gear reducers are used in aviation, aerospace, energy, navigation, shipbuilding, bionic machinery, commonly used ordnance, machine tools, instruments, electronic equipment, mining and metallurgy, transportation, lifting machinery, petrochemical machinery, textile machinery, agricultural machinery and medical treatment Equipment and other aspects are increasingly widely used, especially in the servo system with high dynamic performance, the use of harmonic gear transmission shows its superiority. The power it transmits ranges from tens of watts to tens of kilowatts, but high-power harmonic gear drives are mostly used in short-term work situations.