Summary:Planetary reducer precision introduction:
The precision unit of the planetary reducer is an arc minu...
Planetary reducer precision introduction:
The precision unit of the planetary reducer is an arc minute: 1 degree is divided into 60 arc minutes. For example, when the return clearance is marked as 1min, it means that the angular deviation of the output end is 1/60 for each revolution of the reducer. In practice, this angular deviation is related to the diameter of the shaft, b = 2.tc.2/360. That is to say, when the radius of the output end is 500mm, the contact degree of the gearbox is 10, that is, a"=3/60, the deviation of one revolution of the reducer is B = 0.44mm, and the transmission accuracy of the planetary gearbox is also called the backlash The backlash of the reducer is when the output end is fixed and the input end rotates clockwise and counterclockwise, so that the output end produces 2% of the rated torque, the input end of the reducer has a slight angular displacement, which is the backlash clearance.
Classification of reducer accuracy:
The accuracy of the reducer can be within 3 arc minutes, the accuracy of the second-stage planetary reducer is 3-5 arc minutes (Arcmin), and the accuracy of the third-stage planetary reducer is 5-8 arc minutes (Arcmin), usually divided into three grades. The transmission accuracy of the planetary reducer can be within 1 arc minute, so the transmission accuracy of the gearbox can be positioned, and it is suitable for industrial equipment with high transmission accuracy requirements. The reducer with a return gap of 1 arc minute belongs to the high-precision reducer series, which is widely used in transmission equipment, automobile transmission, robot transmission, 5G communication equipment, shipbuilding industry, aerospace, electronics, optical equipment and other fields.
What will be the impact of low precision planetary reducer?
When designing and manufacturing precision gears, attention should be paid to errors in gear accuracy, including tooth pitch errors and tooth direction errors. In order to ensure the accuracy of the gear, these errors should be eliminated, so as to improve the efficiency of the planetary reducer. When the gears are assembled with different centers, the shafting will run unbalanced. If the high-precision gear is unbalanced, it will have an adverse effect on the running accuracy of the planetary reducer. If the tooth surface hardness is too low, the rigidity of the planetary reducer will decrease.
How to improve the precision of planetary reducer:
The principle of the planetary reducer is precise, and the hybrid drive equipment is a kind of high-precision equipment. It is very important to improve the working accuracy of the planetary reducer. However, due to the limitation of working equipment, the improvement of manufacturing accuracy is limited, and the cost will increase greatly. In internal grinding heads (electric spindles), the method of applying preload to radial thrust ball bearings to improve accuracy has been widely used. Now apply this principle to the planetary reducer, and improve the transmission accuracy by applying a preload to the meshing tooth surface through the eccentric planetary shaft. According to the characteristics of planetary reducer hybrid drive system, planetary transmission is adopted as a new speed synthesis method of reducer hybrid drive system, and its structure design, force analysis, power distribution and installation method are introduced in detail. Practice has proved that it has the advantages of simple linear increment and high comprehensive precision. The method of using the eccentric planetary shaft to generate pre-tightening force between the meshing tooth surfaces of the symmetrical planetary reducer can greatly improve the transmission accuracy and reduce the system cost. The calculated value of the eccentricity of the planetary shaft can well ensure the elimination of the backlash between the teeth.