What are the specific requirements for the performance of Geely flexible bearings?
Publish Time: 2024-08-22
The performance requirements of Geely flexible bearings usually include the following aspects:
High precision:
Dimensional accuracy: The inner and outer diameters, widths and other dimensions of the flexible bearings need to be precisely controlled within a small tolerance range to ensure accurate matching with other components of the harmonic reducer (such as wave generators, flexible wheels, rigid wheels, etc.) to ensure the transmission accuracy and performance stability of the reducer. For example, the inner diameter tolerance of the bearing may be required to be at the micron level to ensure the matching accuracy with the shaft and reduce clearance and shaking.
Shape accuracy: including indicators such as roundness and cylindricity. Flexible bearings will undergo elastic deformation during operation, but they still need to maintain a high shape accuracy to ensure uniform contact between the rolling element and the inner and outer rings, reduce friction and wear, and improve the service life and transmission efficiency of the bearings.
High load-bearing capacity:
Static load-bearing capacity: It can stably withstand the static loads generated by the harmonic reducer during operation, including pressure from components such as flexible wheels and rigid wheels, as well as its own gravity. For example, in some large industrial robot harmonic reducers, flexible bearings need to withstand large axial and radial static loads to ensure the position accuracy and stability of each component of the robot when it is stationary.
Dynamic load-bearing capacity: During the operation of the harmonic reducer, the flexible bearing must bear the dynamic loads generated by the movement, such as the additional forces caused by acceleration and vibration. Having good dynamic load-bearing capacity can ensure that the bearing will not suffer from fatigue damage, excessive deformation and other problems under complex working conditions, and ensure the long-term reliable operation of the reducer.
Good elasticity and deformation capacity:
Elastic deformation range: The outer ring of the flexible bearing is usually thin and prone to radial deformation. It is round before being installed in the cam and becomes elliptical after installation to meet the performance requirements of the harmonic drive transmission to achieve a high reduction ratio through the elastic deformation of the bearing. This requires the bearing to have a suitable elastic deformation range, which can achieve the required deformation during operation without causing damage or failure due to excessive deformation.
Deformation recovery ability: After undergoing elastic deformation, when the load disappears, the bearing should be able to quickly return to its original shape to ensure that it can still work normally when it is used next time, and this deformation recovery ability should remain stable during long-term use, and will not cause permanent deformation or performance degradation due to repeated deformation.
Low friction and wear:
Friction coefficient: During operation, the rolling element and the inner and outer rings of the flexible bearing will produce relative motion, so it should have a low friction coefficient to reduce the heat and energy loss generated by friction and improve transmission efficiency. Low friction coefficient can also reduce the wear rate of the bearing and extend its service life.
Wear resistance: Due to long-term exposure to complex working environments and alternating loads, the material and surface treatment of the bearing should have good wear resistance, be able to resist the wear between the rolling element and the raceway, and maintain the precision and performance of the bearing. For example, the use of high-quality bearing steel materials and appropriate heat treatment and surface strengthening treatment can improve the wear resistance of the bearing.
Long life and reliability:
Fatigue life: During the long-term use of the harmonic reducer, the flexible bearing needs to withstand a large number of cyclic loads, so it should have a high fatigue life, that is, under the specified load and speed conditions, the time or number of cycles that can continue to work should meet the design requirements. The fatigue life of the bearing can be improved by optimizing the structural design, material selection and manufacturing process of the bearing.
Reliability: Under various working conditions, including different environmental factors such as temperature, humidity, dust, and different load and speed changes, flexible bearings should be able to work stably and reliably, and not prone to failure, so as to ensure the normal operation of the harmonic reducer and reduce the downtime and maintenance costs caused by bearing failure.
Good rotation accuracy:
Running and swing accuracy: During the rotation process, the flexible bearing should minimize radial runout and axial swing to ensure the motion accuracy and stability of the harmonic reducer output. High-precision rotation accuracy can make the robot's movements more accurate and coordinated, and improve the robot's work quality and efficiency. For example, in some industrial robot applications with extremely high requirements for motion accuracy, the rotation accuracy requirements of flexible bearings are very strict.
Synchronicity: If multiple flexible bearings are used in a harmonic reducer, or flexible bearings are used in multiple joints of a multi-axis robot, these bearings should have good synchronization, that is, they can maintain the same speed and phase to ensure the coordinated movement of each joint of the robot and avoid motion deviation or incoordination.
Appropriate clearance:
Radial clearance: The radial clearance of the flexible bearing should be controlled within a reasonable range. Too small a clearance will cause the bearing to heat up severely during operation, poor lubrication, increased friction and wear; too large a clearance will reduce the rotation accuracy of the bearing and affect the transmission accuracy of the harmonic reducer. According to different application scenarios and requirements, selecting a suitable radial clearance can improve the overall performance of the harmonic reducer while ensuring the performance of the bearing.
Axial clearance: Similarly, the axial clearance also needs to be reasonably designed and controlled according to the specific situation to meet the working requirements of the harmonic reducer in the axial direction and prevent problems such as loosening, displacement or jamming of components caused by inappropriate axial clearance.
Good temperature adaptability:
Working temperature range: Geely flexible bearings may be used in different environments and need to be able to work normally within a certain temperature range, whether in high temperature environments (such as some industrial production sites) or low temperature environments (such as outdoor equipment in cold areas). For example, in a high temperature environment, the material properties of the bearing should not change significantly, and the grease should maintain good lubrication performance and will not be lost or deteriorated due to high temperature; in a low temperature environment, the material of the bearing should have sufficient toughness and will not become brittle and crack due to low temperature.
Impact of temperature change: When the working environment temperature changes, the performance parameters such as the size, clearance, and friction coefficient of the flexible bearing should remain relatively stable, and will not cause significant performance fluctuations due to temperature changes, affecting the normal operation of the harmonic reducer.
Vibration and impact resistance: In some working occasions, the harmonic reducer may be subjected to vibration and impact loads, such as when the robot is moving, carrying heavy objects, or performing high-speed movements. Geely's flexible bearings should have a certain degree of vibration and impact resistance, be able to withstand these loads without damage or performance degradation, and ensure the reliability of the harmonic reducer under complex working conditions.
Good sealing performance (if applicable): If Geely flexible bearings are used in some special environments, such as those with dust, moisture, corrosive gases, etc., they may need to have good sealing performance to prevent external pollutants from entering the bearing and affecting the lubrication and normal operation of the bearing. At the same time, it can also avoid grease leakage inside the bearing and keep the working environment clean and safe.
