Planetary reducer is a widely used industrial product with performance comparable to other military grade reducers, but at the same price as industrial grade products. Planetary reducers are widely used in various industrial applications. It can also be used as a supporting component in industries such as lifting, excavation, transportation, and construction.
With the continuous development of the gearbox industry, more and more companies are using planetary gearboxes. Planetary gearboxes are industrial products and are a type of transmission mechanism. Their structure consists of an internal gear ring tightly connected to the gearbox housing, with a sun gear driven by external power at the center of the ring teeth. Between the two, there is a set of planetary gear sets consisting of three gears evenly divided and combined on a tray. The planetary gears float on the platform supported by the output shaft, internal gear ring, and sun gear; When the input side power drives the sun gear, it can drive the planetary gear to rotate and follow the trajectory of the inner ring gear to revolve around the center. The rotation of the planet drives the output shaft connected to the tray to output power.
What factors will affect the accuracy of planetary gearboxes
Compared to other reducers, planetary reducers have the characteristics of high rigidity, high precision (up to 1 point per stage), high transmission efficiency (97% -98% per stage), high torque/volume ratio, and lifetime maintenance free. Most of them are installed on stepper motors and servo motors to reduce speed, increase torque, and match inertia.
1. The main source of error in the transmission accuracy of the gearbox transmission chain
The transmission chain in general mechanical equipment is composed of transmission pairs such as gears and gears, gears and racks, worm gears and worms, lead screws and nuts. In the entire transmission chain, transmission errors are transmitted from the power input link to the end effector and accumulated according to the transmission ratio. The transmission accuracy of the transmission chain has a significant impact on the machining errors of lathe threads and gear hobbing machines. The transmission accuracy of a walking reducer refers to the degree to which the accuracy of each link in the transmission chain affects the accuracy and uniformity of the motion of the terminal actuator. The common sources of error in transmission accuracy during equipment maintenance are:
(1) The error of transmission components has a significant impact on the accuracy of equipment transmission.
(2) The error of matching parts and their assembly quality have a significant impact on transmission accuracy.
(3) During operation, transmission components inevitably undergo deformation due to heat and force, which can have a certain impact on the transmission accuracy of the transmission chain.
2. The main error sources of guide rail guidance accuracy
The guiding accuracy of a guide rail refers to the accuracy of the motion trajectory formed by the moving parts of a mechanical equipment when they move along the guide rail. The factors that affect the accuracy of guide rail guidance, in addition to the type, combination form, and size of the guide rail selected in the design, are commonly the main factors in equipment maintenance:
(1) The influence of whether the clearance between the guide rails is appropriate.
(2) Affected by the stiffness of the guide rail itself.
(3) Affected by the geometric accuracy of the guide rail.
The adjustment of mechanical equipment such as planetary reducers mainly involves selecting appropriate matching relationships between components to ensure that the equipment has reasonable working accuracy and normal working function. Therefore, overall, the adjustment of mechanical equipment cannot be carried out only after the assembly of components. This issue must be considered from the analysis of equipment failures and the determination of repair related parts.
3. The main sources of error in the rotational accuracy of the reducer spindle
Spindle rotation accuracy refers to the magnitude of radial runout, end face runout, and axial displacement of the working components at the front end of the spindle. The main sources of error in spindle rotation accuracy are as follows.
(1) Processing errors and assembly quality of matching parts
1) There is a parallelism error on both ends of the bearing liner spacer.
2) Whether the bearing clearance adjustment is appropriate during assembly has a significant impact on the spindle rotation accuracy.
3) The bearing holes on the gearbox body have roundness errors; There is a dimensional error when matching with the bearing ring; There is a perpendicularity error between the axial positioning end face and the central axis of the hole.
4) The nut for locking the main shaft of the walking reducer and adjusting the bearing clearance has a flatness error on the end face; There is a perpendicularity error between the nut end face and the thread center axis; There are connection errors between threads.
(2) Machining error of spindle
1) There is a roundness error in the journal.
2) The axial positioning surface of the bearing has a perpendicularity error with the main shaft axis.
3) There is a coaxiality error between the two journals on the spindle.
4) The spindle taper hole has a coaxiality error relative to the journal.
(3) Machining error of bearings
1) There are dimensional and roundness errors between the rolling elements of rolling bearings; The inner circular hole is eccentric relative to the raceway; The inner raceway has roundness error; There is coaxiality error between the front and rear bearings.
2) Sliding bearings have roundness errors and coaxiality errors in the inner and outer circles; There is coaxiality error between the front and rear bearings; There are dimensional errors between the bearing hole and the journal.