How to adjust the precision error of transmission equipment such as reducer?

Date:25 Apr 2020
Summary:

The adjustment of reducer and other mechanical equipmen […]

The adjustment of reducer and other mechanical equipment is mainly through the selection of appropriate cooperative relations between parts and components, so that the equipment has reasonable operating accuracy and normal operating function. Therefore, on the whole, the adjustment of mechanical equipment cannot be started only after the assembly of parts. It is necessary to begin to consider this issue when analyzing equipment failures and deciding to repair related parts.
The accuracy of the transmission equipment such as the reducer is mainly reflected in the reverse accuracy of the main shaft, the guide accuracy of the guide rail and the transmission accuracy of the transmission chain.
1. The primary error source of the spindle reverse accuracy of the reducer
Spindle reversal accuracy refers to the size of the radial circle runout, end face circle runout and axial runout of the working parts at the front end of the spindle. The primary source of error in spindle reverse accuracy is as follows.
(1) Machining errors of the spindle
1) There is a coaxiality error between the two journals on the main shaft.
2) The conical hole of the main shaft has a coaxiality error relative to the journal.

NON-STANDARD FITTINGS

3) The journal has roundness errors.
4) There is a straightness error between the axial positioning surface of the bearing and the axis of the spindle.
(2) Processing errors of bearings
1) There are scale errors and roundness errors between the rollover bodies of the rollover bearings; the inner round holes have a partial pain relative to the raceway; the roundness errors of the inner round raceways; the coaxiality errors between the front and rear bearings.
2) There are roundness errors and coaxiality errors of the inner and outer circles of the sliding bearing; there are coaxiality errors between the front and rear bearings; there are scale errors between the bearing hole and the journal.

(3) Processing errors and assembly quality of common parts
1) The bearing hole on the gear reduction case has a roundness error; there is a scale error when cooperating with the bearing ring; there is a straightness error in the axial positioning end face and the central axis of the hole.
2) The nut that locks and adjusts the bearing gap on the reducer main shaft has a flatness error on the end surface; there is a straightness error between the end surface of the nut and the center axis of the thread; there is a connection error between the threads.
3) There are errors in parallelism at both ends of the bearing bush spacer.
4) Whether the bearing clearance adjustment is appropriate during assembly directly affects the spindle reversing accuracy significantly.
Second, the primary source of error in guide rail accuracy
The guide accuracy of the guide rail refers to the accuracy of the motion trajectory when the moving parts of the mechanical equipment move along the guide rail. In addition to the type, combination form and scale of the guide rail selected in the design, the first factors that are common in equipment repair are:
(1) Influenced by the geometric accuracy of the guide rail.
(2) It is affected by whether the clearance of the guide rail is suitable.
(3) Influenced by the rigidity of the guide rail itself.
3. The primary error source of the transmission accuracy of the reducer drive chain
Transmission accuracy refers to the degree of influence of the accuracy of each link in the transmission chain on the accuracy and uniformity of the movement of the terminal performance parts.
The transmission chain in general mechanical equipment is composed of gears and gears, gears and racks, worm gears and worms, screws and nuts and other transmission pairs. In the entire transmission chain, transmission errors are transmitted from the power input link to the terminal performance parts, and accumulated according to the transmission ratio. The transmission accuracy of the transmission chain has a significant impact on the machining errors of the lathe thread and the hobbing gear of the hobbing machine.
The common sources of errors in transmission accuracy during equipment repair are:
(1) Errors in transmission parts have a primary influence on the transmission accuracy of the equipment.
(2) The errors of the general matching parts and their assembly quality have a significant impact on the transmission accuracy.
(3) In the operation of the transmission parts, due to heat and force, it will inevitably cause deformation, which will also have a certain impact on the transmission accuracy of the transmission chain.

0