Study on the technology of thin walled bearing mounting2018-10-11 16:23:51

Bearing mount large thin-walled workpieces is a complex structure, dimensional accuracy, high geometric tolerance requirements for large end, the bore deformation, the deformation factor is determined by adjusting process route, i.e. the annular groove milling, milling a deep groove step after finishing the half advanced to be increased and stabilized; increase in half-finishing step of the large end face and the inner bore; jig made finishing, the large end surface adjustment allowance using a reasonable amount of cutting in order to reduce the amount of deformation of the workpiece. The large-bore end face and effectively controlled deformation of the workpiece, the workpiece so as to ensure compliance with requirements of the drawings.

Structural features of the workpiece 1

bearing mount wool for the precision casting, the casting material is a titanium alloy, dimensional accuracy and high technical requirements, processing is difficult to ensure.

2 Difficulties processing

larger (1) diameter of the workpiece, the minimum wall thickness is thin, and prone to vibration during deformation processing, dimensional accuracy of the workpiece, the conditions difficult to meet technical drawings.

(2) high dimensional accuracy and technical requirements, size of the bearing mounting hole and the mounting hole and the large size of the graphite ring from the small end face to axial end face of the coaxial cylindrical bore of the large internal bore internal bore concentricity during machining are difficult to ensure.

3 processing problems exist in

the second surface (1) semi-intensive cars, since the locating and clamping unreasonable manner, the large end surface deformation allowance Ambassador.

The first surface (2) after finishing the large end face deformation, oval inner opening, the pore size and the axial dimension tolerance.

(3) after stress release in the deep grooves and the milling of the annular groove 7, so that the large end surface and the hole is deformed, resulting in the pore size and the axial dimension tolerance.

Analysis 4

(1) Because the circumferential direction of the ring groove deep and removed more balance, changes in the structure of the workpiece, causing a large stress releasing end surface processed, the deformation of the inner bore hole size tolerance.

(2) when the second half finishing large end face machining allowance is large, irrational clamp structure, so that the large end face is deformed, so that when the other end surface side of the workpiece in order to ensure a large thickness auxiliary support to be adjusted, so that the large end face is deformed. And then when the large end faces of the positioning hole processing, since the large end surface flatness is not good, after pressing the large end faces the bore will produce compression deformation, after processing release platen deformation caused by the inner bore hole size tolerance.

5 solutions

(1) to develop a reasonable process route

will mill deep grooves, the annular groove to adjust the semi-finishing step performed after the first side, and increase the stability of the process to eliminate the large end face due to the stress relief slot milling, hole deformed.

(2) with the correct way of processing

by a plurality of auxiliary supporting pressure gauge adjusting screw to reduce the deformation of the workpiece in the processing to control the oscillation process large end face.

(3) increase the half-finishing large end face and the bore and the cutting step and to adjust the amount of oversize

increases half-finishing processes to remove large end margin; adjusting spindle revolutions n = 20-30r / min, depth of cut ap≤ 0.3mm and with a reasonable tool materials, tool rake angle is increased, the angle, ensure sharp tool; flood coolant during cutting to reduce the processing temperature and the like, in order to control the deformation of the large end face machining, the inner bore.

(4) self-locating and clamping the clamp jig change the way

of manufacturing a dedicated jig change the orientation of a clamping manner pressed to eliminate distortion.

Processing test 6

(1) milling the annular groove

is performed after the milling step of the annular groove arranged to semi-finish turning, the recording of the front surface runout all milled ring grooves. Deformation cylindrical, face and bore of the workpiece obtained after the change of the routing of the data recording has been significantly improved than that before change, effectively reduces stress generated by machining annular grooves of the cylindrical workpiece, the end faces and deformation of the hole generated.

Deformation control (2) the large end face machining

Modify the work piece is positioned in a clamping manner; by increasing the semi-finishing step of the large end face and a bore; auxiliary support by a plurality of adjusting screws and pressure check face runout table, and using a reasonable amount of cutting tool angle and flood coolant, greatly reducing end face deformation.

(3) the inner hole machining deformation control

by controlling a large amount of deformation end surface, and then positioned to the large end face and pressing the large end face so that the deformation is not transmitted to the large end face bore, and finally fine holes vehicle. Upon examination bore size fully meet the requirements of design drawings.

Conclusion

After analysis, mainly due to the impact of the identified workpiece deformation. By routing and processing methods to develop a reasonable, solving the problems of the workpiece bore, the end face deformation processing, justifies the feasibility of this process scheme. But also in practice we learned some practical working experience, laid down certain technical basis for future research, provided valuable experience for the machinery manufacturing and processing similar workpieces.