Shaft sleeve is a cylindrical mechanical part that is placed on the rotating shaft and is an integral part of the sliding bearing. In general, the shaft sleeve and the bearing housing have an interference fit and a clearance fit with the shaft.
Part process
(1) Parts material: 45 steel. Good machinability.
(2) Surface composition of parts: outer surface (Φ50, 35, 33), inner surface (Φ31.5, 20.5), type hole, both end faces, inner and outer step faces, inner and outer retracting grooves, inner and outer Chamfering.
(3) Main surface analysis: Φ20.5 inner hole is not only the supporting surface for supporting other parts, but also the main reference surface of the part; Φ50 outer circle and its step surface are also used to support other parts.
(4) Main technical conditions: the coaxiality of Φ50 outer circle and Φ20.5 inner hole is controlled within 0.03mm; the verticality of step surface and Φ20.5 inner hole is controlled by Φ44 inner hole itself with dimensional tolerance of mm; The roughness Ra is 0.8 μm; the heat treatment hardness of the parts is HRC 50-55.
Parts manufacturing process design
(1) Blank selection: According to the part material is 45 steel, the production type is medium batch production, the diameter difference of the parts is large, the parts are thin, the rigidity is low, the deformation is easy, the processing precision is high, the parts need to be quenched and so on. In terms of factors, choose between bar and die forging: die forgings.
(2) Benchmark analysis: The main positioning reference should be Φ20.5 inner hole center
(3) Installation scheme: When processing the big end and the inner hole, the three-jaw chuck can be directly used for clamping; the rough-cut small end can be used with the big end of the reverse claw clamp. When semi-finishing and finishing the small end, the mandrel should be equipped. , axially clamp the workpiece with Φ20.5 hole positioning. When the hole is machined, it can be installed by the indexing head, and the spindle is lifted by 90o, and the direct indexing method is adopted to ensure the equal position of the 3×Φ6 on the circumference of the part. For the four end screws of the big end, the special clamp is used: the large end face and the Φ20.5 hole are used as the main positioning reference, the hole is prevented from rotating, and the workpiece is axially clamped.
(4) Surface processing method of parts: Φ20.5 inner hole, using precision grinding to achieve precision and roughness requirements; outer circle and its step surface are grounded; the other rotating surfaces meet the processing requirements with semi-finished car; Milling.
(5) Heat treatment arrangement: Since the surface of the die forging has a hard skin, the tool wear and passivation will be accelerated. In order to improve the machinability, the blank is annealed after the die forging to soften the hard skin; the final treatment of the part is quenching due to The wall thickness of the parts is small, easy to deform, and the processing precision of the parts is high. In order to control the quenching deformation as much as possible, the quenching and tempering treatment is arranged for pretreatment after rough machining of the parts.
