What are the methods for maintaining follower bearings?

Maintenance method of follower bearings:

(1) Check the bending of the following bearings axis. With the journals at both ends as the fulcrum, the radial runout shall not be greater than 0.03mm. If it exceeds 0.10mm, it can be corrected by cold pressing correction method.

(2) When the lift of the cam is not less than 5% of the specified value, it is allowed not to grind the cam, but check the radial circle runout tolerance of the cam base circle and the cam base circle to the camshaft axis; Overhaul standard is 0.03mm, and the overhaul is allowed to be no more than 0.05mm.

(3) The surface of the following bearings shaft shall be polished if it is rough, damaged or pitted. When the wear on the top of the cam exceeds 1.00 mm, the top of the cam shall be polished after surfacing to restore the original size and shape,Or replace it.

(4) If the tooth surface of the oil pump drive gear on the follower bearings shaft is rough or worn more than 0.50mm, it should be repaired. Individual gear teeth are damaged. It is allowed to

Continue to use after grinding off sharp corners. The surface roughness of the eccentric wheel driving the fuel transfer pump shall not exceed O.80 μ m。 When the wear of eccentric wheel exceeds 2.00mm, the camshaft shall be repaired or replaced by surfacing welding.

(5) Cylindricity tolerance of each journal: overhaul standard is 5 μ m. Overhaul is allowed to be no more than 15 μ m. Use limit is 25 μ m。

(6) The radial circular runout tolerance of journal and the end face circular runout error of axial thrust end face of timing gear shall not be greater than 35 μ m。

Adjustment of axial clearance for follower bearings: 

The axial clearance of camshaft shall comply with relevant regulations. The inspection method is shown in the attached figure. The thickness difference between the thrust flange and the spacer can also be directly measured by using a thickness gauge. When the thrust flange is worn, the shaft

When the axial clearance exceeds the specified value, the thrust flange with standard thickness shall be replaced, and the thickness of the spacer shall not be arbitrarily reduced, otherwise, the axial position of the cam will be changed, affecting the accuracy of the valve timing.