A type of bearing used in automobiles, generally used for automotive camshafts (shafts that control the opening and closing of piston engine valves)

Structural characteristics

1. Combination structure of thick outer ring needle roller bearing and bolt

2. Sizes available in metric and imperial series

3. There is a lubricating oil passage inside the bolts of the bearing

4. For ease of installation, the large end of the bearing is designed with "straight" and "hexagonal hole" wrench assembly methods

5. The outer surface of the outer ring has cylindrical and spherical shapes, which can be selected according to practical applications

6. The full roller type is suitable for situations with high loads and low rotational speeds

7. Eccentric type can easily and accurately adjust the axis position of bolts when installing bearings

Bearing series

Type                                         and structural characteristics

                            CFxx             Standard

                            CFxxF           stainless steel type

                            CFESxx         solid eccentric bolt type

                            CFExx           eccentric type

Metric Series     CFxxW          thrust disc type

                            CFxxRUI      concentrated lubrication spherical outer ring

                            CFxxFUI       concentrated lubrication cylindrical outer ring

                            CFxxSFU      simple assembly type

                             NUCFxx      Heavy Industry Type

                             CFSxx          Small

English                CRxx-x        standard type

                             CRHxx x      Heavy Industry Type

suffix

Structural features                 IKO     INA     SKF     FAG

Retainer type                           -           -           -          -

Full roller type                         V         V         V        V

Attached hexagonal hole     B         SK       SK        -

Sealed                                      UU       PP       PP      2RS

Spherical outer ring               R          -           -           -

Stainless steel                          F          -           -          -

Thrust disc type                      W        -            -         -

Cylindrical outer ring              -          ×         ×      DZ

Interchangeability of bearings

IKO            INA              SKF           FAG        Remarks

CF...            KR... X         KR...        KR... D      with retainer standard type

CF... R        KR...             KR...         KR...         with retainer spherical outer ring type

CF... V        KRV... X       KRV...        -             Full Roller Standard Type

CF...VR       KRV...          KRV...        -             Full Roller Spherical Outer Ring Type

CFE...          KRE... X          -              -            eccentric standard type with retainer

CFE... R       KRE...             -              -            eccentric spherical outer ring type with retainer 

CFE... V       KRVE... X       -              -            Full Roller Eccentric Standard Type

CFE... E        KRVE             -              -           full roller eccentric spherical outer ring type

CR...            CFC...             -              -            English standard with retainer

CR... R         CFC... Y         -              -            Inch system with retainer spherical outer ring type

Maintenance of camshaft

(1) Check the curvature of the camshaft. Using the journal at both ends as the fulcrum, the radial runout should not exceed 0.03mm. When it exceeds 0.10mm, the cold pressing correction method can be used for correction.

(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 the radial runout tolerance of the cam base circle and the cam base circle to the camshaft axis should be checked; The overhaul standard is

0.03mm, overhaul is allowed to be no greater than O.05mm.

(3) The surface of the cam should be polished for roughness, damage, and pitting. When the wear of the cam tip exceeds 1.00mm, it should be repaired after welding to restore its original size and shape,

Or replace it.

(4) If the oil pump drive gear on the camshaft has rough or worn tooth surfaces exceeding 0.50mm, it should be repaired. Individual teeth of the gear are damaged, and it is allowed to

Grind off sharp corners and continue to use. The surface roughness of the eccentric wheel driving the oil delivery pump shall not exceed O.80 μ m。 When the wear of the eccentric wheel exceeds 2.00mm, the camshaft should be repaired by welding or replaced.

(5) Cylindricity tolerance of each camshaft journal: overhaul standard is 5 μ m. Overhaul allows no more than 15 μ m. The usage limit is 25 μ m。

(6) The radial runout tolerance of the camshaft journal for timing gear installation and the end face runout error of the axial thrust end face shall not exceed 35 μ m。

Adjustment of camshaft axial clearance

The axial clearance of the camshaft should comply with relevant regulations, and the inspection method is shown in the attached figure. Use a thickness gauge to measure, or directly measure the thickness difference between the thrust flange and the spacer. When the thrust flange is worn, the shaft

When the clearance exceeds the specified value, the standard thickness of the thrust flange should be replaced, and the thickness of the spacer ring should not be arbitrarily reduced. Otherwise, it will change the axial position of the cam and affect the accuracy of the valve timing.