1.Methods for checking the outside diameter

1)Load checkin(DIN 1494-2:Test A)

The checking rig consists of two checking block halves. Align the "zero" position of the checking blocks by a setting plug dch. 2 and make the bush's split place at the upper halve of the checking blocks and then add the same checking load Fch on both of the checking halves.Read the moving distance of the halves displayed on the distance indicator and record the readingΔz.

2)Measuring of gauge (DIN 1494-2:Test B)

The checking is carried out by two ring gauges,a "GO" ring gauge and a "NO GO" ring gauge.It must be possible to press the bushing in "GO" ring gauge with hand pressure(max 250N).With the same force it must not be possible to press the bushing in "NO GO"ring gauge.

Note: In some cases,such as the bushing with roundness problem,or the butt joints not close tightly,hand pressure with hand pressure the accuracy of the checking may be affected.

3)Measuring of rule(ISO3547-2:Test D)

For bushing with rather big diameter,their circumference can be checked out by a measuring tape.Firstly,the measuring tape is calibrated around a mandrel of diameter equal to the nominal outside diameter of the bushing. An indicating device is attached to the "free"end of the measuring tape and set to the calibration size. Secondly, move away the mandrel and take in its place with a bushing. Make sure to let the split of the bushing fully closed by pulling more strength on the tape.Finally After the bushing has been cheched,the circumference indicator readingΔZD is the difference between he calibrated value of the setting mandrel and the measured value if the bushing.Form this,the outside diameter of the bushing can be worked out.

1-Precise measuring

line;

2-Dial indicator;

3-Pulling spanner;

4-Locating spindle;

5-Wrapped bushing

2.Inside diameter checking methods for wrapped bushing

1)Plug gauge checking(DIN 1494-2:Test C)

Press the bush into the ring gauge,the tolerance class of which is H7,and check the inside diameter of the bushing with plug gauges.

1) Plug gauge checking(DIN 1494-2:Test C)

Check the wall thickness of the bushing a wall thickness micrometer and then calculate out the value of the inside diameter.According to ISO3547-2 make sure not to mark both the wall thickness and inside diameter on the drawing.

3.Thrust washer test method

Beside the thickness, the flatness of washer is also important for service life of washer and grinding parts'. We use very helpful test in which the washer falls through the gap between two plain parallel plates of a gauge with its own weight.The plates must be big enough to cover the whole washer.