Specialised inspection tools should be used to measure the geometric profile inspection, such as wheel diameter ruler, railway wheel pair inside distance measuring ruler, special measuring ruler for wheel rim shape (to measure the QR value of inclination), rim height/thickness measuring ruler, special measuring instrument for wheel rim dimensions, special measuring instrument for wheel rim side bulge, and so on.

wheel set

Checking the qR value of locomotive wheels

The minimum thickness of the root of the rim is 26mm and the rim angle is 700. Since the measurement of the rim angle is very difficult, the manufacturer provides a special gauge for measuring the shape of the rim based on factors such as the rim angle and the width of the root of the rim, and uses the specific "qR" value of the gauge to indicate the combined value of the rim. 

The qR value of the measuring tape rim should be measured at two points of the rim close to 180°, checking whether the contacts of the gauge are in contact with the rim, if the contacts are outside the rim tolerance (i.e., in contact with the rim), then it is necessary to use it after turning, or else replace the wheel pair.

The qR value should not exceed ~ this range, otherwise the wheel should be turned

Rim height check

Check the rim height using the rim height checking gauge. Check whether the contact point of the gauge touches the tread of the wheel, if the contact point is outside the rim tolerance (i.e., does not touch the tread) then the wheel needs to be turned and used, otherwise replace the wheelset. The maximum rim height is 31mm.

Flange thickness check

Use a special measuring tape to check the rim thickness. Check whether the contacts of the gauge touch the tread of the wheel, if the contacts are outside the tolerance of the rim (i.e. touching the tread) then it needs to be turned and used, otherwise replace the wheelset. Minimum rim thickness is 22mm.

Wheel rim side bulge inspection

Use a special gauge for wheel rim side bulges to check for wheel rim side bulges. If the edge of the gauge touches the wheel rim, the wheel needs to be turned and used, otherwise replace the wheel pair. If the edge of the gauge touches the wheel rim, the wheel must be turned and used, otherwise the wheel pair must be replaced. The maximum bulge thickness of the wheel rim is 6mm.

Checking wheel rim width

Use a suitable gauge to check the rim width of the wheel. If the edge of the gauge is in contact with the rim, the wheel needs to be turned and used, otherwise replace the wheel pair. The maximum width of the wheel rim is 140mm.

Wheel Inside Pitch Inspection

Check the wheel rim signs of overheating, if the wheel has overheating or braking after the appearance of abnormal signs of overheating must be measured wheel medial distance. Under no-load conditions, the measured value of the wheel pair between 1353 ~ 1355mm, it is necessary to compare with the initial value of the wheel pair medial distance, under no-load conditions, the wheel displacement shall not exceed.