1, the car bearing is broken can still open：
A car can’t drive if its bearings are broken. If the tire bearing is damaged, the wheels will make a buzzing noise when the vehicle is moving. If you hear this kind of abnormal sound, slow down the car and carefully feel the source of the intention to exclude the tire noise factor. Lift the vehicle, swing the wheel from side to side with your hand, check whether there is a gap in the bearing, and then turn the wheel with your hand, and feel whether there will be a buzzing noise again. If the abnormal sound has been clear, the tire bearing on the side of the abnormal sound can be removed, and check whether the bearing is running smoothly, if the bearing is found to operate freely, and there is no sign of damage, it can be guessed that the lack of lubrication at the spline of the shaft is caused, try to grease the spline of the shaft and the bearing spline and then test.
2, the difference between automotive bearings and industrial bearings：
Although bearings specially designed for skateboards and industrial bearings have the same size specifications, the working environment of the two is very different, so the performance that needs to be met is also very different; Industrial bearings generally work in a high-speed, stable, vibration-free and dust-free environment, while the working environment of skateboard bearings is outdoors. Outdoor gray, water, the huge impact brought by the user’s spring training landing to the bearing, and a lot of the phase force brought by the slide, making the skateboard bearing must overcome these harsh working environments, of course, this is also the reason why the industrial bearing can not fully show the skateboard: the higher the grade, the smaller the tolerance, the more precise the bearing, Bearings with high precision and small tolerances are mainly suitable for motors that operate at high speeds, such as motors that cut the copying iron of skateboards, running at 20,000 to 30,000 revolutions per minute; At a speed of 20,000 revolutions per minute, a 54 mm skateboard wheel will reach 127 miles per hour; Because all skateboards are going under 30 miles per hour, which equates to 4,700 revolutions per minute, when in fact most of them are going under 2,000 revolutions per minute; Skateboard bearings do not require the use of high-precision motor bearings
