How to detect the motor's round jump?
The motor's round runout consists of three items: (1) the circular runout of the motor shaft extension to the motor axis or the axis of rotation; (2) the circular runout of the surface of the collector ring of the wound rotor motor to the motor axis or the axis of rotation; The flange end cap and its flange mating surface should be checked for compliance with the requirements of the radial circular runout. For the flanged end cap stop motor, the flange stop face and axial runout should also be checked. Xiaobian today gave a brief introduction to the content.
Shaft extension and collector ring radial round runout detection
A lever dial gauge with a magnetic seat or a height gauge with a lever dial gauge can be used. From the actual testing experience, the lever dial gauge with magnetic seat is more convenient. In this paper, the measurement method is briefly described by taking the lever dial gauge with magnetic seat as the measuring instrument.
●Adsorb the magnetic seat of the dial gauge to the iron platform or motor end cover near the measured point. The adsorption process should ensure its firmness and prevent the gauge from being damaged due to the unreliable adsorption.
● Adjust the dial indicator to make the measuring head of the watch touch the measured point. For shaft extensions and collector rings, the measuring point should be at the midpoint of its axial length or width.
● After adding a certain top pressure to the dial indicator, tighten the screws at each break point and set the dial indicator to zero (ie, the bezel 0 position is aligned with the pointer).
● Slowly rotate the motor shaft for one week (for the detection of shaft extension, avoid the keyway to avoid damage to the meter head), and record the maximum swing range of the pointer. The above swing range value is the radial runout value of the measured shaft extension or collector ring. For example, if the pointer swings between +0.01 mm and -0.02 mm, the swing range is 0.03 mm, that is, the radial circle jump value is 0.03 mm.
Radial and axial runout measurement of the flange end cap stop to the axis
● Placement of the motor. When measuring, the dial of the dial gauge can be fixed to the shaft extension by its magnetic table. However, there is a problem that needs attention. It is because of the radial clearance of the bearing used. If the motor to be tested is placed horizontally during the measurement, the rotor will sink under its gravity and its axis will be off center. (The theoretical deviation value is half of the radial clearance of the bearing used), which causes the method error of the measured value, which brings certain difficulties to the final result judgment and even causes misjudgment. A more accepted method of placement is to place the flange end of the motor under test upwards so that the motor axis is perpendicular to the ground.
● Measurement method. Install a Class 1 precision dial indicator on the magnetic watch stand. The magnetic watch holder is sucked on the shaft extension (to ensure reliable suction).
(1) A method for measuring the radial circular runout of the flange of the flange end cover. Place the probe of the dial gauge against the side of the flange end cap. Adjust the position of the dial gauge and measure the force and fix it in one position. Adjust the cover so that the pointer points to the zero position. Rotate the shaft slowly by hand for a week, and record the maximum and minimum values indicated by the dial gauge. The difference between the two values (ie, the range of the needle swing) is the value of the radial end jump of the flange end cap to the motor axis.
(2) The method of measuring the circular runout of the end face of the motor by the flange end cover. The method of measuring the flange end cap to the motor axis end face circular runout is basically the same as the method of measuring the radial direction. The only difference is that the probe of the dial gauge should be placed on the end face of the stop.
