How do you calculate the vibration frequency of a motor?
Motor speed is simply a measurement of the revolutions per minute (RPM), while vibration frequency is expressed in Hertz (Hz) and is the number of vibrations per second. To convert from Hz to RPM we simply multiply by 60, as there are 60 seconds in every minute. Similarly, to convert from RPM to Hz we divide by 60.
What is the frequency at which the motor vibrates?
Therefore all AC motors produce a 2 X line frequency vibration. In power systems that operate at 60 Hz, the vibration frequency is 120 Hz. In an induction motor, the poles in the stator winding produce a rotating magnetic force that acts across the air gap between stator and rotor.
What is the frequency of a vibrating?
The number of cycles that a vibrating object completes in one second is called frequency. The unit of frequency is hertz (Hz). One hertz equals one cycle per second.
What is the allowable vibration limits for motor?
More stringent specifications regarding motor vibration call for maximum velocity levels of 0.1 in./sec on the housing and 1.5 mils of displacement vibration on the shaft.
What is 1X 2X in vibration?
A 1X and 2X vibration signal predominant in the axial direction is generally the indicator of a misalignment between two coupled shafts. These signals may be also visible in the radial direction at a lower amplitude and in phase.
Why does a motor vibrate horizontally?
Vibration can be caused by one or more factors at any given time, the most common being imbalance, misalignment, wear and looseness. Misalignment /shaft runout – Vibration can result when machine shafts are out of line. Angular misalignment occurs when the axes of (for example) a motor and pump are not parallel.
What is motor vibration?
Vibration is simply a back and forth movement—or oscillation—of machines and components in motorized equipment. Vibration in industrial equipment can be a symptom, or cause, of a problem, or it can be associated with normal operation. As machine speed increases the effects of imbalance become greater.
What is high frequency vibration?
The noise and vibration behaviour of structures at higher frequencies has been a strong area of research activity of the Dynamics Group for many years. Applications typically concern noise and vibration transmission in land, marine and aerospace structures, buildings etc.
Where do you take a vibration reading on a motor?
You should take housing vibration measurements in three planes (vertical, horizontal, and axial) on both bearing housings, as shown in the Figure on the right. Take shaft vibration measurements in two directions (90° apart) on one drive end of the motor.