JPS6148018B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration balancing method for attenuating low-frequency mechanical vibrations emanating from a plurality of vibrating machines and propagating through the ground. The low-frequency vibrations emitted from vibrating machines such as large piston-type compressors,
The phase of the vibrations of two machines that generate vibrations of the same magnitude, frequency, direction, etc. is attempted to be balanced by using another compressor of the same type and performance that generates similar vibrations. The feature is that the rotation of one machine is electrically controlled so that the two machines are always in opposite phase.

Regarding the vibration balancing device, the applicant has previously proposed a vibrating machine that is installed near a vibrating machine and driven by a motor, a pick-up that detects the vibration of the vibrating machine, and this pick-up. Vibration balancing device (Patent Application No. 52-69419) (Patent Application No. 52-69419) (Patent Application No. 52-69419) (No. 5177, 1973).

The present invention aims to provide a vibration balancing method that can perform vibration damping using machines installed in factories, etc., without using a special device such as a vibrator.

For example, facilities that use large amounts of compressed air, such as steel mills and chemical plants, use a plurality of piston type compressors with equal performance. Such compressors with the same performance are often installed close to each other so that the magnitude and frequency of the vibrations they generate are the same. Therefore, if two compressors are installed with their rotational axes parallel to each other, and the vibrations generated by both compressors are set in opposite phases by 180 degrees out of phase, the vibrations caused by both compressors will cancel out.

The present invention provides a method for balancing the vibrations of a rotating machine by providing an electrical control means that always makes the phases of the vibrations generated by the rotating machine with two types of vibrations opposite to each other. The two rotating machines to be combined do not have to be exactly the same; as long as the magnitude, frequency, direction, etc. of vibrations are similar, control is possible, and vibrations can be damped even if the effectiveness is slightly reduced. I can do it.

Next, the present invention will be explained with reference to illustrated circuit diagrams.
The secondary side of the transformer 2 is connected in series to the controlled rotating machine 1 (general term for machines that produce vibrations, such as piston-type compressors, including the induction motor that drives them), and the primary side of the transformer 2 is One end of the side is switchably connected to a tap 2a branched to the primary side of the transformer 2 by a switching terminal 3a via a suitable load 3, and the switching terminal 3a is moved by a servo motor 4.

The phase difference between the vibrations caused by the two rotating machines 1 and 5 is electrically transmitted directly or in the vicinity of another rotating machine 5 that has vibrations of the same magnitude, frequency, propagation direction, etc. as the controlled rotating machine 1. A phase difference detector 6 is installed to detect the phase difference, and a signal voltage indicating whether the phase difference is positive or negative is sent from the phase difference detector 6 to an electronic controller 7 that amplifies this voltage. The servo motor 4 is driven to switch the primary side tap 2a of the transformer.

Since it is equipped in this way, rotating machines 1 and 5
The taps of the transformer are switched by the phase difference detector 6, the controller 7, and the servo motor 4 based on the phase difference of the vibrations, and the voltage between the primary and secondary sides of the transformer 2 is adjusted. is carried out, the rotational speed of the induction motor driving the rotating machine 1 changes, and therefore the rotational speed of the rotating machine 1 changes.
The phase of the vibration generated by the rotating machine 5 changes, and can be adjusted to be 180 degrees different from the phase of the vibration generated by the rotating machine 5. That is, the vibrations emitted from both machines 1 and 5 and transmitted through the ground have the same period but a phase shift of 180 degrees, and both vibrations can be canceled out. In this case, since the rotation axes of both rotating machines are parallel and installed close to each other, the vibrations from each rotating machine interact with each other at the same amplitude and frequency, and furthermore, the two vibrations are 180 degrees out of phase. Since both rotating machines are close to each other, there is no room for noise to intervene between the vibrations generated from both vibration sources, and the vibrations are canceled out well. As a result of experiments, the amount of this voltage adjustment is about 0.1%, and for example, assuming that the machine to be controlled is a 1000KW compressor, the power consumption for this adjustment is only 1KW. Moreover, transformer 2, servo motor 4, controller 7
The installation area of these parts is so small that it hardly becomes a problem, and the prices of these parts are also relatively low. As the mechanical phase detection means, a method of detecting mechanical vibration using a phase detector (trade name of Omron Corporation) attached to the rotating shaft of the machine or a piezoelectric element can be used.

According to the present invention, when two rotating machines that generate mechanical vibrations are installed, there is no need to install a special vibration exciter to cancel out the mechanical vibrations, and the two machines can be generated purely electrically. By mechanically controlling the rotation of one of the rotary machines, vibration and resonance can be prevented, which is highly effective in preventing pollution such as the vibration that causes the house to rumble.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing an embodiment of the present invention. 1: Rotating machine, 2: Transformer, 3: Load, 4: Servo motor, 5: Rotating machine, 6: Phase difference detector,
7: Electronic controller.

Claims (1)

[Claims] 1 In a method for balancing the mechanical vibrations generated by two rotating machines 1 and 5 that generate vibrations and include driving induction motors, which are installed close to each other with their rotating axes parallel to each other, one rotation The secondary side of a transformer 2 is connected to the drive induction motor of the machine 1, and one end of the primary side of the transformer 2 is switchably connected to a tap branched to the primary side through a load, and vibrations of both rotating machines are connected. a phase detector 6 that detects the phase difference between the two and converts it into an electrical output, and a transformer that is driven by this output via an electronic controller 7 and a servo motor 4 to switch the tap on the primary side and is connected to the one rotating machine 1. A vibration balancing method for a rotating machine, characterized in that the impedance on the secondary side of the rotating machine is converted to cause the rotating machine 1 to generate mechanical vibration of an opposite phase that cancels out the vibration generated by the other rotating machine 5.