Dynamic balancing apparatus and method using simple harmonic angular motion

• US 8,171,789 B2
• Filed: 03/24/2009
• Issued: 05/08/2012
• Est. Priority Date: 03/25/2008
• Status: Expired due to Fees

• Current Assignee: Korea Research Institute of Standards and Science
• Original Assignee: Korea Research Institute of Standards and Science
• Inventors: Cheung, Wan Sup, Lim, Jong Yeon, Yoon, Sae Won
• Primary Examiner(s): Kwok, Helen C.
• Application Number:
  US12/382,773
• Publication Number:
  US 20090255334A1
• Time in Patent Office: 1,141 Days
• Field of Search: 734/62, 734/60, 734/68, 731/46
• US Class Current: 73/462
• CPC Class Codes: G01M 1/24 Performing balancing on elastic shafts, e.g. for crankshafts

Abstract

Provided is a dynamic balancing apparatus using a simple harmonic angular motion, including a rotational shaft on which a rotational body having an unbalanced mass is installed; a simple angular motion generator for periodically vibrating the rotational shaft; a support for supporting both sides of the rotational shaft; an angular vibration measuring sensor for measuring the simple harmonic angular motion of the rotational shaft; and force or vibration transducers for measuring applied force acting on or vibration transferred to the support by means of the simple harmonic motion of the unbalance mass.

Claims

1. A dynamic balancing method using a simple harmonic angular motion using a dynamic balancing apparatus using a simple harmonic angular motion comprising a rotational shaft on which a rotational body having an unbalanced mass is installed;

a simple harmonic angular vibration generator which periodically excites the unbalanced mass;

a support for supporting both sides of the rotational shaft;

transducers which are installed on the support for measuring applied force or vibration generated by the simple harmonic angular vibration generator; and

an angular vibration measuring sensor for measuring an amplitude generated by the simple harmonic angular motion of the rotational shaft, the method comprising;

periodically vibrating a rotational body so as to measure tangential and centrifugal forces generated by the rotating unbalanced mass of the rotational body;

measuring linear vibration generated by the tangential and centrifugal forces, or the tangential and centrifugal forces generated by the rotating unbalanced mass of the rotational body acting on the support which supports the rotational shaft having the simple harmonic angular motion;

estimating multiple Fourier coefficients of the measured tangential and the centrifugal forces; and

estimating an angle and magnitude of the unbalanced mass of the rotational body by using multiple Fourier coefficients of the measured tangential and centrifugal forces generated by the simple harmonic angular vibration generator,

wherein using the horizontal and/or vertical forces acting on the support is determined by the following equations

2. The dynamic balancing method of claim 1, wherein the angular position and magnitude of the rotating unbalanced mass of the rotational body are determined from multiple Fourier coefficients of the tangential and centrifugal forces generated by the rotating unbalanced mass of the rotational body, and the multiple Fourier coefficients are calculated by the following equations:

3. The dynamic balancing method of claim 2, wherein the angular position and unbalanced amount (m·

r) of the unbalanced mass of the rotational body are determined by the following equation using multiple Fourier cosine and sine components of both horizontal and vertical forces measured from the horizontal and vertical directions of the support;

4. The dynamic balancing method of claim 2, wherein the angular position and unbalanced amount of the unbalanced mass of the rotational body are determined by the following equation using multiple Fourier cosine and sine components of the horizontal force measured from the horizontal direction of the support,

5. The dynamic balancing method of claim 2, wherein the angular position and unbalanced amount of the unbalanced mass of the rotational body are determined by the following equation using multiple Fourier cosine and sine components of the vertical force measured from the vertical direction of the support,

6. The dynamic balancing method of claim 1, wherein it exploits horizontal and/or vertical vibration signals that linearly depend on the horizontal and/or vertical components of the tangential and centrifugal forces acting on the support when the unbalanced mass of the rotational body is running, whose outputs of vibration measurement sensors are characterized by the following equation: