Timing Belt Research Articles

Analysis of transverse vibration in engine timing belt

Abstract The purpose of this study is to observe the generating mechanism and the reduction method of belt transverse vibration as a cause of timing belt noise. It is known that belt tension affects the transverse vibration. We have described the following two processes: First, the belt resonance frequency varies with the tension and the amplitude increases when the frequency equals the belt meshing frequency. Second, an excitation source exists in the belt tooth crest and bottom land, whose influence varies with the tension. Therefore, adjustment of pulley tooth height is confirmed to be effective for reducing the transverse vibration.

Analysis of Subharmonic Resonance in V-6 Engine(Identified in Timing Belt Dynamic Response).

We analyzed the timing belt tension fluctuation of a V-6 engine and found that nonlinear resonance, which is not present in in-line engines, existed. In the study of thin phenomenon, we analyzed, through simulation, exactly how the belt tension fluctuated. This resulted in computed reproduction of subharmonic resonance, a kind of nonlinear resonance. In this paper, the generation mechanism of subharmonic resonance due to the tension in a V-6 engine belt is simulated, the belt spring which causes the subharmonic resonance is analyzed, and some cases of nonlinear resonance are presented.

Analysis of Vibration of Timing Belt. Under a Moving Load.

Analytical results are presented for vibration of a wide timing belt under a moving load. The equation of motion is derived from Hamilton's principle, and approximate solutions to the basic equation are obtained using the Galerkin method. The steady-state responses are calculated using the harmonic balance method. Analytical results are presented which show the contributions of moving load position and moving load value to response curves. The response amplitude that varies with the width of timing belt. In the case of variable velocity, the response value shows very complicated behavior with pulley rotation. The response curves of vibration are greatly influenced by the moving load and the velocity.

自動車焼結部品の最近の進歩 タイミングベルトプーリーの高機能化事例について

The pulleys are used to be produced by powder metal due to cost performance and high productivity. Recently, the timing belt pulleys for automotive engine are required extra high functions which have sensor or light weight, and the complex shape pulleys are tend to increase. This report introduces the examples of the design and engineering of these pulleys as follows.1)The light weight pulleys with thin wall curtain shape rim are lighter than stamping pulleys.2)The cam shaft pulleys with sensing cam are manufactured as utilizing powder flow during compacting.3)The crank shaft pulleys with sensing cam at flange portion for miss fire detection have high accuracy of angle phase between key way and sensing cam.

Silicone foam molding method for sealing timing belt cover gasket

Silicone foam molding method for sealing timing belt cover gasket

Load distribution of timing belt drives transmitting variable torques

This paper is concerned with timing belt drives transmitting fluctuating torques. A method is presented for calculating the loads on belt and pulley teeth given the belt strand forces as a function of time. Belt material properties, a generally existing pitch difference as well as friction forces between belt groove and pulley top land are taken into account. It is found that, due to the friction hysteresis, the load distribution at a particular time is affected by the preceding loading states. Experimentally determined loads on a pulley tooth in a drive transmitting a reversed and repeated torque are compared with calculated ones.

Analysis of Nonlinear Oscillations of Timing Belt. 3rd Report. Wide Timing Belt.

Analytical results are presented for nonlinear vibrations of a wide timing belt with parametric excitation in tension and meshing impact forces. The equation of motion is developed from Hamilton's principle, and approximate solutions to the basic equation are obtained using the Galerkin method. The steady-state responses are calculated using the harmonic balance method. Analytical results are presented which show the contributions of pulley speed and tension to natural frequencies. The resonant amplitude varies with cross section y. In the case of variable tension, the resonant peak value varies with the rates of variable tension, and tension. Amplitude reduction by means of periodic variation of tension is effective for tension and rate of variable tension.

Low noise timing belt

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Low noise timing belt

Low noise timing belt

Analysis of Nonlinear Oscillations of Timing Belt. 2nd Report. Under Meshing Impact and Varying Tension by Eccentric Pully.

Analytical results are presented for nonlinear vibrations of a timing belt with parametric excitation in tension and meshing impact forces, with application of the Galerkin method to the basic equation. The steady-state responses are calculated using the harmonic balance method. The numerical results yielcl the following conclusions. The resonant amplitude increases with the increase of pully speed for constant tension. In the case of variable tension, the resonant peak value varies with rate of variable tension, and inceases with increase of tension. Amplitude reduction by means of periodic variation of tension is effective for tension and rate of variable tension.

A Study on Transmission Error in Timing Belt Drives (Effect of Production Error in Polychloroprene Rubber Belt)

Experiments on a transmission error caused by production errors in polychloroprene rubber timing belts were performed under a quasistatic condition and an initial tension. The experimental results were compared with the computed results obtained using the measurement results of the production error in the belt. It was confirmed that the transmission error, having a period of one revolution of the belt, was mainly caused by a single pitch error, a change in cross-sectional area of the load carrying cords and a change in modulus of elasticity for one revolution of the belt. As the experimental results coincided quite well with the computed ones, it was concluded that the measurement methods for the single pitch error and the belt elongation factor, and the arrangement methods of these values used to compute the transmission error were valid. Further, it was found that the transmission error due to the production error in the belt lessens when the initial tension becomes smaller.

歯付ベルトのパラメータ励振

Timing belts are usually used as standard apparatus for power transmission and the timing device in the diesel engines of ships, the OHC engines of cars and the machine tools. In such cases, it is well known that the timing belt is subjected to the fluctuation of tension which is caused by the eccentricity of the pulley shaft, engagement of the belt and the pulley, and the fluctuation of torque given to the pulley shaft. As a basic research on this problem, this paper describes the results of analytical and experimental investigations of the parametric resonance phenomena of the timing belt stretched vertically. As the first step, the author regarded the timing belt as a system with string and applied Mathieu's equation to the behavior of the timing belt which is subjected to periodic tension, and then compared the experimental results with approximate stability chart for Mathieu's equation. As a result, the experimental results agreed almost with approximate stability chart for Mathieu's equation. Namely, the vibration characteristics of timing belt showed remarkable features of the parametric excitations.

Analysis of Nonlinear Oscillations of the Timing Belt. 1st Report. Regions of Resonance of the Timing Belt.

The tension in timing belts is subject to periodic fluctuation. This is brought about by factors such as an eccentric pulley and error of one pitch of the pulley, etc. This paper presents the regions of resonance of a timing belt. The equation of an axially moving timing belt with tension of periodic variation is developed. For theoretical analysis, the perturbation method of multiple scales is used. A study is carried on the instability regions with subharmonic and summonic types of parametric resonance. The effects of various system parameters, such as the timing belt speed and the gyroscopic matrix, upon the instability regions have been studied.

Signal propagation timing check system in multilevel sequential circuits

AbstractThis paper presents the concept of the timing vector as well as the related techniques which are useful in checking the synchronization and the timing in the multistage sequential circuit. In each of the sequential circuits, the output period where the output is unstable and the sense period where the input must be stable are considered. The proposed method is based on the property that, if the output period of the preceding stage in the cascaded circuits overlaps with the sense period of the succeeding stage, the signal cannot be propagated properly. The existence/nonexistence of such an overlap is checked.First, the output period and the sense period of the sequential circuit are modeled in a form which does not depend on the frequency and the duty‐ratio of the clock given to the circuit. In the check process, this clock information is given to the circuit model. A timing belt is constructed where the output and sense periods of each circuit are developed on the real time‐axis, and it is checked whether or not an overlap exists in each circuit. The feature of the method is that the timing check of the cascaded sequential circuit can be executed completely with a high speed. Using the program constructed based on the proposed method, the sequential circuit actually is checked and the usefulness of the method is verified.

Nonlinear Vibrations of a Timing Belt with a Rotor Pulled by Magnetic Force.

Analytical results are presented for nonlinear vibrations of a timing belt with a rotor pulled by a magnetic force. With application of the Galerkin method to the basic equation, the ordinary differential equation in a multi-degree-of-freedom system is reduced. The steady-state responses are calculated using the harmonic balance method. The numerical results show the following conclusions. The resonance frequency in each mode of vibration decreases with the increment of the mass in the rotor. The amplitude of nonlinear response decreases with the increment of the cross section in the belt. The magnetic force acting on the belt changes the characteristics of nonlinear spring from the hardening type to the softening-hardening type. The magnetic force on the belt easily shifts the frequency away from the resonance frequency and facilitates supression of the resonance amplitude.

Continuous Position and Speed Sensor for Center Pivot Sprinkler Systems

AbstractDetermination of center pivot position and speed are frequently required for both research and commercial operations. To represent these variables accurately, a simple device that provides a continuous, high‐resolution representation of center pivot position and speed was constructed of readily available parts. A goal was to develop a device that was an improvement from previous designs. A timing belt was bonded to a center pivot riser, and as the riser turned, the belt meshed with a gear causing it to rotate a 360 ° potentiometer. The device described can be interfaced to a computer at a central location to record center pivot position and calculate rotational speed. Measured position had a coefficient of variation of 1.7% for five trials. The sensor can improve water and chemical management for both research and commercial center pivot irrigation.

Timing Belt Noise of Office Machines II

Timing Belt Noise of Office Machines II

Variable-Ratio Chain Drives With Noncircular Sprockets and Minimum Slack-Theory and Application

The theory has been developed for the design of a new mechanical component: variable-ratio chain drives with noncircular sprockets and minimum slack. The theory is based on a kinematic correspondence between noncircular chain drives and noncircular gears. This in turn permits the development of an algorithm for minimizing chain slack. The theory is applicable to a wide range of mechanical equipment, including bicycles and nonuniform motion transmissions involving band drives, tape drives, and timing belts. Such drives may or may not require a tensioner, but if they do, tensioner displacement will be minimal. Numerical examples illustrate applications to the design of an optimum bicycle configuration and a harmonic-motion generator.

A Study on Timing Belt Noise (How to Reduce Resonant Noise)

Tow methods of suppress the resonant noise of timing belts are proposed. One method is to vary the belt tension periodically by the use of an eccentric pulley and the other method is to vary the mass density of the belt. It was experimentally confirmed that the resonant noise of timing belts is reduced by about 10 dB by the use of each method.

A Study on Timing Belt Noise (Theoretical Analysis for Forced Transverse Vibration of Timing Belt With Parametric Excitation)

A theoretical analysis is made for two kinds of noise reduction methods of timing belts. The methods are confirmed experimentally in a companion paper [1]. Modeling the traveling belt as a string with parametric excitation in tension and density, we obtain an approximate solution for the amplitude of the transverse vibration and carry out some numerical computations for the response of the belt. It is shown that the maximum amplitude of the transverse vibration at resonance is reduced by the two kinds of parametric excitation. The method of variable tension suppresses the maximum amplitude almost for all modes of vibration at resonance and that of the variable density is effective for higher modes except the first mode at resonance.