Effects of Assembly Errors on Crossed Beveloid Gear Tooth Contact and Dynamic Response

2011 ◽  
Author(s):  
Caichao Zhu ◽  
Chaosheng Song ◽  
Teik C. Lim ◽  
Tao Peng
Keyword(s):  
Dynamic Response ◽  
Gear Tooth ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Axial Position ◽  
Tooth Surface ◽  
Tooth Contact ◽  
Rigid Body Dynamic ◽  
Position Errors ◽  
Shaft Angle

It is known that the tooth flank geometry, assembly errors and the operating conditions of a gear pair have significant influence on tooth contact, load distribution and dynamic response. However, the study of the effects of assembly errors on the mesh characteristics and dynamic response for crossed beveloid gears has been limited due to the complicated geometry and time-varying mesh characteristics. In this study, three types of assembly errors including shaft angle, offset and gear axial position error are examined based on a synthesized mesh model and a three-dimensional elastically coupled rigid-body dynamic model. Also, the relation between a dominant geometry design parameter that is the crossed angle between the first principal directions of the tooth surface curvatures (FPD-angle) and the sensitivity of mesh characteristics and dynamic response subject to assembly errors is investigated. Through the sensitivity analysis with different FPD-angles, the shaft angle error is found to be the most sensitive factor affecting the mesh and dynamic behaviors of crossed beveloid gear set. On the other hand, the gear axial position errors have the least influence on the mesh characteristics and dynamic response. In most cases, the influences of assembly errors on mesh characteristics and dynamics become weaker with the increase of FPD-angle.

Coupled Tooth Contact Analysis of Intersected Beveloid Gears for Marine Transmissions

2013 ◽  
Author(s):  
Caichao Zhu ◽  
Haixia Wang ◽  
Mingyong Liu ◽  
Xuesong Du ◽  
Chaosheng Song
Keyword(s):  
Gear Tooth ◽  
Contact Analysis ◽  
Tooth Surface ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Contact Patterns ◽  
Beveloid Gears ◽  
Shaft Angle ◽  
Loaded Tooth Contact Analysis ◽  
Mesh Condition

Beveloid gears are widely applied in fields like ships, automobiles and industrial precision transmissions. In this paper, the formulas of the beveloid gear tooth surface used in marine transmissions were derived and a mesh model for the intersected beveloid gear pair was setup. Then loaded tooth contact analysis was performed using the finite element method considering the coupling of the assembly errors and the elastic deformation of tooth surface. Through the analysis, the influences of assembly errors on contact patterns, mesh force and tooth surface deformations were investigated. In a further step, the tooth profile modifications were performed to alleviate the edge contact and a subsequent major improvement of the mesh condition was obtained. Finally, loaded tooth contact experiments for marine gearboxes with small shaft angle were conducted. The tested results showed good correlation with the computed results. This work may provide some value for the practical design aiming at improved contact characteristics of the beveloid gears with intersected axes.

Development of a Diagnosis Method of a Gear Tooth Surface by Predicting Laser Beam Reflection

2013 ◽  
Author(s):  
Eiichirou Tanaka ◽  
Yuta Kojima ◽  
Hiroki Yoshimi ◽  
Kazunari Okabe ◽  
Hitoshi Takebe ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Laser Beam ◽  
Normal Condition ◽  
Gear Tooth ◽  
Three Dimensional ◽  
Measured Data ◽  
Basic Data ◽  
Tooth Surface ◽  
Laser Sensor ◽  
Diagnosis Method

We developed a new diagnostic method by using a laser beam. This method is as follows: A tooth surface is irradiated by the zonal laser beam from an oblique direction, and then the irradiated laser beam line is shifted along the surface of the tooth according to gear rotation. If the damage on the irradiated tooth surface exists, the voltage proportional to laser reflection increases. We developed the method to predict and make the reflection benchmark on the normal condition according to the gear surface. To make the benchmark of the diagnosis, the three dimensional basic-data map (x: irradiated angle, y: irradiated distance, z: reflection intensity) was created by measuring the gear only whose material, heat treatment, and roughness were same as the targeted gear. By using the equations of tooth profile and fillet curves calculated from the specifications of the targeted gear, the distance and angle relations between the laser sensor and the tooth surface can be derived. By using the three dimensional basic-data map, the benchmark can be created. The measured reflection data of the non-damage gear agreed well with the benchmark, therefore we can diagnose the various specification gears, if the targeted gear’s material, heat treatment, and roughness are same. Finally, by using the benchmark which was made by our developed method, we proposed a novel diagnosis method. The procedure of the method is as follows: 1) The benchmark is made from the targeted gear’s specifications. 2) To take into account the fluctuation of the benchmark line influenced by the roughness on the gear surface, normal condition area of the reflected data is defined in the range between −0.05 V and +0.05 V of the benchmark line. 3) The normal condition area and measured data is compared, if the measured data is deviated from the normal condition area, there is defined as the abnormal area possible to be damaged. To confirm the validity of this diagnosis method, the measured value of the damage area with caliper directly and calculated value from the method as mentioned above. The errors of the area and the location were within 20 %. Therefore, the effectiveness of the method using the benchmark data can be confirmed.

scholarly journals Meshing characteristics of a sphere–face gear pair with variable shaft angle

2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985951 ◽  
Author(s):  
Lei Liu ◽  
Jinzhao Zhang
Keyword(s):  
Gear Tooth ◽  
Transmission Error ◽  
Tooth Surface ◽  
Gear Pair ◽  
Face Gear ◽  
Tooth Contact Analysis ◽  
Contact Points ◽  
Shaft Angle ◽  
Meshing Characteristics ◽  
Curvature Interference

This article presents a sphere–face gear pair by substituting the convex spherical gear for the pinion of a conventional face gear pair. The sphere–face gear pair not only maintains the advantages of the face gear pair with a longitudinally modified pinion but also allows variable shaft angles or large axial misalignments. Meshing characteristics of the proposed gear pair are studied in this article. The mathematical models of the sphere–face gear pair are derived based on machining principles. The tooth contact analysis (TCA) and curvature interference check are conducted for the sphere–face gear pair with variable shaft angles. The loaded TCA is also implemented utilizing the finite element method. The results of numerical examples show that proposed gear pair has the following features. Geometrical transmission error of constant shaft angle or varying shaft angle is zero; contact points of the sphere–face gear set with variable shaft angle are located near the centre region of face gear tooth surface; there is no curvature interference in meshing; and transmission continuity of the gear pair can be guaranteed in meshing.

Effect of Gear Tooth Crack on Spur Gear Dynamic Response by Simulation

2011 ◽  
Author(s):  
Yimin Shao ◽  
Xi Wang ◽  
Zaigang Chen ◽  
Teik C. Lim
Keyword(s):  
Dynamic Response ◽  
Gear Tooth ◽  
Sudden Change ◽  
Element Model ◽  
Spur Gear ◽  
Operating Conditions ◽  
Lumped Parameter Model ◽  
Mesh Stiffness ◽  
Heavy Load ◽  
High Rotational Speed

Geared transmission systems are widely applied to transmit power, torque and high rotational speed, and as well as change the direction of rotational motion. Their performances and efficiencies depend greatly on the integrity of the gear structure. Hence, health monitoring and fault detection in geared systems have gained much attention. Often, as a result of inappropriate operating conditions, application of heavy load beyond the designed capacity or end of fatigue life, gear faults frequently occur in practice. When fault happens, gear meshing characteristics, including mesh stiffness that is one of the important dynamic parameters, can be affected. This sudden change in mesh stiffness can induce shock vibration as the faulty gear tooth passes through the engagement zone. In this study, a finite element model representing the crack at the tooth root of a spur gear is developed. The theory is applied to investigate the effect of different crack sizes and the corresponding change in mesh stiffness. In addition, a lumped parameter model is formulated to examine the effect of tooth fault on gear dynamic response.

Stress Analysis of Spherical Gear Sets

2009 ◽  
Author(s):  
Li-Chi Chao ◽  
Chung-Biau Tsay
Keyword(s):  
Gear Tooth ◽  
Three Dimensional ◽  
Contact Analysis ◽  
Design Parameters ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Contact Points ◽  
Tooth Surfaces ◽  
Loaded Tooth Contact Analysis ◽  
Spherical Gear

The spherical gear is a new type of gear proposed by Mitome et al. [1]. Different from that of the conventional spur or helical gear sets, the spherical gear set can allow variable shaft angles and large axial misalignments without gear interference during the gear drive meshing [1, 2]. Geometrically, the spherical gear has two types of gear tooth profiles, the concave tooth and convex tooth. In practical transmission applications, the contact situation of a spherical gear set is very complex. To obtain a more realistic simulation result, the loaded tooth contact analysis (LTCA) has been performed by employing the finite element method (FEM). According to the derived mathematical model of spherical gear tooth surfaces, an automatic meshes generation program for three-dimensional spherical gears has been developed. Beside, tooth contact analysis (TCA) of spherical gears has been performed to simulate the contact points of the spherical gear set. Furthermore, the contact stress contours of spherical gear tooth surfaces and bending stress of tooth roots have been investigated by giving the design parameters, material properties, loadings and boundary conditions of spherical gears.

Quality Control Method Based on Gear Tooth Contact Evaluation Using Near-Infrared Ray Imagery

2010 ◽  
Vol 447-448 ◽  
pp. 569-573
Author(s):  
Masaki Nagata ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Takahiro Iida ◽  
Yasuhiro Uenishi ◽  
...  
Keyword(s):  
Contact Area ◽  
Near Infrared ◽  
Control Method ◽  
Gear Tooth ◽  
Scattered Light ◽  
Infrared Image ◽  
Tooth Surface ◽  
Image Method ◽  
Tooth Contact ◽  
Gear Manufacturing

Conventionally, tooth contact evaluation has been performed visually by machine operators in gear manufacturing fields when finishing a gear or during assembly. With automation, the contact area’s boundary is unclear due to scattered light when visible light is used to obtain an image for tooth contact evaluation. We therefore focused on using near-infrared to prevent scattered light. First, we confirmed that the tooth contact image obtained by image binarization is hardly affected by the image threshold. Second, we propose a new method to extract the boundary part of the tooth contact by differential calculation of the fine near-infrared image. These methods allow automatic division of near-infrared images into the contact area, the boundary, and the non-contact area. Finally, the obtained result is compared with the tooth contact calculated from the measured tooth surface. We demonstrated that the near-infrared image method is effective for automatic tooth contact evaluation.

Numerical Simulation of Gear Shaping for Planetary Gear Based on the MASTA Software

2013 ◽  
Vol 404 ◽  
pp. 307-311
Author(s):  
Lai Hua Yi
Keyword(s):  
Gear Tooth ◽  
Three Dimensional ◽  
Planetary Gear ◽  
Tooth Surface ◽  
Shaping Process ◽  
Single Tooth ◽  
Simulation Results ◽  
Pitch Deviation ◽  
The Right ◽  
Gear Shaping

In this paper, the gear shaping of some planetary gear was simulated. The simulation results show that via the gear shaping process, the gear tooth surface on the left has a single tooth pitch deviation of about 1.2 um, and the gear tooth surface on the right has a pitch deviation of 1.1 um, accordingly. By combining the simulation of two-dimensional and three-dimensional gear shaping models, this paper can not only realize accurately the gear shaping process of the planetary gear, but also provide some certain reference for the gear shaping processing.

Research on Curvature of Tooth Flank of Gleason Spiral Bevel Gears

2011 ◽  
Vol 189-193 ◽  
pp. 4256-4260
Author(s):  
Ai Mei Zhang ◽  
Lin Yan Li ◽  
Da Wei Li
Keyword(s):  
Mean Curvature ◽  
Gear Tooth ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Bevel Gear ◽  
Machining Process ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Tooth Surfaces ◽  
Spiral Bevel

According to spiral bevel gear machining process, use the method of computer simulation to get the discrete points’ three-dimensional coordinates of Gleason spiral bevel gear tooth surface, and then solve the tooth surfaces’ NURBS surface as the unified mathematical model. On this basis, research the curvature of tooth surfaces of various types of Gleason spiral bevel gear, draw the mean curvature diagram, and study the link between the adjustment of processing parameters and the change of tooth surfaces’ mean curvature. Establish a theoretical foundation for the processing error adjustment based on tooth surface’s curvature diagram.

Parametric Analysis of Gear Mesh and Dynamic Response of Loaded Helical Beveloid Transmission With Small Shaft Angle

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Chaosheng Song ◽  
Caichao Zhu ◽  
Teik C. Lim ◽  
Tao Peng
Keyword(s):  
Dynamic Response ◽  
Transmission Error ◽  
Load Level ◽  
Tooth Surface ◽  
Coupling Mechanism ◽  
Gear Mesh ◽  
Geometry Design ◽  
Torque Load ◽  
Shaft Angle ◽  
Mesh Characteristic

A synthesized gear mesh and dynamic model assuming line contact that is derived from a set of manufacturing parameters is formulated for analyzing the beveloid gear mesh-coupling mechanism. Using the proposed model, the effect of the dominant geometry design parameter that is the crossed angle between the first principal directions of the tooth surface curvatures (FPD-angle) on gear mesh characteristic and dynamic response is investigated. Also, the analysis of the gear mesh characteristic and dynamic response subject to torque load variation is performed. It is shown that the dynamic transmission error and dynamic mesh force worsen as the geometry FPD-angle increases for a specific torque load level. Furthermore, even though higher torque load can produce larger contact area, which is desirable, it also increases the gear mesh stiffness and transmission error that tend to aggravate dynamic response.

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