Tooth Profile Errors Of Gears Research Articles

The Effects of the Planet–Gear Manufacturing Eccentric Errors on the Dynamic Properties for Herringbone Planetary Gears

In the presence of manufacturing errors, the dynamic properties of herringbone planetary gear train (HPGT) can be altered from the originally designed properties to have undesired behavior. In this paper, by considering the herringbone gear actual structure characteristics, manufacturing eccentric errors of members (i.e., carrier and gears) and tooth profile errors of gears, time-varying meshing stiffness, bearing deformation, and gyroscopic effect, a novel lateral–torsional–axial coupling dynamic model for the herringbone planetary gear system is formulated by using the lumped-parameter method, which is able to be employed in the dynamic feature analysis of the HPGT with an arbitrary number of planets and different types of manufacturing errors. By applying the variable-step Runge–Kutta algorithm, the dynamic response of a HPGT system is studied for cases with and without planet–gear eccentric error excitations. The dynamic contact forces of gears and bearings are analyzed for the two cases in time and frequency domains, respectively. Moreover, the effect of the planet–gear eccentricity on the vibration accelerations of the HPGT system is also discussed. The obtained results indicate that manufacturing error excitations such as the planet–gear eccentricity have a pronounced influence on the dynamic behavior of the HPGT system.

Error Detection and Classification of Tangential Radial Single Machining of Non-Circular Gear

The studies on non-circular gear cutting and using errors were generally based on theory of cylindrical gear errors, and the similarities and differences between cylindrical gear and non-circular gear were combined to study the change rule of non-circular gear contacting line and obtained corresponding conclusions. In this paper, from a different perspective, by starting from the non-circular gear engagement principle, on the basis of analyzing the concrete geometric error conditions, new type tooth profile algorithm routine is reasonably modified, and needed non-circular gear tooth profile error contrast figure is obtained. Furthermore, theoretical derivation is carried out by incorporating analytical method and contacting line incremental method, validity of computer simulation is verified, a reasonable classification method is proposed based on the characterization of the error characteristic code in the general case, Summed up the error genetic map which possess enormous significance to direct practice generation[1].

Analogue simulation and analysis of non-circular gear reentry error

The studies on non-circular gear cutting and using errors were generally based on theory of cylindrical gear errors, and the similarities and differences between cylindrical gear and non-circular gear were combined to study the change rule of non-circular gear contacting line and obtained corresponding conclusions. In this paper, from a different perspective, by starting from the non-circular gear engagement principle, on the basis of analyzing the concrete geometric error conditions, new type tooth profile algorithm routine is reasonably modified, and needed non-circular gear tooth profile error contrast figure is obtained. Furthermore, theoretical derivation is carried out by incorporating analytical method and contacting line incremental method, validity of computer simulation is verified, and the characterization of the tangential error characteristic code is obtained, Summed up the error sources for error genetic which possess enormous significance to direct practice generation.

Research on the theoretical tooth profile errors of gears machined by skiving

This study focuses on the theoretical tooth profile errors of gears machined by conventional skiving. The influences of skiving cutter rake angle on tooth profile errors of gears are analyzed. It is found that the inherent error of skiving cutter and the longitudinal deviation of cutting edge contributed to the gear profile errors. The influences of skiving cutter resharpening are then analyzed, and it is found that the resharpening amount of skiving cutter has obvious influence on the tooth profile error of workpiece. Therefore, conventional skiving tools are defective in high accuracy gear machining.

Joint dynamic analysis of space manipulator with planetary gear train transmission

SUMMARYJoints of space manipulators are usually simplified as torsional springs in modeling motion equations, and the nonlinear behaviors of the reducer in the joints are generally neglected. In this study, a dynamic model of a space manipulator that considers the joints that are transmitted through a typical 2K-H planetary gear reducer is developed using the Lagrangian method. The backlash clearances, gear tooth profile error, and time-variant meshing stiffness are integrated into the process. The simulation results show that the backlash clearances lead to the accumulation of positioning errors in the space manipulator when the joints rotate back and forth. The tooth profile error is the main cause of severe acceleration fluctuations and meshing force impacts. These fluctuations influence torque instability, which may accelerate gear system failure.

Research on Mapping Rules of Hob Geometric Errors and Gear Geometric Precision

High precision gear is an necessary support of high-end equipment to meet the requirements of high-speed, heavy-duty,impact, low noise(mute) and other extreme environments. In order to improve the accuracy of hobbing manufacture, to partly achieve"replacing grinding with rolling", and to reduce processing costs, focusing on the insufficient quantitative mapping rules between hob geometry errors and gear geometric error, the quantitative mapping rule research between gear hob tooth profile error, helix error, gear hob installation angle of the radial runout error and the gear tooth profile error, base pitch error with the consideration of machine tool movement error are carried out respectively. Utilizing the counterpart rack law, the gear tooth profile equation enveloping from involute curve hob tooth profile equation is generated, quantitative mapping relational model of hob pitch error and pitch deviation based on differential geometry and envelope principle is builded. At the same time quantitative mapping relational model between hob helix error,radial runout error of hob installation angle and the gear tooth profile error are established respectively. According to the geometric relations between gear tooth profile error and gear base pitch error, the mapping rule of base pitch error is calculated based on the factors mentioned above. A joint equation model between the above three main errors of gear hob and the tooth profile error based on Gaussian distribution with the consideration of machine tool movement error are builded. At last the correctness of the above model by comparing the result of model simulation method with empirical data is verified, so the essential mapping rules of hob error and the main factors which affect tooth geometric precision such as tooth profile error, base pitch error with the consideration of machine tool movement error are revealed, thus a theoretical foundation for roll cutting gear with higher precision is layed.

Modified-Roll Profile Correction for a Gear Shaping Cutter Made by the Lengthwise-Reciprocating Grinding Process

The tooth profile error of a gear shaping cutter made by the lengthwise-reciprocating grinding process (LRGP) is usually corrected by modifying the grinding wheel profile. However, such grinding wheel modification cannot eliminate the twisting profile error along the face of the shaping cutter. A kinematic modified roll motion for generating a shaping cutter is proposed to minimize such twisted profile errors even after cutter resharpening. The tooth profile errors of the work gears generated by the shaping cutter with various resharpening depths are represented as a novel topographic error map. Based on the error map and its sensitivity matrix, the roll ratio between the shaping cutter and the grinding wheel stroke is modified to reduce the twisted profile error as illustrated by the numerical examples. Combining this modified roll motion modification and the grinding wheel profile correction, the high accuracy resharpening depth of the LRGP helical shaping cutter is increased.

Improvement of gear accuracy in hobbing. (4th Report, An improvement of the tooth profile error of a hobbed gear by adjusting the hob eccentricity).

Recent studies showed that the tooth profile errors of hobbed gears were mainly caused by the geometrical error and eccentricity error and eccentricity of the hob under good cutting conditions. Because manufacturing a highly accurate hob is very difficult and maybe a highly accurate gear is not obtained even though a highly accurate hob is used, it is very important to investigate how to improve the actual meshing accuracy of the hob in the cutting process. In general, the meshing error of the edges caused by the hob eccentricity is nearly sinusoidal and also the geometrical errors often contain sinusoidal components. On the basis of these facts, this report proposes a method which makes both of the sinusoidal error components cancel each other out in order to obtain an accurately hobbed gear. The test results clearly show its usefulness to improve the tooth profile errors of the gears.

Improvement of gear accuracy in gear hobbing. 3rd report. Relation between the geometrical and setting errors of hob and the tooth profile errors of gear.

Recently, smooth tooth surfaces have been obtained by hobbing with accurate finish hobs, resulting in the production of as-hobbed gears for practical use. However, further improvement of the gear accuracy in gear hobbing is needed in order to obtain high load-carrying capacity. In this study, the relation between the hob accuracy and the hobbed gear accuracy is investigated by calculating the tooth profile errors of gears caused by the various hob errors. From the analytical comparison of both hob and gear accuracy, the following are summarized. (1) The tooth profile of hobbed gears are not always highly accurate, even if they are hobbed with a highly accurate hob. (2) For the improvement of the gear accuracy, it is necessary not only to reduce the tooth profile error of hob, the lead variation of hob and the eccentricity in hob setting, but also to consider the hob error patterns.