Practical methods to control gear whine in transmission manufacturing process
Gear whine of automotive transmissions should be controlled since it is of a nuisance. While many methods are used to control gear whine at gear design stage, this paper deals with it in transmission manufacturing process including gear manufacturing and transmission assemblies. There are high percentages of effects on transmission error and gear whine in these two processes. Idle gear whine noise can be reduced by the introduction of hard finishing which can optimize the gear shapes and surfaces. Bending of helical gear is found playing an important role in generating high frequency gear whine. It is significant for transmission assemblies to study the correlations of End of Line (EOL) and vehicles. The satisfying correlations can identify and control gear whine of an assembled transmission. All the methods mentioned above have been applied in transmission manufacturing process and good results have been achieved.
Dynamic Loads on the Teeth of Spur Gears
In a theoretical analysis of a single pair of high-class gears three internal sources of vibration are considered:(1)Periodic variations in the velocity ratio due either to running the gears above or below the designed load, or to small manufacturing errors.(2)Period variation in the tooth stiffness.(3)Non-linearity in tooth stiffness.The amplitudes of vibrations caused by (1) depend on damping, while those caused by (2) or (3) will only occur if the damping is below a limit estimated at 0.07 of critical damping. Damping currently reported for tests on steel gears is about 0.1 of critical, but might well be less.Dynamic tooth forces and amplitudes of vibration were found from photo-elastic stress patterns of model gears with both small and large errors. The more accurate gears showed only vibration caused by (1), variation in the velocity ratio, because the damping was too great for the other modes.Information on damping is insufficient for satisfactory prediction of dynamic increments. If the damping in ...
On the Graphical Solution of Transient Vibration Problems
Phase-plane methods have been used with great success in the theory of non-linear mechanics. They have also been applied to a different class of problems; viz. to dynamical systems with transient loading. The paper concerns this second use of the plane and some recent extensions of it.A survey is made of the literature covering the twenty years since these constructions were introduced. This relates to: (1) the transient disturbance of single-degree-of-freedom systems (which may include damping, non-linearity, hysteresis, etc.) and of multi-degree-of-freedom systems; (2) the deflexions of beam columns in the theory of elastic stability; and (3) Jacobsen's general method of graphical integration.Some new additions to the theory are given. These are: (1) a method of graphical differentiation; (2) a simplified approach to multi-degree-of-freedom systems leading to the treatment of transient loading of beams by moving and moving-and-varying loads (damping may be contemplated in these beam problems and the met...