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Therefore, it is necessary to establish a model of a multi-quality system to correctly reflect the actual situation of the system. In this paper, a set of gear transmission experimental devices with prime mover and working machine is taken as the research object, and the influences of the rotor of the motor, the couplings, the helical gear pair and the rotor of the generator (working machine) are considered. In order to facilitate the study of the influence of gear error on vibration and maintain dimensional consistency, the torsional vibration is transformed into line vibration on the gear meshing plane, and its dynamic model is shown.
The basic vibration gear body calculation model simplifies the shape of the gear, and replaces the gear with a disk equal to the gear index circle. In order to compare the influence of the gear body structure on the inherent modal characteristics, the gear structure is divided into general and special categories. There are two types: (1) simplifying the gear structure to a simple disc (a), called the basic structure; (2) using the actual working condition structure (b), with different parameters of the rim and web structure Various forms are called actual structures. The finite element models of both structures adopt inner ring fixed constraints.
The structure of the two gear bodies and the finite element model of the basic structure mode and the low-order basic mode, the calculation of the structure of the multi-order mode shows that the natural mode of the basic structure gear body can be summarized as follows: (1 ) Folding (DZ): includes first-order pair buckling (DZl) and second-order pair buckling (DZ2). The main performance is that the regular wave mode appears in the axial direction and the regular polygon shape on the end face. The combination is a structurally distorted pair of buckling. (2) Torsional vibration (NZ): There is substantially no vibration in the axial direction, and relative torsional vibration is applied to each end surface. (3) Umbrella (SZ): The axial vibration is an umbrella shape. (4) Radial vibration (JZ): including first-order radial vibration (JZl) and second-order radial vibration (JZ2). The main manifestation is that the vibration on the end face exhibits a polygonal vibration mode, and there is substantially no vibration in the axial direction.
In general, only a part of the vibration mode with a relatively low excitation frequency is concerned, and the participation factor of most high-order modes is negligible, and the first few modes of the basic gear body of six different structural parameters are given. The natural frequency and mode shape after the root is removed (R unit is mm, d=R/B).
It can be seen from Table l that when the tooth width and the tooth diameter are relatively large, that is, the wide helical gear, the first 10 modes after removing the heavy root generally have 7 types of modes, and a torsional vibration mode is added, which is narrow. Helical gears such as shifting gears only have six different modes: first-order pair buckling, second-order pair buckling, third-order pair buckling, umbrella-shaped vibration, circumferential vibration and first-order inner vibration. For convenience of explanation, the corresponding correspondence is drawn. The mode shape of the sixth-order mode of the third basic structure.
The basic vibration mode of the basic structure gear body is different due to the influence of different gear structure parameters on the natural frequencies corresponding to the various vibration modes. The order of the mode numbers corresponding to the above six vibration modes will change. : (1) When R/B is constant, as the gear body structure becomes larger (R becomes larger), the natural frequency of each step decreases; (2) When R is constant, the tooth width dimension B becomes larger, the circumferential vibration The natural frequency corresponding to the type is unchanged, and the natural frequencies corresponding to the other modes are enlarged.
Helical gear rotation and related analysis