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A Novel Concept to Design Perfect Noncircular Gears
Published in Stephen P. Radzevich, Theory of Gearing, 2018
In the current industry, gears for noncircular gear pairs are machined in compliance with the continuous generating method (molding generating method). The tooth flanks of a gear and mating pinion in this case are generated as envelopes to consecutive positions of cutting edges of the gear-cutting tool. Shown in Figure 19.4, the gear-shaping process perfectly fits the needs of machining of noncircular gears. This is illustrated in Figure 19.5, where the hobbing operation of a gear for a noncircular gear pair is depicted. A gear generator of a special design is used on the operation. Shown in Figure 19.6, noncircular gears of other designs (Figure 19.7) can also be hobbed by standard hobs.
Model-based design of tube pumps with ultra-low flow rate pulsation
Published in SICE Journal of Control, Measurement, and System Integration, 2022
Jinhui Yang, Kentaro Hirata, Yukinori Nakamura, Kunihisa Okano, Kenichi Katoh
We would like to reduce the flow rate pulsation mentioned above. First of all, one must note that any kind of feedback control using a flow metre is not preferable to preserve the contamination-free characteristic of the tube pump, cf. [12, 13]. This could be a partial reason that the rotation speed regulation (instead of the flow rate regulation) via repetitive control is focused in [8, 9]. Thus, to suppress the flow rate pulsation, various mechanisms have been proposed. The basic idea is to accelerate the pushing roller to compensate for the dip caused by the leaving roller. To this end, two rollers should be driven independently and hence, the driving mechanism must have 2 degrees of freedom. The work [14] is a direct implementation of this idea and the proposals in [10, 15] are its variant to achieve 2 DoF-like motions with only one motor using a cum or non-circular gear mechanism. In this section, we review this idea using our model.
A synthesis method for path generation of a planar five-bar mechanism based on dynamic self-adaptive atlas database
Published in Inverse Problems in Science and Engineering, 2020
Jianwei Sun, Na Xue, Wenrui Liu, Jinkui Chu
Compared with the linkage curve of a planar four-bar mechanism, a planar five-bar mechanism has a richer curve shape, which is more widely used in industrial and medical fields. In recent years, there have been some related studies on the dimensional synthesis of a planar five-bar mechanism. Based on the two-phase synthesis method and a combined discrete Fourier descriptor, the path synthesis and optimization of a five-bar gear mechanism were carried out in [22]. Al-Smadi et al. [23] conducted the gear five-bar path synthesis by using nonlinear optimization method. Mundo et al. [24] proposed to synthesize the path of a non-circular gear five-bar mechanism through inverse kinematics analysis. And the motion could be lowered by using the relationship between the two input angles. Next, the path synthesis of the linkage mechanism was completed by using genetic algorithm for optimization design. Through the curve envelopment theory, the connection mode of the five-bar slider crank was calculated, then, the path synthesis of the linkage mechanism was performed in [25]. Using the continuous method, Starns et al. [26] proposed a five-bar path synthesis method based on synthetic equation. Through a non-iterative algorithm, Balli et al. [27] based on a variable topology and by means of a complex method to synthesize the planar five-bar linkage curve with the predetermined time scale. With the help of sequential transformations, Nokleby et al. [28] used the finite difference method to optimize the sizes of the five-bar mechanism, then converted the sizes, and finally performed the periodic dimensional synthesis. However, most of the above researches on the planar five-bar path are integral period, and the arbitrary design interval path synthesis of the planar five-bar based on the numerical atlas method is rare. Due to the richness of the coupler curve shape of a planar five-bar mechanism, the application prospect is far-reaching. Therefore, based on the numerical atlas method, the open path synthesis of a planar five-bar mechanism becomes a focus.