Toothed gear

Example 1 What is the diametric pitch of a 40-tooth gear with a 5-inch pitch diameter ... 

R 18, modified] [C 2] An overview of the micro structured reactor plant used is given in Figure 4.45. Emerging from the front is a typical micro tooth gear pump, while on the left-hand side a falling-film micro structured reactor can be seen. 

In designing a molecular brake we envisioned the use of a triptycene as a three-toothed gear, and the brake being incorporated as a bipyridine attached to the triptycene through an axle. The brake would be activated by a change of conformation of the bipyridine unit (noncoplanar to coplanar) upon complexation of the bipyridine by a metal ion, thereby obstructing the rotation of the triptycene. Scheme 2 represents the concept in both general and specific terms. 

Gear Pumps When two or more impellers are used in a rotary-pump casing, the impellers will take the form of toothed-gear wheels as in Fig. 10-54, of helical gears, or of lobed cams. In each case, these impellers rotate with extremely small clearance between them and between the surfaces of the impellers and the casing. In Fig. 10-54, the two toothed impellers rotate as indicated by the arrows the suction connection is at the bottom. The pumped liquid flows into the... 

Injection Molding of a Plastic Toothed Gear Type and Position of Sprue. 339... 

Toothed gears for small and medium-sized watch motions and gears for automobiles and toys, in a few cases even for vehicle gears, are injection-molded or pressed out of thermoplastics and occasionally duroplastics as well. Dimensional accuracy is the key to production quality, and it must be sustained throughout the useful life of the part. 

In injection molding of semicrystalline thermoplastics, for example polyamide, polyoxymethylene, ultrahigh molecular polyethylene (very high melt viscosity), linear polyesters (PET, PBT), local variations in molecular orientation result in dimensional variations in the part (warpage, memory effect), especially if the toothed gear is exposed to a thermal stress load. 

Rotary positive displacement pumps. These have two or more impellers in the form of toothed gear wheels or lobed cams which rotate with an extremely small clearance between each other and the pump casing. They have to be primed and they produce a pulsed output. 

In 1994, Kelly et al. synthesized a molecule that could operate as a reversible molecular brake (Figure 83), " in which the wheel—represented as a three-toothed gear and constructed as a triptycene—spins rapidly at 30 °C in the absence of Hg + (or other metal ions), while after the addition of metal ions the rotation of the triptycene is blocked and the brake works. 

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