From Gear Geometry and Applied Theory, Second Edtion


The involute gearing, first proposed by Euler, has found widespread application in the industry due to its many advantages: (i) the tools for generation of involute gears can be produced with high precision, (ii) it is easy to vary the tooth thickness and provide a nonstandard center distance just by changing tool settings for gear generation, (iii) nonstandard involute gears can be generated by using standardized tools applied for standard gears, and (iv) the change of gear center distance does not cause transmission errors.

The invention of Novikov Wildhaber gearing is very attractive in its theoretical aspect and has found application in some areas. However, this gearing is limited to application to helical gears and has not replaced the involute gearing. A new version of Novikov Wildhaber gears based on the latest developments is presented in Chapter 17 of this book.

Spur involute gears are in line contact at every instant, and therefore they are sensitive to the misalignment of gear axes. For this reason, it is necessary to localize their bearing contact, and this can be achieved by crowning the surface of one of the mating gears. It is preferable to crown the pinion tooth surface rather than the gear tooth surface because the number of pinion teeth is smaller than the number of gear teeth. The tooth profile of the spur gears is generated as an involute curve. The meshing of a crowned pinion tooth surface and a conventional involute gear tooth surface should be the subject...

Products & Services
Bevel and Miter Gears

Bevel gears are gears designed to transmit motion between intersecting axes. Perpendicular arrangements are most common, but bevel gears can be manufactured for nearly any angle. The teeth bearing surface of the gear, or surface pitch, is conically shaped or tapered. Miter gears are bevel gears manufactured in a 1:1 ratio, with the same number of teeth on mating gears and with perpendicular axes.

Spur Gears

Spur gears are the simplest type of gear. Transmitting power between parallel axes, the teeth project radially on the disc.

Hypoid Gears

A hypoid gear is a style of spiral bevel gear whose main variance is that the mating gears' axes do not intersect. The hypoid gear is offset from the gear center, allowing unique configurations and a large diameter shaft. The teeth on a hypoid gear are helical, and the pitch surface is best described as a hyperboloid. A hypoid gear can be considered a cross between a bevel gear and a worm drive.

Gear Manufacturing Services
Gear manufacturing services design and fabricate gears to customer specifications.
Metric Gears
Metric gears are defined by module, which designates the center-to-center distance between successive teeth. This criteria of gear selection is used in countries which have adopted the metric system and is intended to standardize gear selection.

Topics of Interest

11.1 INTRODUCTION A gear drive composed of external and internal gears is considered. Application of such a train enables us to reduce the loss of power caused by sliding of tooth profiles. This...

15.1 INTRODUCTION Involute gears, spur and helical ones, are widely used in reducers, planetary gear trains, transmissions, and many other industrial applications. The level of sophistication in the...

18.1 INTRODUCTION A conventional face-gear drive is formed by an involute spur pinion and a conjugated face-gear (Fig. 18.1.1). Such a gear drive may be applied for transformation of rotation between...

Overview Q3-1 With spur gears having twisted teeth (cycloidal), what is the form of the line of contact along the tooth surface? What is the form of pitch surface in spur gears, bevel gears, hypoid...

GEARS AND GEARING Geometry Factors For Gear Teeth Contact and Bending Stresses To calculate the contact and bending stresses acting between the teeth of a pair of gears meshing under load, it is...