Rotary gear honing is a hard gear finishing process that was developed to improve the sound characteristics of
hardened gears by: Removing nicks and burrs; improving surface finish; and making minor corrections in tooth irregularities caused by heat-treat distortion.
In the gearing industry, gears are lubricated and cooled by various methods. At low to moderate speeds and loads, gears may be partly submerged in the lubricant which provides lubrication and cooling by splash lubrication. With splash lubrication, power loss increases considerably with speed. This is partially because of churning losses. It is shown that gear scoring and surface pitting can occur when the gear teeth are not adequately lubricated and cooled.
The search for greater gear life involves improvement in cost, weight and increased power output. There are many events that affect gear life, and this paper addresses those relating to fatigue, gear tooth pitting, fatigue strength losses due to the heat treating processes and shot peening technique. The capability of shot peening to increase fatigue strength and surface fatigue life eliminate machine marks which cause stress risers, and to aid in lubrication when properly controlled, suggests increased use and acceptance of the process.
October 5-8, 1986 AGMA Fall technical Conference & Gearing Exhibit
September 17-19, 1986 Ohio State University Gear Noise Seminar
November 11-13, 1986 SME Gear Processing and Manufacturing Clinic
November 19-21, 1986 Seminar: Gear System Design for Minimum Noise
Anyone involved in the design, manufacture and use of gears is concerned with three general characteristics relative to their application: noise, accuracy, and strength or surface durability. In the article, we will be dealing with probably the most aggravating of the group, gear noise.
The manufacturing process to produce a gear essentially consist of: material selection, blank preshaping, tooth shaping, heat treatment, and final shaping. Only by carefully integrating of the various operations into a complete manufacturing system can an optimum gear be obtained. The final application of the gear will determine what strength characteristics will be required which subsequently determine the material and heat treatments.
Gear surface fatigue endurance tests
were conducted on two groups of 10
gears each of carburized and hardened
AlSI 9310 spur gears manufactured from
the same heat of material
Advancements in machining and assembly techniques of thermoplastic gearing along with new design data has lead to increased useage of polymeric materials. information on state of the art methods in fabrication of plastic gearing is presented and the importance
of a proper backlash allowance at installation is discussed. Under controlled conditions, cast nylon gears show 8-14 dBA. lower noise level than three other gear materials tested.
The use of plastic gearing is increasing steadily in new products.
This is due in part to the availability of recent design data. Fatigue
stress of plastic gears as a function of diametral pitch, pressure angle,
pitch line velocity, lubrication and life cycles are described based
on test information. Design procedures for plastic gears are presented.