C & B Machinery has been awarded an order by Allison Transmission to build a “Flexible” double disc grinding cell for its Chennai, India facility; Allison Transmission India Private Limited.
The grinding cell is designed to grind the faces of transmission pinion gears for Allison’s 1000 and 2000 series transmissions. Double disc grinders remove equal material from both faces simultaneously. This particular machine will be arranged to grind four various pinion configurations with the capability to grind 11 more already being produced at the plant (on grinders previously provided by C & B).
The machine employs a “rotary plunge” grinding cycle which means the pinions are introduced to the grinding wheels via a rotary carrier one at a time while the grinding wheels plunge grind simultaneously through axis interpolation. There are several advantages for grinding in this manner, with the most important one being that the grinding wheels are adjusted perfectly parallel and concentric to each other. (Conventional double disc grinding most often requires compound head settings.) Keeping the wheels parallel results in more uniform wheel wear and reduced frequency of dress cycles; ultimately saving in abrasive expenditures. Cost per piece is reduced and return on investment is quicker.
This grinding cycle, developed by C & B engineers also allows 100% gage feedback on every component ground. Size control is tightened resulting in higher statistical capability. For example the grinding cells previously shipped by C & B far exceeded 2.0 Ppk in OAL (± 0.030mm) and parallelism (0.026mm).
The entire grinding cell including the grinder, automation, gaging system, coolant system and even the production (bench) gages are provided and integrated by C & B Machinery.
“Flexibility is a very strong requirement for customers today. In parallel, it is now one of the main selling features of C & B Machinery’s grinding systems as well as our very company”. These special grinding cells are designed to change over from part to part in as little as three minutes. Considering that production double disc grinders have been historically dedicated machines, it is quite an about face.
“The most important aspect of this project is to convey on a global scale, that the American Machine Tool Industry is still alive and well. We have the talent base and the ingenuity to compete globally and produce and support some of the highest quality and most flexible grinding systems available anywhere in the world.”