Meets High Torque & Temperature Requirements, Saves Assembly Costs

Pragati Automation, India manufactures Machine Tool accessories. They assembled torque motors for Bio-Directional Tool Turret, where very high torques are induced. During the assembly, the Rotor was heat shrink fit on to the shaft and Stator was heat shrink to housing with high interference. These motors develop temperatures of 120 deg C continuous. Shrink fit of assemblies involves – heating costs and time, additional labor and still lower reliability and customer wanted to improve on these.

Eliminates Need for Expensive Machining

A leading manufacturer of industrial cleaning equipment in India developed a new model of portable cleaning machines. The drive bearing needed to be mounted in the cast iron gear housing. As the Gear housing is cast, it is very difficult to maintain the tolerances. Machining the bearing seat area involved high machining cost and time. The unmachined seat area had gaps to 0.2mm.

Strengthens Assembly, Prevents Moisture Ingress

Train bogie wheels are assembled utilising a heavy interference fit of 0.001” per inch of axle diameter, (typically 0.009” for a 9” diameter shaft). In addition, press-on tonnage of between 65-110 tonnes must be achieved and documented to ensure optimal assembly strength.
This can be an extremely difficult task, and the consequences of poor assembly can be expensive or even catastrophic. Therefore if metal pick-up occurs during assembly, the components will be scrapped, and if the tonnage is not achieved within specification, the wheel and axle must be separated and re-matched.

Eliminates Need for Expensive Machining or Brazing

A leading tool manufacturer in Australia was launching new model of pliers for electronic components. Customer considered press fits or brazing the pliers hands to the jaw. They found that all these methods were undesirable. Press fit involved expensive machining to maintain very tight tolerances. Brazing needed expensive brazing machines, was very much dependant of operator skills and was expensive too.

Replaces Expensive Shrink Fit, Reduces Assembly Time and Costs

Interference fit methods of press fit or shrink fit are commonly used for joining cylindrical parts. The bonding is provided by the friction between mating surfaces. In shrink fit mating parts have a high degree of interference and fit together either by heating or cooling the components. Shrink fit needs requires heating equipment and creates bottleneck in mass production. Further there are risks that during the assembly elastic limits of parts might be exceeded or parts may be deformed.