Powder Metal Carriers
Powdered metal is an ideal method for manufacturing strong, lightweight planetary gear carriers capable of meeting the demands placed on modern transmissions. Using the conventional PM process, we produce the carrier as two separate pieces then employ sinter brazing to create a metallurgical bond that is higher in strength than the base material of the two components themselves. A carrier made from powdered metal requires minimal machining as a finishing step, eliminating the cost and inefficiency associated with the extensive machining often required with other metal forming processes such as casting and forging. The result is a robust, cost-effective component that is successfully powering many vehicles on the road today.
Secondary operations include machining/drilling, tumbling (for burr removal), laser etching, and—if desired—complete assembly, including insertion of the pinion gears, pinion shafts, washers, and other components as necessary.
As a full-service powdered metal supplier, Keystone provides in-house assembly for planetary carriers. We perform machining, assembly, and testing for our carriers entirely onsite.
For the carrier assembly shown, our customer came to us with an original design that contained only one powdered metal part. This design required sourcing of the components from many different suppliers and presented a very challenging assembly process. We suggested a number of ways to improve upon this design and at the same time lower the total cost:
- Keystone would use the powdered metal process to manufacture seven of the components, including the carrier, the helical pinion gears, and the pump gear.
- For parts such as the steel shaft that are not ideal candidates for powdered metal, Keystone would manage the sourcing of all purchased components.
- With responsibility for all components, Keystone would assemble and test the carrier system in-house.
In addition to providing the customer complete manufacturing services and quality control through a single supplier relationship, our carrier assembly represented a 30% cost savings from the original design.