Truck Axle Bearing and Bushing Presses Assembly

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Challenge:

A Tier 1 automotive supplier was experiencing performance issues with premature failure and high maintenance with their existing Electro-Mechanical – Roller Screw type actuators used in an axle damper / wheel bearing press. The repeated load cycle was causing accelerated wear of the roller screw. In addition, the variation in friction between damper bushings and driveshaft tube components was causing force spikes and shock loads further damaging the roller screw actuators.

To replace the existing Roller Screw type actuator, the supplier would need high force and precision control in a compact space envelope. A traditional hydraulic cylinder bearing press system approach and a larger electro-mechanical actuator were considered to replace the system. However, the hydraulic system would have occupied too much floor space and did not provide accurate control. If the assembly press used a larger electro-mechanical actuator, the footprint would grow considerably in size and cost would become prohibitive.

Solution:

A Kyntronics SMART Electro-Hydraulic Actuator (SHA) with 40-inch stroke was selected based on force and speed requirements. The solution was an all-in-one system with servo motor, drive, and actuator that was drop-in ready.

In addition, the unit was provided with an internal feedback device to provide accurate positioning without possible interference when pressing into long axle tubes.

Results:

• The SHA provided the high force required in a compact footprint which fit into the available space on the machine easily.
• The SHA combines power and precision resulting in a more-reliable solution for this Tier 1 customer while providing the position and force accuracy for repeatable quality for this assembly process.
• Due to the SHA’s tolerance of “shock loads” and “load spikes” it will provide long, maintenance-free operation compared with the Electro-Mechanical Roller Screw actuator it replaced.