Case Study: Crankshaft Bearing Cap Tightening Machine

The Requirement

ESA were tasked with designing and building a semi-automated machine to support engine block assembly.

The system needed to:

Tighten crankshaft bearing caps accurately and consistently
Handle multiple fixing positions and variants
Record tightening results for quality control
Integrate into an existing production process

The Solution

ESA developed a semi-automatic assembly system built around a Bosch Rexroth TS2 conveyor, allowing engine blocks to move through each stage of the process.

Key elements of the machine included:

Conveyor-based transfer system using custom workpiece pallets
Servo-controlled positioning to accommodate different fixing locations
Multi-spindle tightening system for simultaneous operations
Integrated PLC control system for monitoring and data capture

The system was designed with flexibility in mind, allowing for future product variations.

Working process

How the Machine Works

1. Loading & Verification
The engine block is loaded onto the system and positioned. A poka-yoke fixture checks that all components are correctly in place before the cycle begins.
2. Automated Tightening Process
Multi-spindle units automatically engage with the fixing points and carry out a programmed tightening sequence, including:
Snugging
Pre-tightening
Final torque application
3. Servo Positioning
Servo-driven adjustment ensures accurate alignment with different fixing positions across product variants.
4. Final Operations
A lift-and-rotate mechanism allows access to all required fixing points on the component.
5. Data & Quality Control
All tightening results are logged and linked to the individual engine block for full traceability.