PSI - Issue 14

Varatharaj Neelakandan et al. / Procedia Structural Integrity 14 (2019) 345–353 Varatharaj Neelakandan / Structural Integrity Procedia 00 (2018) 000–000

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converts the torque to output shaft attached with the pinion. This is the overall operation of starter motor. The Housing bracket is holding the motor and solenoid unit and providing the support for the loading condition. The starter motor is mounted on the engine through housing bracket which is highly important on the design aspects.

Figure 1: Starter motor and ring gear engagement

Need of Starter motor housing bracket optimization: • Emission norms of the engines and vehicles. • Fuel efficiency. • Increased Starter Durability or Fatigue life. • Increase of material cost. • Market demand on compact size and light weight.

To achieve the need of optimization, the housing bracket is required to optimize for the acceptable level of weight as well as the performance in terms of strength. The strength is calculated with finite element stress analysis and fatigue calculation using FEA software. During the engine cranking at the higher torque and power as required by the engine loads like flywheel mass and rotational and translational mass of the engine parts adding to the frictional loads. Cranking operation as classified in different modes of 1. Live cranking and 2. Dead cranking. During the dead cranking the engine inertial and frictional load act on the starter motor and during the live cranking, the flywheel inertial load impacts suddenly to the starter motor.

Figure 2: Starter motor and torque performance curve