Page 31 - ISCAR_WORLD_2021
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Stator housing machining                                     Bearing Seat Reaming After Assembly
 One of the most notable trends of the electric               Unlike the ICE, the electric motor generates its maximum
 vehicle powertrain is its simplicity. There are far          torque from a standing start. This means it does not
 fewer moving parts compared to the traditional               require a complex transmission system to operate. A
 internal combustion engine (ICE), therefore                  simple reduction gear is enough for the average electric
 manufacturing time, and cost dramatically drop               vehicle. This reduction gear sits between the stator
 when producing BEV's.                                        housing and the gear cover.
 One of the main components of an electric                    To maintain concentricity between bearing seats of the
 motor is the motor (stator) housing made                     stator and gear cover, the reaming operation
 from aluminum. A special approach is                         must be performed in the same machining sequence.
 needed to achieve this part’s critical key                   For this operation, ISCAR provides a special "push and
 characteristics of lightweight, durability,                  pull" reaming type tool with adjustable PCD blades that
 ductility, surface finish and precision,                     manage to retain the geometrical tolerances required in
 including geometrical tolerances. The partially              different inner diameters
 hollow form represents an additional challenge               on this Aluminum part.
 and maintaining low cutting forces is essential for
 roughness and cylindricity requirements.                     Rotor Turning
 ISCAR’s complete machining solution for this                 The rotor consists of many stacked plates of electric
 process has facilitated the transformation from              steel. Lamination sheets are used instead of a solid body
 the standard costly lathe-based process to an                to reduce current loss. The surface must be completely
 economical machining center. Our aim is to reduce            clean of chips, oil, water, dust or dirt, and coolant fluid
 scrapped parts and reach an optimal CPK ratio.               cannot be used, only air. This is a challenge as a lot of
 (Process Capability Index- producer's capability to          heat is generated on the cutting area and the fragmented
 produce parts within the required tolerance.)                chips stick to the surface. Surface finish requirements for
                                                              this interrupted turning operation remain strict.
 Main Diameter Reaming                                        ISCAR has overcome these challenges by developing
 The most challenging operation in machining the              a combined tool with coolant holes both on top and
 Aluminum stator housing is the main diameter                 bottom of the cutting edge to cool and blow away the
 boring and reaming. Because of the trend                     chips. The two round inserts are positioned for semi
 to use low power machines, the tool's                        finish and finishing operations, generating an excellent
 large diameter and long overhang require                     surface finish.
 creative thinking to minimize weight and
 spindle load while maintaining rigidity. Exotic
 materials such as titanium and carbon fiber
 are used for the tool body, as well as the
 welded frame design.
 The use of Finite Element Method (FEM)
 helps resolve the obstacles associated with
 this challenging application by enabling the
 consideration of many parameters, such as cutting
 forces, displacement field during machining, natural
 frequency, and maximum deformation.
















 TELLIGENTLY
 30  MACHINING  IN  DUSTRY 4.0                                                                           ISCAR    31
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