Molding parameters for injection molded rotor production
AssigneeABB Schweiz AG
InventorsSheng Zhong, Darren D. Tremelling, Elio Alberto Perigo
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Abstract
A method for molding a magnetic material into a rotor stack, including providing a polymer melt including magnetic compound particles and a polymer binder, providing a rotor including a plurality of cavities, the rotor being arranged in a mold having a mold cavity surface, and providing a gap between the outer periphery of the rotor and the mold cavity surface. The method also includes filling a first volume of the polymer melt into the cavities of the rotor at a first pressure and filling a second volume of the polymer melt into the rotor at one or more second pressures, the one or more second pressures being less than the first pressure and above an ambient pressure.
Claims18
A method for molding a magnetic material into a rotor stack, comprising:
- providing a polymer melt including magnetic compound particles and a polymer binder;
- providing a rotor comprising a plurality of cavities, the rotor being arranged in a mold having a mold cavity surface;
- providing a gap between an outer periphery of the rotor and the mold cavity surface;
- filling a first volume of the polymer melt into the cavities of the rotor at a first injection pressure during a first time period;
- and
- filling a second volume of the polymer melt into the cavities of the rotor at one or more second injection pressures during a second time period, the one or more second injection pressures being less than the first injection pressure and above an ambient pressure, and the second time period following successively after the first time period such that the first and second volumes of the polymer melt are injected continuously into the cavities of the rotor from a beginning of the first time period to an end of the second time period.
A method for determining optimal molding parameters for molding a magnetic material into a rotor stack, comprising:
- providing a polymer melt including magnetic compound particles and a polymer binder;
- providing a rotor comprising a plurality of cavities;
- determining a maximum first injection pressure at which a first volume of the polymer melt can be filled into the cavities of the rotor during a first time period;
- and
- determining a maximum second injection pressure at which a second volume of the polymer melt can be filled into the cavities of the rotor during a second time period that follows successively after the first time period such that the first and second volumes of the polymer melt are injected continuously into the cavities of the rotor from a beginning of the first time period to an end of the second time period.
A method for molding a magnetic material into a rotor stack, comprising:
- providing a polymer melt including magnetic compound particles and a polymer binder;
- providing a rotor comprising a plurality of cavities, the rotor being arranged in a mold having a mold cavity surface;
- providing a gap between the outer periphery of the rotor and the mold cavity surface;
- filling a first volume of the polymer melt into the cavities of the rotor at a first pressure;
- filling a second volume of the polymer melt into the cavities of the rotor at one or more second pressures, the one or more second pressures being less than the first pressure and above an ambient pressure,
- measuring pressure within a molding system over the course of the filling of the first and second volumes of the polymer melt into the rotor;
- and
- after filling the second volume of the polymer melt into the rotor, determining whether a pressure spike occurred prior to the second volume of the polymer melt being filled into the rotor,
- wherein the pressure spike includes a rapid increase in pressure followed immediately by a rapid decrease in pressure.
Dependencies are inferred from the claim text.