Injection molded motor assembly

An injection molded electrical motor assembly comprising:

• a rotor assembly having a central rotor portion on a rotor shaft, and a rotor bearing disposed near each end of the rotor shaft;
• a unitary stator assembly including a stator lamination stack forming stator poles, stator windings carried on the stator poles, a front end cap positioned on one end of the lamination stack, and a high strength plastic unitizing member comprising a unitary injection molded plastic mass that substantially encapsulates the stator poles and the windings and fills interior voids of the lamination stack, thereby unitizing the stator assembly, the plastic mass extending to and forming an unitary rear end cap disposed on an end of the lamination stack opposite the front end cap;
• and
• a continuous bore formed in the stator assembly through the front end cap, the stator lamination stack, and the unitary rear end cap, the continuous bore defining mounting services in the front and rear end caps for receiving and supporting the rotor bearings, the rotor assembly being carried within the bore formed in the stator assembly with the rotor bearings engaging the mounting surfaces in the end caps for support thereby, an air gap being defined between the central rotor portion and the stator lamination stack;
• and
• wherein the front end cap is fabricated from metal and has pilot holes, the lamination stack having anchor holes, the plastic mass extending from the anchor holes in the lamination stack to the pilot holes in the front end cap to form plastic rivets which secure the front end cap to the lamination stack.

An injection molded electrical motor assembly comprising:

• a rotor assembly having a central rotor portion on a rotor shaft, and a rotor bearing disposed near each end of the rotor shaft;
• a unitary stator assembly including a stator lamination stack forming stator poles, stator windings carried on the stator poles, a front end cap positioned on one end of the lamination stack, and a high strength plastic unitizing member comprising a unitary injection molded plastic mass that substantially encapsulates the stator poles and the windings and fills interior voids of the lamination stack, thereby unitizing the stator assembly, the plastic mass extending to and forming an unitary rear end cap disposed on an end of the lamination stack opposite the front end cap;
• and
• a continuous bore formed in the stator assembly through the front end cap, the stator lamination stack, and the unitary rear end cap, the continuous bore defining mounting services in the front and rear end caps for receiving and supporting the rotor bearings, the rotor assembly being carried within the bore formed in the stator assembly with the rotor bearings engaging the mounting surfaces in the end caps for support thereby, an air gap being defined between the central rotor portion and the stator lamination stack;
• and
• wherein the front end cap is fabricated from metal and has pilot holes which align the anchor holes in the lamination stack, threaded fasteners inserted through the pilot holes into the anchor holes for securing the front end cap to the lamination stack and preventing creep, the plastic mass surrounding the threaded fasteners and filling the front end cap.

An injection molded electrical motor assembly comprising:

• a rotor assembly having a central rotor portion on a rotor shaft, and a rotor bearing disposed near each end of the rotor shaft;
• a unitary stator assembly including a stator lamination stack forming stator poles, stator windings carried on the stator poles, a front end cap positioned on one end of the lamination stack, and a high strength plastic unitizing member comprising a unitary injection molded plastic mass that substantially encapsulates the stator poles and the windings and fills interior voids of the lamination stack, thereby unitizing the stator assembly, the plastic mass extending to and forming an unitary rear end cap disposed on an end of the lamination stack opposite the front end cap;
• and
• continuous bore formed in the stator assembly through the front end cap, the stator lamination stack, and the unitary rear end cap, the continuous bore defining mounting, services in the front and rear end caps for receiving and supporting the rotor bearings, the rotor assembly being carried within the bore formed in the stator assembly with the rotor bearings engaging the mounting surfaces in the end caps for support thereby, an air gap being defined between the central rotor portion and the stator lamination stack;
• and
• wherein a matrix of conductive pins is electrically connected to the stator windings, and the molded rear end cap includes a connector housing integrally formed of injection molded plastic that is disposed around the matrix of pins, the housing adapted to receive a mating connector.

An injection molded electrical motor assembly comprising:

• a rotor assembly having a central rotor portion on a rotor shaft, and a rotor bearing disposed near each end of the rotor shaft;
• a unitary stator assembly including stator poles and means for magnetizing the stator poles, a front end cap positioned on one end of the lamination stack, and a plastic unitizing member comprising a unitary injection molded non-cured plastic mass that substantially encapsulates the stator poles and fills interior voids of the stator, thereby unitizing the stator assembly, the plastic mass extending to and forming an unitary rear end cap disposed on another end of the lamination stack opposite the front end cap;
• and
• bearing support surfaces in the front and rear end caps separated by a bore of a size sufficient to receive the central rotor portion, the bearing support surfaces defining mounting surfaces in the end caps for directly receiving and supporting the rotor bearings, the rotor assembly being carried in the bore formed in the stator assembly with the rotor bearings engaging the mounting surfaces in the end caps for support thereby, an air gap being defined between the central rotor portion and the stator lamination stack.

An injection molded electrical motor assembly comprising:

• a rotor assembly having a central rotor portion on a rotor shaft, and a rotor bearing disposed near each end of the rotor shaft;
• a unitary stator assembly including stator poles and means for magnetizing the stator poles, a front end cap positioned on one end of the lamination stack, and a plastic unitizing member comprising, a unitary injection molded plastic mass that substantially encapsulates the stator poles and fills interior voids of the stator, thereby unitizing the stator assembly, the plastic mass extending to and forming an unitary rear end cap disposed on an end of the lamination stack opposite the front end cap;
• and
• bearing support surfaces in the front and rear end caps separated by a bore of a size sufficient to receive to the central rotor portion, the bearing support surfaces defining mounting surfaces and the end caps for receiving and supporting the rotor bearings, the rotor assembly being carried in the bore formed in the stator assembly with the rotor bearings engaging the mounting surfaces in the end caps for support thereby, an air gap being defined between the central rotor portion and the stator lamination stack;
• and
• wherein the bearing support surface for the front end cap has a larger diameter than the bearing support surface for the rear end cap.