Patent application number | Description | Published |
20090021090 | Power Tools With Motor Having a Multi-Piece Stator - A power tool has a motor having a stator made by separately forming pole pieces, return path pieces and field coils. The field coils are placed over necks of the pole path pieces and the return path pieces are affixed to the pole pieces. An armature having an outside diameter of at least 0.625 the outside diameter of the stator is placed in the stator. The field coils may be formed so that they extend beyond pole tips of the pole pieces. | 01-22-2009 |
20090126184 | Method of making an armature - An armature for an electric motor has a lamination stack on a shaft with a commutator mounted on one end of the shaft. Magnet wires wound in slots in the lamination stack, the commutator and armature shaft are at least partially encapsulated in thermoset. The commutator has a commutator ring divided into a plurality of segments with slots between the segments that are filled with a second plastic when the commutator is made by molding a core of the second plastic, such as phenolic, in the commutator ring before the commutator ring is mounted on the armature shaft. Prior to molding the thermoset, the commutator ring is sealed. The seal prevents the thermoset from flowing into the slots between the commutator ring segments or over the commutator ring. | 05-21-2009 |
20090159737 | Tool for Manufacturing Coils for Dynamoelectric Machines and Method Therefor - A tool and method for winding and forming a field coil for field assembly, such as a stator, includes separable tool halves defining a winding cavity therebetween. The winding cavity receives magnet wire that is wound therein, such as by rotating the tool or a winding nozzle. The magnet wire generally conforms to the shape of the winding cavity such that when the tool halves are separated, a field coil having a net shape is produced. Once the magnet wire is sufficiently deposited within the winding cavity, wires of the coil may be bonded together either through a resistive heating process such as by passing an electrical current through the coil or through other heating or chemical bonding methods to thereby maintain the net shape of the field coil once it is removed from the tool. | 06-25-2009 |
20090200891 | Electric Motor Having A Field Assembly With Slot Insulation - An electric motor has a field assembly, such as a stator, for a dynamoelectric machine has field coils that are wound to a net shape. Lead wires are brought out from the ends of each field coil. The field coils are insulated with insulating sleeves or insulating slot liners. The field coils are assembled with stator core pieces, such as pole pieces and return path pieces, into the stator. The stator core pieces are formed prior to being assembled with the field coils. In an aspect of the invention, the pole pieces and return path pieces are separately formed and then assembled together with the field coils, which have also been separately formed. | 08-13-2009 |
20090275273 | Power Tool Having an Electronically Commutated Motor and Double Insulation - A power tool has a housing a housing having an electronically commutated motor disposed therein. The motor has a rotor and a stator. The rotor has permanent magnets. The stator has a lamination stack and windings wound therein. Features are provided to provide double insulation. | 11-05-2009 |
20100013336 | Anchoring System For A Stator Housing Assembly Having An Overmolding; Power Tool With Same - A permanent magnet electric motor has a stator and a rotor The stator has a stator housing with opposed axial ends and features skived in the stator housing to extend radially inwardly from an inner surface of the stator housing proximate to at least one of the axial ends of the stator housing. An overmolding of material is molded around the features. In an aspect, the overmolding of material is a magnetic composite material and is molded to form magnets. In an aspect, magnets are placed on the inner surface of the stator housing and the overmolding of material is a plastic that is over molded around the magnets and the features. In an aspect, the features hold the magnets in place during the molding of the overmolding around the magnets. In an aspect, the magnets have essentially the same inner radius and outer radius and the overmolding of material is thicker at edges of each magnet than at the center of each magnet. In an aspect, the magnets are flat magnets and the overmolding of material is thicker at edges of each magnet than at the center of each magnet. In an aspect a power tool has such a permanent magnet DC motor. In an aspect, a power tool has a housing with a permanent magnet electric motor in the housing, with an member coupled to the electric motor. The electric motor has a rotor and a stator but not an end plate. The stator has a stator housing having opposed axial ends and a plurality of magnets affixed to an inner surface of the stator housing and an overmolding of material molded around the magnets. The overmolding of material includes a pilot feature that mates with a pilot feature of a bearing support of the power tool. | 01-21-2010 |
20100033036 | Motor With Permanent Magnets and Method of Manufacturing; Power Tool With Same - An electric motor has a rotor and a stator. The rotor or the stator has arced permanent magnets that have essentially the same inner radius (IR) and outer radius (OR). In an aspect, the stator has a stator housing having a plurality of poles. Each pole includes a plurality of flat magnets affixed to an inner surface of the stator housing. In an aspect, flats on the outside of the stator housing key the stator assembly in a power tool housing. In an aspect, flat magnets are pre-magnetized, pre-assembled with alternating magnetic polarities, inserted into a stator housing, and remagnetized to a final, desired magnetic polarity configuration. In an aspect, pre-magnetized magnets and unmagnetized magnets are pre-assembled with unmagnetized magnets between magnetized magnets, the pre-assembled magnets inserted into a stator housing, and the unmagnetized magnets magnetized to a final, desired magnetic polarity configuration. In an aspect, pre-magnetized magnets are inserted between anchors inwardly extending from an inner surface of a stator housing with the anchors retaining each magnet placed in the stator housing between anchors from being angularly displaced by subsequently inserted magnets. In an aspect, pre-magnetized magnets are inserted in recesses in an inner surface of a stator housing with the recesses retaining each magnet placed in the stator housing between anchors from being angularly displaced by subsequently inserted magnets. In an aspect, each pole has at least three magnets, at least one of the magnets being thinner than the other magnets. In an aspect, the outer most magnets are made of magnetic material that is more resistant to demagnetization than at least one of the other magnets. In an aspect, the magnets of each pole are unevenly spaced over the pole In an aspect, a power tool includes such an electric motor. | 02-11-2010 |
20100300641 | POWER TOOL HAVING AN ELECTRONICALLY COMMUTATED MOTOR AND DOUBLE INSULATION - A power tool has a housing a housing having an electronically commutated motor disposed therein. The motor has a rotor and a stator. The rotor has permanent magnets. The stator has a lamination stack and windings wound therein. Features are provided to provide double insulation. | 12-02-2010 |
20100308673 | POWER TOOL HAVING AN ELECTRONICALLY COMMUTATED MOTOR AND DOUBLE INSULATION - A power tool has a housing a housing having an electronically commutated motor disposed therein. The motor has a rotor and a stator. The rotor has permanent magnets. The stator has a lamination stack and windings wound therein. Features are provided to provide double insulation. | 12-09-2010 |
20110115314 | POWER TOOLS WITH MOTOR HAVING A MULTI-PIECE STATOR - A power tool has a motor having a stator made by separately forming pole pieces, return path pieces and field coils. The field coils are placed over necks of the pole path pieces and the return path pieces are affixed to the pole pieces. An armature having an outside diameter of at least 0.625 the outside diameter of the stator is placed in the stator. The field coils may be formed so that they extend beyond pole tips of the pole pieces. | 05-19-2011 |
20110126399 | METHOD OF MAKING AN ARMATURE - An armature for an electric motor has a lamination stack on a shaft with a commutator mounted on one end of the shaft. Magnet wires wound in slots in the lamination stack, the commutator and armature shaft are at least partially encapsulated in thermoset. The commutator has a commutator ring divided into a plurality of segments with slots between the segments that are filled with a second plastic when the commutator is made by molding a core of the second plastic, such as phenolic, in the commutator ring before the commutator ring is mounted on the armature shaft. Prior to molding the thermoset, the commutator ring is sealed. The seal prevents the thermoset from flowing into the slots between the commutator ring segments or over the commutator ring. | 06-02-2011 |
20110278966 | Motor With Overmolded Permanent Magnets - A permanent magnet electric motor has a stator and a rotor. The stator has a stator housing with at least a North pole and a South pole. Each pole includes at least two permanent magnets arranged on an inner surface of the stator housing near the pole tips and an overmold of magnetic material molded around the permanent magnets and over the inner surface of the stator between the permanent magnets. Alternatively, an overmold of magnetic material may be provided over an inner surface of the stator, where the thickness of the overmold layer is greater near tips of each pole than in the middle portion of each pole. | 11-17-2011 |