Abstract: A permanent magnet rotor for an electric motor has a shaft, a coupler mounted on the shaft, a flux ring fitted to the coupler and located within a ring magnet. The flux ring is a split ring having a nominal outside diameter greater than the inside diameter of the magnet and is keyed to the coupler.

Abstract: A bearing retainer 20 has a hollow body 21 with an open end forming a mouth 25. The mouth opens into an inner void 23 having a bearing support surface 28 for receiving a bearing. The void also has a plurality of axially extending ribs 30 defining a number of lubrication reservoirs or recesses 33. A plurality of teeth 26 extend axially from the open end for engaging a hole in the motor casing to prevent rotation between the retainer and the casing and are deformable to prevent axial separation. Proud co-planar abutment surfaces 27 are respectively disposed between adjacent teeth and bear against the casing to axially align the casing and retainer. The bearing is made by forging, casting or sintering.

Abstract: A planar carbon segment commutator has contact members, with terminals, attached to the front surface of an insulating base member by means of overmoulded carbon segments formed integral with anchor pieces disposed within apertures in the base member. Each aperture has a second part disposed rearwardly of a first part having a smaller cross-section than the second part and the anchor piece disposed within the aperture has a locking portion which fills the second part of the aperture to thereby resist withdrawal of the anchor piece from the aperture. The contact members are embedded in the carbon segments and have holes filled with carbon segment material to increase interlocking between the contact members and the segments.

Abstract: Carbon commutator segments are secured to a base member by means of integral anchor pieces disposed within axially extending, cruciform-section slots formed in the outer cylindrical surface of an insulating base member. Elongate contact members having lateral edges seated in lateral parts of the slots are embedded in the anchor pieces and are each provided, at one end, with a terminal for connection to an armature winding lead wire. The carbon segments and the integral anchor pieces are formed by enclosing the base member, together with assembled contact members, in a mold and then injecting a moldable mixture of carbon powder and carrier material into the space between the mold and the assembly with the moldable mixture filling the slots and embedding that portion of each contact member disposed within the slots. When the injection molded layer has solidified, an annular-section outer portion of this injection molded layer is divided into segments by means of axially-extending radial cuts.

Abstract: A brush assembly for an electric motor has a brush 20, a brush terminal 30 and a brush spring 40. The brush spring is fashioned from an elongate strip 41 of resilient, electrically conductive material and is fixed to the brush terminal at its ends to form a loop with an intermediate portion fixed to the brush to electrically connect the brush to the brush terminal and to urge the brush into contact with a commutator of the motor. Brush guiding arrangements for guiding the brush to the commutator has a guide pin 51 fixed at one end 52 to the brush terminal and co-operating with a guide hole 21 formed in the brush to define the position of the brush on the commutator 11.

Abstract: An assembled commutator has a segment support portion and a housing portion. The housing portion has housing members formed with axially extending "T"-shaped recesses and transversely extending slots for receiving armature leads. Insulation displacing terminals are inserted in the "T"-shaped recesses and formed with slots which cooperate with the transversely extending slots to grip and contact the armature leads. The terminals are held in place by commutator segments which are formed separately from the terminals. Each commutator segment has a retainer with two prongs which straddle a terminal, and convergent sides which cooperate with the sides of an inner, circumferentially extending portion of a "T"-shaped recess to grip the terminal as the retainer is pressed axially into the "T"-shaped recess.

Abstract: Carbon commutator segments are secured to a base member by means of integral anchor pieces disposed within axially extending, cruciform-section slots formed in the outer cylindrical surface of an insulating base member. Elongate contact members having lateral edges seated in lateral parts of the slots are embedded in the anchor pieces and are each provided, at one end, with a terminal for connection to an armature winding lead wire. The carbon segments and the integral anchor pieces are formed by enclosing the base member, together with assembled contact members, in a mould and then injecting a mouldable mixture of carbon powder and carrier material into space between the mould and the assembly. When the injection moulded layer has solidified, an annular-section outer portion of this injection moulded layer is divided into segments by means of axially-extending radial cuts.

Abstract: A self-aligning bearing for a 0.5 kW PMDC electric motor has a bearing member having a cylindrical inner surface for receiving a rotatable shaft and an outer surface comprising a first external, part-spherical, surface-of-revolution and a second external surface-of-revolution comprising a first part extending inwardly from the first external, part-spherical, surface-of-revolution and a cylindrical second part extending from the first part. A housing has a convergent end defining an internal surface of revolution which engages the first external, part-spherical, surface-of-revolution and encloses a retainer engaging the first part of the second external surface-of-revolution. The housing also encloses a support ring which holds the retainer in place and has a radially inner part which surrounds the second part of the second external surface-of-revolution with a clearance space. The support ring thereby limits tilting movement of the bearing member about axes perpendicular to the axis of the bearing member.

Abstract: An assembled commutator has an insulating commutator body having a cylindrical outer surface, radially extending axial support means and an axial extension on the opposite side of the axial support means to the cylindrical outer surface. Three commutator segments each have an arcuate brush-contacting portion seated on the cylindrical outer surface of the commutator body, an axial terminal stem extending through a passage formed in the axial support means, and a radial terminal stem seated in one of three equiangularly extending radial grooves formed in the axial support means. An apertured insulating clamping member which is press-fitted on a first part of the axial extension clamps an apertured varistor which is seated on a second part of the axial extension in electrically conductive engagement with the radial terminal stems.

Abstract: An end cap of a fractional horsepower electric motor has channels 27 in which female terminals 18 connect to a power supply plug. The terminals 18 are shaped and configured to ensure good electrical connection with the plug terminals and to prevent the plugs inadvertently disengaging during operation of the motor.

Abstract: A brush holder 14 has mounted therein a suppression circuit consisting of chokes H1 and H2, and capacitors C1, C2 and C3. Brush mounting plates 19 are integrally formed with slotted wings 19C for receiving and gripping the wire ends of the chokes and supply terminals 18 have slotted wings 18C for likewise receiving and gripping respective wire connections. The plates 19 and terminals 18 have integrally formed end portions which are soldered or otherwise electrically connected to a circuit board 24 on which the capacitors are mounted. The brush holder 14 is a single plastics molding having compartments, shaped and formed for receiving and holding the various components, as shown in FIG. 3.

Abstract: An assembled commutator comprises a cylindrical base and a plurality of segments glued on the base. To secure the segments on the base a loop, formed by stamping out a tang, is urged over a boss on the end of the base. A tongue is inserted in a recess at the other end of the base, as is known in the art. The loop pulls the segment down onto the base and also prevents circumferential movement.

Abstract: The commutator comprises a commutator base and a plurality of commutator segments. The base is in two parts. One part is a pre-formed base part and the other part is moulded to the base part after the segments have been located on the base part to firmly secure the segments thereto. The commutator is of the barrel-type and the base part is tubular and has castellated ends. The segments have apertured lugs which engage with the castellated ends of the base part and extend inside opposite ends of the base part to locate the segments relative to the base part. The other part of the base forms a sleeve inside the pre-formed base part and firmly secures the lugs and hence the segments to the pre-formed base part.

Abstract: An assembled commutator comprises a base carrying segments. Each segment 16 has a connector portion with a wall portion having an aperture to locate the connector portion about a projection on a collar formed on the base, to locate the segment. The connector portions each have a U-shaped portion having a radially inner arm which rests on the collar and is wider than the radially outer arm, to form wings which can be used when hot forging a tang to an armature coil wire, with a first electrode bearing down on the arm and a second electrode bearing down on the wings.

Abstract: A splashproof cover 7 for an electric motor comprises a plastics body 8 having a socket 15 molded thereon for connection to a power supply. Two conductors 17 are molded in the body 8 and each comprises a terminal 16 and a body part 18 from which a tongue 20 projects. The tongues 20 are received in slots 6 in the motor end cap 3 to secure the cover thereon. Slots 19 in the body part receive the motor terminals 5. A skirt 9 on the body 8 surrounds the periphery 10 of the end cap 3.

Abstract: A rotor for an electric motor comprises a shaft having a laminated armature stack mounted thereon. A collar is fitted on the shaft at each end of the stack, and an epoxy resin coating coats the stack and bonds the collar to the shaft to fix the stack in position on the shaft. The collar may be formed by a cylinder which is split along its length and has an internal diameter equal to, or slightly less than the shaft diameter, so as to form a space between the shaft and collar and facilitate entry of the epoxy resin.

Abstract: An electric motor has a casing having two opposed planar side walls and two opposed curved walls. A permanent magnet is located inside each curved wall and a wound armature is mounted in the casing. A commutator is connected to the winding and two brush arms are supported by a holder at one end of the casing. Each brush arm informed by two electrically conductive strips forming, respectively, a terminal part and a more resilient brush supporting part. The terminal parts extend out of one end of the casing in a plane of symmetry of the casing thereof and the brush supporting parts are secured to respective terminal parts at positions which are offset from the plane of symmetry, on opposite sides thereof.

Abstract: A commutator comprises a commutator base 10 having segments 12 mounted thereon. Each segment has a terminal 14 adapted to straddle and grip a connector portion 66 of an armature winding, to make electrical contact with the winding. The terminals 14 are supported in housings 50 of a terminal support 48. Fingers 72 on the support 48 engage in recesses 74 in the base 10 to align the support and base before the terminals 14 are inserted into the housings 50.

Abstract: An armature for a motor comprises a winding and a commutator. Each commutator segment has a brush contacting portion and an integral terminal portion connected to a connector portion of the winding. A commutator base includes housings which receive the terminal portions and which have slots for positioning the connector portions of the winding relative to each housing. Each terminal portion has a slot which straddles and grips the connector portion positioned relative to a respective housing. At least one and preferably all terminal portions have two slots arranged side-by-side so that the two side-by-side slots of one of the terminal portions can straddle and grip the lead end and tail end of the winding, respectively.

Abstract: An assembled commutator comprises a base carrying segments. Each segment has a tang with laterally extending arms which are folded into recesses in a collar supporting the tangs. An edge 30 of each arm abuts a wall of a recess to prevent axial movement of the segments.