Abstract: A permanent magnet motor for operation at elevated temperatures wherein the magnets are clamped to the motor shaft by means of high temperature plastic bushings. The bushings have a coefficient of thermal expansion that exceeds the coefficient of thermal expansion of the motor shaft.

Abstract: An electric motor incorporates a positive temperature coefficient resistor 18 between a supply terminal and a brush. The resistor can be inserted from outside the motor through an aperture 17 in an end cap 2. A body 19 of heat conducting material, also insertable from outside the end cap, can be provided and held against to resistor 18 to alter its effective thermal mass and so adjust its operating characteristics.

Abstract: Heat pipes having predetermined configurations and positioned within the wedges and wedge retainers for maintaining the rotor field windings in position for efficiently collecting heat generated along the length of the rotor field windings and rotor surface and transporting this heat to the ends of the rotor where it is transferred to a coolant medium such as a gas or spray liquid are disclosed. The particular heat pipe positioning and configuration provides an optimal amount of heat transfer surface area for transferring heat from the wedge material to a volatile fluid within the heat pipe. Heat is thus efficiently transferred to the volatile fluid which changes the volatile fluid from a liquid phase to a vapor phase where the vapor flows at a high speed to a condenser section beyond the axial length of the rotor field windings where heat is dissipated from the volatile fluid to the cooling medium.

Abstract: Provided is a rotor structure of a radial type synchronous motor having a rotor core (10) is held between permanent magnets (12) wherein end plates (14) are attached to ends of the rotor (8) in a direction of the central axis (6) of the rotor, each of which plates is provided with projecting portions (16) to regulate a radial position of an outer face of the rotor core. This prevents a projection of the rotor core and permanent magnets in the radial direction due to a centrifugal force caused by a rotation of the rotor. Therefore, a rotor structure able to withstand a strong centrifugal force can be provided.

Abstract: A rotor for a permanent magnet-type dynamoelectric machine comprises a rotor shaft and a rotor magnet assembly including a plurality of permanent magnet segments each having a chamferred axially-extending outer side edges defining, together with the chamferred outer side edge of the adjacent magnet segment, a plurality of axial recesses when the magnet segments are mounted around the rotary shaft. The machine rotor further comprises a nonmagnetic support tube member for contacting and supporting the outer circumferential surface of each of the permanent magnet segments of the rotor magnet assembly, the support tube member having a plurality of inwardly extending projections for contacting and supporting the chamferred side surfaces of the magnet segments. The nonmagnetic support tube member may comprise a pair of metallic cup-shaped member having a substantially tubular members disposed around the rotor magnet assembly and a radially extending end plate member attached to the rotary shaft.

Abstract: A control motor for a servo-valve includes elements of a control motor including a yoke, permanent magnet, control coil and armature mounted to one another. An output member transmits the pivotal movements of the armature. A frequency dependent passive electric dampening means is formed as an annular disc, and located adjacent the control means to compensate for non-linearities in frequency response.

Abstract: A ferromagnetic stator employed in a linear motor system is provided with a plurality of internal chambers interconnected to one another for the introduction of coolant to maintain the stator at a uniform temperature and to eliminate hot spots. The compartments are coupled to one another to permit free circulation of the coolant throughout the platen. This circulation is induced by heating of the coolant. Each chamber is connected to the adjacent chamber (or chambers) by at least two sets of openings which respectively provide for communication of hotter and cooler coolant therethrough to facilitate passive cooling. As an alternative, in extreme cases, the coolant may be pumped through the platen compartments by an external pump.

Abstract: Disclosed is a spindle motor comprising: a housing, a hub member which is rotatable with respect to the housing and to which a recording member is attached, and a bearing arranged between the housing and the hub member and having an outer member which is rotatably attached thereto through the intermediation of a plurality of spherical members, the hub member being fixed to the above-mentioned outer member by press fitting or shrinkage fitting, and the inner periphery of the hub member being equipped with an annular recess in correspondence with a ball lodging grooved formed on the outer member.

Abstract: A small size electric motor comprises a motor housing having a built-in stator and secured to a supporting member. The motor housing is made of a synthetic resin and has a substantially tubular heat conductive plate embedded in a portion thereof which is attached to the supporting member. The heat conductive plate is made of a metallic material, and its inner peripheral portion is projecting toward the inner side of the housing so that the heat conductive plate is brought into contact with the stator, and its outer peripheral portion is exposed to the surface to which the supporting member is attached so that the heat conductive plate is brought into contact with the supporting member. Therefore, the heat generated by the motor is radiated while transmitted from the stator to the supporting member through the heat conductive plate.

Abstract: A carbon brush used for a miniature motor, which has a permanent magnet field and is caused to rotate through current commutation via a commutator, formed by bonding graphite powder and used for making sliding contact with the commutator for current commutation, in which the carbon brush is a metal-plated graphite brush formed by pressure-forming and sintering the graphite powder after covering particles of the graphite powder with a metallic layer; the graphite powder used for the metal-plated graphite brush being purified to reduce the ash content of the graphite powder to 0.05 wt. %, and the method of making the same.

Abstract: A resin-molded motor constituted by a rotor, a laminated stator having generally axially and radially extending slots defining pole pieces therebetween and resin material molded in the inner portions of the slots and over the inner ends of the slots for insulation and bonding of the laminated stator, a generally cylindrical resin material shroud at each end of the stator extending from the corresponding axial end face at the inner peripheral portion thereof and extending axially of the motor, a steel sheet bracket on the axially outer end of each of the shrouds and having journal means therein supporting the rotor, a plurality of windings around the pole pieces of the stator and having axially outer coil ends against the shrouds, a connector having connector terminals to which conductor ends of the windings are connected for supplying power to the windings, and a housing of resin material molded around the stator, the windings, the shrouds, the brackets and the connector with the terminals exposed from the ho

Abstract: The protection of submersible electric pump motors against hostile environments involving corrosive, abrasive and erosive fluids including an elastomeric boot or sleeve which substantially envelops the motor and which is sealed at its mouth to the periphery of the motor at one end. The interior of the boot between the motor and the boot wall is substantially filled with a heat transfer fluid such as ethylene glycol or a mixture of same and water.

Abstract: A spindle motor includes a bracket, a shaft member fixed to the bracket, a hub member rotatably mounted on the shaft member with a bearing member therebetween, a rotor magnet mounted on the hub member, a stator disposed in opposed relation to the rotor magnet, and a magnetic fluid sealing means disposed on an outer side of the bearing means. The shaft member or bracket has a magnetized portion for suppressing a magnetic flux leaking from a magnetic fluid retaining means of the magnetic fluid sealing means.

Abstract: A transfer apparatus for transferring a sheet-like medium has a vibrational element or elements which vibrate under control of electrical energy to move the sheet-like medium along a transfer medium. The vibrational element has a tubular hexagonal body with piezoelectric elements on its faces other then the upper and lower face. The lower face is fixed and the upper face has a projection in the shape of a ball which engages the bottom surface of the sheet-like medium during vibration of the vibrational element.

Abstract: A vibration damping system, for supporting a substantially vertically extending member having a bottom to be supported relative to a foundation, comprising a first and a plurality of second vibration damper members. The first damper member is mounted between the bottom of the member to be supported and the foundation and having a predetermined spring characteristic and a predetermined damping characteristic. The second vibration damper members are mounted between an upper portion of the member to be supported and the foundation and extending substantially horizontally to the foundation and at a predetermined angle relative to each other, the second vibration damper members having a predetermined spring characteristic and a predetermined damping characteristic. A vehicular a.c. generator and a dynamoelectric machine utilizing such the vibration damping system are also disclosed.

Abstract: A hollow shaft motor which has a ball screw shaft (24) passed therethrough and which drives the ball screw shaft (24) to rotate, wherein provision is made for flow paths (28, 30, 32) for passing compressed air for cooling purposes to one end of the motor so that the heat generated by the motor is not conducted to the ball screw shaft (24) through the ball nut (22) attached to one end of the cylindrical shaft (20) of the through type motor and engaged with the ball screw shaft.

Abstract: A shaded pole motor includes a squirrel-cage rotor and a stator assembly. The stator assembly having a bore for rotatably receiving the rotor and pole separation parts on an inner circumference of the bore so that adjacent separated portions are excited alternately to an N-pole and an S-pole when a winding is energized. The inner circumference of the bore is divided into plural sections represented by 2(2n+1). The magnetically divided two pole portions have pole sections having an alternating N-pole and S-pole, and non-pole sections, when a winding of the stator is energized.

Abstract: A permanent magnetic type stepping motor which is suitably used in such office automation machines and apparatuses and which parameters are set to satisfy the following conditions (1) to (4).(1) The magnetic poles for the stator be 6 in number and be arranged as equally spaced by an identical pitch.(2) Each of the magnetic poles of the stator be provided on its tip end with pole teeth which are equal in pitch to the pole teeth of the rotor magnetic poles or the pitch .tau..sub.s of the pole teeth of the stator magnetic poles and the pitch .tau..sub.R of the pole teeth of the rotor should satisfy the following correlations..tau..sub.S =180.tau..sub.R /(180.+-..tau..sub.R)60/.tau..sub.S =m(where m=1, 2 . . .)(3) An angle .sigma..sub.r made between one of the stator magnetic poles and adjacent one of the rotor magnetic poles satisfy a relationship .theta..sub.r =120.degree./Z. The number of pole teeth in the rotor magnetic poles meet an equation Z=6n.+-.4 (where n is a positive integer).

Abstract: A rotatable rectifier assembly has four rectifiers each comprising a group of bead type diodes mounted between axially spaced electrical conductors, the conductors being pre-loaded together to enable the diode connections to better withstand centrifugal forces. The assembly includes a spacing material to take up manufacturing tolerances and thereby ensure that each of the diode groups takes a substantially equal proportion of the applied pre-load.

Abstract: An axial gap motor for use in a disk drive includes a rotatable magnet rotor and fixed first and second windings closely spaced from the rotor. The rotor and windings are disposed coaxially about a rotatable spindle to which the rotor is mounted. Current supplied to one winding actuates the rotor to rotate in a run mode. Current supplied to the other winding positions the rotor for maximum torque for starting the motor, and enables the sensing of the speed of the rotating rotor.