Abstract: A mover includes a permanent magnet array having a plurality of permanent magnets that are magnetized in a direction perpendicular to a motion direction of the mover such that magnetic poles having different polarities alternately appear on magnetic pole surfaces of the plurality of permanent magnets in the motion direction. A stator includes first and second magnetic pole portion arrays and three excitation windings. Each of the magnetic pole portion arrays include a plurality of plate-like magnetic pole portions disposed on both sides of the permanent magnet array in the perpendicular direction. Each of the excitation windings is hollow-structured whereby two magnetic pole portions included in the first magnetic pole portion array and two magnetic pole portions included in the second magnetic pole portion array are located in an internal space of the coil and are excited by the corresponding one of the excitation windings.

Abstract: A linear synchronous motor, in which one or more intermediate annular magnetic pole portions and yoke assemblies can be connected easily while positioning the intermediate annular magnetic pole portions. A fitting concave portion that is opened in an axial direction and a direction away from a direct drive shaft is formed in each connected portion of the intermediate annular magnetic pole portions. A plurality of fitting grooves are formed on an outer peripheral surface of a pair of magnetic cylindrical members at a plurality of portions facing the plurality of intermediate annular magnetic pole portions. The intermediate annular magnetic pole portions are fixedly positioned between the pair of magnetic cylindrical members by fitting a peripheral portion defining the fitting concave portion of the intermediate annular magnetic pole portion into the corresponding fitting groove of the magnetic cylindrical member.

Abstract: When a pitch between centers of two adjacent magnetic pole portions disposed on an armature is defined as ?s, the length W of permanent magnets disposed in the middle is equal to the pitch ?s (W=?s). The length of each of the two end permanent magnets respectively disposed at either end of a permanent magnet magnetic pole row is denoted by W1. A ratio w1/W of the length W1 to the length W is defined as 0.43<W1/W<0.49. With this definition, cogging torque of a linear motor may sufficiently be reduced.

Abstract: A linear motor not requiring a yoke structure is provided. A first unit forming a stator is constructed of two permanent magnet rods. The permanent magnet rods each have a magnetically permeable shaft and a permanent magnet row having a plurality of permanent magnets so arranged that opposite polarities of their magnetic poles alternately appear. The permanent magnet row of the permanent magnet rod is arranged with a positional difference of 180° in an electrical angle from the permanent magnet row of the permanent magnet rod. The second unit that constitutes a moving member includes unit cores and winding sets arranged alternately in an axial direction of the shaft. The winding set includes two excitation windings through each of which the permanent magnet rod loosely extends. One excitation winding of the winding set is excited with a phase difference of 180° in an electrical angle from the other excitation winding.

Abstract: A first pair of connected portions of one end magnetic pole portion, a first pair of connected portions of an end bracket, a first pair of connected portions of the other end magnetic pole portion, and a first pair of connected portions of each of five magnetic pole portions are connected by a pair of magnetic cylindrical members. A second pair of one connected portions of one end magnetic pole portion, a second pair of the other end magnetic pole portion, and a second pair of connected portions of each of five magnetic pole portions are connected by a pair of magnetic conductive parts. One pair of guide shafts are slidably fitted into the one pair of magnetic cylindrical members through linear bearings. A yoke is constituted from the one pair of magnetic cylindrical members and one pair of magnetic conductive parts. The five magnetic pole portions are each formed by laminating a plurality of magnetic steel plates in the axial direction.

Abstract: When a pitch between centers of two adjacent magnetic pole portions disposed on an armature is defined as ?s, the length W of permanent magnets disposed in the middle is equal to the pitch ?s (W=?s). The length of each of the two end permanent magnets respectively disposed at either end of a permanent magnet magnetic pole row is denoted by W1. A ratio w1/W of the length W1 to the length W is defined as 0.43<W1/W<0.49. With this definition, cogging torque of a linear motor may sufficiently be reduced.

Abstract: A linear motor for which armature core can readily be manufactured is provided. An armature 10 is constituted from an armature core main portion 19 and first magnetic pole constituent components 21A to 21C. The armature main core portion 19 comprises second magnetic pole portions 25A to 25D which are not wound with a winding conductor and magnetic pole connecting sections 27, and is constituted by stacking a plurality of magnetic steel sheets in an orthogonal direction D3. The first magnetic pole constituent portions 21A to 21C respectively include magnetic pole main portions 29 and winding portions 31. The magnetic pole main portion 29 includes a wound portion and a pair of non-wound portions integrally provided at each end of the wound portion. End portions of the wound portions of the first magnetic pole portion (20A to 20C) in the orthogonal direction D3 are located more inwardly than end surfaces of the second magnetic pole portions 25A to 25D in the orthogonal direction D3.

Abstract: A movable assembly used in a cylinder type linear motor is provided which can be manufactured at low cost without requiring a cutting process while preventing its magnetic characteristics from deteriorating. The movable core is constructed of a laminated yoke which is formed of a plurality of electromagnetic steel plates laminated in an axial direction of the first and second direct drive shafts. A plurality of permanent magnets 31 fixed to the laminated yoke 29 are arranged in such a manner that the polarity appearing on the outer surface of the two permanent magnet 31 opposing each other through the laminated yoke 29. The first and second direct drive shafts each have a yoke mounting portion and paired supported portions at both axial ends of the yoke mounting portion. The first and second direct drive shafts are so shaped that the cross section of the yoke mounting portion orthogonal to the axial direction is smaller than that of the supported portions.

Abstract: A linear motor capable of reducing thickness thereof in a direction orthogonal to a moving direction of a movable element therein is provided. A first claw pole type yoke unit 11A and a second claw pole type yoke unit 11B are arranged for a pair of linear portions 9a of a coil 9, respectively. The first and second claw pole type yoke units 11A and 11B are arranged so that first pole teeth 15 of the first claw pole type yoke unit 11A face second pole teeth 17 of the second claw pole type yoke unit 11B and the second pole teeth 17 of the first claw pole type yoke unit 11A face the first pole teeth 15 of the second claw pole type yoke unit 11B.

Abstract: A sheet feeding apparatus includes a sheet placing tray on which a sheet is placed, a feeding member for feeding the sheet placed on the sheet placing tray, a first sheet detection unit for detecting presence of the sheet on the sheet placing tray at a first detection position, and a second sheet detection unit for detecting presence of the sheet on the sheet placing tray at a second detection position disposed on an upstream side of the first detection position in a sheet feeding direction. A control unit controls the feeding member so as not to perform the sheet feeding operation when the first detection unit detects the sheet and the second detection unit does not detect the sheet.

Abstract: A linear motor not requiring a yoke structure is provided. A first unit forming a stator is constructed of two permanent magnet rods. The permanent magnet rods each have a magnetically permeable shaft and a permanent magnet row having a plurality of permanent magnets so arranged that opposite polarities of their magnetic poles alternately appear. The permanent magnet row of the permanent magnet rod is arranged with a positional difference of 180° in an electrical angle from the permanent magnet row of the permanent magnet rod. The second unit that constitutes a moving member includes unit cores and winding sets arranged alternately in an axial direction of the shaft. The winding set includes two excitation windings through each of which the permanent magnet rod loosely extends. One excitation winding of the winding set is excited with a phase difference of 180° in an electrical angle from the other excitation winding.

Abstract: When a pitch between centers of two adjacent magnetic pole portions disposed on an armature is defined as ?s, the length W of permanent magnets disposed in the middle is equal to the pitch ?s (W=?s). The length of each of the two end permanent magnets respectively disposed at either end of a permanent magnet magnetic pole row is denoted by W1. A ratio w1/W of the length W1 to the length W is defined as 0.43<W1/W<0.49. With this definition, cogging torque of a linear motor may sufficiently be reduced.

Abstract: A linear motor not requiring a yoke structure is provided. A first unit forming a stator is constructed of two permanent magnet rods. The permanent magnet rods each have a magnetically permeable shaft and a permanent magnet row having a plurality of permanent magnets so arranged that opposite polarities of their magnetic poles alternately appear. The permanent magnet row of the permanent magnet rod is arranged with a positional difference of 180° in an electrical angle from the permanent magnet row of the permanent magnet rod. The second unit that constitutes a moving member includes unit cores and winding sets arranged alternately in an axial direction of the shaft. The winding set includes two excitation windings through each of which the permanent magnet rod loosely extends. One excitation winding of the winding set is excited with a phase difference of 180° in an electrical angle from the other excitation winding.

Abstract: There is provided a linear motor in which the number of armature windings can be reduced, and an armature iron core can be readily fixed to a member for supporting the armature iron core. Each of three inductors 1A to 1C is so arranged that a tooth row 7 therein is located on each side thereof in a width direction thereof orthogonal to a moving direction of an armature 3. The three inductors are arranged spaced apart from each other by a predetermined spacing in the width direction. An armature iron core 9 of the armature 3 includes four magnetic pole portions 15A to 15D and three yoke portions 17A to 17, and is constituted by a plurality of electromagnetic steel plates laminated in the moving direction of the armature 3. The four magnetic pole portions 15A to 15D are arranged in parallel and spaced apart from each other by a predetermined spacing so that each of the three inductors 1A to 1C is positioned within the spacing.

Abstract: A movable assembly used in a cylinder type linear motor is provided which can be manufactured at low cost without requiring a cutting process while preventing its magnetic characteristics from deteriorating. The movable core is constructed of a laminated yoke which is formed of a plurality of electromagnetic steel plates laminated in an axial direction of the first and second direct drive shafts. A plurality of permanent magnets 31 fixed to the laminated yoke 29 are arranged in such a manner that the polarity appearing on the outer surface of the two permanent magnet 31 opposing each other through the laminated yoke 29. The first and second direct drive shafts each have a yoke mounting portion and paired supported portions at both axial ends of the yoke mounting portion. The first and second direct drive shafts are so shaped that the cross section of the yoke mounting portion orthogonal to the axial direction is smaller than that of the supported portions.

Abstract: A movable assembly used in a cylinder type linear motor is provided which can be manufactured at low cost without requiring a cutting process while preventing its magnetic characteristics from deteriorating. The movable core is constructed of a laminated yoke which is formed of a plurality of electromagnetic steel plates laminated in an axial direction of the first and second direct drive shafts. A plurality of permanent magnets 31 fixed to the laminated yoke 29 are arranged in such a manner that the polarity appearing on the outer surface of the two permanent magnet 31 opposing each other through the laminated yoke 29. The first and second direct drive shafts each have a yoke mounting portion and paired supported portions at both axial ends of the yoke mounting portion. The first and second direct drive shafts are so shaped that the cross section of the yoke mounting portion orthogonal to the axial direction is smaller than that of the supported portions.

Abstract: A linear motor for which armature core can readily be manufactured is provided. An armature 10 is constituted from an armature core main portion 19 and first magnetic pole constituent components 21A to 21C. The armature main core portion 19 comprises second magnetic pole portions 25A to 25D which are not wound with a winding conductor and magnetic pole connecting sections 27, and is constituted by stacking a plurality of magnetic steel sheets in an orthogonal direction D3. The first magnetic pole constituent portions 21A to 21C respectively include magnetic pole main portions 29 and winding portions 31. The magnetic pole main portion 29 includes a wound portion and a pair of non-wound portions integrally provided at each end of the wound portion. End portions of the wound portions of the first magnetic pole portion (20A to 20C) in the orthogonal direction D3 are located more inwardly than end surfaces of the second magnetic pole portions 25A to 25D in the orthogonal direction D3.

Abstract: There is provided a linear motor in which the number of armature windings can be reduced, and an armature iron core can be readily fixed to a member for supporting the armature iron core. Each of three inductors 1A to 1C is so arranged that a tooth row 7 therein is located on each side thereof in a width direction thereof orthogonal to a moving direction of an armature 3. The three inductors are arranged spaced apart from each other by a predetermined spacing in the width direction. An armature iron core 9 of the armature 3 includes four magnetic pole portions 15A to 15D and three yoke portions 17A to 17, and is constituted by a plurality of electromagnetic steel plates laminated in the moving direction of the armature 3. The four magnetic pole portions 15A to 15D are arranged in parallel and spaced apart from each other by a predetermined spacing so that each of the three inductors 1A to 1C is positioned within the spacing.

Abstract: There is provided a linear motor in which the number of armature windings can be reduced, and an armature iron core can be readily fixed to a member for supporting the armature iron core. Each of three inductors 1A to 1C is so arranged that a tooth row 7 therein is located on each side thereof in a width direction thereof orthogonal to a moving direction of an armature 3. The three inductors are arranged spaced apart from each other by a predetermined spacing in the width direction. An armature iron core 9 of the armature 3 includes four magnetic pole portions 15A to 15D and three yoke portions 17A to 17, and is constituted by a plurality of electromagnetic steel plates laminated in the moving direction of the armature 3. The four magnetic pole portions 15A to 15D are arranged in parallel and spaced apart from each other by a predetermined spacing so that each of the three inductors 1A to 1C is positioned within the spacing.

Abstract: A linear motor capable of reducing thickness thereof in a direction orthogonal to a moving direction of a movable element therein is provided. A first claw pole type yoke unit 11A and a second claw pole type yoke unit 11B are arranged for a pair of linear portions 9a of a coil 9, respectively. The first and second claw pole type yoke units 11A and 11B are arranged so that first pole teeth 15 of the first claw pole type yoke unit 11A face second pole teeth 17 of the second claw pole type yoke unit 11B and the second pole teeth 17 of the first claw pole type yoke unit 11A face the first pole teeth 15 of the second claw pole type yoke unit 11B.