Patents Assigned to Japan Servo Co.
  • Patent number: 7019484
    Abstract: A stepping motor driver according to the present invention includes a torque component current calculating means for calculating a torque component current from phase currents and a rotor rotation angle, an absolute value converting means for obtaining an absolute value of the torque component current, a high speed-response judging means adapted for outputting a first control signal when a speed deviation between a command speed and a rotor speed is not more than a reference level, and outputting a second control signal when the speed deviation exceeds the reference level, and a current command outputting means adapted for outputting a current command according to the absolute value of the torque component current when the first control signal is outputted, and outputting a maximum current command value as the current command when the second control signal is outputted.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: March 28, 2006
    Assignee: Japan Servo Co., Ltd.
    Inventors: Akio Takemori, Yoshifumi Kuwano, Hiroaki Taka
  • Patent number: 6975052
    Abstract: A terminal arrangement of a motor has a terminal base formed with a plurality of terminal pins, the terminal base being fixed detachably on a stator iron core of a motor, terminal pins formed on bobbins, connected electrically with windings wound around the bobbins, a printed circuit board arranged on the stator iron core so as to connect electrically the terminal pins formed on the bobbins with the terminal pins formed on the terminal base, and an end bracket arranged so as to cover the printed circuit board. A hole is formed in the stator iron core, and an earth electrode is projected from the terminal base, and inserted into the hole so as to be connected electrically with the stator iron core, the earth electrode being connected electrically to one of the terminal pins formed on the terminal base. A capacitor motor has a motor having a stator iron core, and a phase advancing capacitor fixed detachably on the stator iron core.
    Type: Grant
    Filed: August 19, 2004
    Date of Patent: December 13, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Keiji Uchida, Hiroyuki Tanaka, Hitoshi Ishii, Yasushi Niwa, Toshio Kobayashi
  • Patent number: 6954014
    Abstract: The invention relates to a motor with a frequency generator attached thereto, equipped with the frequency generator (FG) for detecting a rotational speed of the motor.
    Type: Grant
    Filed: May 13, 2004
    Date of Patent: October 11, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Shoji Ohiwa, Yuji Enomoto, Tomoyoshi Maruyama, Yuji Takagai, Sachio Hatori, Kazuto Nagai
  • Publication number: 20050207888
    Abstract: A centrifugal fan includes a scroll casing having an almost cylindrical shape. The casing consists of first and second casings. The first casing constitutes one base wall and a part of a side circumferential wall of a cylinder, and the second casing constitutes the other base wall and the remaining part of the side circumferential wall. An air inlet is formed on a center portion of the base wall of the first casing, and an exhaust port that is formed on the side circumferential wall. An impeller having many blades and a motor for driving the impeller are contained in the casing. A cylindrical partition that is formed on the inside of the base wall of the second casing over the entire circumference. The partition consists of a high partition formed in at least a region close to the exhaust port and a low partition formed in the other region.
    Type: Application
    Filed: March 14, 2005
    Publication date: September 22, 2005
    Applicant: JAPAN SERVO CO., LTD.
    Inventors: Yoshio Kashiwazaki, Youichi Nagata
  • Patent number: 6946814
    Abstract: A stepping motor driver comprises: an excitation angle generating means which generates an excitation angle from an external command pulse; a current control means which controls exciting currents for a stepping motor according to the excitation angle and a current command; a current detection means which detects phase currents of the stepping motor; an angle detection means which detects a rotor rotation angle of the stepping motor; a torque component current calculating means which calculates a torque component current from the phase currents and the rotor rotation angle; an absolute converting means which obtains the absolute value of the torque component current; and a current command output means which outputs the current command depending on the absolute value of the torque component current.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: September 20, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Akio Takemori, Yoshifumi Kuwano, Yukinari Takahashi, Hiroaki Taka
  • Patent number: 6943475
    Abstract: A permanent magnet motor for driving a fan is rotated while a movement of the rotor in a direction of thrust of a rotary shaft with a rotation of the fan is prevented by magnetic attraction force of a permanent magnet and a stator core. A surface magnetic flux density of the permanent magnet facing the stator core is lower at an end portion than at a central portion of the permanent magnet in the direction of thrust of the rotary shaft.
    Type: Grant
    Filed: February 12, 2004
    Date of Patent: September 13, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Yuji Enomoto, Osamu Sekiguchi, Hitoshi Ishii, Katsuo Kawashima
  • Patent number: 6927526
    Abstract: A rotor of a motor is attached to a rotor axis slidably both in axial direction and rotational direction, each of elastic bodies is attached to each of side faces of the rotor, and the rotor is fastened to the rotor axis through the elastic body, mechanically by applying pressure on each of the side faces of the rotor in the axial direction through the elastic body, or chemically by bonding the rotor axis and each of the elastic bodies as well as each of the elastic bodies and each of the corresponding side faces of the rotor.
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: August 9, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Hitoshi Ishii, Katsuo Kawashima, Hideo Takahashi, Toshio Kobayashi, Toshimi Abukawa
  • Patent number: 6913055
    Abstract: A lamination system comprises a thermocompression bonding means for bonding laminate films on top and/or back surfaces of cards, applying heat and pressure using a pair of heat rollers. The lamination system is provided with contact type temperature detection devices for detecting surface temperatures of the heat rollers and a heat roller attaching/detaching device for attaching or detaching the heat rollers. The heat roller attaching/detaching device places the temperature detection devices in contact with surfaces of the heat rollers when the heat rollers are being installed in the lamination system, and places the temperature detection devices apart from the heat rollers when the heat rollers are to be attached to, or detached from, the lamination system.
    Type: Grant
    Filed: August 4, 2004
    Date of Patent: July 5, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Kenji Sugaya, Kensuke Shoji
  • Patent number: 6903476
    Abstract: A permanent magnet type three-phase stepping motor that is simple in construction, with vibration, a reduced unbalance force in the radial direction, and high torque that can be manufactured at a low cost is disclosed. The permanent magnet type three-phase stepping motor has a stator having 3L pieces of stator pole and a rotor having a permanent magnet magnetized so as to form a plurality (Nr) of N and S pole pairs, wherein a condition of 0.3?{(Nr/?) (Ws+Wr)/(Ds+Dr)}?0.5 is established, where L is an integer not less than 1, Nr is L (3n±1), n is an integer not less than 1, Da is an inner diameter of the stator, Dr is an outer diameter of the rotor, Ws is a width of the stator pole tooth, and Wr is a width of the rotor tooth.
    Type: Grant
    Filed: July 17, 2002
    Date of Patent: June 7, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventor: Masafumi Sakamoto
  • Patent number: 6897633
    Abstract: A stepping motor driver which drives a stepping motor for position and speed control. The stepping motor driver comprises: a current control means which outputs values corresponding to applied voltages; current sensors which detect phase currents; and a magnetic pole position estimation unit which uses the values corresponding to applied voltages and detected phase current values as outputs of the current sensors to obtain a magnetic pole position estimate. The magnetic pole position estimation unit calculates a magnetic pole position estimate from speed electromotive force estimates or from differences between phase currents at zero speed and detected phase current values.
    Type: Grant
    Filed: March 9, 2004
    Date of Patent: May 24, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Yoshifumi Kuwano, Akio Takemori, Hiroaki Taka, Yasuo Matsuda, Yoshihiro Okumatsu, Atsuo Kawamura, Yukinari Takahashi
  • Patent number: 6893521
    Abstract: In a double-side lamination system having a thermocompression bonding device for laminating laminate films on both surfaces of a card by applying heat and pressure using a pair of heat rollers, a temperature measurement device for measuring temperatures of the heat rollers are provided, and whether the lamination system is in a double-side lamination mode in which laminations are carried out on both surfaces of the card, or in a single-side lamination mode in which lamination is carried out on one of the surfaces of the card, is automatically distinguished by comparing measured temperatures of the heat rollers at a predetermined time after turn-on of the power of the system with a predetermined reference temperature.
    Type: Grant
    Filed: March 25, 2004
    Date of Patent: May 17, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Naotaka Sasaki, Shunichi Kawamata, Kenji Sugaya, Hideaki Ito
  • Patent number: 6883573
    Abstract: In a lamination system for laminating a film with a heat adhesive layer on at least a surface of a plastic card applying heat and pressure by heat rollers, each of two rectification devices for rectifying warp in the laminated card is provided independently of each other, at the downstream of the heat rollers, respectively along each of sides of the card along card transfer direction. Each of the rectification devices comprises a pair of rotatable rollers.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: April 26, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Naotaka Sasaki, Kenji Sugaya, Shunichi Kawamata, Kensuke Shoji
  • Patent number: 6876118
    Abstract: In an abduction-type motor having a divided core 5(a-l) formed by dividing a stator core into plural blocks and a motor stator having such a structure as the divided core may be reassembled, the motor has a coil winding frame 6 continuously formed a continuous unit of coupling parts, a part of which is flexible and made of insulation material, embedded into the individual divided cores, and a coil 7 arranged and wound by supporting the divided core so that the teeth top parts of the divided core may be directed inside and located on a circle, in which its coil winding structure has the number of coil stages at the teeth top part (external peripheral part) of the divided core larger than the number of the coil stages at the internal peripheral part, and the diameter of the teeth top part of the divided core after assembly is identical to the diameter of the teeth top part while coil winding work, and the length of the crossover line 7s between the coil windings is made enough to be equivalent to a single slot
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: April 5, 2005
    Assignees: Hitachi, Ltd., Japan Servo Co., Ltd.
    Inventors: Yuji Enomoto, Masashi Kitamura, Miyoshi Takahashi, Makoto Ochiai, Takashi Ando, Sachio Hatori, Yasuaki Motegi, Toshimi Abukawa
  • Publication number: 20050067903
    Abstract: In an outer rotor type hybrid stepping motor, when assuming that a teeth pitch is ? and a tooth width is Tw (tooth width ratio is Tw/?) and in case of Tw/?=0.3, the maximum torque can be obtained when a gap average magnetic flux density Bg is 1.6-1.8T, which is determined by dividing a total magnetic flux amount calculated from residual magnetic flux density Br of a magnet and surface area A of the magnet with small teeth surface area At of a rotor. Since the small teeth surface area At can be expressed by a product of the small tooth width Tw, number of small teeth Nr and a lamination thickness L, an optimum lamination thickness can be determined with only one solution. Further, in case of different teeth width ratios, the following gap magnetic flux densities Bg assume optimum values, in that when Tw/?=0.35, 1.4-1.5T, when Tw/?=0.4, 1.2-1.4T, when Tw/?=0.45, 1.0-1.2T are set.
    Type: Application
    Filed: August 19, 2004
    Publication date: March 31, 2005
    Applicant: Japan Servo Co. Ltd.
    Inventors: Yuji Enomoto, Kenji Miyata, Yasuaki Motegi, Shoji Ohiwa
  • Publication number: 20050069436
    Abstract: The tube pump includes a base that holds a drive shaft; a rotor portion that rotates with the driving shaft, the rotor portion having a pair of rollers; a casing having a U-shaped internal surface along which an elastic tube is arranged, the casing being mounted on the base so that the casing can slide with respect to the base in a direction parallel to the linear portions; a cover that is rotatably mounted on the casing; a moving mechanism including a rack that is formed on the base and a pinion that is fixed to the rotation shaft of the cover. The moving mechanism moves the casing to the operating position where the roller deforms the elastic tube when the cover closes, and the moving mechanism moves the casing to the exchange position where the roller comes apart from the elastic tube when the cover opens.
    Type: Application
    Filed: September 23, 2004
    Publication date: March 31, 2005
    Applicant: JAPAN SERVO CO., LTD.
    Inventor: Masanori Shibasaki
  • Publication number: 20050023905
    Abstract: A toroidal-coil multi-phase linear stepping motor includes a cylindrical housing, an axis coaxially arranged inside the housing, a cylindrical element supported by the axis and an armature fixed to the housing around the cylindrical element through an air gap in the radial direction. The axis is fixed to the housing and the cylindrical element linearly moves along the axis. The cylindrical element has toroidal permanent magnets that are alternately magnetized in N pole and S pole in the axial direction. The armature consists of armature units arranged around the axis. Each armature unit has a toroidal coil and a pair of armature yokes that hold the toroidal coil. Each armature yoke has toroidal magnetic teeth on its inner surface. The invention also includes a toroidal-coil single-phase linear reciprocating motor and a cylinder compressor and a cylinder pump using these motors.
    Type: Application
    Filed: July 30, 2004
    Publication date: February 3, 2005
    Applicant: JAPAN SERVO CO., LTD.
    Inventor: Masafumi Sakamoto
  • Patent number: 6850027
    Abstract: The stepping motor driver comprises an inverter for feeding stepped currents to windings of a stepping motor, a position detector for obtaining a detected angle of a rotor of the stepping motor and a current controller for controlling the inverter. In a d-q rotational coordinate system in which the d-axis is in the direction of the magnetic flux of the rotor and the q-axis is in the direction perpendicular to the d-axis, an excitation angle for a winding is determined from a d-axis component and a q-axis component of a command current to the winding, a lead angle control signal is computed from the excitation angle, and a phase of an applied voltage to the stepping motor is controlled using the lead angle control signal.
    Type: Grant
    Filed: March 18, 2003
    Date of Patent: February 1, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Yoshifumi Kuwano, Akio Takemori, Yasuo Matsuda, Yoshihiro Okumatsu, Atsuo Kawamura
  • Patent number: 6850026
    Abstract: The stepping motor driver comprises an angle computing element that receives rotor position detection signals from an encoder and calculates a detected angle representing the rotational angle of the rotor, and a lead angle controller that generates a corrected command angle based on the difference between a command angle given from outside and the detected angle. The lead angle controller calculates an angle deviation that is the difference between the command angle and the detected angle, compares the angle deviation with a predetermined value, outputs the command angle as the corrected command angle if the angle deviation is less than the predetermined value, and outputs a value obtained by adding an approximated lead angle to the detected angle as the corrected command angle if the angle deviation is greater than, or equal to, the predetermined value, and the phase of voltage applied to the motor is controlled according to the corrected command angle.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: February 1, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Akio Takemori, Yoshifumi Kuwano, Yukinari Takahashi, Hiroaki Taka
  • Patent number: 6831434
    Abstract: In order to prevent stator windings and power amplification semiconductor devices from being damaged by heat when a rotor is locked, a current feed term setting circuit that maintains an output signal circuit of a logical circuit in “OFF” state to completely cut off currents to the stator windings, when the number of repetitions of “ON” and “OFF” states of the output signal circuit reaches a predetermined value, is added to a driving IC of a control circuit for a brushless DC motor equipped with a protective circuit.
    Type: Grant
    Filed: July 8, 2003
    Date of Patent: December 14, 2004
    Assignee: Japan Servo Co., Ltd.
    Inventor: Shinichi Yoshihara
  • Patent number: 6823919
    Abstract: A lamination system comprises; a film transfer means for transferring along a film transfer path a laminate film in which small windows are provided, a film detection sensor for detecting the laminate film, a cutting means for cutting the laminate film into a predetermined length. The film transfer means further transfers the cut laminate film along the film transfer path, the lamination system further comprises a card transfer means for transferring a card on the surface of which a terminal of an IC tip is provided along a card transfer path, a positioning mean for making the terminal and the small window into a predetermined positional relation, a thermocompression bonding means for laminating laminate film with the card.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: November 30, 2004
    Assignee: Japan Servo Co., Ltd.
    Inventor: Naotaka Sasaki