Ebara Corporation

Matsushita Electric Industrial Co., Ltd.

Kazuyuki Kasahara

Shunichi Aiyoshizawa

Kazuto Hirokawa

Yoshio Sato

Daisuke Konno

Sachihiko Miwa

Toshisuke Sakai

Shigeru Narakino

Yoshimitsu Aizono

Kyo Niwatsukino

Yumiko Noda

Masashi Hirose

Shinya Koga

Toshihiko Matsuda

Toshiyuki Kubota

Masashi Yamaguchi

Katsumi Sasaki

Yoichi Kanemitsu

Yuji Shirao

Yasushi Hisabe

Shotaro Mizobuchi

YOshikazu Kimura

Toshihiro Ohtani

Masahiko Kishi

Takashi Kataoka

Manabu Toshimitsu

Toshiya Kanamori

Motohiko Matsuguma

Tohru Maruyama

Noriyuki Osada

Hideo Tsuboi

Yoshikazu Suganuma

Yasumasa Fukami

Yasuhiko Ezaki

Takashi Ehara

A cooling device for cooling a heat-generating component includes a circulating passage arranged to have coolant circulate therein, a centrifugal pump including a first case made of metallic material, a second case made of resin material, and an impeller accommodated in the pump chamber, and a radiator provided at the circulating passage and being operable to release heat from the coolant. The first case has a surface arranged to contact the heat-generating component. The second case forms a pump chamber between the first case and the second case. The pump chamber stores the coolant therein. The impeller includes open-type vanes arranged to pressurize the coolant as to have the coolant flow through the circulating passage. The cooling device has a high cooling efficiency as well as a high operating efficiency of the motor while having a simple construction and a small overall size and a small thickness.

Cooling device and an electronic apparatus including the same

A pump for circulating a coolant has a housing thereof in direct thermal connection with an electronic component. This provides both the improvement of cooling efficiency of a cooling device and the realization of a compact, slim design of the device.

A circulation path, a radiator and a reserve tank which can remove air bubbles from the fluid passageway, constitute parts of a closed circulation path, and are formed by joining a flow path wall-forming radiation board on which curved surfaces as flow path walls are formed, with a flat plate-like flow path wall-forming radiation board as another curved surface by welding or the like. Therefore, the efficiency of heat exchange of a cooling apparatus for electronic equipment can be improved, removal of air bubbles from the flow passageway and reduction in size, weight and thickness is made possible without causing air lock.

Cooling apparatus for electronic equipment

A vortex flow meter includes a measuring tube in which a fluid is carried, a vortex generator provided in the measuring tube for developing a Karman vortex in the fluid, a magnetic field generator generating a magnetic field across the measuring tube downstream of the vortex generator, a pair of electromotive force measuring electrodes provided downstream of the vortex generator for measuring an electromotive force generated by the Karman vortex passing across the magnetic field, a pair of reference electrodes provided at locations upstream and downstream of the electromotive force measuring electrodes, respectively, for measuring a potential at each location, and a detector circuit electrically connected to the electromotive force measuring electrodes and the reference electrodes for calculating the flow of the fluid from the electromotive force and the potential measured by the reference electrodes. The flow is calculated by subtracting the potential difference of the reference potential measuring electrodes from the electromotive force measured by the electromotive force measuring electrodes. This allows the flow meter to have an increased measuring range, meet a wide range of flow conditions, have a simple construction, and have measurement accuracy.

Vortex flow meter

A spindle motor with an H-type pneumatic dynamic bearing has a high durability against repeated starts and stops of rotation. The H-type bearing is composed of a radial bearing member, thrust plates firmly fixed to opposite ends of the radial bearing member and a cylindrical radial sleeve, which form a radial pneumatic dynamic bearing and thrust pneumatic dynamic bearings. A stator core is fixedly secured around a rotary member, which is in turn fixedly secured around the cylindrical radial sleeve. A total thrust clearance a+a' of the thrust bearings is represented by an inequality of (a+a')/A&lt; 2.5/10.sup.4 based on a sliding surface diameter A of each thrust plate, a and total radial clearance b+b' of the radial bearing is represented by an inequality of (b+b')/B&lt;5/10.sup.4 based on a sliding surface diameter B of the radial bearing member.

Spindle motor using dynamic pressure bearings

Hydrodynamic bearing

A spindle motor has a rotor supported by a stator through a thrust bearing and a radial bearing. At least the thrust bearing is a hydrodynamic bearing. The spindle motor is provided with a device for adjusting the thrust laod that is applied to the thrust bearing. The load adjusting device has an electromagnet that is provided on the stator and a permanent magnet that is provided on the rotor in opposing relation to the electromagnet. Either the repelling force or the attraction force, which acts between the electromagnet and the permanent magnet, is controlled by changing the current supplied to the electromagnet.

Spindle motor

A bearing structure suitable for a spindle motor or the like, which enables such a motor to rotate with minimal vibrations. The bearing structure comprises a stator including a support shaft which is disposed on a base, and a rotor which is rotatably disposed around the support shaft. A radial hydrodynamic bearing and a thrust hydrodynamic bearing are disposed between the stator and the rotor. The stator has the support shaft, a thrust plate and a radial cylindrical member which is concentric with the support shaft. The thrust plate is secured to an end surface of the radial cylindrical member. The support shaft extends through the centers of the radial cylindrical member and the thrust plate. The rotor has a radial sleeve. The radial hydrodynamic bearing is formed from the inner peripheral surface of the radial sleeve and the outer peripheral surface of the radial cylindrical member, which face each other and either of which is formed with herringbone-shaped grooves for generating dynamic pressure. The thrust hydrodynamic bearing is formed from an end surface of the radial sleeve and a sliding surface of the thrust plate, which face each other and either of which is formed with spiral grooves for generating dynamic pressure. A rolling bearing may be added in order to minimize the starting torque in the bearing structure.

Bearing structure

A spindle motor which is designed to rotate with minimal vibrations and hence is suitable for a hard disk driver. The spindle motor employs hydrodynamic bearings as radial and thrust bearings. A support shaft is formed in a cylindrical configuration with a center hole, and a rotor has a columnar portion which is inserted into the center hole in the support shaft. A thrust bearing collar is attached to the lower end of the rotor, and a thrust bearing member is secured to a base in opposing relation to the thrust bearing collar. A group of stator coils and a radial bearing member are disposed on either the inner peripheral surface of the center hole in the support shaft or the outer peripheral surface of the support shaft, and a group of rotor magnets and a radial bearing sleeve are disposed on either the outer peripheral surface of the columnar portion or the inner peripheral surface of the rotor in opposing relation to the stator coil group and the radial bearing member.

A spindle motor comprising a stator including a support shaft positioned on a base, a cap-shaped rotor rotatably and concentrically disposed around the support shaft, thrust and radial bearings disposed between the stator and the rotor, a stator coil secured to the stator, and a rotor magnet member secured to the rotor opposing the stator coil. The thrust and radial bearings are hydrodynamic bearings. A movable piece that constitutes a part of the thrust bearing is secured to the lower end of a cylindrical portion of the rotor and extended outwardly or inwardly from the cylindrical portion, or is disposed above the rotor. The stator coil is secured to the outer peripheral portion of the support shaft above or below the radial bearing. The rotor magnet member is securd to the inner peripheral surface or inner top surface of the rotor. Either a radial or axial gap is provided between the stator coil and the rotor magnet member.

Gas dynamic bearing for spindle motor

A novel thrust bearing is provided in which a spiral element having a disc shape is loosely interposed between a pair of flat elements one of which is rotatable and the other of which is stationary, the spiral element having a spiral groove pattern on each of the opposite surfaces of the disc with the patterns on the respective surfaces reverse in relation to each other in their spiral direction.

Thrust bearing

Growing community of inventors

Kanagawa, Japan

Kazuyuki Kasahara