Ntn Corporation

Heishin Sobi Kabushiki Kaisha

Teruaki Akamatsu

Tsugito Nakazeki

Toshihiko Nojiri

Mikio Yamashita

Nobuhisa Suhara

Takayoshi Ozaki

Minoru Suzuki

Motoharu Niki

Hiroyoshi Ito

Saburo Oshima

Tetsuo Nomachi

A rotor drive mechanism and pump apparatus according to the present invention may cause an external screw type rotor of a uniaxial eccentric screw pump to rotate and carry out a revolution movement. The rotor drive mechanism further comprises a shaft sealing structure configured such that a gap between an outer peripheral portion of an end portion of the revolution shaft is located on the external screw type rotor side and an inner peripheral portion of the casing in the pump apparatus is sealed. The rotor drive mechanism provides for a reduced amount of heat and vibrations to be generated when the rotor is rotated at high speed and further allows for lowering of contact pressure between an outer surface of the rotor and an inner surface of a stator inner hole.

Rotor drive mechanism and pump apparatus

A pump apparatus includes a first rotor drive mechanism configured to transfer rotation of an input shaft portion to an output shaft portion coupled to an external screw type rotor of a uniaxial eccentric screw pump, the input shaft portion being rotated with a central axis thereof kept in a certain position, and a uniaxial eccentric screw pump. The output shaft portion is rotatably provided via a bearing at a position eccentrically located with respect to the input shaft portion. The rotation of the input shaft portion is transferred through a first power transmission mechanism, including an inner gear, to the output shaft portion to cause the output shaft portion to carry out an eccentric rotational movement. The input shaft portion and the output shaft portion are arranged inside a pitch circle of the inner gear.

Rotor drive mechanism, eccentric shaft sealing structure, and pump apparatus

A centrifugal fluid pump assembly has a pump body and a controller. The pump body has a housing, a pump section having an impeller rotating inside the housing, an impeller rotational torque generating section having a motor for rotating the impeller and an impeller position control section. The impeller rotates without contacting the housing. The controller has an impeller-floating position control function for changing the floating position of the impeller inside the housing by using the impeller position control section, a function of measuring electric current for driving the motor and a fluid viscosity calculation function for calculating a viscosity of fluid by utilizing a variation amount of the motor-driving electric current obtained by changing the floating position of the impeller.

Centrifugal fluid pump assembly

When a current is set, a PI control portion performs proportional integration control, a power amplifying circuit performs power amplification, whereby a current flowing through a motor is controlled to have a constant value. Further, the changes of the number of rotation is positively feedback and the changes are added to the set current by an adder. Further, blood viscosity is detected by a viscosity detecting circuit, an amount of correction is calculated by a correcting amount operating circuit so that it becomes equal to a reference value, and the calculated correcting amount is added to the adder.

Method of controlling blood pump

A centrifugal blood pump assembly according to one aspect of the invention includes a housing, an impeller adapted to rotate within the housing for feeding blood, an impeller position control device, and an impeller rotation torque generating device. The impeller rotates without contacting the inner surface of the housing when the position control device and torque generating device are operative. Even when the position control device is inoperative, operation of the torque generating device enables rotation of the impeller while a blood flowpath is defined between the surface of the impeller facing the torque generating device and the inner surface of the housing. A centrifugal blood pump assembly according to another aspect of the invention involves a pump including a housing having blood inlet and outlet ports and an impeller adapted to rotate within the housing for feeding blood. The assembly also includes an uncontrolled magnetic bearing arrangement for the impeller, and controlled magnetic bearing arrangement for the impeller. The bearing arrangements are removably mounted to the pump.

Centrifugal blood pump assembly

In a magnetically suspended type pump, an operating state of the pump can be obtained without using a pressure gauge and a flowmeter. In addition, in the case where the magnetically suspended type pump is applied to a blood pump, in order to reduce the number of connections in a flow path and to avoid thrombus formation, a correlation between current flowing in a motor and flow or a correlation between current flowing in the motor and pressure is obtained in advance, and the speed of rotation of motor is varied by a speed of rotation control circuit in response to an instruction from a CPU circuit, based on the obtained correlation between current and flow or between current and pressure, whereby flow or pressure is controlled.

Magnetically suspended type pump

A turbo pump is disclosed, having a magnetically supported impeller. The turbo pump includes a casing (31) made of a non-magnetic material, an impeller (32) provided in the casing (31), a triaxial controlled magnetic bearing provided outside of the casing (31) for magnetically supporting the impeller (32), and a rotor (37) magnetically coupled to the impeller (32) for rotating the impeller. The triaxial controlled magnetic bearing includes a magnetic member (35) provided on one plane of the impeller and a plurality of electromagnets (39) provided in the casing in such a way as to be opposed to the magnetic member. Coupling between the impeller (32) and the rotor (37) is effected by a plurality of permanent magnets (33, 38) respectively provided thereon. In another aspect of the invention, a plurality of stator windings for generating the rotating magnetic field may be provided on the side of the stator in place of rotating means utilizing a magnetic coupling.

Growing community of inventors

Kyoto, Japan

Teruaki Akamatsu