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Patent
Dynax Corporation | Date: 2015-01-28

To reduce eddy current loss occurring to a supporting member of a rotor of an axial gap motor, and improve efficiency of a motor. The axial gap motor of the present invention includes a rotor 10 and stators 20 and 22 arranged opposite to this rotor 10. The rotor has a disk-shaped supporting member 12 on which a plurality of permanent magnet segments 11 is mounted. In the stators 20 and 22, a plurality of field winding slots is arranged for generating a rotating magnetic field.


Patent
Dynax Corporation | Date: 2017-01-11

To reduce eddy current loss occurring to a supporting member of a rotor of an axial gap motor, and improve efficiency of a motor. The axial gap motor of the present invention includes a rotor 10 and stators 20 and 22 arranged opposite to this rotor 10. The rotor has a disk-shaped supporting member 12 on which a plurality of permanent magnet segments 11 is mounted. In the stators 20 and 22, a plurality of field winding slots is arranged for generating a rotating magnetic field.


Pahlovy S.A.,Dynax Corporation | Mahmud S.F.,Dynax Corporation | Kubota M.,Dynax Corporation | Ogawa M.,Dynax Corporation | Takakura N.,Dynax Corporation
SAE International Journal of Engines | Year: 2016

A significant reduction of C02 emission can be achieved by improving the efficiency of transmission of cars. A reduction of drag torque or spin loss of disengaged clutches can improve the efficiency of transmissions. Generally, the drag torque is measured by conducting drag test which needs making samples, manpower, power and wastage of raw materials. In this paper, an analytical model is proposed to predict the drag torque of a disengaged wet clutch at different rotation speeds, clearances, disk sizes and oil temperatures without making any samples and conducting any drag tests. Various assumptions are made from the results of visualization investigations. Visualization results show that the volume of oil existed in between the clutch disk and clutch plate decreases with increasing speed due to centrifugal force. It is also noticed that several visible air bubbles are formed in the oil film at lower speeds and the size of the bubbles increase with increasing speeds. We consider that the gas cavitation has a significant role in air bubble formation. The model is validated with test results and it shows that they are almost coincident with each other. Copyright © 2016 SAE International.


Sone K.,Hokkaido University | Takemoto M.,Hokkaido University | Ogasawara S.,Hokkaido University | Takezaki K.,Dynax Corporation | Hino W.,Dynax Corporation
2013 IEEE Energy Conversion Congress and Exposition, ECCE 2013 | Year: 2013

Small electric vehicles called city commuters are used for commuting and traveling short distances within cities. These vehicles have been extensively researched and developed because of their high environmental performance and small battery size. The in-wheel permanent magnet synchronous motor (PMSM) for electric city commuters generally utilizes powerful rare earth permanent magnets (PMs). However, the employment of rare earth PMs should be reduced, owing to increasing prices and export restrictions on rare earth materials, making it necessary to develop an in-wheel PMSM that does not use rare earth PMs. We propose a ferrite PM-type axial gap motor that generates high torque density and has features such as a coreless rotor structure and a reduction gearbox on the inner side of the stator. Detailed operational characteristics of the proposed motor remain unverified by experiment, so this paper presents such operational characteristics as obtained from experimentation on a prototype. © 2013 IEEE.


Takahashi T.,Hokkaido University | Takemoto M.,Hokkaido University | Ogasawara S.,Hokkaido University | Hino W.,Dynax Corporation | Takezaki K.,Dynax Corporation
2015 18th International Conference on Electrical Machines and Systems, ICEMS 2015 | Year: 2015

In-wheel type permanent magnet synchronous motors (PMSMs) for electric city commuters are required to be compact and light in weight in order to utilize limited wheel space effectively and reduce unspringing weight. Therefore our previous papers presented a low cost in-wheel axial gap motor using ferrite permanent magnets. This motor adopted open slot structure to reduce production cost. However, owing to achieving further size and weight reduction, we newly examine to adopt semi-closed slot structure instead of open slot structure. This paper introduces its examination results in detail. Moreover, experimental results show that the semi-closed slot structure is effective in realizing size and weight reduction. © 2015 IEEE.


Sone K.,Hokkaido University | Takemoto M.,Hokkaido University | Ogasawara S.,Hokkaido University | Takezaki K.,Dynax Corporation | Hino W.,Dynax Corporation
2014 International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014 | Year: 2014

In general, the in-wheel type permanent magnet synchronous motor (PMSM) for electric city commuters uses powerful rare earth permanent magnets (PMs). However, the employment of the rare earth PMs should be reduced due to high prices. Therefore, it is important to develop an in-wheel PMSM that does not use the rare earth PMs. We proposed 5kW in-wheel type axial gap motor that can generate high torque density and has features such as a coreless rotor structure with ferrite PMs and a reduction gearbox in the inner side of the stator. And we have presented details of experimental results on a prototype. So, in this paper, in order to achieve further higher power output, we considered a 10 kW in-wheel motor with the proposed structure. The motor with 10-kW output was examined by means of using 3D-FEM and experimental results in order to attain the further higher power as a rare earth free motor. © 2014 IEEE.


Mahmud S.F.,Dynax Corporation | Pahlovy S.A.,Dynax Corporation | Kubota M.,Dynax Corporation | Ogawa M.,Dynax Corporation | Takakura N.,Dynax Corporation
SAE Technical Papers | Year: 2016

Drag torque reduction is one of the key targets to improve the efficiency of transmission. Drag torque is generated by the automatic transmission fluid (ATF) that is circulated in the gap between the friction disks and separator plates for cooling purpose. Due to the relative motion between the friction disks and separator plates in disengaged mode, a shear stress is developed on the disks' wall which gives rise to drag loss. The most conventional technique to suppress the drag loss is to cut grooves on the friction disk to facilitate smooth and faster discharge of the ATF. The shape of the grooves also plays a substantial role on the drag torque characteristics. Previously, we presented a simplified simulation model to predict the drag torque behavior of different grooves. However, the simplified model doesn't include the oil inflow and outflow behavior from the oil inlet and outlet holes respectively. In this research, we presented an improved simulation model with an extended simulation domain to consider the effect of oil inflow and outflow behavior on the drag torque. This model helps us to realize the influence of the groove size and shape on the multi-phase drag torque behavior in more detail. The comparative profile of different grooves obtained from simulation reflects close similarity with the test result. Therefore, the simulation model leads to a convenient method of optimizing the size and shape of the grooves and plays a pivotal role to select better groove pattern for the suppression of drag loss. © 2016 SAE International.


Patent
Dynax Corporation and Hokkaido University | Date: 2014-10-03

To reduce eddy current loss in a supporting member of a rotor of an axial gap motor, and improve efficiency of a motor. The axial gap motor of the present invention includes a rotor 10 and stators 20 and 22 arranged opposite to this rotor 10. The rotor has a disk-shaped supporting member 12 to which a plurality of permanent magnet segments 11 is installed. In the stators 20 and 22, a plurality of field winding is arranged for generating a rotating magnetic field. The axial gap motor is provided with a notched part 18 radially extending between amounting hole 16 of the supporting member 12, in which each of the plurality of permanent magnet segments 11 is fitted, and an outer peripheral edge 17 of the supporting body 12.


Patent
Dynax Corporation and Hokkaido University | Date: 2016-10-19

To reduce eddy current loss in a supporting member of a rotor of an axial gap motor, and improve efficiency of a motor. The axial gap motor of the present invention includes a rotor 10 and stators 20 and 22 arranged opposite to this rotor 10. The rotor has a disk-shaped supporting member 12 to which a plurality of permanent magnet segments 11 is installed. In the stators 20 and 22, a plurality of field winding is arranged for generating a rotating magnetic field. The axial gap motor is provided with a notched part 18 radially extending between a mounting hole 16 of the supporting member 12, in which each of the plurality of permanent magnet segments 11 is fitted, and an outer peripheral edge 17 of the supporting body 12.


Trademark
Dynax Corporation | Date: 2014-04-14

Chemical additives and sizing compounds for the fiber, textile, paper, leather, plastic, synthetic resin, coating, wax, polish and ink industries. Finishes in the nature of coatings for the fiber, textile, paper, leather, plastic, synthetic, resin, coating, wax, polish and ink industries.

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