Aisin Seki Co., Ltd.|
2-1, Asahi-machi, Kariya
Aichi 448, Japan
Tel: 81-0566-24-8323; Fax: 9045
|Date Visited:||January 29, 1997 (during visit to Nagoya University)|
|WTEC Attendees:||M. Nisenoff (report author), M. Beasley, G. Gamota, H. Morishita, F. Patten, R. Ralston, J. Rowell|
T. Inoue, Deputy Research Director, Cryogenics Group|
N. Okumura, Manager, Cryogenic System Development Group
Although the principal activity of Aisin Seki is manufacturing automobile parts for Toyota, the company has been in the cryogenic refrigeration business for more than 20 years. The primary cryogenic product of Aisin Seki's cryogenic group has been cryogenic vacuum pumps, but recently it has developed an interest in cryogenic refrigeration systems for other applications such as infrared sensor and high temperature superconducting (HTS) applications.
The cryogenic vacuum pumps built by Aisin Seki have been based on the Gifford-McMahon (GM) cycle. The new activity is in the area of pulse tube cryocoolers employing either the orifice configuration or the valved type. Aisin Seki researchers are looking at single-stage pulse tube systems with cooling capacity of about 10 watts at 80 K and zero heat load temperatures near 30 K for an electrical input power of about 700 watts. They are also developing a two-stage pulse tube system with three rotary valves that will have a zero heat load temperature near 4.5 K and provide 1 watt of cooling at 7 K, or 2 watts at 10 K with an electrical input power of 2.8 kW.
In response to possible interest from the HTS cellular base station community, Aisin Seki is also investigating a cryogenic refrigerator using a compressor with two opposed linear actuated pistons driven at 50 Hz, which would provide about 5 watts of cooling at 77 K and zero heat load at 50 K for 200 to 250 watts of electrical input power. The panel's hosts indicated that they thought that the Personal Communications System (PCS) based on HTS may be inserted in 1998 in the United States as well as Japan, but they felt that HTS filters for such applications may not be available in Japan in that time frame, and therefore, if such systems are used, they may have to be procured from U.S. vendors. However, they would like to provide cryogenic refrigeration systems for HTS wireless applications in the future.