Ōsaka, Japan
Ōsaka, Japan

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Watanabe M.,Osaka Vacuum Ltd. | Fujita K.,Osaka Vacuum Ltd.
Journal of the Vacuum Society of Japan | Year: 2015

Turbomolecular pump is featured by mainly two performance, they are pumping speed (or volume flow rate) and ultimate pressure, which mean how fast and how lower the pressure pump can evacuate a vacuum chamber, respectively. The measurement methods of these pump's characteristics are specified in the JAPANESE INDUSTRIAL STANDARDS (JIS B 8328), and specific numerical values are provided by turbo molecular pump's manufacturers. These days, the turbomolecular pump that has the ability to handle larger rate of gas under low vacuum is required in the field of semiconductor and liquid-crystal display panel device manufacturing, for example. This kind of pump's performance characteristics are expressed by the terms such as the maximum throughput, maximum working pressure, maximum backing pressure, critical backing pressure and so on. But recently, the definitions in the manufacture's specifications do not always coincide each other, and sometimes seems different from relevant standards. In this report, we refer to the current standards with regard to turbomolecular pumps performance characteristics and related terms, and refer to concerns about definitions of the maximum backing pressure, ultimate pressure and maximum throughput which seem especially inaccurate in terms of the definition of terms and way of expression. © 2015, Vacuum Society of Japan. All rights reserved.


Provided is a radial direction controller capable of handling changes in negative bearing stiffness according to the mounting orientation. This radial direction controller, which is a magnetic bearing device that lifts and supports a rotating body by electromagnets, is equipped with: a radial control circuit for controlling displacement of the axis of the rotating body in the radial direction; a negative bearing stiffness elimination circuit that is connected in parallel with the radial control circuit and outputs a signal about the negative bearing stiffness; converters that output current values for controlling the electromagnets, based on the output signals from these circuits; filters that extract the DC component from the current values; computing units that compute correction coefficients based on the extracted DC components and the bias current of the electromagnets; and multiplication units that multiply the computed correction coefficients with the signal output from the negative bearing stiffness elimination circuit.


Patent
Osaka Vacuum Ltd. | Date: 2015-07-15

A molecular pump (1A) includes a pump body (2) provided with a turbo molecular pump portion (2a), a control unit (4) provided with a control portion and a power supply portion, and a cooling unit (3) for cooling the pump body (2) and the control unit (4). A first temperature detecting portion (90) is provided in a first position, which is a position inside the control unit (4) and has a low temperature. A second temperature detecting portion (80) also serving as a humidity detecting portion is provided in a second position, which is a position inside the control unit (4) and has a high temperature. The control portion controls the operation of the cooling unit (3) in accordance with a relative humidity in the first position, calculated based on temperature information detected by the first temperature detecting portion (90) and based on temperature information and humidity information detected by the second temperature detecting portion (80) also serving as a humidity detecting portion.


Provided is a radial direction controller capable of handling changes in negative bearing stiffness according to the mounting orientation. This radial direction controller (10A), which is a magnetic bearing device (1) that lifts and supports a rotating body (2) by electromagnets (4a, 5a), is equipped with: a radial control circuit (11) for controlling displacement of the axis (Ax) of the rotating body (2) in the radial direction; a negative bearing stiffness elimination circuit (12) that is connected in parallel with the radial control circuit (11) and outputs a signal pertaining to the negative bearing stiffness; converters (61, 62, 63, 64) that output current values for controlling the electromagnets (4a, 5a), based on the output signals from these circuits (11, 12) ; filters (76, 77, 78, 79) that extract the DC component from the current values; computing units (81, 82, 83, 84) that compute correction coefficients (C) based on the extracted DC components and the bias current (10) of the electromagnets (4a, 5a); and multiplication units (55, 56, 57, 58) that multiply the computed correction coefficients (C) with the signal output from the negative bearing stiffness elimination circuit (12).


Dsp

Trademark
Osaka Vacuum Ltd. | Date: 2011-06-24

Vacuum pumps.


Trademark
Osaka Vacuum Ltd. | Date: 2012-03-20

Vacuum pumps (machines).


Trademark
Osaka Vacuum Ltd. | Date: 2012-03-20

Vacuum pumps (machines).


Trademark
Osaka Vacuum Ltd. | Date: 2012-03-20

Vacuum pumps (machines).


Trademark
Osaka Vacuum Ltd. | Date: 2012-05-08

Vacuum pumps (machines).


Patent
Osaka Vacuum Ltd. | Date: 2013-08-27

A molecular pump includes a pump body provided with a turbo molecular pump portion, a control unit provided with a control portion and a power supply portion, and a cooling unit for cooling the pump body and the control unit. A first temperature detecting portion is provided in a first position, which is a position inside the control unit and has a low temperature. A second temperature detecting portion also serving as a humidity detecting portion is provided in a second position, which is a position inside the control unit and has a high temperature. The control portion controls the operation of the cooling unit in accordance with a relative humidity in the first position, calculated based on temperature information detected by the first temperature detecting portion and based on temperature information and humidity information detected by the second temperature detecting portion also serving as a humidity detecting portion.

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