Abstract: To provide a characteristic evaluation device that can properly evaluate a characteristic of a shaft coupling while considering a delay in a response of a motor, a characteristic evaluation device of a shaft coupling includes: a motor system including a drive motor, a rotation angle sensor configured to acquire a rotation angle of a drive shaft, and a motor control unit configured to control the drive motor based on a torque command; a rotational load connected to a driven shaft; and a processor configured to output the torque command and calculate a frequency response of a gain of an amplitude of an angular velocity ? of the rotation angle, wherein the processor is configured to calculate a characteristic of the shaft coupling based on a response characteristic of the motor system and the frequency response.

Abstract: A flexible shaft coupling demonstrates a high performance in transmitting torque and accommodating positional deviations, and is yet highly durable. A first elastomer member (82) having a relatively high rubber hardness is circumferentially interposed between a first claw (32) of a first shaft coupling member (20) and a second claw (62) of a second shaft coupling member (50), and a second elastomer member (84, 86) having a lower rubber hardness than the first elastomer member is interposed between a surface portion (end surface) (30) of the first shaft coupling member (20) and the second claw (62) and/or between a surface portion (end surface) (60) of the second shaft coupling member (50) and the first claw (32).

Abstract: Provided is a flexible shaft coupling which demonstrates a high performance in transmitting torque and accommodating positional deviations, and is yet highly durable. A first elastomer member (82) having a relatively high rubber hardness is circumferentially interposed between a first claw (32) of a first shaft coupling member (20) and a second claw (62) of a second shaft coupling member (50), and a second elastomer member (84, 86) having a lower rubber hardness than the first elastomer member is interposed between a surface portion (end surface) (30) of the first shaft coupling member (20) and the second claw (62) and/or between a surface portion (end surface) (60) of the second shaft coupling member (50) and the first claw (32).

Abstract: An infrasound absorbing structure is simple in construction and is capable of effectively controlling infrasonic noises. The infrasound absorbing structure is applied to an engine test cell or an engine runup hangar to reduce infrasonic noises generate therein. The infrasound absorbing structure includes a porous layer facing an infrasound source, and a back wall disposed opposite to the porous layer so as to define a back air layer of a thickness between 2 and 10 m between the porous layer and the back wall. The porous layer has a surface density in the range of 0.5 to 10 kg/m2.

Abstract: An aircraft engine run-up hangar comprises a building defining a test chamber capable of receiving an aircraft therein, an air inlet structure, and an exhaust structure. The air inlet structure is formed in a front end part of a roof structure corresponding to a front end part of the building, the exhaust structure is connected to a rear end part of the building and defines an exhaust passage extending obliquely upward from the back end of the building, and one or a plurality of current deflecting members are disposed near a lower end of the air inlet structure to deflect air currents flowing through the air inlet structure into the building toward an aircraft housed in the building. A current-straightening structure is incorporated into the air inlet structure. A current-straightening space is defined under the air inlet structure.

Abstract: An aircraft engine run-up hangar comprises a building defining a test chamber capable of receiving an aircraft therein, an air inlet structure, and an exhaust structure. The air inlet structure is formed in a front end part of a roof structure corresponding to a front end part of the building. The exhaust structure is connected to a rear end part of the building and defines an exhaust passage extending obliquely upward from the back end of the building. A ceiling included in the building has an inclined section sloping down backward to straighten air currents, and a groove is formed in a middle part, with respect to width, of the inclined section to permit a vertical tail fin of an aircraft to pass when the aircraft is carried into or out of the test chamber.

Abstract: An aircraft engine run-up hangar comprises a building defining a test chamber capable of receiving an aircraft therein, an air inlet structure, and an exhaust structure. The air inlet structure is formed in a front end part of a roof structure corresponding to a front end part of the building, the exhaust structure is connected to a rear end part of the building and defines an exhaust passage extending obliquely upward from the back end of the building, and one or a plurality of current deflecting members are disposed near a lower end of the air inlet structure to deflect air currents flowing through the air inlet structure into the building toward an aircraft housed in the building. A current-straightening structure is incorporated into the air inlet structure. A current-straightening space is defined under the air inlet structure.

Abstract: An aircraft engine run-up hangar comprises a building defining a test chamber capable of receiving an aircraft therein, an air inlet structure, and an exhaust structure. The air inlet structure is formed in a front end part of a roof structure corresponding to a front end part of the building. The exhaust structure is connected to a rear end part of the building and defines an exhaust passage extending obliquely upward from the back end of the building. A ceiling included in the building has an inclined section sloping down backward to straighten air currents, and a groove is formed in a middle part, with respect to width, of the inclined section to permit a vertical tail fin of an aircraft to pass when the aircraft is carried into or out of the test chamber.