Abstract:
An angular velocity sensor having a tuning-fork structure comprising a first vibrator including a first actuator and a first detector each attached to a metal plate and joined orthogonally to each other, and a second vibrator including a second actuator and a second detector each attached to another metal plate and joined orthogonally to each other, the two vibrators being coupled by an electrode block to each other in a generally parallel relationship along the axis of detection of the sensor. The first and second detectors have a rectangular plate shape each holding a piezoelectric element. The rectangular plate shape has a lengthwise edge and a widthwise edge where the lengthwise edge parallel to the axis of detection of the sensor and is longer than the width wise edge. At least one of the lengthwise edges of the detectors has a beveled surface formed by removing metal at an angle from the lengthwise edge of the detector to balance the sensor.
Abstract:
An induction heating type cooking appliance is adapted to heat a pan by induction heating. An input unit includes touch control keys and has a timer function so that the power supply is turned on only when at least two keys are actuated properly within a given length of time. Alarms are operatively associated with the timer function so as to alert the operator automatically when the pan is shifted or the appliance is operated under a no-load condition. Such an induction heating type cooking appliance therefore enjoys a high degree of safety.
Abstract:
Provided is a dielectric ceramic which exhibits desired high temperature load resistance characteristics even under a high electric field strength on the order of 15 kV/mm. The dielectric ceramic contains, as its main constituent, a perovskite compound represented by the general formula (Ba1-h-i-mCahSriGdm)k(Ti1-y-j-n-o-pZryHfjMgnZnoMnp)O3, 0≦h≦0.03, 0≦i≦0.03; 0.042≦m≦0.074; 0.94≦k≦1.075; 0≦(y+j)≦0.05; 0.015≦n≦0.07; 0≦o≦0.04; 0≦p≦0.05; and 1.0
Abstract:
An oilless screw compressor incorporating water-cooled cooling units for cooling compressed air discharged from compressor bodies having a pair of male and female screw rotors which can be rotated in a contactless and oilless manner, the cooling units comprising a plate type heat-exchanger, and the amount of cooling water for the plate type heat-exchanger being adjustable. With this configuration, a difference between a temperature during load operation and a temperature upon automatic stopping and during unload operation of the compressor can be reduced, so that the cooling unit can be restrained from being damaged or broken within a short period, thereby it is possible to provide a highly reliable oilless screw compressor.
Abstract:
A screw compressor comprising: a pair of male and female screw rotors; and an air-cooled heat exchanger, wherein the air-cooled heat exchanger is provided above a motor for driving the compressor body; wherein, with respect to a cooling wind for the air-cooled heat exchanger, the air-cooled heat exchanger is inclined to the upstream side; wherein the uppermost portion of a unit suction port for the air-cooled heat exchanger cooling winds is positioned below the uppermost portion of the air-cooled heat exchanger positioned at the uppermost portion; wherein the lowermost portion of the unit suction port for the air-cooled heat exchanger cooling wind is positioned below the lowermost portion of the air-cooled heat exchanger positioned at the lowermost portion; and wherein the cooling wind for the air-cooled heat exchanger is exhausted from a ceiling portion of the compressor unit. With this structure, it becomes possible to provide a compact screw compressor with less noise whose installation area can be reduced.
Abstract:
The invention downsizes and simplifies structures of a compressor and its driving system apparatus, and achieves a reduction of a noise. An oil free screw compressor is constituted by compressor main bodies compressing a gas, a motor driving rotors of the compressor main bodies via step-up gears, a gear casing storing the step-up gears, cooling apparatuses cooling a discharge air and the like. An oil tank is provided independently from the gear casing, the motor is fixed to a common base, the gear casing is integrally attached to the motor via a flange, and the compressor main bodies are integrally attached to the gear casing via the flange. Further, the cooling apparatuses are arranged in an upper side of the driving system apparatus, and a cooling fan is installed in an upper side thereof.
Abstract:
A screw compressor comprising: a low pressure stage compressor body; a high pressure stage compressor body that further compresses a compressed air compressed by the low pressure stage compressor body; pinion gears for example, respectively, provided on, for example, a male rotor of the low pressure stage compressor body and, for example, a male rotor of the high pressure stage compressor body; a motor; a bull gear for example, provided on a rotating shaft of the motor; and an intermediate shaft supported rotatably and provided with a pinion gear, which meshes with the bull gear, and a bull gear, which meshes with the pinion gears. Thereby, it is possible to make the motor relatively low in rotating speed while inhibiting the gears from being increased in diameter, thus enabling achieving reduction in cost.
Abstract:
An oil free screw compressor having a low-pressure stage compressor body and a high-pressure stage compressor body. Power of a motor driven by an inverter is transmitted to the compressor bodies through gears. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. During no-load operation, a controller gives a command to the inverter to make the rotational speed of the motor a set lower limit rotational speed, and also gives an open command to the low-pressure stage blow-off two-way valve.
Abstract:
In an oil-free type screw compressor including a low-pressure-stage compressor main body and a high-pressure-stage compressor main body, when the power of an motor is transmitted to an oil pump via a gear to start the pump, the lubrication oil stored in an oil sump formed at the bottom of a gear casing flows through an oil strainer. A part of the oil is introduced to an oil cooler, while the rest is introduced to a junction portion by bypassing the oil cooler. Further, a part of the oil introduced to the oil cooler is directed to the junction portion. After adjusting the temperature of the oil appropriately, it is introduced to a lubrication portion of the compressor, while the oil cooled by the oil cooler using the full capacity thereof is introduced to oil jackets of the compressor main bodies via different passages.
Abstract:
Provided is a highly reliable oil free screw compressor including a first sensor for detecting a temperature of lubrication oil, second sensors for detecting temperatures of intake air, and a cooling fan controller having a storage portion storing therein a set temperature of lubrication oil and a set temperature of intake air, and a computing portion for computing a control signal for increasing the speed of the cooling fan if a detected value of a temperature of the lubrication oil, delivered from the first sensor, becomes higher than the set value of lubrication oil stored in the storage portion, and computing a control signal for increasing the speed of the cooling fan if a detected value of a temperature of the intake air, delivered from the second sensor, becomes higher than the set temperature of the intake air, stored in the storage portion.