VACUUM PUMP
First Claim
1. A vacuum pump, comprising:
- a casing provided with an inlet port and an outlet port;
a stator portion provided inside the casing;
a rotor portion having a shaft rotatably supported inside the casing, and a rotor disposed on the shaft and provided with a gas transfer mechanism that transfers a gas from the inlet port to the outlet port, the rotor portion being arranged with a predetermined clearance between the rotor portion and the stator portion;
a motor rotating the shaft;
vibration detection means for detecting vibration; and
contact detection means for detecting an occurrence of contact between the stator portion and the rotor portion when, in the vibration detected by the vibration detection means, a specific vibration caused by contact between the stator portion and the rotor portion exceeds a predetermined threshold value.
1 Assignment
0 Petitions
Accused Products
Abstract
Provided is a vacuum pump which can detect precisely physical contact between a rotor portion and a stator portion, and contact between the rotor portion and the stator portion that occurs as the amount of deposited solid product reaches the clearance between the rotor portion and the stator portion.
A vibration sensor is provided, taking advantage of a clearance, at the outer peripheral of a thread groove spacer. Contact between the rotor portion and the stator portion is decided, when a particular vibration during contact between the rotor portion and the stator portion exceeds a predetermined threshold value. The vibration sensor is mounted on the outer peripheral of the thread groove spacer at the end of the side of an exhaust port. The thread groove spacer is fixed on a casing via an elastic member (an O-ring) that have a vibration absorption (vibration damping) function of a cutoff frequency (fc1). A vibration signal outputted from the vibration sensor is converted into a digital vibration signal, and is inputted to a digital filter having a passing band of fc1 to fc2 [Hz]. If the vibration level of the vibration signal having passed through the digital filter exceeds a predetermined threshold value, it is detected that contact between the rotor portion and the stator portion has occurred in a turbo-molecular pump.
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Citations
15 Claims
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1. A vacuum pump, comprising:
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a casing provided with an inlet port and an outlet port; a stator portion provided inside the casing; a rotor portion having a shaft rotatably supported inside the casing, and a rotor disposed on the shaft and provided with a gas transfer mechanism that transfers a gas from the inlet port to the outlet port, the rotor portion being arranged with a predetermined clearance between the rotor portion and the stator portion; a motor rotating the shaft; vibration detection means for detecting vibration; and contact detection means for detecting an occurrence of contact between the stator portion and the rotor portion when, in the vibration detected by the vibration detection means, a specific vibration caused by contact between the stator portion and the rotor portion exceeds a predetermined threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A vacuum pump, comprising:
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an casing provided with an inlet port and an outlet port; a stator portion provided inside the casing; a rotor portion having a shaft rotatably supported inside the casing, and a rotor disposed on the shaft and provided with a gas transfer mechanism that transfers a gas from the inlet port to the outlet port, the rotor portion being arranged with a predetermined clearance between the rotor portion and the stator portion; a motor rotating the shaft; an elastic member having a vibration damping characteristic, disposed between the casing and the stator portion; vibration detection means disposed on the stator portion; a filter to which an output of the vibration detection means is inputted, and having, as a pass band, a frequency band higher than a cutoff frequency of the vibration damping characteristic of the elastic member; and contact detection means for detecting an occurrence of contact between the stator portion and the rotor portion when an output of the filter exceeds a predetermined threshold value. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification