Kabushiki Kaisha Toshiba

Hiroaki Tazawa

Hidero Anno

Katsuhiro Ono

Takayuki Kitami

Hiroyuki Sugiura

A rotary X-ray tube of the anode type wherein a jacket which serves to prevent lubricant from being scattered into the space in a vacuum envelope is attached to at least one of a rotary structure to which an anode target is fixed and a stationary structure for holding the rotating body, enclosing a clearance opening which forms a border relative to the space in the vacuum envelope.

Rotary anode type X-ray tube having a jacket to prevent lubricant from

In a rotary-anode type X-ray tube, a rotary-anode is fixed to a cylindrical rotary structure, and a columnar stationary shaft is fitted in the rotary structure. A gap is formed between the rotary structure and the stationary shaft. The gap is filled with a liquid metal lubricant. Spiral grooves are formed in part of the outer surface of the stationary shaft to form a radial sliding bearing between the stationary shaft and the rotary structure. Spiral grooves are formed in the end faces of the stationary shaft to form a thrust sliding bearing between the stationary shaft and the rotary structure. A recess is formed in the stationary shaft to communicate with gaps in the radial sliding bearing. A lubricant storage chamber for storing the liquid metal lubricant is formed in the stationary shaft along the center axis. The storage chamber communicates with communicating holes which radially extend to be open to an outer surface region, of the stationary shaft, in which no spiral grooves are formed. With this structure, a sufficient amount of liquid metal lubricant required for a long-term operation of the sliding bearings can be stored in the X-ray tube, thereby maintaining a stable dynamic pressure type sliding bearing operation for a long period of time.

Rotary-anode type X-ray tube

A rotary-anode type X-ray tube wherein bubbles produced in the gap of a sliding bearing are securely and easily replaced with liquid metal lubricant, and the metal lubricant is prevented from leaking. The rotary anode is secured to a cylindrical rotary structure. A columnar fixed structure is secured to the rotary structure forming a gap between the rotary structure and fixed structure. A liquid metal lubricant fills the gap. Spiral grooves are formed on a part of the outer surface of the fixed structure and the sliding bearing is installed between the fixed structure and the rotary structure. The rotary structure and fixed structure are housed in a vacuum envelope. The gap of the sliding bearing is connected to the space inside the vacuum envelope through an annular space. A gap is formed between a ring block for blocking the opening of the rotary structure and the fixed structure. A spiral groove to return the metal lubricant to the annular space is formed on the outer surface of the ring block facing the gap, and the annular space is coated with a film repelling the metal lubricant. The annular space and the gap between the ring block and the fixed structure serve to separate from the metal lubricant in the sliding bearing, the bubbles produced therein.

Growing community of inventors

Ootawara, Japan

Hiroaki Tazawa