Patents by Inventor Yasuoki Tomita

Yasuoki Tomita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20020090295
    Abstract: In a cooling structure for a gas turbine, cooling air diffusion holes are formed from inner surface to outer surface of a platform so as to open from high pressure side blade surface of a moving blade offset in a direction toward low pressure side blade surface of adjacent moving blade confronting the high pressure side blade surface, in a direction of primary flow.
    Type: Application
    Filed: December 3, 2001
    Publication date: July 11, 2002
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Shunsuke Torii, Jun Kubota, Yasuoki Tomita, Hiroyuki Aoki, Masamitsu Kuwabara
  • Patent number: 6318960
    Abstract: A gas turbine stationary blade having passages (23, 24) that are provided in the stationary blade (10). A front cylindrical insert (2) is provided in the passage (23) and a rear cylindrical insert (5) is provided in the passage (24), and the inserts are supported at two supporting portions (3a, 3b), (6a, 6b), respectively. A projection (1) is provided at a leading edge portion of the blade so that the leading edge, where the thermal loads are high, is made smaller in size and the number of rows of cooling holes (11a) in the leading edge portion is reduced. Air blowing holes (4b) are provided on the dorsal side rear portion of the front insert (2) and film cooling holes (12) are provided on the dorsal side of the blade, both have diameters that are larger than other air blowing and cooling holes provided in the insert (2) and the blade (10), so that dust in the cooling air is caused to flow out, thereby preventing clogging of the holes.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: November 20, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Masamitsu Kuwabara, Yasuoki Tomita, Eisaku Ito
  • Patent number: 6290462
    Abstract: A gas turbine cooled blade is constructed without an increase in the number of parts or time requirements, in which seal air is maintained at a lower temperature with the heat exchange rate being suppressed, and the heat transfer rate of the cooling medium in cooling passage is enhanced. A plurality of cooling passages (A, B, C, D, E) is provided in a blade, and the first row cooling passage (A) is covered at the blade inner and outer peripheries and communicates with the second row cooling passage (B) through communication holes (6) and with the main flow gas path through film cooling holes (7). The second row cooling passage (B) communicates with the blade inner peripheral cavity (10) to form a seal air supply passage. A plurality of ribs (31) are disposed on the inner wall of cooling passage (22) with a predetermined pitch (P).
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: September 18, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Tatsuo Ishiguro, Koji Watanabe, Masaaki Matsuura, Kenichiro Takeishi, Junichiro Masada, Yasuoki Tomita, Kiyoshi Suenaga
  • Publication number: 20010021343
    Abstract: Gas turbine cooled stationary blade is improved in the structure of a blade and outer and inner shrouds to enhance cooling efficiency and to prevent occurrence of cracks due to thermal stresses. Blade (1) wall thickness between 75% and 100% of blade height of a blade leading edge portion is made thicker and blade (1) wall thickness of other portions is made thinner, as compared with a conventional case. Protruding ribs (4) are provided on a blade (1) convex side inner wall between 0% and 100% of the blade height. Blade (1) trailing edge opening portion is made thinner than the conventional case. Outer shroud (2) is provided with cooling passages (5a, 5b) for air flow in the shroud both side end portions. Inner shroud (3) is provided with cooling passages (9a, 9b) for air flow and cooling holes (13a, 13b) for air blow in the shroud both side end portions.
    Type: Application
    Filed: March 8, 2001
    Publication date: September 13, 2001
    Inventors: Masamitsu Kuwabara, Yasuoki Tomita, Akihiko Shirota, Eisaku Ito
  • Publication number: 20010016163
    Abstract: Gas turbine moving blade is improved so as to prevent occurrence of cracks caused by thermal stresses due to temperature differences between blade and platform when gas turbine is stopped. In steady operation time of moving blade (20), cooling air (40 to 43) enters cooling passages (23 to 26) to flow through cooling passages (23a, 24a to 24c, 25a to 25c) for cooling the blade (20) to then flow out of the blade (20). Recessed portion (1) having smooth curved surface is provided in platform (22) near blade fitting portion on blade trailing edge side. Fillet (R) of the blade fitting portion on the blade trailing edge side is formed with curved surface having curvature larger than conventional case. Hub slot below the fillet (R) for blowing air is formed having slot cross sectional area larger than other slots of blade trailing edge. TBC is applied to blade (20) surface.
    Type: Application
    Filed: February 23, 2001
    Publication date: August 23, 2001
    Inventors: Yasuoki Tomita, Yukihiro Hashimoto, Kiyoshi Suenaga, Hisato Arimura, Shunsuke Torii, Jun Kubota, Akihiko Shirota, Sunao Aoki, Tatsuo Ishiguro
  • Patent number: 6270311
    Abstract: In gas turbine split rings, end faces having bent surfaces are formed in flanges. Adjoining split rings are coupled together with a groove therebetween to form a cylindrical split ring. Notches are formed in the flanges. These notches are sealed by inserting a seal plate into the notches of adjoining split rings. A hole for passing cooling air is drilled obliquely in the flange. Cooling air is allowed to flow out along the direction of rotation (of the turbine). This cooling air cools the outlet of the groove due to the effect of film cooling. Because of such cooling, high temperature gas is prevented from staying in this area, cooling effect is enhanced, and hence burning of the end portions can be prevented.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: August 7, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Masamitsu Kuwabara, Yasuoki Tomita, Kiyoshi Suenaga, Masahito Kataoka, Yoshichika Sato, Koji Watanabe
  • Patent number: 6264426
    Abstract: In cooling a gas turbine stationary blade, steam and air are used as cooling media, the steam is recovered surely without leakage and used effectively, and the amount of air required for cooling is decreased to provide a margin for combustion air, by which the gas turbine efficiency is improved. A steam cooling section is provided at the rear from the blade leading edge, and an air cooling section is provided at the blade trailing edge. The steam cooling is effected by cooling the blade by the cooling steam flowing in the serpentine flow path having turbulators after impingement cooling of an outside shroud and by impingement-cooling an inside shroud during the cooling process, the cooling steam being led to a recovery section from the outside shroud. On the other hand, the air cooling section consists of an air flow path extending from the outside shroud to the inside shroud and slot cooling at the blade trailing edge.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: July 24, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Hiroki Fukuno, Yasuoki Tomita, Kiyoshi Suenaga
  • Patent number: 6257830
    Abstract: In a steam cooling system proposed heretofore, high-pressure steam is supplied into an internal space of a blade for effecting cooling thereof with the high-pressure steam to thereby recover heat energy. This system however suffers from problems concerning the strength of the blade and the like. The present invention solves these problems and provides a gas-turbine blade which does not suffer from problems concerning the strength thereof nor problems concerning the flow of high-pressure steam. To this end, a coolant flow passage is formed within the blade extending in the longitudinal direction of the blade, and reinforcing ribs which interconnects a dorsal wall and a ventral wall of the blade is disposed within the coolant flow passage so as to extend in the flow direction of the coolant. Hence, the strength of the blade can be ensured without any obstacle to the flow of the coolant.
    Type: Grant
    Filed: June 2, 1999
    Date of Patent: July 10, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Masaaki Matsuura, Kiyoshi Suenaga, Sunao Aoki, Kazuo Uematsu, Hiroki Fukuno, Yasuoki Tomita
  • Patent number: 6253537
    Abstract: Stress occurring in a moving blade in a gas turbine stopping process is decreased. Time t1 is load decrease start or fuel throttling start, time t2 is no load operation start, time t3 is fuel shut-off and time t4 is a time of largest stress. A 4/4 load maintained until t1 decreases gradually to a 0/4 load at t2, which is then maintained until t3 and then decreases further. The rotational speed is the rated speed until t2, at which point it is controlled to be decreased gradually to about 60% of the rated rotational speed at t3. The metal differential temperature between a moving blade point A and a platform point B is constant until t1 and is then decreased slightly between t1 and t2 and between t2 and t3. Differential temperature &Dgr;t, largest after t3, occurs at t4.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: July 3, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kiyoshi Suenaga, Yukihiro Hashimoto, Yasuoki Tomita
  • Patent number: 6254346
    Abstract: The present invention relates to a gas turbine cooling moving blade and is applied to a large-sized blade for a high temperature so as to reduce its thickness and increase cooling efficiency and easily process the moving blade. A cavity is formed in the interior of the moving blade from the root portion to a shroud at the tip of the moving blade. Many turbulators are arranged in parallel with each other on an inner wall face of the moving blade. Cooling air from a turbine rotor enters the cavity formed within the moving blade from a cooling air inlet. This cooling air is dispersed and disturbed by the turbulators so that heat transfer is improved. Accordingly, the moving blade is efficiently cooled by the cooling air in comparison with a conventional cooling system having a multiplicity of holes. The cooling air is then discharged out of a cooling air outlet through air cooling holes of the shroud located at the tip of the moving blade.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: July 3, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Hiroki Fukuno, Yasuoki Tomita, Kiyoshi Suenaga
  • Patent number: 6217279
    Abstract: A sealing device for a gas turbine stator blade, in which an outer shroud (32) is mounted by heat insulating rings (32a,32b) on a blade ring (50). The blade ring (50) has a first air hole (1), which communicates with a space (53), and a second air hole (51), which communicates with a seal tube (2). The seal tube (2) is inserted into the second air hole (51), and a spring (6) is arranged between a projection (4) of the tube (2) and a retaining portion (5) of the air hole (51) to removably secure the seal tube (2). Cooling air (54) flows through the first air hole (1) to cool the shrouds and the inside of a stator blade (31) until it is released from the trailing edge of the blade. The cooling air also flows into a cavity (36) so that a high pressure can be maintained without a pressure loss because the tube (2) is independent of the space (53) in the blade ring.
    Type: Grant
    Filed: February 10, 1999
    Date of Patent: April 17, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Toshishige Ai, Masanori Yuri, Yasuoki Tomita, Kiyoshi Suenaga, Sunao Aoki, Hiroki Fukuno
  • Patent number: 6196799
    Abstract: A gas turbine moving blade platform having a simplified cooling structure for effecting uniform cooling of the platform. The platform (1) includes cavities (2, 3, 4) and an impingement plate (11) provided below the cavities (2, 3, 4). A cooling hole (5) communicates with cavity (2), cooling hole (6) communicated with cavity (3) and cooling holes (7, 8) communicate with cavity (4) and all of the cooling holes pass through the platform (1) at an inclined angle. Cooling air (70) flows into the cavities (2, 3, 4) through holes (12) in the impingement plate (11) for effecting impingement cooling of platform (1) plane portion. The cooling air (70) further flows through the cooling holes (5, 6, 7) to blow outside angularly upward for cooling peripheral portions of the platform. Thus, the platform is cooled uniformly, no lengthy and complicated cooling passage is provided, and workability is enhanced.
    Type: Grant
    Filed: February 18, 1999
    Date of Patent: March 6, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Ichiro Fukue, Eiji Akita, Kiyoshi Suenaga, Yasuoki Tomita, Koji Watanabe
  • Patent number: 6196791
    Abstract: In gas turbine cooled moving blade, a cooling air passage is made shortest and temperature elevation and pressure drop of the cooling air are suppressed. The cooling air passage (16) is bored in a turbine cylinder wall (15) located below a first stage stationary blade (11). The cooling air passage (16) communicates at one end (16a) with a turbine cylinder and at the other end (16b) with a space (13) between the stationary blade and the moving blade. The passage (16) is directed to an air inflow hole (6) provided in a shank portion (4) of a lower portion of a platform (2) of the moving blade (1). Cooling air is jetted from the cooling air passage (16) toward the air inflow hole (6) so as to flow into the shank portion (4) and then into the moving blade (1) for cooling thereof.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: March 6, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Hiroki Fukuno, Sunao Aoki, Kiyoshi Suenaga
  • Patent number: 6196798
    Abstract: A number of air-transpiration holes (4) are provided at a leading edge portion (2) of a cooled blade (1). Cooling air flowing through a cooling air passage (15) formed inside of the blade blows out to the blade surface of the leading edge portion (2) of the cooled blade (1) by way of the air-transpiration holes (4), to thereby shower-head cool the surface of the leading edge portion (2). The air-transpiration holes (4) are formed so as to extend substantially orthogonal to the leading edge surface of the cooled blade (1) such that the acute-angled portions are eliminated, whereby thermal stress is reduced and cracking is prevented.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: March 6, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Hiroki Fukuno, Yasuoki Tomita, Shigeyuki Maeda, Yukihiro Hashimoto, Kiyoshi Suenaga
  • Patent number: 6190128
    Abstract: A cooled moving blade for a gas turbine which has a blade profile capable of more effectively reducing thermal stress in a blade base portion and, thus, preventing cracks from occurring. A moving blade (1) is fixedly secured to a platform (2). On the other hand, a cooling air passage (3) is formed in a serpentine pattern inside of the blade for cooling with cooling air. The moving blade (1) has a base portion of a profile formed by an elliptically curved surface (11) and a rectilinear surface portion (12), wherein the rectilinear surface portion (12) is provided at a hub portion of the blade where thermal stress is large. The cross-sectional area of the blade is increased by providing the rectilinear surface portion (12) The heat capacity is increased, compared with the conventional blade, due to the increased cross-sectional area of the blade. This, in turn, results in a decrease of the temperature difference due to the thermal stress.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: February 20, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Hiroki Fukuno, Yasuoki Tomita, Shigeyuki Maeda, Yukihiro Hashimoto, Kiyoshi Suenaga
  • Patent number: 6190130
    Abstract: A gas turbine moving blade platform having a simplified platform cooling structure. A cooling effect of the platform side end portions is increased resulting in uniform cooling of the entire platform. Cooling passages (2, 3) are bored in the platform (1) front portion so as to communicate with a cooling air passage (52) of the moving blade (51) and open at both platform side end surfaces. The openings are closed by inserting covers (2a, 2b) therein. Cooling passages (6, 4) are bored in platform (1) side end portions so as to communicate with the front end cooling passages (2, 3), respectively, and open in the platform rear end surface. A plurality of cooling holes (5) are bored so as to communicate with the cooling passage (4) and open at the platform side end surface. Thus, the entire platform is cooled uniformly and the platform side portions are cooled by the cooling holes (5) so that an effective cooling performance is ensured and also the workability of the cooling lines is enhanced.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: February 20, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Ichiro Fukue, Eiji Akita, Kiyoshi Suenaga, Yasuoki Tomita
  • Patent number: 6189891
    Abstract: A gas turbine seal structure provided between end portions of a moving blade platform and a stationary blade inside shroud. The sealing performance of the seal structure is improved by increasing the resistance to the flow of air. A seal plate (21, 31) is mounted to an end portion of a platform (2, 2′) of the moving blade (1) and a seal portion is formed by seal fins (22, 32) and a honeycomb seal (16, 17) disposed on a lower surface of an end portion (12a, 12b) of an inside shroud (12) of a stationary blade (11). Sealing air from the stationary blade (11) produces a high temperature in a cavity (14) and flows into a space (18, 19), and also air leaking from the cooling air of the moving blade (1) is able to escape into a high temperature combustion gas passage through a seal portion. However, since the seal plate has three seal fins (22, 32) that are inclined in a direction so as to oppose the air flow, air resistance is increased and the flow of air into the combustion gas passage is prevented.
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: February 20, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Kazuharu Hirokawa, Hiroki Fukuno, Kiyoshi Suenaga, Yukihiro Hashimoto, Eisaku Ito
  • Patent number: 6152690
    Abstract: A seal ring (1) securing inner shroud members (32) of stationary blades (31) is provided with arm portions (2, 3) projecting along lower surfaces of end portions of the inner shroud members (32). Honeycomb seals (4a, 4b) are mounted on the arm portions (2, 3), respectively. The honeycomb seal (4a) is disposed opposite fins (11a) provided on a rotor arm portion (11) of a platform (22) of a moving blade (21) so that a predetermined clearance (t) can be maintained between the honeycomb seal and the fins. On the other hand, the honeycomb seal (4b) is disposed opposite fins (14b) provided on a seal portion (14a) of a sealing plate (14) of the moving blade (21) so that a predetermined clearance (t) can be maintained between the honeycomb seal and the fins. The inner shroud members (32) undergo deformation after operation of the gas turbine.
    Type: Grant
    Filed: May 19, 1999
    Date of Patent: November 28, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Hiroki Fukuno, Katsunori Tanaka, Toshiaki Sano
  • Patent number: 6152695
    Abstract: In a gas turbine moving blade 1, the convection of cooling air is promoted to enhance the heat transfer rate, the cooling effect of a shroud 2 is enhanced and the entire cooling effect of the blade is enhanced. An inner cavity 10 is formed in the blade over the entire length thereof. A multiplicity of pin fins 5 are provided in the inner cavity, being fixed to wall thereof. An enlarged cavity 6 is formed in the shroud 2 of a terminal end of the blade 1. Cooling air entering the inner cavity 10 of the blade 1 flows into the enlarged cavity 6 and flows out of the shroud 2 downwardly through holes 7 of a peripheral portion of the enlarged cavity 6. The entire portion of the shroud 2 is cooled uniformly, and the cooling effect of the entire blade is enhanced by an enhanced heat transfer rate in the blade and by uniform cooling of the entire shroud.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: November 28, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Ichiro Fukue, Eiji Akita, Kiyoshi Suenaga, Yasuoki Tomita
  • Patent number: 6146098
    Abstract: A tip shroud for a moving blade that is made thin and light for use at a gas turbine downstream stage. Cooling air holes (13 to 16) having a slot shape, are formed in a tip shroud (11) of the moving blade (10). The cooling holes are opened in two side faces of the tip shroud to release the cooling air from the inside of the moving blade (10). In the upper face of the tip shroud 11, there are formed cooling air holes 20, which communicate with the higher pressure side in a combustion gas flow direction R to release the cooling air so that the cooling air flows from the higher pressure side to the lower pressure side so as to cool a high stress portion Y. A high stress portion X is likewise cooled with the cooling air coming from an adjoining moving blade. The slot shapes of the cooling air holes (13 to 16) allow the cooling air to flow widely, thereby cooling the face of the tip shroud (11), and the cooling air holes 20 cool the high stress portions X and Y effectively.
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: November 14, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Hiroki Fukuno, Yasuoki Tomita, Eisaku Ito