Patents by Inventor Takuma KOINUMA

Takuma KOINUMA 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).

  • Patent number: 11885398
    Abstract: A transmission (21) as a power transmission device for a vehicle comprises an input shaft (22), an output shaft (23), a planetary continuously variable transmission mechanism (31), a direct connecting mechanism (27), and an idler gear (29). The direct connecting mechanism (27) comprises a direct connecting clutch (30). The planetary continuously variable transmission mechanism (31) comprises a planetary gear mechanism (32), a pump side clutch (33), a hydraulic pump (36), a hydraulic motor (38), and a motor side clutch (40). The hydraulic pump (36) and the hydraulic motor (38) are connected via a pair of main lines (37A, 37B). An electromagnetic on-off valve (41) capable of switching between a communicating state and a blocking state between the pair of main lines (37A, 37B) is provided between the pair of main lines (37A, 37B).
    Type: Grant
    Filed: September 1, 2021
    Date of Patent: January 30, 2024
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Makoto Nakagaki, Takuma Koinuma
  • Patent number: 11859703
    Abstract: A transmission (21) as a power transmission device for a vehicle comprises an input shaft (22), an output shaft (23), and a planetary continuously variable transmission mechanism (31). The planetary continuously variable transmission mechanism (31) comprises a planetary gear mechanism (32), a pump side clutch (33), a hydraulic pump (36), a hydraulic motor (38), and a motor side clutch (40). The hydraulic pump (36) and the hydraulic motor (38) are connected via a pair of main lines (37A, 37B). When the transmission (21) is switched from a traveling state to a neutral state, at least one clutch (33, 40) of the pump side clutch (33) and the motor side clutch (40) is released.
    Type: Grant
    Filed: September 23, 2021
    Date of Patent: January 2, 2024
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Hiroki Ueno, Takuma Koinuma
  • Publication number: 20230349456
    Abstract: A transmission (21) as a power transmission device for a vehicle comprises an input shaft (22), an output shaft (23), a planetary continuously variable transmission mechanism (31), a direct connecting mechanism (27), and an idler gear (29). The direct connecting mechanism (27) comprises a direct connecting clutch (30). The planetary continuously variable transmission mechanism (31) comprises a planetary gear mechanism (32), a pump side clutch (33), a hydraulic pump (36), a hydraulic motor (38), and a motor side clutch (40). The hydraulic pump (36) and the hydraulic motor (38) are connected via a pair of main lines (37A, 37B). An electromagnetic on-off valve (41) capable of switching between a communicating state and a blocking state between the pair of main lines (37A, 37B) is provided between the pair of main lines (37A, 37B).
    Type: Application
    Filed: September 1, 2021
    Publication date: November 2, 2023
    Inventors: Makoto NAKAGAKI, Takuma KOINUMA
  • Patent number: 11674576
    Abstract: A speed-changing device (21) is provided with an input shaft (22), an output shaft (23), a planetary gear mechanism (29), a first variator (33), a second variator (34), and a controller (25). The planetary gear mechanism (29) is configured to include a carrier (29A) connected to the input shaft (22), a first sun gear (29B) connected to the first variator (33), and a second sun gear (29C) connected to the output shaft (23). The second variator (34) transmits power transmitted from the first variator (33) to the output shaft (23), or transmits power transmitted from the output shaft (23) to the first variator (33). The controller (25) changes the rotation speed of the first variator (33), thereby changing the rotation speed of the output shaft (23) in relation to the rotation speed of the input shaft (22).
    Type: Grant
    Filed: September 29, 2020
    Date of Patent: June 13, 2023
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Takuma Koinuma
  • Publication number: 20230147860
    Abstract: A speed-changing device (21) is provided with an input shaft (22), an output shaft (23), a planetary gear mechanism (29), a first variator (33), a second variator (34), and a controller (25). The planetary gear mechanism (29) is configured to include a carrier (29A) connected to the input shaft (22), a first sun gear (29B) connected to the first variator (33), and a second sun gear (29C) connected to the output shaft (23). The second variator (34) transmits power transmitted from the first variator (33) to the output shaft (23), or transmits power transmitted from the output shaft (23) to the first variator (33). The controller (25) changes the rotation speed of the first variator (33), thereby changing the rotation speed of the output shaft (23) in relation to the rotation speed of the input shaft (22).
    Type: Application
    Filed: September 29, 2020
    Publication date: May 11, 2023
    Inventor: Takuma KOINUMA
  • Publication number: 20230105106
    Abstract: A transmission (21) as a power transmission device for a vehicle comprises an input shaft (22), an output shaft (23), and a planetary continuously variable transmission mechanism (31). The planetary continuously variable transmission mechanism (31) comprises a planetary gear mechanism (32), a pump side clutch (33), a hydraulic pump (36), a hydraulic motor (38), and a motor side clutch (40). The hydraulic pump (36) and the hydraulic motor (38) are connected via a pair of main lines (37A, 37B). When the transmission (21) is switched from a traveling state to a neutral state, at least one clutch (33, 40) of the pump side clutch (33) and the motor side clutch (40) is released.
    Type: Application
    Filed: September 23, 2021
    Publication date: April 6, 2023
    Inventors: Hiroki UENO, Takuma KOINUMA
  • Patent number: 11506246
    Abstract: A first rotating shaft (22) and a second rotating shaft (43) are connected so as to be capable of transmitting rotation by engagement of a first pawl portion (38) of a piston (32) and a second pawl portion (47) of the second rotating shaft (43) based upon delivery of hydraulic oil to an oil chamber (37). The first pawl portion, when in engagement with the second pawl portion based upon the delivery of the hydraulic oil, is engaged with a third pawl portion (52) of a synchronizer ring (51) prior to the engagement with the second pawl portion. Engagement surfaces of the first and second pawl portions are formed as inclination surfaces so that a force is applied to the first pawl portion and the second pawl portion in a direction of axially moving away from each other when the rotation is transmitted between the first and second rotating shafts.
    Type: Grant
    Filed: April 22, 2019
    Date of Patent: November 22, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Takuma Koinuma
  • Publication number: 20220128100
    Abstract: A first rotating shaft (22) and a second rotating shaft (43) are connected in a state of being capable of transmitting rotation by the engagement of a first pawl portion(38) of a piston (32) and a second pawl portion(47) of the second rotating shaft (43) based upon the delivery of hydraulic oil to an oil chamber (37). The first pawl portion(38) of the piston (32), when being engaged with the second pawl portion(47) of the second rotating shaft (43) based upon the delivery of hydraulic oil to an oil chamber (37), is engaged with a third pawl portion(52) of a synchronizer ring (51) prior to the engagement with the second pawl portion(47). Engagement surfaces of the first pawl portion(38) and the second pawl portion(47) are formed as inclination surfaces so that a force is applied to the first pawl portion(38) and the second pawl portion(47)in a direction of axially moving away from each other when the rotation is transmitted between the first rotating shaft (22) and the second rotating shaft (43).
    Type: Application
    Filed: April 22, 2019
    Publication date: April 28, 2022
    Inventor: Takuma KOINUMA