Patents by Inventor Daichi OKA

Daichi OKA 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: 11976648
    Abstract: Even when abnormal heat generation occurs during operation in a state where the temperature of a compressor is not increased, abnormality cannot be detected. A fluid machine includes a fluid machine body; a motor that drives the fluid machine body; a temperature sensor that measures a temperature of the fluid machine body; and a control unit that controls the fluid machine body. The control unit changes a temperature threshold value based on at least one of a pressure of a fluid discharged by the fluid machine body and a frequency of a voltage input into the motor, and issues a notification when the temperature of the compressor body measured by the temperature sensor exceeds the temperature threshold value.
    Type: Grant
    Filed: November 28, 2019
    Date of Patent: May 7, 2024
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Akihiro Yamamoto, Yoshiyuki Kanemoto, Daichi Oka
  • Patent number: 11937410
    Abstract: A package-type fluid machine includes a compressor unit including a compression portion that compresses a fluid, a motor that drives the compression portion, and a cooling fan that is driven by the motor; a machine chamber in which the compressor unit is disposed; an inverter chamber which is adjacent to the machine chamber and in which an inverter is disposed; a partition wall that partitions off the machine chamber from the inverter chamber and has an opening; and an inverter intake port that is disposed in the inverter chamber to take in a cooling gas. The cooling fan is disposed on a side of the machine chamber, the opening being located on the side. The cooling fan is driven to cause the cooling gas to flow from the inverter intake port to the opening to cool the inverter.
    Type: Grant
    Filed: September 13, 2018
    Date of Patent: March 19, 2024
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Fuminori Kato, Yoshiyuki Kanemoto, Hiroaki Saito, Daichi Oka, Akihiro Yamamoto
  • Patent number: 11898544
    Abstract: A package type fluid machine includes a plurality of compressor bodies; a machine compartment in which the plurality of compressor bodies are disposed; an exhaust duct that exhausts a cooling gas from the machine compartment; a plurality of aftercoolers that are disposed inside the exhaust duct to cool a compressed fluid from the compressor bodies; and a shield that is disposed between the aftercoolers to shield a flow of the cooling gas.
    Type: Grant
    Filed: September 13, 2018
    Date of Patent: February 13, 2024
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Kosuke Sadakata, Hiroaki Saito, Daichi Oka
  • Patent number: 11585335
    Abstract: A gas compressor includes inverters, a plurality of compressor units and a control device for controlling each of the inverters. The control device increases the number of compressor bodies to be operated after confirming that the rotational speed of the operational motors will reach a steady value immediately after causing the number of the compressor bodies to be operated to increase.
    Type: Grant
    Filed: July 26, 2019
    Date of Patent: February 21, 2023
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Norio Aoyagi, Akihiro Yamamoto, Yoshiyuki Kanemoto, Hiroaki Saito, Fuminori Kato, Daichi Oka
  • Patent number: 11542951
    Abstract: The purpose of the present invention is to provide a gas compressor capable of reducing variation in discharge pressure through control of the number of compressor bodies and a control method for the gas compressor. In order to solve the problem, this gas compressor includes a plurality of compressor units each having a compressor body, a motor for driving the compressor body, and an inverter for controlling a rotational speed of the motor, and a control device for controlling the inverters. Discharge pipes of the compressor bodies converge on one main discharge pipe. A drive frequency of the motor of each compressor body is controlled by the corresponding inverter, whereby a pressure of each discharge pipe is controlled and a discharge pressure of the main discharge pipe is controlled.
    Type: Grant
    Filed: July 26, 2019
    Date of Patent: January 3, 2023
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Akihiro Yamamoto, Yoshiyuki Kanemoto, Norio Aoyagi, Hiroaki Saito, Fuminori Kato, Daichi Oka
  • Publication number: 20220049691
    Abstract: There are provided an operation number control device and a method for controlling the same that can level the operation times of the fluid machines, which are connected to the operation number control device. A fluid machine system comprises a plurality of fluid machines, and an operation number control device capable of individually controlling start and stop of the fluid machines. The operation number control device sets a continuous operation time for each of the fluid machines based on total operation times of the fluid machine and other fluid machines. When among fluid machines in operation, there is a fluid machine for which the continuous operation time set for the fluid machine has elapsed and there is a fluid machine at stop, the operation number control device causes the fluid machine at stop to start and causes the fluid machine to stop.
    Type: Application
    Filed: November 29, 2019
    Publication date: February 17, 2022
    Inventors: Norio AOYAGI, Hiroaki SAITO, Fuminori KATO, Daichi OKA, Akihiro YAMAMOTO
  • Publication number: 20210310479
    Abstract: Even when abnormal heat generation occurs during operation in a state where the temperature of a compressor is not increased, abnormality cannot be detected. A fluid machine includes a fluid machine body; a motor that drives the fluid machine body; a temperature sensor that measures a temperature of the fluid machine body; and a control unit that controls the fluid machine body. The control unit changes a temperature threshold value based on at least one of a pressure of a fluid discharged by the fluid machine body and a frequency of a voltage input into the motor, and issues a notification when the temperature of the compressor body measured by the temperature sensor exceeds the temperature threshold value.
    Type: Application
    Filed: November 28, 2019
    Publication date: October 7, 2021
    Inventors: Akihiro YAMAMOTO, Yoshiyuki KANEMOTO, Daichi OKA
  • Publication number: 20210289670
    Abstract: A package-type fluid machine includes a compressor unit including a compression portion that compresses a fluid, a motor that drives the compression portion, and a cooling fan that is driven by the motor; a machine chamber in which the compressor unit is disposed; an inverter chamber which is adjacent to the machine chamber and in which an inverter is disposed; a partition wall that partitions off the machine chamber from the inverter chamber and has an opening; and an inverter intake port that is disposed in the inverter chamber to take in a cooling gas. The cooling fan is disposed on a side of the machine chamber, the opening being located on the side. The cooling fan is driven to cause the cooling gas to flow from the inverter intake port to the opening to cool the inverter.
    Type: Application
    Filed: September 13, 2018
    Publication date: September 16, 2021
    Inventors: Fuminori KATO, Yoshiyuki KANEMOTO, Hiroaki SAITO, Daichi OKA, Akihiro YAMAMOTO
  • Publication number: 20210215147
    Abstract: A package type fluid machine includes a plurality of compressor bodies; a machine compartment in which the plurality of compressor bodies are disposed; an exhaust duct that exhausts a cooling gas from the machine compartment; a plurality of aftercoolers that are disposed inside the exhaust duct to cool a compressed fluid from the compressor bodies; and a shield that is disposed between the aftercoolers to shield a flow of the cooling gas.
    Type: Application
    Filed: September 13, 2018
    Publication date: July 15, 2021
    Inventors: Kosuke SADAKATA, Hiroaki SAITO, Daichi OKA
  • Publication number: 20210025380
    Abstract: The purpose of the present invention is to provide a gas compressor that can achieve reduced fluctuation of discharge pressure during compressor body number control, and a method for controlling the gas compressor. This gas compressor includes a plurality of compressor units each having a compressor body, a motor for driving the compressor body, and an inverter for controlling a rotational speed of the motor, and a control device for controlling each of the inverters, in which discharge pipes of the compressor bodies are merged with one main discharge pipe and discharge pressure of the main discharge pipe is controlled through control of pressure of the respective discharge pipes by controlling, by means of the respective inverters, driving frequencies of the compressor bodies.
    Type: Application
    Filed: July 26, 2019
    Publication date: January 28, 2021
    Inventors: Norio AOYAGI, Akihiro YAMAMOTO, Yoshiyuki KANEMOTO, Hiroaki SAITO, Fuminori KATO, Daichi OKA
  • Publication number: 20200400154
    Abstract: The purpose of the present invention is to provide a gas compressor capable of reducing variation in discharge pressure through control of the number of compressor bodies and a control method for the gas compressor. In order to solve the problem, this gas compressor includes a plurality of compressor units each having a compressor body, a motor for driving the compressor body, and an inverter for controlling a rotational speed of the motor, and a control device for controlling the inverters. Discharge pipes of the compressor bodies converge on one main discharge pipe. A drive frequency of the motor of each compressor body is controlled by the corresponding inverter, whereby a pressure of each discharge pipe is controlled and a discharge pressure of the main discharge pipe is controlled.
    Type: Application
    Filed: July 26, 2019
    Publication date: December 24, 2020
    Inventors: Akihiro YAMAMOTO, Yoshiyuki KANEMOTO, Norio AOYAGI, Hiroaki SAITO, Fuminori KATO, Daichi OKA
  • Patent number: D917570
    Type: Grant
    Filed: February 26, 2019
    Date of Patent: April 27, 2021
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Fuminori Kato, Hiroaki Saito, Daichi Oka, Yusuke Watabe, Akihiro Yamamoto