Abstract: A helical gear pump includes a casing including a body (11), a front cover (12), and a rear cover (13), a pair of helical gears (23) and (24) that are housed in a hole portion formed on the body (11) and mesh with each other, and a pair of bearing cases (25) and (26) that sandwich the helical gears (23) and (24) in the hole portion. Of the helical gears (23) and (24), the number of teeth of the helical gear (23) on the driving side is larger than the number of teeth of the helical gear (24) on the driven side.

Abstract: A gear pump or a gear motor in which a tooth groove is easily filled with a liquid. A gear pump includes a casing, a gear storage chamber, a suction passage, a discharge passage, a gear that is housed in the gear storage chamber and including a drive gear and a driven gear that rotate while meshing with each other, and a suction-side communication path that connects a first space and a tooth groove of the gear, the first space being a closed space formed by the drive gear and the driven gear meshing with each other, the tooth groove being opened to the suction passage.

Abstract: A gear pump is capable of maintaining the pump volumetric efficiency for preferably supplying a hydraulic liquid while adequately securing a sealing area, even if a cross sectional area of a flow-in passage is increased. The cross section of a suction passage has a rectangular shape in a side close to a hollow space in a body, and has a circular shape in the outside of the body. The rectangular shape of the suction passage in the hollow space side in the body has a long side extending in a direction along the tooth width of the spur gears, and a short side extending along a direction perpendicular to the tooth width direction. The suction passage has a shape that smoothly connects the rectangular shape in the hollow space side in the body with the circular shape in the outside of the body.

Abstract: A gear pump is capable of maintaining the pump volumetric efficiency for preferably supplying a hydraulic liquid while adequately securing a sealing area, even if a cross sectional area of a flow-in passage is increased. The cross section of a suction passage has a rectangular shape in a side close to a hollow space in a body, and has a circular shape in the outside of the body. The rectangular shape of the suction passage in the hollow space side in the body has a long side extending in a direction along the tooth width of the spur gears, and a short side extending along a direction perpendicular to the tooth width direction. The suction passage has a shape that smoothly connects the rectangular shape in the hollow space side in the body with the circular shape in the outside of the body.

Abstract: A helical gear pump includes a casing including a body (11), a front cover (12), and a rear cover (13), a pair of helical gears (23) and (24) that are housed in a hole portion formed on the body (11) and mesh with each other, and a pair of bearing cases (25) and (26) that sandwich the helical gears (23) and (24) in the hole portion. Of the helical gears (23) and (24), the number of teeth of the helical gear (23) on the driving side is larger than the number of teeth of the helical gear (24) on the driven side.

Abstract: A hydraulic device is provided. Working fluid stored in a fluid storage portion is supplied by a fluid supply portion to a power output portion. The fluid supply portion is driven by a brushless motor. A bypass flow path portion can be switched between a first state of supplying the working fluid from the fluid supply portion to the fluid storage portion and a second state of blocking the fluid supply portion from the fluid storage portion. A control to switch the bypass flow path portion from the first state to the second state after the brushless motor is started and a control to switch the bypass flow path portion from the second state to the first state when the brushless motor is stopped is performed. Backflow of the working fluid from the power output portion to the bypass flow path portion is prevented by a backflow prevention valve.

Abstract: Provided is a gear pump or a motor provided with: a casing internally provided with a gear housing compartment in which a pair of gears are housed; a side plate interposed between the casing and the gears; and a gasket which is disposed on a non-slide surface, and which divides a space between the non-slide surface and the casing into a high pressure side and a low pressure side. The gear pump or the motor is configured such that, in order to discover early the mounting of the side plate in a wrong attitude, such as the upper and lower sides thereof being reversed or the high pressure portion side and the low pressure portion side being reversed, flow rate efficiency is decreased when the side plate is in an attitude other than a predetermined attitude, compared to when the side plate is in the predetermined attitude.

Abstract: A hydraulic device is provided. Working fluid stored in a fluid storage portion is supplied by a fluid supply portion to a power output portion. The fluid supply portion is driven by a brushless motor. A bypass flow path portion can be switched between a first state of supplying the working fluid from the fluid supply portion to the fluid storage portion and a second state of blocking the fluid supply portion from the fluid storage portion. A control to switch the bypass flow path portion from the first state to the second state after the brushless motor is started and a control to switch the bypass flow path portion from the second state to the first state when the brushless motor is stopped is performed. Backflow of the working fluid from the power output portion to the bypass flow path portion is prevented by a backflow prevention valve.

Abstract: Provided is a gear pump or a motor provided with: a casing internally provided with a gear housing compartment in which a pair of gears are housed; a side plate interposed between the casing and the gears; and a gasket which is disposed on a non-slide surface, and which divides a space between the non-slide surface and the casing into a high pressure side and a low pressure side. The gear pump or the motor is configured such that, in order to discover early the mounting of the side plate in a wrong attitude, such as the upper and lower sides thereof being reversed or the high pressure portion side and the low pressure portion side being reversed, flow rate efficiency is decreased when the side plate is in an attitude other than a predetermined attitude, compared to when the side plate is in the predetermined attitude.