US 11,667,366 B2
Steering device, steering device for ship and switching valve
Xing Sun, Hitachinaka (JP); and Hayato Tsutsui, Hitachinaka (JP)
Assigned to HITACHI ASTEMO, LTD., Hitachinaka (JP)
Filed by HITACHI ASTEMO, LTD., Hitachinaka (JP)
Filed on Mar. 16, 2021, as Appl. No. 17/203,089.
Claims priority of application No. JP2021-009147 (JP), filed on Jan. 22, 2021.
Prior Publication US 2022/0234709 A1, Jul. 28, 2022
Int. Cl. B63H 20/12 (2006.01); F15B 15/14 (2006.01); F15B 13/02 (2006.01); F15B 11/024 (2006.01)
CPC B63H 20/12 (2013.01) [F15B 11/024 (2013.01); F15B 13/021 (2013.01); F15B 15/149 (2013.01); F15B 2211/20561 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A steering device comprising:
a cylinder demarcated into a first chamber and a second chamber by a piston;
a main valve having a first shuttle chamber and a second shuttle chamber;
a hydraulic source of a forward/reverse rotation type having a first discharge port and a second discharge port;
a first oil passage configured to connect the first chamber of the cylinder and the first shuttle chamber;
a second oil passage configured to connect the second chamber of the cylinder and the second shuttle chamber;
a third oil passage configured to connect the first shuttle chamber of the main valve and the first discharge port;
a fourth oil passage configured to connect the second shuttle chamber of the main valve and the second discharge port; and
a tank connected to the main valve via the third oil passage and the fourth oil passage, wherein
one of the first shuttle chamber and the second shuttle chamber of the main valve is in an opened state when the hydraulic source is stopped,
the main valve has:
a first piston arranged on the first oil passage;
a second piston arranged on the second oil passage; and
a spool arranged between the first piston and the second piston, and
the spool is pushed by a high pressure-side piston arranged on an oil passage on a high pressure-side, which is one of the first piston and the second piston, thereby closing the oil passage on the high pressure-side, and pushes a low pressure-side piston arranged on an oil passage on a low pressure-side, which is the other of the first piston and the second piston, thereby opening the oil passage on the low pressure-side.