US 12,377,908 B2
Hydraulic steering system and traveling crane
Xiaodong Hu, Xuzhou (CN); Tao Zhu, Xuzhou (CN); Jianchun Yang, Xuzhou (CN); Xiuzhi Ren, Xuzhou (CN); and Xiaojie Du, Xuzhou (CN)
Assigned to Xuzhou Heavy Machinery Co., Ltd., Xuzhou (CN)
Appl. No. 17/923,520
Filed by Xuzhou Heavy Machinery Co., Ltd., Xuzhou (CN)
PCT Filed May 6, 2020, PCT No. PCT/CN2020/088837
§ 371(c)(1), (2) Date Nov. 4, 2022,
PCT Pub. No. WO2021/223120, PCT Pub. Date Nov. 11, 2021.
Prior Publication US 2023/0182808 A1, Jun. 15, 2023
Int. Cl. B62D 5/20 (2006.01); B62D 5/09 (2006.01); B66C 23/62 (2006.01)
CPC B62D 5/20 (2013.01) [B62D 5/09 (2013.01); B66C 23/62 (2013.01); B66C 2700/0378 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A hydraulic steering system, comprising:
a steering pump;
a plurality of digital steering cylinder assemblies, wherein at least one of the plurality of digital steering cylinder assemblies comprises:
a steering cylinder;
a digital hydraulic valve having a valve core, the valve core configured to selectively communicate a rodless cavity of the steering cylinder with one of the steering pump and a return oil circuit, and communicate a rod cavity of the steering cylinder with the other of the steering pump and the return oil circuit;
a motor in driving connection with the valve core of the digital hydraulic valve, and configured to receive a digital pulse signal and cause the valve core of the digital hydraulic valve to move towards a first working position or a second working position;
an internal feedback structure connected between a piston rod of the steering cylinder and the valve core of the digital hydraulic valve, and configured to, when the valve core of the digital hydraulic valve moves towards the first working position or the second working position, be moved by the piston rod of the steering cylinder to drive the valve core of the digital hydraulic valve to move towards a neutral position;
a sensor assembly configured to detect a stroke of the steering cylinder; and
a controller located in at least one of the plurality of digital steering cylinder assemblies or communicatively connected to the motor in the digital steering cylinder assembly and the sensor assembly, and configured to, when a detection result from the sensor is greater than a preset stroke, emit a digital pulse signal including at least one of a pulse number signal or a pulse frequency signal, the controller is configured to at least one of (1) adjust, by the pulse number signal, a displacement of the valve core of the digital hydraulic valve or (2) adjust, by the pulse frequency signal, a speed of the valve core of the digital hydraulic valve.