ABSTRACT
Seawater hydraulic pump is a key component in buoyancy regulation systems. In this paper, a novel full-water-lubricated three-plunger seawater pump was designed in which the plunger suction and drainage are driven by the crankshaft. For this structure, the sliding bearing that supports the crankshaft is a very important factor affecting the pump characteristics. The pressure flow model and the thermal coupling system model of the left/right sliding bearings were established, and the deformation of the left/right sliding bearings in the deep sea environment was analysed by ANSYS Workbench. The change of the fit clearance has a great influence on the work of the hydraulic pump. Different fit clearances at different seawater depths under different radius gaps are obtained. The results show that the fit clearance of the left/right sliding bearings decreases as the depth of the seawater increases. As the depth of the seawater increases, the sliding bearing is gradually changed from the frictional lubrication of the liquid to the boundary friction lubrication. With the increases of the radius gap, the working water depth of the hydraulic pump first increases and then decreases, and the optimal radius clearance and the optimal working depth are obtained.
Nomenclature
φ | = | Dissipation function |
= | Hamiltonian | |
ρ | = | Density of seawater [Kg/m3] |
µ | = | Dynamic viscosity of seawater [Pa·s] |
e | = | Eccentricity [mm] |
F | = | Water film bearing capacity [N] |
F1 | = | Crankshaft force [N] |
r | = | Journal radius [mm] |
r0 | = | Bearing inner diameter [mm] |
D | = | Plunger diameter [mm] |
r1 | = | Crank length [mm] |
l | = | Link length [mm] |
e1 | = | Eccentricity between crankshaft and plunger [mm] |
t | = | Crankshaft rotation time [s] |
= | Crankshaft rotational angular velocity [rad/s] | |
θL | = | Left plunger lag angle [rad] |
θR | = | Right plunger lag angle [rad] |
= | Thermal diffusion coefficient [m2/s] | |
c | = | Radius gap [mm] |
x | = | Water film eccentricity |
xm | = | Displacement of intermediate plunger [mm] |
vm | = | Speed of intermediate plunger [mm/s] |
xL | = | Displacement of left end plunger [mm] |
vL | = | Speed of left end plunger [mm/s] |
xR | = | Displacement of right end plunger [mm] |
vR | = | Speed of right end plunger [mm/s] |
f | = | Fluid pressure [N] |
P | = | Seawater pressure [Pa] |
fmx | = | An intermediate position plunger applies a force in the x direction to the crankshaft [N] |
fmy | = | An intermediate position plunger applies a force in the y direction to the crankshaft [N] |
flx | = | An left end position plunger applies a force in the x direction to the crankshaft [N] |
fly | = | An left end position plunger applies a force in the y direction to the crankshaft [N] |
frx | = | An right end position plunger applies a force in the x direction to the crankshaft [N] |
fry | = | An right end position plunger applies a force in the y direction to the crankshaft [N] |
fl | = | The force received by the left end sliding bearing [N] |
fr | = | The force received by the right end sliding bearing [N] |
Rec | = | Critical Reynolds number |
hmin | = | Fit clearance [mm] |
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Funding
Notes on contributors
Yinshui Liu
Yinshui Liu, born in October 1973, is a professor at Huazhong University of Science and Technology and a flying scholar at Lanzhou University of Technology. His research interests are water hydraulic components, fluid transmission and control.
Jiangkun Zou
Jiangkun Zou, graduate student of Lanzhou University of Technology.
Yipan Deng
Yipan Deng, he is currently studying for a PhD in Huazhong University of Science and Technology.
Hong Ji
Hong Ji, doctor. He received a doctorate in 2005 and received funding from the State Key Laboratory of Fluid Transmission and Control of Zhejiang University. The research direction is modern hydraulic components and engineering machinery hydraulic technology.