Modeling and Analysis for the Transmission Characteristics of a Proposed Dual-Drive Hydrostatic Lead-Screw System

2021 ◽  
pp. 1-16
Author(s):  
Jiajia Lu ◽  
Xianying Feng ◽  
Zhe Su ◽  
Yandong Liu ◽  
Dechen Wang
Keyword(s):  
Axial Load ◽  
Load Capacity ◽  
Damping Coefficient ◽  
Axial Stiffness ◽  
Feed Speed ◽  
Stiffness Coefficient ◽  
Transmission Performance ◽  
Modeling And Analysis ◽  
Lead Screw ◽  
Axial Load Capacity

Abstract This paper proposes a novel dual-drive hydrostatic lead-screw system (DDHLS). The design enables a lower feed speed and a better transmission performance than the conventional hydrostatic lead screw (HLS). Considering the nut-misalignment, the lubricating mathematical model of the DDHLS is established based on the perturbation method and solved by the finite difference method. The influences of the nut-radial-displacement, the nut-tilt, and the dual-drivable design on the transmission performance of the DDHLS are researched. The results show the nut-misalignment can regularly reduce or increase the axial load capacity, the axial stiffness coefficient, and the axial damping coefficient. Significantly, the dual-drivable design can improve the axial load capacity and the axial stiffness coefficient while hardly affects the axial damping coefficient.

scholarly journals Research on boundary slip of hydrostatic lead screw under different driving modes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yandong Liu ◽  
Xianying Feng ◽  
Yanfei Li ◽  
Jiajia Lu ◽  
Zhe Su
Keyword(s):  
Bearing Capacity ◽  
High Speed ◽  
Damping Coefficient ◽  
Axial Stiffness ◽  
Stiffness Coefficient ◽  
Flow State ◽  
Boundary Slip ◽  
Rotating Speed ◽  
Navier Slip ◽  
Lead Screw

AbstractThe flow state of oil film in the hydrostatic lead screw directly affects the transmission performance of the screw pair. The static and dynamic characteristics of a new type of double driven hydrostatic screw-nut pair (DDHSNP) are studied under different motion modes. The boundary condition of navier slip model is introduced into the lubricating mathematical model of DDHSNP, and the influences of boundary slip on the axial bearing capacity, axial stiffness and damping coefficient in micro scale are researched by finite difference method. The results show that when the motor runs at high speed (the rotating speed range of the screw and nut driven motor is 1000–9000 rpm), the existence of boundary slip leads to a improvement of the axial bearing capacity and stiffness coefficient of DDHSNP in the case of single-drive operation and dual-drive differential feed (the range of rotation difference is 10–100 rpm), which is more obvious under the single-drive mode. The increase rate of stiffness coefficient induced by boundary slip is much larger than that of bearing capacity. In addition, the boundary slip has little effect on the damping coefficient of DDHSNP in either single drive operation or dual drive differential operation.

scholarly journals Spherical Squeeze-Film Hybrid Bearing With Small Steady-State Radial Displacement

1967 ◽  
Vol 89 (3) ◽  
pp. 254-262 ◽  
Author(s):  
T. Chiang ◽  
S. B. Malanoski ◽  
C. H. T. Pan
Keyword(s):  
Asymptotic Approximation ◽  
Axial Load ◽  
Radial Displacement ◽  
Reynolds Equation ◽  
Load Capacity ◽  
Squeeze Film ◽  
Axial Stiffness ◽  
Axial Load Capacity ◽  
Hybrid Bearing ◽  
Squeeze Number

Spherical squeeze-film hybrid bearings were analyzed theoretically. Based on an asymptotic approximation for large squeeze number, the solution of the Reynolds’ equation applicable to the system under investigation was obtained. Perturbation method has been used; the results are valid for small radial displacement only. It has no limitation, however, in the values of compressibility number, axial displacement ratio, and excursion ratio. Numerical calculations have been programmed on the GE205 computer. Axial load capacity, axial stiffness, and radial and tangential stiffnesses were obtained.

Axial load-capacity of rectangular cement stabilized rammed earth column

2015 ◽  
Vol 99 ◽  
pp. 402-412 ◽  
Author(s):  
Deb Dulal Tripura ◽  
Konjengbam Darunkumar Singh
Keyword(s):  
Axial Load ◽  
Load Capacity ◽  
Rammed Earth ◽  
Axial Load Capacity

Axial load capacity of cylindrical shells with local geometric defects

1991 ◽  
Vol 31 (2) ◽  
pp. 104-110 ◽  
Author(s):  
S. Krishnakumar ◽  
C. G. Foster
Keyword(s):  
Axial Load ◽  
Load Capacity ◽  
Cylindrical Shells ◽  
Axial Load Capacity

EFFECT OF ASPECT RATIO ON THE BEHAVIOR OF GFRP-RC CIRCULAR COLUMNS UNDER SIMULATED SEISMIC LOADING

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Amr Elsayed Mohammed Abdallah ◽  
Ehab Fathy El-Salakawy
Keyword(s):  
Aspect Ratio ◽  
Axial Load ◽  
Load Capacity ◽  
Load Level ◽  
Experimental Results ◽  
Rc Columns ◽  
Drift Capacity ◽  
Glass Fiber Reinforced ◽  
Axial Load Capacity ◽  
Code Provisions

The mechanical and physical properties of glass fiber-reinforced polymer (GFRP) reinforcement are different from steel, which requires independent code provisions for GFRP-reinforced concrete (RC) members. The currently available code provisions for GFRP-RC members still need more research evidence to be inclusive. For example, the available provisions for confinement reinforcement of FRP-RC columns do not consider the effects of column aspect ratio, which is not yet supported by any available research data. In this study, two full-scale spirally reinforced GFRP-RC circular columns were constructed and tested under concurrent seismic and axial loads. Both specimens had an aspect ratio (shear span-to-diameter ratio) of 7.0, while other two specimens with an aspect ratio of 5.0, from a previous stage of this study, were included for comparison purposes. For each aspect ratio, each specimen was loaded under one of two levels of axial load; 20 or 30% of the axial load capacity of the column section. All test specimens had a 35 MPa concrete compressive strength, 350-mm diameter, 85-mm spiral pitch and 1.2% longitudinal reinforcement ratio. The experimental results were analyzed in terms of hysteretic response, drift capacity and inelastic deformability hinge length. Based on the experimental results, it can be concluded that the aspect ratio affects the magnitude of secondary moments and inelastic deformability hinge length. In addition, the aspect ratio may affect drift capacity of GFRP-RC columns, depending on axial load level.

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