Calculation of Geometrical Parameters of Geokhod Transmission With Hydraulic Cylinders

Developed analytical expressions for determining parameters of transmission hydraulic cylinders' arrangement are considered, as well as the conditions for internal arrangement of a required number of hydraulic cylinders

Calculation of Geometrical Parameters of Geokhod Transmission With Hydraulic Cylinders

Developed analytical expressions for determining parameters of transmission hydraulic cylinders' arrangement are considered, as well as the conditions for internal arrangement of a required number of hydraulic cylinders

Optimization of Hydraulic Cylinder Positioning for Wind Tower Hydraulic Erection System

Wind produced electricity is a rapidly growing field with wind towers serving as critical components. Conventionally, special cranes are commonly used for wind tower erection. This study explores the use of hydraulic cylinders for small-scale wind tower erection. The thesis aims to find the optimal position of hydraulic cylinder connections in a hydraulic erection system for safe and energy-efficient tower erection and retraction and to enhance the performance and longevity of the system. Structural analysis was conducted to investigate various hydraulic cylinder positioning configurations, ensuring minimal force exertion while maintaining structural integrity. The study included the selection of locally available hydraulic cylinders and the construction of a physical prototype of the hydraulic erection system to measure energy consumption. This study sheds light on an alternative approach to small-scale wind tower erection, highlighting the significance of hydraulic cylinder positioning for safe and energy-efficient tower erection and retraction. The findings offer valuable insights for enhancing the wind energy sector\u27s sustainability and performance. The study identified the optimal connection point at 7.5 feet on the wind tower and 5 feet on the ground, away from the tower\u27s base. Nevertheless, locally available hydraulic cylinders were found to be insufficient for the safe lowering of the tower, prompting the design of custom hydraulic cylinders to ensure both safety and economic feasibility

Full- and Reduced-order Model of Hydraulic Cylinder for Motion Control

This paper describes the full- and reduced-order models of an actuated hydraulic cylinder suitable for system dynamics analysis and motion control design. The full-order model incorporates the valve spool dynamics with combined dead-zone and saturation nonlinearities - inherent for the orifice flow. It includes the continuity equations of hydraulic circuits coupled with the dynamics of mechanical part of cylinder drive. The resulted model is the fifth-order and nonlinear in states. The reduced model neglects the fast valve spool dynamics, simplifies both the orifice and continuity equations through an aggregation, and considers the cylinder rod velocity as output of interest. The reduced model is second-order that facilitates studying the system behavior and allows for direct phase plane analysis. Dynamics properties are addressed in details, for both models, with focus on the frequency response, system damping, and state trajectories related to the load pressure and relative velocity.Comment: 6 pages, 6 figures, IEEE conferenc

Оцінка надійності гідроагрегатів в умовах МЗТГ

The article analyzes the existing system for trial hydraulic cylinders. New methodology to conduct accelerated trials to assess the basic indicators of quality and reliability was developed

Tensile forces in lift carrier ropes exerted by the fluid pressure

DOI nefunkční (6.11.2019)This paper describes the methodology by which it is possible to compare different tensile forces that are caused by the uneven distribution of loads in carrier ropes of lifts. In order to compare the applied tensile forces in a certain number of carrier ropes, it is possible to use the device called "rope hydraulic tension compensator", when, for example, building new elevators, changing carrier ropes during renovations or servicing existing lifts. The comparison of tensile forces in lift carrier ropes by the described device is based on the method of liquid pressure diffusion in a closed vessel. The rope hydraulic tension compensator consists of a number of structural parts, the main of which are double-acting hydraulic cylinders. The number of these cylinders is equal to the number of carrier ropes of the given lift. The pressure of the hydraulic fluid, which is supplied to the inner shell of individual hydraulic cylinders, controls the length of extension of individual piston rods of the hydraulic cylinders. The position of the piston in each of the hydraulic cylinders is directly proportional to the length of the extended piston rod, which corresponds to compression of the cylindrical coiled spring, above which the respective hydraulic cylinder is located. Different compressions of individual cylindrical springs exert different magnitude of tensile forces in suspension eye-bolts, into whose longitudinal axes the total load size is distributed unevenly. The paper also describes the description and hydraulic circuit diagram of a hydraulic power unit, which is used to control the piston positions of two-way hydraulic cylinders.Web of Science133373

High-speed T-38A landing gear extension loads

Testing of T-38A landing gear extension at high speed and high altitude is described. The mechanisms are shown together with peak hydraulic pressure data during landing gear deployment with active and inactive strut door flaps. Results of strain gage measurements of stress on various structural members are included