scholarly journals HYDROSTATIC SYSTEM FOR OPERATIONS WITH HEAVY CARGO

2018 ◽  
Vol 28 (1) ◽  
pp. 183-188
Author(s):  
A.К Sandler ◽  
◽  
E.V. Drozd ◽  
◽  
◽  
...  
Keyword(s):  
Hydrostatic System

scholarly journals Impact-Rubbing Dynamic Behavior of Magnetic-Liquid Double Suspension Bearing under Different Protective Bearing Forms

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1105
Author(s):  
Jianhua Zhao ◽  
Lanchun Xing ◽  
Sheng Li ◽  
Weidong Yan ◽  
Dianrong Gao ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Ball Bearing ◽  
Magnetic Liquid ◽  
Electromagnetic System ◽  
Fixed Ring ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Protection Devices ◽  
Hydrostatic System ◽  
The Impact

The magnetic-liquid double suspension bearing (MLDSB) is a new type of suspension bearing, with electromagnetic suspension as the main part and hydrostatic supports as the auxiliary part. It can greatly improve the bearing capacity and stiffness of rotor-bearing systems and is suitable for a medium speed, heavy load, and frequent starting occasions. Compared with the active electromagnetic bearing system, the traditional protective bearing device is replaced by the hydrostatic system in MLDSB, and the impact-rubbing phenomenon can be restrained and buffered. Thus, the probability and degree of friction and wear between the rotor and the magnetic pole are reduced drastically when the electromagnetic system fails. In order to explore the difference in the dynamic behavior law of the impact-rubbing phenomenon between the traditional protection device and hydrostatic system, the dynamic equations of the rotor impact-rubbing in three kinds of protection devices (fixed ring/deep groove ball bearing/hydrostatic system) under electromagnetic failure mode are established, and the axial trajectory and motion law of the rotor are numerically simulated. Finally, the dynamic behavior characteristics of the rotor are compared and analyzed. The results show that: Among the three kinds of protection devices (fixed ring/deep groove ball bearing/hydrostatic system), the hydrostatic system has the least influence on bouncing time, impact-rubbing force, and impact-rubbing degree, and the maximum impact-rubbing force of MLDSB is greatly reduced. Therefore, the protective bear is not required to be installed in the MLDSB. This study provides the basis for the theory of the “gap impact-rubbing” of MLDSB under electromagnetic failure, and helps to identify electromagnetic faults.

scholarly journals Three in one: evolution of viviparity, coenocytic placenta and polyembryony in cyclostome bryozoans

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
U. A. Nekliudova ◽  
T. F. Schwaha ◽  
O. N. Kotenko ◽  
D. Gruber ◽  
N. Cyran ◽  
...  
Keyword(s):  
Ultrastructural Study ◽  
Main Part ◽  
Structural Diversity ◽  
Early Embryo ◽  
Unique Combination ◽  
Nutritive Tissue ◽  
Pore Cells ◽  
Secondary Embryos ◽  
Cytoplasmic Bridges ◽  
Hydrostatic System

Abstract Background Placentation has evolved multiple times among both chordates and invertebrates. Although they are structurally less complex, invertebrate placentae are much more diverse in their origin, development and position. Aquatic colonial suspension-feeders from the phylum Bryozoa acquired placental analogues multiple times, representing an outstanding example of their structural diversity and evolution. Among them, the clade Cyclostomata is the only one in which placentation is associated with viviparity and polyembryony—a unique combination not present in any other invertebrate group. Results The histological and ultrastructural study of the sexual polymorphic zooids (gonozooids) in two cyclostome species, Crisia eburnea and Crisiella producta, revealed embryos embedded in a placental analogue (nutritive tissue) with a unique structure—comprising coenocytes and solitary cells—previously unknown in animals. Coenocytes originate via nuclear multiplication and cytoplasmic growth among the cells surrounding the early embryo. This process also affects cells of the membranous sac, which initially serves as a hydrostatic system but later becomes main part of the placenta. The nutritive tissue is both highly dynamic, permanently rearranging its structure, and highly integrated with its coenocytic ‘elements’ being interconnected via cytoplasmic bridges and various cell contacts. This tissue shows evidence of both nutrient synthesis and transport (bidirectional transcytosis), supporting the enclosed multiple progeny. Growing primary embryo produces secondary embryos (via fission) that develop into larvae; both the secondary embyos and larvae show signs of endocytosis. Interzooidal communication pores are occupied by 1‒2 specialized pore-cells probably involved in the transport of nutrients between zooids. Conclusions Cyclostome nutritive tissue is currently the only known example of a coenocytic placental analogue, although syncytial ‘elements’ could potentially be formed in them too. Structurally and functionally (but not developmentally) the nutritive tissue can be compared with the syncytial placental analogues of certain invertebrates and chordates. Evolution of the cyclostome placenta, involving transformation of the hydrostatic apparatus (membranous sac) and change of its function to embryonic nourishment, is an example of exaptation that is rather widespread among matrotrophic bryozoans. We speculate that the acquisition of a highly advanced placenta providing massive nourishment might support the evolution of polyembryony in cyclostomes. In turn, massive and continuous embryonic production led to the evolution of enlarged incubating polymorphic gonozooids hosting multiple progeny.

Parameter Estimation in a Hydrostatic System Using Extended Kalman Filter

2001 ◽  
Author(s):  
Yuvin A. Chinniah ◽  
Richard Burton ◽  
Saeid Habibi
Keyword(s):  
Kalman Filter ◽  
Bulk Modulus ◽  
Extended Kalman Filter ◽  
High Performance ◽  
State Space Model ◽  
System Response ◽  
Actuation System ◽  
Accuracy And Precision ◽  
Hydrostatic System ◽  
Entrained Air

Abstract In this paper, the Extended Kalman Filter (EKF) estimation technique is applied to a novel hydrostatic actuation system referred to as the Electrohydraulic Actuator (EHA). A state space model of the EHA is developed and the effective bulk modulus is estimated in simulation. The EHA is a high performance actuation system capable of moving large loads with very high accuracy and precision. In a practical situation, this parameter is very difficult to measure directly as it depends on entrained air which cannot be known at a particular point of time. The bulk modulus is critical for system response and a low bulk modulus as a result of air in the system can seriously hinder the performance of EHA and cause safety problems.

Second Paper: Some Aspects of the Design and Operation of the Three-Wheeled Road Roller

1966 ◽  
Vol 181 (1) ◽  
pp. 91-109
Author(s):  
F. H. Wass
Keyword(s):  
Torque Converter ◽  
Hydraulic Systems ◽  
Engine Torque ◽  
The Road ◽  
Additional Equipment ◽  
Recent Developments ◽  
Hydrostatic Transmissions ◽  
Hydrostatic System ◽  
Unit Output ◽  
Finishing Processes

Following an introduction of general historic nature dealing with the evolution of the modern road roller from the first practicable steam roller of 100 years ago, the paper is confined generally to an examination of the mechanical engineering content and operational requirements of this item of engineering plant universally employed in today's surface consolidation, compaction and finishing processes. The mechanical constitution of the road roller is examined with particular reference to recent developments in design concerning clutches, mechanical, hydrokinetic and hydrostatic transmissions, steering, brakes, bearings and hydraulic systems, all of which are in close accord with modern automotive design practice. Curves illustrate the basic co-ordination requirements of engine/torque converter combination, the torque converter and hydrostatic unit output performance characteristics and vehicle road performance (gradient/ mile/h) with the mechanical ‘stepped’ transmission, the overlapping torque converter transmission and infinite ratio ‘stepless’ hydrostatic system. Additional equipment fitted to the roller for performing operations other than surface rolling is also considered together with features designed to produce maximum operational efficiency. Modern design trends to satisfy present-day demands of maximum machine utilization with minimum servicing and maintenance ‘down-times’ are considered with particular reference to lubrication and accessibility for servicing. Conclusions to past and present are given in the author's views on probable future trends in design and construction.

Sliding Mode Controller and Filter Applied to an Electrohydraulic Actuator System

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Shu Wang ◽  
Richard Burton ◽  
Saeid Habibi
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Variable Structure ◽  
Structure Control ◽  
Estimation Strategy ◽  
Mode Control ◽  
New Strategy ◽  
Actuator System ◽  
Hydrostatic System ◽  
Electrohydraulic Actuator

A common problem pertaining to linear or nonlinear systems is the design of a combined robust control and estimation strategy that can effectively deal with noise and uncertainties. The variable structure control (VSC) and its special form of sliding mode control (SMC) demonstrate robustness with regard to uncertainties, although their performance can be severely degraded by noise. As such they can benefit from using state estimates obtained from filters. In this regard, this paper considers the use of a recently proposed robust state and parameter estimation strategy referred to as the variable structure filter (VSF) in conjunction with SMC. The contribution of this paper is a new strategy that combines sliding mode control with the variable structure filter. In the presence of bounded parametric uncertainties and noise, this combined method demonstrates robust stability both in terms of control and state estimation. Furthermore, the combined strategy can be used to achieve high regulation rates or short settling time. The combined VSF and SMC strategy is demonstrated by its application to a high precision hydrostatic system, referred to as the electrohydraulic actuator system.

Hydrostatic-system palsas at Toolik lake, Alaska: Field observations and simulation

1986 ◽  
Vol 11 (1) ◽  
pp. 79-94 ◽  
Author(s):  
S. I. Outcalt ◽  
F. E. Nelson ◽  
K. M. Hinkel ◽  
G. D. Martin
Keyword(s):  
Field Observations ◽  
Hydrostatic System ◽  
Toolik Lake

Analysis of decay characteristics of an accumulator in an open-circuit hydrostatic system with pump loading

2017 ◽  
Vol 231 (4) ◽  
pp. 312-326 ◽  
Author(s):  
Ajit Kumar ◽  
K Dasgupta ◽  
J Das
Keyword(s):  
Open Circuit ◽  
Drive System ◽  
Test Results ◽  
System Pressure ◽  
Parametric Studies ◽  
Resistive Loads ◽  
Hydraulic Accumulator ◽  
Hydrostatic System ◽  
Mining Vehicles ◽  
Made In

The effects of the decay characteristics of a hydraulic accumulator on the responses of the hydrostatic drive system used in mining vehicles are studied in this article. The system considered for the analysis basically consists of a hydraulic pump, hydro-motor, accumulator and a loading circuit. The studies have been carried out with respect to two different sizes of accumulators. The system model has been made in MATLAB/Simulink® environment. The simulation test results are obtained with respect to the hydro-motor speeds and the system pressure at different resistive loads and capacities of the accumulator and they are verified with the experimental test data. Using the validated model, the parametric studies are also made on the speed responses of the hydrostatic drive for different precharge pressures of the accumulator and inertial load on the motor shaft. The studies made in this article may be useful for the selection of proper capacity of accumulators incorporated in the hydrostatic drive system in mining vehicles.

Infinitely Variable Transmission (IVT) of John Deere 7000 TEN Series Tractors

2002 ◽  
Author(s):  
Sanjay I. Mistry ◽  
Gregory E. Sparks
Keyword(s):  
Transmission System ◽  
Electric Signal ◽  
Mechanical Transmission ◽  
Power Train ◽  
Performance Improvements ◽  
Reverse Mode ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Hydrostatic System ◽  
And Control

The John Deere 7000 TEN series tractors represent a significant change in the transmission system compared to previous John Deere tractor models in this category. John Deere 7710 and 7810 series tractors are the first of the 7000 TEN series tractors offering an infinitely variable transmission (IVT). These tractors provide infinite vehicle speeds in the forward mode from 50 meters/hr to 40 km/hr or an optional 50 km/hr. Reverse mode provides infinite vehicle speeds from 50 meters/hr to 17 km/hr. The IVT provides performance improvements in several areas for unmatched operator convenience and control. The new IVT uses an electric signal to control the electro-hydraulic hydrostatic system with mechanical power train. The IVT represents a hydro-mechanical transmission system using electronics, hydraulics and mechanical systems’ integration to achieve the required performance. This paper describes the IVT system configuration, components, operation, characteristics and some of the engineering considerations dealt with in the development process. The overall IVT system truly represents a “drive-by-wire” mechatronic design.

scholarly journals The Hydrostatic System of Trees

1926 ◽  
Vol 134 (6) ◽  
pp. 378-379 ◽  
Author(s):  
D. T. MacDougal
Keyword(s):  
Hydrostatic System
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