Applied Mechanics and Materials Vol. 164

Abstract: This article introduces a rotating clamping device, using with the disassemblage machine of monomer hydraulic prop. It was used for clamping hydraulic prop, which was mainly comprised by the coupling mechanism, clamping mechanism and compressing mechanism. The coupling mechanism sleeve was bolted to the spindle. Clamping mechanism located at the end of sleeve, working with the spindle rotation. Compressing mechanism hang around the sleeve, not working with the spindle rotation. Compressing mechanism passed the clamping force through the thrust bearing, clamping the hydraulic prop. It was easy to operate. Clamping force is decentralized, the stress in cylinder was even, so the cylinders seldom distort, which reduced the impact, extending the life of the equipment.

Abstract: For overhead or gantry crane direct relationship between electric total loss and stator voltage or load torque is obtained based on the asynchronous motor’s Γ-shape equivalent circuit because the stator’s copper loss and iron loss are regarded as invariable loss that only relates to stator voltage and the rotor’s copper loss is regarded as variable loss that is changed following load torque’s changing. The optimal regulation voltage is obtained through mathematical calculation on the condition that make the asynchronous motor be stable running. The electric total loss will be minimum when the stator’s voltage is the optimal regulation voltage. The research results showed: the electric total loss’s error between the exact solution and the approximate solution obtained according to the approximate slip ratio while the asynchronous motor’s stable running was bigger when the stator voltage was less than 200V, and the error was nearly zero when the stator voltage was more than 200V, but the optimal voltage error would not be more than 7V; the crane’s effect of energy saving was prominent with optimal voltage regulation mode according to the load torque’s changing.

Abstract: This article describes the structure, working principle and technical parameters of the lubricant oil pressure and liquid level indicating alarm system of the mine hoist. In order to send signals to the main control room displaying pressure and liquid level， the use of digital circuit-designed smart modular pressure transmitter, level transmitter, with the light beam warning indicator, display the fluid pressure and fluid level signal in the main control room, the limit alarm, and the upper and lower limit settings.

Abstract: Crude oil is the most important material for the modern industry, while its volatility risk’s threatening to the industry developments is increasing stronger and stronger. In 2008 and 2009, some Chinese corporations have suffered from huge losses from their earlier hedging operations on crude oil prices. These incidents reflected the shortage of management methods and experiences on risks. In fact, those corporations might hedge their short positions on the crude oil puts by longing the US Treasury Bonds puts so as to avoid the huge losses.

Abstract: This paper provides a method of supply constant pressure air for air conditioning system. It analysis the energy consumption betwwen the damper adjuste air flow with variable frequency speed regulation adjuste air flow. The paper Introduce the Energy conservation principle of the frequency control blower. The supplying air Pipeline subject to a uniform force, the equipments mechanical properties was improved.The results show that Uses the frequency conversion velocity modulation to carry on supply constant pressure air, obviously reduces the energy consumption.The electrical motor starting characteristic is improved, realizes the electrical motor soft start.

Abstract: When designing the centrifugal cooling pump, the people have been accustomed to design the normal clearance of the impeller shroud by mechanical assembly principle only for preventing parts from interference. But in the practice, the shroud clearance magnitude of the cooling pump is very difficult to be confirmed because of either serious leakage or high power consumption. As so far, it hasn’t been specific theory about its magnitude which was designed only by a large of experiment. The boundary-layer thickness theory can be introduced to calculate the impeller clearance magnitude. This method first breached conventional experiment way in determine the shroud clearance magnitude and applied scientific theory to the engineering design. As a result, this method can save a great deal of industrial resources such as manpower, materials and funds, and give the more precise scientific reference to relative research about pump

Abstract: The extended range device for hanging above the pump to increase the pump piston stroke.The diameter of the extended range is greater than the diameter of the tubing. The extended range and pump tube connection transition tubing and excessive sucker rod. Transition tubing and excessive sucker rod length is accurate. The limit position pump piston stroke is not from the pump body and not collide with the pump with the pump. The extended-range device installation location is away from two pumping tubing length.The output rod of extended-range device does not bear the weight of the sucker rod

Abstract: The fit clearance between the impeller and the impeller shell directly affect the characteristics of the turbocharger. Assembly dimension chain is the basis of the design and analysis of workpiece size.Reducing the fit clearance of the impeller and the impeller shell can improve the booster effect. The impeller of the small inertia is beneficial to increase the rotation speed of the impeller and the impeller rotation stability requirements.The turbocharger of installation small inertia impeller is characterized by small size. Followed by its supercharged performance

Abstract: In this paper, a sophisticated and a simplified parametric 3-D finite element model for helical planetary gearing were developed sequentially with the help of ANSYS APDL. Based on the proposed two models, the meshing characteristics of planetary gear were analyzed and the simulation results were then compared. The comparison indicates that the simplified finite element model is capable of evaluating the gear stress with satisfactory accuracy. Therefore, an investigation on effects of primary design variables on gear stress and strain was conducted on the basis of proposed simplified finite element model. The investigation reveals that the tooth width affects the meshing characteristics mostly, followed by the factors of rim thickness, helix angle successively.

Abstract: Walking is a complex dynamic task that requires the regulation of the whole-body angular momentum to maintain dynamic balance while performing walking subtasks such as propelling the body forward and accelerating the leg into swing. To investigate the characteristic of slips and falls during gait self-balancing, a method was proposed that could better understand the effects of pre-slip gait response biomechanics on the risk for falls. A new segmental model of the human body was developed and this model would be used continuously measured locations from nearly 85 points on the body to produce a dynamic postural record of human movement. The muscles surrounding the hip were found to be most important in maintaining control of the trunk and preventing collapse in response to the forward perturbations (FP).