Recent Patents on Mechanical Engineering - Volume 8, Issue 1, 2015

Measurement of asphaltene precipitation onset is important to detect the precipitation of asphaltene during production, transport and refining of petroleum fluids that can result in production losses and large increases in maintenance costs. A large quantity of methods can help determine the onset of asphaltene precipitation, including gravimetric analysis, visual observation, electromagnetic beam absorbance and physical properties measurement such as viscosity, particle size analysis, electrical conductivity, light transmission, acoustic techniques and heat transfer analysis. Numerous apparatuses have also been applied to study the onset of asphaltene precipitation based on the methods mentioned above. The purpose of this study is to provide an overview about the asphaltene precipitation by addressing recent patents and scholarly articles on the subject of the onset measurement.

In recent years, many double-prism mechanism patents have become promising solutions for precision engineering applications, which can perform superior optical pointing and tracking functions. The paper focuses on surveying recent patents related to rotating double-prism scanner used in the fields of free-space laser communications, laser radar, optical switches, laser scanning, and other precision engineering. A general overview of various rotating double-prism mechanisms is provided, and various aspects of rotating double-prism researches are introduced, including forward problem, inverse problem, drive mechanism, mechanical analysis, error analysis and control system. Patents related to rotating double-prism mechanisms, issued since 2010, are selected for the survey. With a comparison of these patents, some valuable conclusions are drawn to predict the future research and development in rotating double-prism scanner.

As a main component of injection molding machine, nozzle is used to prevent polymer melt from leaking during plasticizing and provide an access injecting polymer melt into the mold cavity during injecting process. The straight-through nozzles and shut off nozzles with hydraulic or pneumatic are adopted in the traditional injection molding machine. The paper reviews various patents on nozzles with new structures and optimized design in recent years. A spring-sliding valve type nozzle is introduced to solve melt leaking, nozzle blocking, and melt thermal decomposition. Moreover, this new type of shut off nozzle is more compacted and low-cost.

The paper reviews recent patents by applying the boundary slippage technology to conserve the energy consumption in hydrodynamic lubricated gears and bearings. This technology has also the benefits of increasing the load-carrying capacity of hydrodynamic lubricated mechanical components. Several inventions were discussed outlining how to apply the boundary slippage technology in gears and bearings for different operating conditions. The future direction of the boundary slippage technology may be to develop special surface coatings which are hydrophobic or oil-phobic to generate significantly low lubricant-contact interfacial shear strengths for greatly improving the performances of hydrodynamic lubricated mechanical components.

A 3D model of oil film between friction pair was built and based on the principle of computational fluid dynamics (CFD), the distribution law of pressure field, temperature field, and velocity field of oil film were investigated thoroughly. We can find that distribution law of pressure is very regular; from inlet to outlet, the value decreases gradually, and with the highest value of 0.3MPa on the inner radius. Nevertheless, the temperature in the middle layer of thickness of the oil film is much lower and the temperature rise is 0.12K in the oil film. Velocity of the oil film is much faster on the outlet, and near the rotating wall, with much quicker velocity; which shows a parabolic shape flow, which is mainly caused by shear stress and extrusion force. The purpose of this study is to provide an overview about the fluid state and transmission characteristics of the oil film by addressing recent patents and scholarly articles on the subject of design, control and application of such systems.

In recent years, many patents have been devoted to develop the walnut mechanical cracking and kernel fetching, kernel shell separation and walnut classification techniques that can significantly improve the walnut shell cracking rate and decrease the walnut kernel breaking rate. However, those machines adjust poorly to different sizes of walnuts, requiring size grading by human with high kernel breaking rate, low efficiency. This paper analyzes the patent on new walnut cracking, kernel fetching and shell kernel separation equipment in recent years. Based on the sphere walnut models and the advantages of variety of walnut shell machine, the walnut shearing, pressing and cracking device is designed by the author. Different sizes of walnuts are adjusted to these machines, including the conveyor belt shear extrusion flexible shell system, flexible blade hammer kernel fetching system and the air-flexible screw blade coupling walnut kernel shell roller two-way separation system, realizing the function of walnut crashing, kernel fetching and shell kernel separation, with the walnut shell cracking rate being 98%, the kernel breaking rate 2.9% and the kernel revealing rate 70%, improving the walnut shell cracking rate and reducing the kernel breaking rate.

The paper presents an engineering surface technology registered in patents by designing the surface topography for improving the performance of a lubricated sliding contact. According to this technology, the surface topography should be artificially formed with a certain width of the flattened top, or the surface asperity should be truncated in a certain degree with a formed top plateau of a certain width parallel to the surface sliding. It was shown that by this surface technology, the elastic contact stiffness of the coupled surfaces will be significantly increased, while the temperature rise at the rubbing surface will be significantly reduced, and the anti-scuffing capability of the surface will thus be remarkably increased. These effects are especially significant for the operating condition of high sliding speeds and relatively heavy loads.

In this work, the critical design factors in the development of an adapter capable of enabling the use of projectiles that are of diameters less than the optimal 0.5 inches (in ballistics, a projectile having a half inch diameter is commonly called a caliber .50 projectile) are explored. This recently- patented slug adapter enables the users of the standard caliber .50 disruptor (the Mk 2 disruptor) to successfully implement sub-caliber .50 projectiles. There are three critical design factors explored in this work: 1) projectile support during launch, 2) gas pressure reduction during launch and 3) adapter failure during projectile impact.

The experimental study was carried out on axial force of shearer drum cutting coal and rock on the coal-cutting test bed, in order to find the influence on the axial force of drum structural parameters when shearer drum cutting coal and rock. The structure parameter of drum is the main object of this research. The results of research indicate that when the cone angle of conical pick is equal to 90°, the axial force on both sides has small fluctuation, the coal seam side has small impact on load peak, caused by coal-rock cutting. The cutting line space of conical pick has great influence on axial force of drum. When the cutting line space is about 2.5~3 times as much as cone diameter, the conical pick has equilibrium condition of forces. When the helix angle is equal to 20°, the picks have equilibrium condition of forces, caused by the smaller axial force through the coal charging and coal-rock cutting progress. Seen from the standard deviation of axial force on both sides, sequence drum has more stability and reliability. With the increase of speed, the mean value of the axial force also tends to a steady value, and the axial force on the coal seam side has small fluctuation, which is conducive to the stability and reliability of the shearer during the cutting process.

To eliminate the static unbalance mass of the propeller through once grinding or counterweighing, the key problem is how to obtain solution of the static unbalance. Based on the suspension theory for the hydrostatic spherical bearing, a special detection device of vertical static balance for large marine propeller is researched and developed. The device can be used to detect the static unbalance mass. Moreover, two effective models based on the principle of moment balance are proposed. One is the offset model for the principal inertia axis, which can be used to calculate the mass and the location of the gravity center of the propeller. The other is the attached mass model, which is used to figure out the unbalance mass and the location of the unbalance mass for the propeller. According to the above two models and the static equilibrium condition for a rotor, the mass and location of the propeller, which need to be grinded or counterweighted, can be obtained. The purpose of this study is to provide an overview about specific algorithm for the static unbalance of propeller by addressing issues in recent patents and scholarly articles on such device.