Tooth Surface Modelling and Mesh Behaviors for Paralleled Beveloid Gears

This paper proposed a new tooth surface modeling method for beveloid gear based on the real cutter surface using two orthogonal variables. Then, the analytical mesh model with and without misalignments were derived and solved to study the influences of geometry design parameters on contact behaviors for paralleled beveloid gear pair. Loaded tooth contact analysis is used to validate the proposed mesh model by abaqus software, and the error is below 5%. Results suggest that the increase in pressure, cone, and helical angles enlarge the contact area for meshing without misalignments. The addendum coefficient has unsubstantial impacts on the contact behaviors. For meshing with axis error in the horizontal direction, the growth of pressure angle, cone angle, helical angle, and addendum coefficient improves the carrying capacity of single tooth. But the transmission error deteriorates with the increase in pressure, cone, and helical angles. All three types of misalignments have little influence on the size of the contact ellipse. The growth of axis errors in horizontal and vertical directions significantly increases the transmission error, but the center distance error has a little influence on the transmission precision.

A Study of the Sealing Performance of a New High-Pressure Cone Valve for Deep-Sea Gas-Tight Water Samplers

The cone valve plays an important role in high-pressure sealing applications. In this paper, a new high-pressure cone valve, based on the titanium alloy poppet-to-polyetheretherketone seat sealing structure, is proposed for deep-sea gas-tight water samplers. In order to study the sealing performance of the new valve, both the conforming poppet-seat contact model and the nonconforming poppet-seat contact model were evaluated. Finite element analysis based on the two models was performed and validated by experiments. The results indicate that the nonconforming poppet-seat contact model has a better sealing performance than the conforming poppet-seat contact model. The new cone valve also was applied in a gas-tight hydrothermal fluid sampler and successfully tested in a sea trial during the KNOX18RR cruise from 9 July to 12 August 2008.

Non-Intrusive Technique for Measuring Instability Wave Amplitudes at Simplex Swirl Atomizer Exit

An optical method for non-intrusive wave amplitude measurement is examined. An experimental setup was constructed to produce sprays of various fluids including Canola oil and glycerin-water mixtures, such that precise control of pressure up to 140 psi was possible. A spray was produced by a 20 Gallon per hour oil burner nozzle at varying pressures. Initially, a smooth laminar conical sheet was noticed which eventually was found to break up into droplets. A laser was passed through the laminar conical sheet and was projected onto a surface on the other side and resulted in a vertical linear projection. This projection is postulated to be formed due to the scanning motion of the laser beam as instability waves pass through the laser. The angle of this scan was found to be a function of pressure, cone angle, and distance of laser from nozzle. High resolution images were taken of the film profile as well as the projected image and image analysis software was used to calculate cone angles and angular scan of the laser. Tests were performed with Canola Oil as well as a mixture of glycerin and water in order to evaluate the effect of viscosity and surface tension on the measurements. The resulting data was used to illustrate a principle for determining the instability wave amplitude using this technique.

A portable data collection system for simultaneous cone penetrometer force and volumetric soil water content measurements

A new mechanism and sensors are described that can improve the quality of soil penetration resistance data. The electric-motor-driven mechanism pushes the cone into the soil at a constant rate. The force measurement is made with a miniature load cell sensor located adjacent to the cone head to reduce errors caused by friction between the soil and penetrometer shaft. A small water-content sensor is located on the shaft just above the load sensor, so that soil volumetric water content measurement is made on the hole walls just after the cone force is measured. The general nature of the electrical performance of the water content sensor was evaluated for different probe geometries by optimizing the portion of the electromagnetic energy passing into the soil compared to that remaining in the probe. Some early field and laboratory test results are shown, which were obtained using a complete prototype instrument. The resolution of each sensor is ±0.03 m3m−3 for water content, ±0.0007 MPa for cone penetration pressure (cone index) and ±0.003 m for depth. Key words: Water content, cone index, soil strength