Pressure angle

About: Pressure angle is a research topic. Over the lifetime, 1373 publications have been published within this topic receiving 10245 citations. The topic is also known as: angle of obliquity.

Effect of the load location along the involute curve of spur gears on the applied stress at the fillet radius

Abstract: In this study, attempts are carried out to determine the amount of stress at the fillet radius region of spur gears when the applied load location changes, along the involute curve, from the top surface to the bottom. For this purpose the photoelastic method and numerical MSC/NASTRAN software are used. The gears with pressure angle (ϕ) 20o, and 25o were prepared from photoelastic material type PLM-4B in this study. Practical calibration is used to determine the fringe order value of this material. Four different modules (m); 6, 10, 14, and 20 mm were prepared for two different numbers of teeth (N); 18 and 26, with different face widths (B1, B2, B3); 10, 17, 25.4 mm respectively. Four load values were applied on each tooth at five to six different load locations along the involutes curve profile. In order to accomplish the comparison between the results for different methods, the same sample dimensions and parameters were prepared again for the MSC/NASTRAN software. The results showed that the maximum applied stress at the fillet radius occur when the applied load location is on the top land of a tooth, and then that amount is decreased when the applied load positions change toward the bottom land. The results of the NASTRAN method showed that the applied stress at the fillet radius would be minimum when the loading point locates between the pitch circle and dedendum circle, in particular around 1.5 times module (1.5 m) of the total tooth height which equals 2.25 module, and then the applied stresses are increased again. However, in the photoelastic method the applied stresses were decreased continuously to the bottom land. The reasons behind such results can be attributed to the type of failure theories that can be used in NASTRAN software for characterization the applied stresses, i.e. considering types of applied stresses into account, such as bending, direct compressive, and shear stresses. Moreover, in order to compare the applied stress values at fillet regions, obtained by theoretical and practical approaches, four different standard mathematical equations are used for stress calculation at fillet radius of spur gears to show the difference of the parameters and variables that can affect the applied stress results.

Cosine gear transmission mechanism

Abstract: The present invention belongs to the field of mechanical transmission technology, and is especially one kind of cosine gear and one kind of conjugate cosine gear transmission mechanism. The present invention solves the technological problem for providing one kind of cosine gear transmission mechanism with improved gear transmission performance and raised gear bearing capacity. Technologically, the present invention features that the cosine gear has cosine tooth profile curve, its conjugate gear has cosine tooth profile curve with amplitude and period determined y the required transmission ratio, two gears have near linear contact path, and the tooth profile curve of the cosine gear has the zero line of cosine curve as the pitch line, the period of cosine curve as the tooth pitch and amplitude of cosine curve as the addendum. The cosine gear transmission mechanism has great pressure angle, small slide coefficient, high contacting and bending strength and other advantages.

Tests on air propellers in yaw

Abstract: This report contains the results of tests to determine the thrust (pull) and torque characteristics of air propellers in movement relative to the air in a line oblique to the line of the shaft, and specifically when such angle of obliquity is large, as in the case of helicopter flight with the propeller serving for both sustentation and traction.

Drum shape teeth type coupling

Abstract: The utility model discloses a drum tooth-shaped coupling, comprising an external tooth axle sleeve, an annular ring gear and a bolt used for reaming, and the utility model is characterized in that an inner tooth and an external tooth are meshed with an involute spline with a drum shape, an angle of a pressure angle between the inner tooth and the external tooth ranges from 28 degrees to 30 degrees, a tooth length direction of the external tooth takes a shape of a three-segment arc and a middle arc radius is larger than the arc radius of two ends. The utility model has the advantages of high transmission ability, big angle offset and long service life and convenient for production.

Modeling and Simulation of Mild Wear of Spur Gear Considering Radial Misalignment

Abstract: An appropriate clearance is required between mating gears for effective power transmission. In the present work, the effect of radial misalignment on mild wear of spur gear is modeled and simulated. The changes in the gear tooth contact geometry due to progressive wear have also been accounted in the model. The simulation results show that in the pinion dedendum region, pressure angle increases, while the contact pressure and wear depth decrease with increase in number of wear cycles. As far as the effect of radial misalignment is concerned, contact pressure decreases and wear depth increases with the increase in misalignment. In the pinion addendum region, pressure angle and wear depth increase with the increase in wear cycles, while the contact pressure and wear depth decrease with the increase in misalignment. The pressure angle and pitch point change from initial 20° (23rd pitch point) to 20.95° (26th pitch point) and 21.86° (28th pitch point) due to 0.5- and 1-mm radial misalignment, respectively. The wear depths after 50,000 wear cycles are − 1.32 × 10−2 μm, − 3.33 × 10−3 μm and − 4.39 × 10−4 μm at 23rd, 26th and 28th pitch points, respectively. The effect of radial misalignment on backlash, pressure angle, pitch point, contact ratio, double tooth contact region and speed ratio is also discussed.