Showing papers on "Pressure angle published in 2009"

Rolling Force and Rolling Moment in Spline Cold Rolling Using Slip-line Field Method

Abstract: Rolling force and rolling moment are prime process parameter of external spline cold rolling.However,the precise theoretical formulae of rolling force and rolling moment are still very fewer,and the determination of them depends on experience.In the present study,the mathematical models of rolling force and rolling moment are established based on stress field theory of slip-line.And the isotropic hardening is used to improve the yield criterion.Based on MATLAB program language environment,calculation program is developed according to mathematical models established.The rolling force and rolling moment could be predicted quickly via the calculation program,and then the reliability of the models is validated by FEM.Within the range of module of spline m=0.5–1.5 mm,pressure angle of reference circle α=30.0°–45.0°,and number of spline teeth Z=19–54,the rolling force and rolling moment in rolling process(finishing rolling is excluded) are researched by means of virtualizing orthogonal experiment design.The results of the present study indicate that:the influences of module and number of spline teeth on the maximum rolling force and rolling moment in the process are remarkable;in the case of pressure angle of reference circle is little,module of spline is great,and number of spline teeth is little,the peak value of rolling force in rolling process may appear in the midst of the process;the peak value of rolling moment in rolling process appears in the midst of the process,and then oscillator weaken to a stable value.The results of the present study may provide guidelines for the determination of power of the motor and the design of hydraulic system of special machine,and provide basis for the farther researches on the precise forming process of external spline cold rolling.

A Study on Reducing the Root Fillet Stress in Spur Gear Using Internal Stress Relieving Feature of Different Shapes

Abstract: Gear teeth failure due to fatigue is a common phenomenon observed. Even a slight reduction in the root tensile stress results in great increase in the fatigue life of a gear. If gear fails in tensile fatigue, the results are catastrophic and occur with little or no warnings. Therefore for all the reasons mentioned above, this work is of more practical importance. For many years, gear design has been improved by using improved material, hardening surfaces with heat treatment and carburization, and shot penning to improve surface finish etc. Few more efforts have been made to improve the durability and strength by altering the pressure angle, using the asymmetric teeth, altering the geometry of root fillet curve and so on. Most of the above methods do not guarantees the interchangeability of the existing gear systems. This work presents the possibilities of using the stress redistribution techniques by introducing the stress relieving features in the stressed zone to the advantage of reduction of root fillet stress in spur gear. This also ensures interchangeability of existing gear systems. In this work, combination of circular and elliptical stress relieving features are used and better results are obtained than using circular stress relieving features alone which are used by earlier researchers. A finite element model with a segment of three teeth is considered for analysis and stress relieving features of various sizes are introduced on gear teeth at various locations. Analysis revealed that, combination of elliptical and circular stress relieving features at specific, locations are beneficial than single circular, single elliptical, two circular or two elliptical stress reliving features.

Accuracy Measurement and Evaluation of Straight Bevel Gear Manufactured by End Mill Using CNC Milling Machine

Abstract: Straight bevel gears are usually manufactured with various machines and systems, and the tooth profiles are produced by grinding or machining by means of a tool with many cutting edges. In recent years, the straight bevel gear has been manufactured by an end mill using a computer numerical control (CNC) milling machine because the use of the auxiliary apparatus, special cutters, and special machine tools is not needed. Using this method, the gear manufacturing with high accuracy is an important problem. In this paper, the coordinate measurement of the straight bevel gear manufactured in this method is performed and the gear accuracy is evaluated. The tooth profiles of the straight bevel gear generated by a quasi-complementary crown gear instead of a conventional complementary crown gear are introduced. For this study, the tooth profiles of the straight bevel gear were modeled using a 3D computer-aided design system and the gear was manufactured by an end mill using a CNC milling machine based on a computer-aided manufacturing process. Afterward, the coordinates of many points on the gear tooth surfaces were measured at random using a coordinate measuring machine. This coordinate measurement provides the information about the factors related to the gear accuracy such as pressure angle, tooth angle error, workpiece setting angle, apex to back, and so on. Therefore, the values of the above factors were estimated and were compared with the theoretical ones, respectively.

Inverted tooth chain and sprocket drive system with reduced meshing impact

Abstract: An inverted tooth chain drive system defines a meshing contact angle Tau (τ) between the tangent line TL and an initial contact reference line that passes through a controlling pin center and the initial contact location A link plate entrance angle Beta (β) is defined between the initial contact reference line and an inside flank reference line that passes through an arc center of the inside flank radius and the initial contact location A meshing impact angle Sigma (σ) is defined between the tangent line and the inside flank reference line such that σ = τ + β, wherein β < 9°and σ ≤ 34° The pressure angle of the sprocket tooth can be adjusted and the chain optimized such that β ≤ 7°and σ ≤ 31 ° The system thus provides a reduction of the link impact force FL and the resultant impact energy E The inverted tooth chain, itself, defines a pitch P and an inside flank projection Lamda ( λ ) such that 0007 x P ≤ λ ≤ 0017 x P when said chain is pulled straight The outside flanks include a chamfer to ensure that initial contact between the chain and sprocket is always on the leading inside flanks of the chain

A Pressure Angle Function Method for Describing Tooth Profiles of Planar Gears

Abstract: A general mathematical model for describing the geometries and the geometric characteristics of meshing tooth profiles of planar gears is established. The function of pressure angle in the angular displacement of gears, called the pressure angle function (PAF), is introduced to characterize this model. The different tooth profiles and their geometric properties could be generated and analyzed logically and systematically by using this model and defining various PAFs. This new method is applicable to any type of gear pairs including circular or noncircular. In addition, by using this method, it is relatively easy to realize the desired geometrical and mechanical properties into the design.

Parametric analysis of Asymmetric Spur Gear Tooth

Abstract: is a machine element used to transmit motion and power between rotating shafts by means of progressive engagement of projections called teeth. Gears are classi- fied according to the relative position of the axes of the shaft, type of gearing, peripheral velocity of the gears and position of teeth on gear surface. Presently gears are suffered by backlash the amount by which the width of a tooth space exceeds the thickness of the engaging tooth on the pitch circles, undercut a condition in gen- erated gear teeth when any part of the fillet curve lies inside of a line drawn tangent to the working profile at its lowest point and interference is an important aspect of kinematics of gearing. When the gear tooth tries to dig below the base circle of mating gear then the gear tooth action shall be non conjugate and violate the fun- damental law of gearing this non conjugate action is called the interference . These defects can be eliminated by increasing the pressure angle, by increasing the addendum of mat- ing gear and another way of increasing the load capacity of transmissions is to modify the involute geometry. This has been a standard practice in sophisticated gear design for many years. The nomenclature describing these types of gear modifications can be quite confusing with reference to addendum modification or profile shift. An additional alteration that is very rarely used is to make the gears asymmetric with different pressure an- gles for each side of the tooth. An asymmetric spur gear drive means that larger and smaller pressure angles are applied for the driving and coast sides. The two profiles of a gear tooth are functionally different for most gear drives. The workload on one side of profile is significantly higher than the other Gears.

Capacitance diaphragm gauge and vaccum apparatus

Abstract: A capacitance diaphragm gauge includes an inclination angle sensor which detects the inclination angle of the gauge. The pressure dependences of capacitance obtained when the capacitance diaphragm gauge is mounted on a vacuum apparatus at the first inclination angle (+90°), the second inclination angle (0°), and the third inclination angle (−90°) are stored in a storage unit in advance. A pressure measurement value is then corrected based on the inclination angle information detected by the inclination angle sensor and the capacitance-pressure characteristic data is actually measured at the first, second and third inclination angles, and stored in the gauge.

Angular contact rolling-element bearing, especially double row ball roller bearing in tandem arrangement

Abstract: A double row roller bearing which has an outer and inner bearing ring and ball rollers, which have lateral faces and are arranged next to each other in rows, arranged between the bearing rings. The rollers roll in raceways incorporated into the inner face of the outer bearing ring and outer face of the inner hearing ring. The raceways run in parallel and have pressure angle axes that are pitched at a pressure angle relative to a bearing radial axis. The rollers have a distance relative to each other which excludes mutual frictional contacts. For this purpose, the distance of the pressure angle axes of the raceways is enlarged and both rows of rollers are guided in separate bearing cages, while the raceway of the rollers of the row with the larger reference circle arranged on the inner bearing ring has a one-sided axial extension using the distance.

Improving the B-Spline Method of Dynamically-Compensated Cam Design by Minimizing or Restricting Vibrations in High-Speed Cam-Follower Systems

Abstract: This paper presents an improved method for dynamically-compensated (tuned) cam design by minimizing or restricting vibrations in high-speed cam-follower systems. Using this approach, cams can be synthesized with a variety of design requirements and reduced residual vibrations. An example of the dynamically-compensated B-spline method illustrates the application process and demonstrates the improvement effect. While preserving the features of the B-spline method, the improved design method allows the cams to satisfy requirements, such as pressure angle, radius of curvature, and contact stress, and also reduces the residual vibrations caused by deviations in actual cam speed or system damping ratio from their design values.

Involute Spur Gear Template Development by Parametric Technique Using Computer Aided Design

Abstract: There are many methods available for developing profiles of gear and spline teeth. Most of the techniques are inaccurate because they use only an approximation of the involute curve profile. The parametric method developed in this paper provides accurate involute curve creation using formulas and exact geometric equations. In addition, the involute curve by equation technique allows using either Cartesian in terms of X, Y, and Z or cylindrical coordinate systems to create the involute curve profile. Since spur gear geometry is controlled by a few basic parameters, a generic gear can be designed by three common parameters namely the pressure angle (a), the module (m), and the number of teeth (z). Most of the present day CAD systems have no built-in tool for designing such gears. This paper is an attempt in utilizing the concept of parametric technology to develop a template gear. The gear so developed has true involute profile, which is a realistic design. This will allow making changes to the gear design by using parametric input. If one gear file is developed using this parametric technology, with which, different size and variety of spur gears can be created. The specific objective is to design and develop a template spur gear with 3 module, 30 Teeth, 20° pressure angle based on parametric technique by using CATIA V5R14 package. The later portion it is shown how this model may be retrieved and utilized for developing gears of different modules and number of teeth with change in these input parameters. Keywords : Parametric design, Template gear, involute curve, x and y coordinates, Laws for x and y co-ordinates, Extrapolated spline, circular pattern, extrusion

Method for designing swinging follower cylindrical cam contour line

Abstract: The invention relates to a design method of a cylindrical cam profile of an oscillating follower. The method is characterized by comprising the following steps: introducing a coordinate expression of a 3D evolute of a displacement curve of the oscillating follower, putting forward a concept of a deviation angle, deducting the expression of the deviation angle according to a geometrical relation, and establishing a profile equation which is convenient for analyzing, designing and constructing the cylindrical cam of the oscillating follower; deducting an expression of a pressure angle according to the geometrical relation of the profile evolute, drawing a relation curve of a base radius R in relation to a maximum pressure angle alpha, and obtaining the minimum base radii which are corresponding to different allowable pressure angles; and programming an MATLAB program according to a known expression, namely, S=f(phi), 1, a and R, extracting coordinate values of the curve by MATLAB software after the operation of the program, pasting the coordinate values to AutoCAD software under a 'PLINE' command after processing, and then processing the coordinate values to 3D CAD software to obtain the profile. The solution process and the design process of the method are concise, visual, and easy to be controlled and practical, and have no design error.

Estimating Gear Tooth Surface Geometry by Means of the Vibration Measurement: Distinction of the Vibration Characteristics of Gears With Tooth Surface Form Error

Abstract: Tooth surface measurement is an important way to verify the quality of produced gears. To reduce inspection time and cost, only a few tooth profiles and traces on some teeth are inspected. Measured data are not likely representatives of all gear teeth because errors may occur in assembly procedure and affect tooth contact condition. Frequently, tooth surface measuring data cannot show contact condition and used to predict gear vibration accurately. Field inspection method whose measured results relate directly to the messing condition is required. This paper derives the relationship between meshing vibration components and the common gear tooth surface geometries of helical gears. The tooth surface geometries considered here are lead crowning, profile convex, pressure angle error, and bias-in modification. The polar plot representation, which plots meshing components in a complex plane, is proposed here to distinguish vibration characteristics of gears with various tooth surface forms. It is found that the vector of the second order of meshing component is valuable for classifying the type of tooth surface geometry.

Injection molded asymmetric spur gear — development and preliminary performance evaluation

Abstract: Innovative gear designs are essential to meet the increasing demands of high load carrying capacity, high endurance, low cost, long life, and high speeds in automobile, aerospace, and wind turbine industries. Conventional gears are having symmetric teeth; however most of the applications necessitate power/motion transmission in one direction. This unidirectional transmission leads to the design of asymmetric teeth in a gear. Extensive research work on design and optimization and asymmetric gear tooth profile for improved bending and contact strength has been attempted. However, very little experimental investigation has been attempted and no work has been attempted in the experimental investigation of asymmetric polymeric gears. In this work, unreinforced polypropylene material is injection molded for the asymmetric spur gears. Gears are molded to the size of 3 mm module, 18 number of teeth and having pressure angle of 34° and 20° at drive and coast side respectively. To examine surface durability and the kinematic characteristics of asymmetric gear, a gear test rig is developed in the laboratory with permanent magnet direct current motor and powder clutch dynamometer as driving and power absorption unit with necessary inline torque sensors and non contact temperature sensor. Preliminary transmission efficiency and surface temperature of test gears promises wide scope for asymmetric composite gears in motion transmission application. Due to the increase in pressure angle at drive side of gear tooth, relative sliding velocity found to decrease and hence asymmetric gear exhibit superior gear pair efficiency and less surface temperature.

Design of Cylindrical Cam with Oscillating Follower Based on 3D Expansion of Planar Profile Model

Abstract: Cylindrical cam with oscillating follower is widely applicable and used in many mechanical devices and machines.However,a common error exists in the methods of designing planar profile for oscillating follower cylinder cam.In this study,we propose a new hypothesis to solve this design problem with the inclusion of deviation angle.On the basis of this new concept,equations for planar profile expansion and methods of calculating pressure angle are deduced by applying 3D expansion formula of the follower's motion orbit.When the pressure angle is less than allowable value,the minimum base radius can be determined by using MATLAB software.Accordingly,the planar profile of oscillating follower cylinder cam is generated by CAD software.This new method is practical and can be easily adopted for the design of oscillating follower cylindrical cam with desirable accuracy.We applied the method in the design of cylindrical cam for paper feeding mechanism used in high-speed printers.We calculated the planar profile and used it to direct the NC machine for the manufacture of the groove of cylindrical cam.The improved cylindrical cam met all of the requirements of speed and accuracy demanded by high-speed printers.Therefore,our new method has been validated by practical application.

The pressure angle effects of spur gears on stress concentration factor

Abstract: Purpose – The purpose of this paper is to investigate the effect of pressure angle, and module of spur gear teeth on stress concentration factor, using photoelasticity method, and numerical MSC/NASTRAN finite element package.Design/methodology/approach – The stress concentration factor is determined as a ratio between maximum stress (determined in the fillet radius by photoelastic and finite element methods), and nominal stress (calculated by a common standard formulas). In order to specify the geometric parameters (height and thickness) of gears, both standard Deutsches Institut fur Normung (DIN)/Japanese Gear Manufactures Association (JGMA), and five other non‐standard approaches are used.Findings – The results show that the stress concentration factor increases by decreasing the pressure angle. In addition, the values which are obtained by finite element analyses exhibit more uniformity than photoelastic method.Practical implications – An accurate determination of stress concentration factors will limi...

Method and machine for internal gear machining

Abstract: PROBLEM TO BE SOLVED: To provide a method and a machine for internal gear machining correcting a gear profile error in tooth profile grinding of an internal gear using a barrel type screw-like grinding wheel and achieving high accuracy in tooth profile grinding. SOLUTION: An NC device 31 functioning as a tooth profile error correction unit for an internal gear grinding machine (internal gear cutting machine) is configured to reduce pressure angle errors Δfa L , Δfa R on the tooth surface of a workpiece W (internal gear) measured by correcting a radial directional position, lateral directional position of the grinding wheel, turning angle of the grinding wheel, and helical motion, to reduce a tooth trace error ΔL on the tooth surface of the workpiece W measured by correcting the helical motion, and to reduce a tooth thickness error Δth on the tooth surface of the workpiece W measured by correcting the radial directional position, lateral directional position of the grinding wheel, and helical motion. COPYRIGHT: (C)2011,JPO&INPIT

CNC Press Based on the High-Speed Linear Servo Motor and Two-Stage Symmetrical Orthogonal Toggle Force Amplifying Mechanism

Abstract: The mechanical press driven by the common AC motor and based on the crank-linkage-slider mechanism is still widely used in the field of mechanical manufacturing. Such press is characterized by poor dynamics performance, serious noise pollution, low energy efficiency, unbalanced overall structure and cumbersome appearance. The object of this paper is to introduce a CNC press driven by the high-speed linear servo motor and based on the two-stage symmetrical orthogonal toggle force amplifying mechanism. Its working principle is to amplify the thrust or tension generated by the high-speed linear servo motor through the two-stage orthogonal toggle force amplifier and then to transmit to the output slider, called pressure head, which finishes the press work on the work piece. The electromechanical integration press has the following advantages: (1) Comparatively low noise pollution for the removal of rapid rotating motor and components. (2) Improved dynamics performance by the computer numeral control of the speed of the pressure head. (3)The magnitude of the stroke and output force of the pressure head can be adjusted in a wide range by editing the program to control initial pressure angle and end pressure angle of the toggle mechanism. (4) Because the force acted on the pressure head in the horizontal direction is symmetric and balanced, theoretically, there is no friction on the pressure head. It is not only good for energy saving, but also for the prolonging of the service life of the machine. (5) Higher level of automation and intelligence than the hydraulic press, and it is free from hydraulic oil pollution.© 2009 ASME

Manufacturing method for worm wheel and worm reduction gear

Abstract: PROBLEM TO BE SOLVED: To high-dimensionally achieve both securement of durability of the tooth 8a of a worm wheel 5a and reduced machining margin (cost reduction). SOLUTION: The pressure angle θ 1 of each tooth of a helical gear 13 formed in the peripheral surface of intermediate raw material 12a is set smaller than the pressure angle θ 2 of each tooth 8a of the worm wheel 5a after completion. As a result, even if the thickness of the tooth is increased, a root circle diameter size remains the same (depth of a bottom groove remains the same). COPYRIGHT: (C)2009,JPO&INPIT

Male and female full rolling gears

Abstract: Male and female full rolling gears use a couple rolling curves which can transmit power by engaged rolling as tooth profile. The rolling curves are synthetic curves executing both circular motion and radially linear motion. One of the tooth profile of two mutual mating gears uses convex rolling curve tooth profile (2), and another uses concave rolling curve tooth profile (7). The engaging transmission turns into concave-convex contact transmission, and line of contact engagement lies on the line of centres (6) of two intersecting gear circles. The tooth profile angle is 45°,the pressure angle is equal to 0, the length of tooth is equal to t/2, and the addendum circle is pitch circle. Said male and female full rolling gears do not cause sliding friction and vibration during the transmission.

Involute Spur Gear Template Development by Parametric Technique Using Computer Aided Design (Pp. 415-429)

Abstract: There are many methods available for developing profiles of gear and spline teeth. Most of the techniques are inaccurate because they use only an approximation of the involute curve profile. The parametric method developed in this paper provides accurate involute curve creation using formulas and exact geometric equations. In addition, the involute curve by equation technique allows using either Cartesian in terms of X, Y, and Z or cylindrical coordinate systems to create the involute curve profile. Since spur gear geometry is controlled by a few basic parameters, a generic gear can be designed by three common parameters namely the pressure angle (a), the module (m), and the number of teeth (z). Most of the present day CAD systems have no built-in tool for designing such gears. This paper is an attempt in utilizing the concept of parametric technology to develop a template gear. The gear so developed has true involute profile, which is a realistic design. This will allow making changes to the gear design by using

Bidirectional geared motor

Abstract: The invention relates to a bi-directional gear motor; a transmission gear inside the outside shell of the motor is a pair of meshed driving and driven gears, and a main shaft of the driving gear and an auxiliary shaft of the driven gear are equipped. The motor is characterized in that the transmission gear has the following standards: the pressure angle is 22.5 degrees, the central distance is 31.3mm, the modulus is 2.75 and the number of gears is 11. The motor effectively reduces the overlap coefficients of gears, automatically adjusts the radial gap of gears and the gap at the meshing line of gears, reduces the radial size, improves the working press and mechanical efficiency, and promotes the high-temperature starting performance, lowers the production cost and improves the economic benefit, through improving the general structure comprising a shaft sleeve, a sealing ring, etc.

Gap-eliminating mechanism gear rack drive

Abstract: The utility model provides a gap eliminator for gears and racks, wherein a motor inputs motion into a first gear shaft via a helical gear couple provided with a gap elimination correction gasket, the axle end of the first gear shaft is provided with an end face bearing, a bearing support sleeve, a disc spring, a spring support shaft, an adjusting cover adjusting the spring and a correction gasket, the first gear shaft is further provided with an another helical gear couple having same tooth number, modulus and pressure angle for transferring motion to another two gear shafts, the two gear shafts respectively drive a helical gear of same tooth number, modulus and pressure angle and a gear couple meshed with the rack and provided with same geometry parameters The gap eliminator has simple structure, adjustment and use, and can effectively eliminate the gear clearance at the positive and negative motions of the rack

Kinematical Equations of High Flow Sea(Fresh) Water Ball Piston Pump

Abstract: Simulations based the displacement and pressure angle parameter equations of ball piston to cylinder gained by analyzing and solving the sea(fresh) water ball piston pump's kinematical parameter equations are carried on and the very important parameters such as the ball piston's maximum velocity,maximum pressure angle related the cylinder and so on.It provides theoretical foundation for design of higher efficiency sea(fresh) water ball piston pump.

Precise Solution and Parametric Modeling on Tooth Profile of Involute Gear

Abstract: According to the basic principle of involute generation,a precise solution of involute was proposed by taking the radius as the increase parameter.This method may avoid solving the complex pressure angle transcendental equation.By programming SolidWorks API,the 3D model and 2D engineering drawing were generated automatically with precise tooth profile.This provides a method for involute gear tooth profile accurate modeling and gear parametric series design.

Axial-thrust balancing device for single-stage cantilever petrochemical process pump

Abstract: The utility model relates to an axial force balancing device for a single-step cantilever petrochemical process pump, which relates to a pump. A bearing body is internally provided with a paired angle contact ball bearing which is internally provided with a main spindle, an angle contact ball bearing is arranged between the paired angular contact ball bearing and an impeller, the angle contact ball bearing is a great pressure angle contact ball bearing having an angle of 40 degrees, the load in the axial positive and negative directions is supported by the paired angle contact ball bearing and the serially connected angle contact ball bearing, so that the load of a simple bearing is reduced, the bearings are not easy to be damaged, the service life is long, and the operation is stable and reliable; and the utility model is applicable to the single-step cantilever petrochemical process pump.