Showing papers on "Pressure angle published in 2000"

Fundamentals of kinematics and dynamics of machines and mechanisms

Abstract: INTRODUCTION The Subject of Kinematics and dynamics of Machines Kinematics and Dynamics as Part of the Design Process Is it a Machine, a Mechanism, or a Structure? Example of Mechanisms Terminology Mechanism's Mobility Kinematic Inversion KINEMATIC ANALYSIS OF MECHANISMS Vector Algebra and Analysis Position Analysis Velocity Analysis Acceleration Analysis Intermittent-Motion Mechanisms: Geneva Wheel FORCE ANALYSIS OF MECHANISMS Force and Moment Vectors Free-Body Diagram for a Link Inertial Forces Application to Simple Mechanisms CAMS Circular Cam Profile Displacement Diagram' Cycloid, Harmonic, and Four-Splines Cams Effect of Base Circle Pressure Angle GEARS Kennedy's Theorem Involute Profile Transmission Ratio Pressure angle Involutometry Gear Standardization Types of Involute Gears Parallel-Axis Gear Trains Planetary Gear Trains INTRODUCTION TO LINEAR VIBRATIONS Solution of Second-Order Non-homogeneous Equation with Constant Coefficients Free Vibration of an SDOF System with no Damping Forced Vibrations of an SDOF System with no Damping Steady-State Forced Vibrations of an SDOF System Free Vibration of an SDOF System with Damping Forced Vibration of a Damped (x

Design Method of Vibrationally Optimum Tooth Flank Form for Involute Helical Gears with Scattering in Pressure Angle and Helix Angle Deviation.

Abstract: The detail in geometrical shape of each tooth flank of mass-production gears is usually not the same. Even a slight deviation of tooth flank form of several micrometers has a big influence on the running vibration/noise of the transmisstion gear box. The influence of the scattering in tooth flank form on the vibrational characteristics of gears must therefore be taken into consideration at the design stage to achieve low vibration gears. In this report, the influence of typical types of scattering, i.e.inpressure angle deviation and helix angle deviation, on the vibrational excitation is clarified in terms of the relationship between vibrational excitation and actual contact ratio. Those types of scattering decrease the actual contact ratio of a gear pair from that value of the tooth flank form designed on a draft. Gears with scattering in tooth flank form can run silenter, when some less amount of tooth flank form modification than the optimum one for gears without the scattering is given. The design algorithm for optimum modification of tooth flank form with scattering is proposed.

Silent chain drive mechanism

Abstract: A silent chain drive mechanism includes a silent chain for transmitting power between a larger sprocket and a smaller sprocket, wherein the inside flanks of one link plate of the silent chain are profiled to project outward of the outside flanks of the adjacent link plates, and tooth flank configurations of the larger and smaller sprockets are formed by involute curves arranged to satisfy the expression A1>Ac≧A2 where A1 is a pressure angle of the smaller sprocket, A2 is a pressure angle of the larger sprocket, and Ac is a pressure angle of the inside flanks of teeth of the link plates. With this arrangement, the chordal action of the silent chain is suppressed at both the larger sprocket side and the smaller sprocket side, thereby reducing vibrations and noises accompanied with the chordal action and improving the driving performance and durability.

Non-circular gears—graphic generation of involutes and base outlines

Abstract: Base and involute contours associated with non-circular pitch outlines were generated by graphic construction and implemented by computer algorithms. The singular unambiguous definitions of a base circle and involute for circular gears lead to multiple interpretations when applied to non-circular pitch outlines. Four different base outlines were generated for each pitch outline presented here. These were arrived at by combining two means of fixing the pressure angle and two means of terminating the conjugate line. Involutes were then generated by applying the principle of unrolling a hypothetical cord from the base outlines and by tracing a point moving along the conjugate lines. Because of the difficulties associated with dealing analytically with generalized non-circular pitch outlines, the approach taken was the numerical equivalent of geometric constructions, reflecting the application of the principles of gearing. The outlines used were ellipses of the first three orders.

Design Method of Vibrationally Optimum Tooth Flank Form for Involute Helical Gears With Scattering in Pressure Angle and Helix Angle Deviation

Abstract: The detail in geometrical shape of each tooth flank of mass-production gears is usually not the same. Even a slight deviation of tooth flank form of several micrometers has a big influence on the running vibration/noise of the transmisstion gear box. The influence of the scattering in tooth flank form on the vibrational characteristics of gears must therefore be taken into consideration at the design stage to achieve low vibration gears. In this report, the influence of typical types of scattering, i.e.inpressure angle deviation and helix angle deviation, on the vibrational excitation is clarified in terms of the relationship between vibrational excitation and actual contact ratio. Those types of scattering decrease the actual contact ratio of a gear pair from that value of the tooth flank form designed on a draft. Gears with scattering in tooth flank form can run silenter, when some less amount of tooth flank form modification than the optimum one for gears without the scattering is given. The design algorithm for optimum modification of tooth flank form with scattering is proposed.

Clutchless variable-capacity type compressor

Abstract: A variable capacity type compressor has a swash plate which can incline with respect to the drive shaft. An angle decreasing spring urges the swash plate to decrease the inclination angle and a return spring urges the swash plate to increase the inclination angle from the minimum inclination angle beyond the limit angle. The minimum inclination angle is smaller than a limit angle at which the swash plate can be assuredly returned in the direction to increase the inclination angle by a reaction force of the discharge pressure, and the angle decreasing spring balances with the return spring at an angle greater than the limit angle. A minimum spring load (F0) of the return spring is greater than 20N. A maximum spring load (F100) of the angle decreasing spring is F100(N) = (180 ± 30) - 4 × (VD - 120).

Helical concave conical gear and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To surely provide a helical concave conical gear provided with the predetermined main curvature radius with one working by expressing the relation between the basic data and the main curvature radius of a gear and a pitch radius and torsion angle of a rack type rotary tool with specified expressions. SOLUTION: A pitch radius rc and a torsion angle ϕ of a tooth trace of a generating rack type rotary tool are decided so as to satisfy expressions I, II, III, IV, V expressing the relation between a reference pitch radius rb, a pressure angle α0, a cone angle δ, each minimum curvature radius R and each maximum curvature radius R' at pitch points of a right and a left tooth surface of a gear and a pitch radius rc and a torsion angle ϕ of a tooth trace in the rack center surface of the generating rack type rotary tool. A helical concave conical gear, in which desirable teeth can contact with each other in the condition similar with the linear contact so as to have a large contact area and which can transmits a large motive power and which can restrict the gear noise, can be surely obtained.

Manufacturing method and machining device for face gear wheel

Abstract: PROBLEM TO BE SOLVED: To provide a manufacturing method and machining device for a face gear that can lower the cost of a high-speed and heavy-load speed change gear for a helicopter transmission and the like. SOLUTION: The machining device for a face gear wheel comprises a cutting means for feeding a milling cutter 11A with a straight or near-straight tooth shape in a radial direction of a face gear wheel 3 while adjusting the pressure angle of the face gear wheel 3 to a proper value, and a grinding means for feeding a disklike grinding wheel in a radial direction of the face gear wheel 3 while adjusting the pressure angle of the face gear wheel 3 to a proper value. The cutting and grinding work manufactures the face gear wheel 3.

Silent chain driving mechanism

Abstract: PROBLEM TO BE SOLVED: To provide a silent chain driving mechanism where power is transmitted between sprockets having different number of teeth, that is improved in reduction in oscillation and noises by suppressing cordial action of silent chains of both the sprocket having much number of teeth and the sprocket having less number of teeth, also improved in driving performance and durability by suppressing fluctuation of chain tensile sgrength SOLUTION: An inner side flank tooth surface of a silent chain is expanded compared to an outer side flank tooth surface by amplitude of polygonal movement Shape of teeth surfaces of a camshaft side sprocket and a crankshaft side sprocket are formed of involute curves which satisfy the formula A1>Ac>=A2, where A1 denotes a pressure angle of the camshaft side sprocket, A2 denotes a pressure angle of the crankshaft side sprocket, Ac denotes a pressure angle of the inner side flank Cordial action on both crankshaft side and camshaft side can thus be suppressed

Analysis and design of the globoidal indexing cam mechanism

Abstract: We first design and analyze the contour surface of the globoidal indexing cam with the aid of computer, and then do optimum design according to the requirements of dynamics. Finally, we discuss the problem of the pressure angle of the globoidal indexing cam mechanism in detail and put forward a new concept of equivalent pressure angle.

Reclining structure of seat

Abstract: PROBLEM TO BE SOLVED: To prevent generation of an abnormal noise even if a lock is released in a state that person leans on a back rest. SOLUTION: In this recliner structure of a seat having a first bracket fixed to the seat bottom, a second bracket fixed to the seat back and connected to the first bracket so as to be relatively rotatable around the rotational center and a lock plate moving in the radial direction between the first and second brackets by operation of an operation rod and having locking teeth on the tip and arranging a regulating means in the first bracket for regulating a movement except in the radial direction of the lock plate and arranging internal teeth 34 meshing with the locking teeth 46 on the tip of the lock plate in the second bracket, and in the locking teeth 46, a front inclined face of front locking teeth 461 existing in the forefront position is set at an angle by adding an extracting angle of a prescribed angle to a pressure angle.

Structure of a pair of involute gears

Abstract: PROBLEM TO BE SOLVED: To provide structure of a pair of involute gears which maintains strength of the tooth root, improving the contact ratio and sufficiently coping with the change of center distance, in the case the tooth number of a small gear is extremely small. SOLUTION: In this structure of a pair of involute gears, the pressure angle of the tooth end of the small gear is made smaller than that of the tooth root, and the pressure angle of the tooth end of the large gear is made equal to the pressure angle of the tooth root of the small gear. Furthermore, the pressure angle of the tooth root of the large gear is made equal to the pressure angle of the tooth end of the small gear.

Forging formation of bevel gear

Abstract: PROBLEM TO BE SOLVED: To obtain a forging formation of a bevel gear, with which teeth of the bevel gear can be formed in a high precision SOLUTION: The tooth-form 32 in a forming apparatus 10 used to the forging formation of the bevel gear, is formed to a shape adding a correcting amount under consideration of the deformed amount generated in the tooth of the formed bevel gear In such a case, the deformed amount and the correcting amount are shown with value of each element in digitized gear thickness, twist angle, pressure angle, etc, with the center of a gear surface in a desired shape of the gear as the reference point, respectively

Hypoid gears a drive-on-coast application

Abstract: A hypoid gear set including a ring-shaped gear positioned about an axis and having a plurality of curved gear teeth arranged about the axis Each tooth has a second side having a forward face with a shallow pressure angle relative to an axially extending line and defining the drive side of the gear Each tooth has a first side having a rear face with a steep pressure angle relative to an axially extending line and defining the coast side A pinion gear drives the rear faces of the ring-shaped gear such that the ring-shaped gear rotates in the direction of the forward faces of the teeth of the ring-shaped gear

Spare tire holding device

Abstract: PROBLEM TO BE SOLVED: To improve the transmission efficiency of internal and external gears meshed with each other in a spare tire holding device by reducing their pressure angle, to reduce the operation force, to reduce the fluctuation of the winding force, and to improve the working efficiency. SOLUTION: In a holding device, a wire reel is rotatably supported by a drive shaft 4 having an eccentric cam pivotably supported by a casing 3, and an internal gear 6 is fixed to a side surface of the wire reel. An oscillation plate 8 having an external gear 7 meshed with the internal gear and fewer in gear both tooth number than the internal gear is rotatably supported by the eccentric cam, and a tire hanger 10 is fitted to an outer end part of a wire 9 wound around the wire reel. The pressure angle of each tooth of the internal gear 6 and the external gear 7 is set to 15 deg. to 25 deg., the transmission efficiency of the gears is high, the operation force during the winding up can be small, the fluctuation of the operation force is small irrespective of the winding-up or winding-down operation, and the operation efficiency can be improved.

Cavity Design Method for Injection-Molded Spur Gears

Abstract: Mold cavities of gears should be made larger than the product specification since plastics shrink when changing from a molten to a solid state. For injection molded spur gears, two design methods for the compensation of shrinkage are widely used. One is the module correction method and the other is the pressure angle correction method. Both methods are based on the assumption that shrinkage occurs toward the center of a molded gear. This paper deals with the shrinkage rate and proposes a method of designing gear cavity derived from the measured shrinkage rates which govern the outside diameter, the tooth depth and the tooth thickness of a molded gear. The proposed method imposes no restriction on the shrinkage direction and provides a cavity with all of the fundamental gear design parameters.

Gear row power transmission characteristic analyzing device

Abstract: PROBLEM TO BE SOLVED: To obtain a gear arrangement with smaller axial force without trying by inputting diversified gear arrangement data by providing an axial force reduction calculation part for obtaining a gear arrangement where an axial force becomes smaller than a gear arrangement being inputted by a user, in a gear row power transmission characteristic-analyzing device. SOLUTION: By inputting gear position, size, pressure angle, load, axial diameter, and friction coefficient and by allowing a drive force/axial force/motor torque calculation part 41 to perform calculation, the results are stored at an axial force storage part 25, a drive force storage part 27, and a motor torque storage part 24. When an axial force reduction calculation method by changing the size is selected, an axial force reduction calculation part 43 by changing the size changes the size of the gear so that the axial force can be reduced while maintaining the contact with an adjacent gear without changing the position of the adjacent gear successively for each gear other than a fixed gear. Also, when the axial force reduction calculation method by changing the position is selected, a position change axial force reduction calculation part 44 obtains the direction of increase/decrease to see whether the relative position and the angle between gears should be increased as compared with the current status or not, thus determining the order of priority.

Infiltration preventing structure of transmission case

Abstract: PROBLEM TO BE SOLVED: To significantly reduce amount of water infiltrating in a starter by a method, wherein the progress of water scraped up through rotation of a ring gear is suppressed. SOLUTION: A recessed part 15 to prevent infiltration of water scraped up through rotation of a ring gear 2 to a starter mounting is formed into a circular inner peripheral surface to form the gear chamber 3 of a transmission case 1. The recessed parts 15 are formed in two spots between the lowermost part of a circular inner peripheral surface 14 in the rotational direction of the ring gear 2 of the circular inner peripheral surface 14 forming the gear chamber 3 and a starter mounting part 5. The recessed part consists of an introduction surface formed approximately at a pressure angle θof the ring gear 2 along the tangential line of the circular peripheral surface 14 in the rotation direction of the ring gear 2, and a damping surface formed in a manner to extend from the deepmost part of the recessed part 15 in the direction of the approximate center of the circular inner peripheral surface 14. Furthermore, the recessed part 15 is formed through integral molding of a mold togetherwith the gear chamber 3 and the starter mounting part 5.

Support of tool for explosion-proof electric equipment, explosion-proof instrument system, and conduit, and apparatus therefor

Abstract: PROBLEM TO BE SOLVED: To eliminate any welding operation for simple work by attachably/ detachably mounting respective tools for explosion-proof electric equipment and an explosion-proof instrument system, and a conduit on the beam and column of a building using a hanging unit and a bolt nut. SOLUTION: The L-shaped angle of a hanging unit 20 is fixed to a beam 52 using an L-shaped clamp with fixing bolts 26 and nuts 26a. The position (height) thereof is determined, a lower angle 23 is fixed to an upper angle 21 with fixing bolts 26 and nuts 26a, and a square pipe steel 28 on the side of a lighting unit 30 is fixed to the perforated L-shaped angle with an L-shaped pressure angle 27, the fixing bolts 26, and nuts 26a. The lighting unit 30 (square pipe steel 28, conduit 34, positioning box 31, hanging fitting mounting plate 82) is assembled in a plant in advance and carried in a site, the square pipe steel 28 is fixed to the perforated L-shaped angle with the L-shaped angle 27, fixing bolts 26, and nuts 26a.

A Study on Curvature Determination Approach of Disk Cams Using relative Accelerations of Followers

Abstract: There are two major factors which affect the cam design : the pressure angle and the radius of curvature, Cam shape will have an instantaneous radius of curvature at every point. Even though the design constraint of the pressure angle has been satisfied the follower may still not complete the desired contact motion. If the radius of the follower roller is larger than the concave(negative) radius on the cam it occurs the gap between the cam and the follower roller at the contact point. And also if the curvature of the pitch curve of the cam is too sharp the cam profile may be undercut. This paper proposes a new approach which uses the relative velocity of the follower roller parallel to the tangent line at the contact point on the cam surface for determining the pressure angle and the relative acceeration for determining the radius of curvature.

Compact pump unit, electric thermo-pot and method of manufacturing lead screw for screw pump

Abstract: PROBLEM TO BE SOLVED: To provide a compact pump unit and an electric thermo-pot each employing a high efficiency screw pump, and a method of manufacturing a lead screw for a screw pump which makes the pump operation highly efficient. SOLUTION: A screw pump having a spirally shaped screw vane 17c constitutes at least one of pumping mechanisms of a compact pump unit. The screw vane 17c has a linear structure at almost no pressure angle (pressure angle β≈0 deg.) an inverse taper structure at the pressure angle set to a minus value (pressure angle β≈-χ deg.) such that no stepped portion is formed on the surface.

Cylindrical electrophotographic photoreceptor and electrophotographic device

Abstract: PROBLEM TO BE SOLVED: To provide a cylindrical electrophotographic photoreceptor and an electrophotographic device excellent in the meshing accuracy of the driving gear of a cylindrical electrophotographic photoreceptor and capable of accurately controlling and rotating the photoreceptor SOLUTION: In the cylindrical electrophotographic photoreceptor 1 where a flange 3 is fit at the end of a cylindrical photoreceptor drum 2 and the driving gear made of synthetic resin is integrally or independently attached to the flange 3, the driving gear simultaneously satisfies an expression I: m[Z invα+π(n-05)]+m/5>D(n) and an expression II: D(n)> m[Zinvα+π(n-05)]Cosα+m/10 (wherein the symbols stand for following values in the expressions I and II D(n): displacement over a given number of teeth (n), m: the module of the gear, α: a pressure angle, Z: the total number of teeth, and n: displacement number)

Machining method of tooth for worm wheel

Abstract: PROBLEM TO BE SOLVED: To improve machining efficiency of a worm wheel by a grinding tool. SOLUTION: This machining method, in the case of grinding a tooth 11 generated of a worm wheel in a material 20 through a grinding tool 10 of worm shape having the tooth 11 of pressure angle α and lead angle γ, vibrates the grinding tool 10 synchronized respectively by amplitude (a), a/tan γ and a/tan α in the direction of the axial center C1 of the grinding tool 10, in the direction of the axial center C2 of the material 20, and the direction of the common perpendicular line C3 of the grinding tool 10 and the material 20. The grinding tool 10 can properly finish the tooth 11 of the material 20 in the pressure angle α and the lead angle γ.