Showing papers on "Pressure angle published in 2004"

Computerized Tooth Profile Generation and Analysis of Characteristics of Elliptical Gears with Circular-Arc Teeth

Abstract: This study describes rack cutters with circular-arc profile teeth to generate elliptical gears which rotate about one of their foci. A mathematical model for elliptical gears with circular-arc teeth is developed according to gear theory. The influence of the design parameters, such as the number of teeth, gear module, pressure angle at the pitch point and the major-axis, are investigated. The effects of the circular-arc radius of the rack cutter on both the undercutting of teeth and on pointed teeth of the generated circular-arc elliptical gear are also studied. Three numerical examples are presented to elucidate the generation of gear tooth profiles using the proposed mathematical model, and to investigate the phenomena of tooth undercutting and pointed teeth.

A Computational Approach to Profile Generation of Planar Cam Mechanisms

Abstract: A new approach, called a Relative Motion Method (RMM), is proposed for designing the shape of the disk cam, which uses the relative velocity and the relative acceleration of a follower respect to a cam to discover the profile coordinate, the pressure angle and the radius of curvature on the cam. It is characterized by the procedures of automatic derivation and solution with computers and the suitability not only for general disk cams with different kinds of follower, such as sharp edge follower, roller follower flat-faced follower, and so on, but also for the double-disk conjugate cams, single-disk conjugate cams and roller gear conjugate cams. A program for design automation of shape of the disk cam and the kinematics simulation of this kind of mechanism has been developed using the proposed approach with C++ language. Finally, an example is given.

Internal planetary gear mechanism

Abstract: An internal planetary gear mechanism reduces a load applied to tooth surfaces of an external gear and an internal gear, a sliding portion such as a bearing and the like. By setting the amount of eccentricity α of an eccentric part to be larger than a theoretical value, a distance between the center of the external gear and the center of the internal gear is increased to allow the reduction of a loss in the bearing and on the tooth surfaces of the gears, and a mesh zone between the internal gear and the external gear can be reduced to decrease a part at a large pressure angle, thereby reducing a loss generated by a large pressure angle. As a result of reduction in the mesh zone between the external gear and the internal gear, rolling contact of the gears is maintained.

Random engagement roller chain sprocket and timing chain system including same

Abstract: A sprocket and a roller chain drive system including same are disclosed. The sprocket is a random engagement sprocket comprising a first plurality of A-profile teeth formed with a first asymmetric profile and a second plurality of B-profile teeth formed with a second asymmetric profile. The A-profile teeth each define a first pressure angle and the B-profile teeth each define a second pressure angle that is at least 5 degrees greater than said first pressure angle so that a minimum separation Δ is defined. The sprocket is defined with added chordal pitch reduction of 0.2% up to 1% relative to the link pitch of the associated roller chain. The sprocket can be defined with root relief and/or can comprise resilient cushion rings. Initial roller contacts made with the A-profile and B-profile teeth are modulated owing to the pressure angle separation and added chordal pitch reduction.

Geometry analysis and optimal design of Geneva mechanisms with curved slots

Abstract: A systematic procedure is proposed for the design of Geneva mechanisms with curved slots. Based on the theory of conjugate surfaces, mathematical expressions for the slot profile, pressure angle and cutter's location for manufacturing are presented. In addition, to evaluate the combined kinematics and structural performance of the mechanism, the maximum contact stress and degree of wear are established as the performance index. Effects of variations in various design parameters on the values of the performance indices are investigated. Using the indices as the objective function, the optimum design that takes into account the initial crank angle, offset and roller radius is performed.

Powder metallurgy internal hilical gear, and its manufacturing method and die using same method

Abstract: The invention discloses a powder metallurgical internal inclined gear, according to weight percent, containing elements Cu 1-3%, Ni 1-3%, Mo 0.1-1%, and the rest Fe and unavoidable component, where its spiral angle is not greater than 35 degrees, its pressure angle is 5-25 degrees, and its mode is 0.5-2.5 degrees. It mixes the alloy powder of Cu, Ni and Mo to make press molding, firing and shaping so as to make it. Its making mould is top, bottom and middle moulds and core stick. It gears stably and accurately, has small friction coefficient and low mechanical noise. It adopts special designed mould, presses by mould core's rotary ascending or descending along screw, which converts the rotary pressing into axial pressing, can press internal inclined gears of various spiral angles.

On the determination of basic dimensions of a cam with a translating roller-follower

Abstract: The problem of determination of basic dimensions from the point of view of follower jamming of a cam with translating roller-follower is addressed. Departing from the common practice of using only a constant pressure angle to assess jamming of the follower in its guide, this paper presents a detailed analysis of the problem taking into consideration the follower-guide friction. This leads to new bounds on the pressure angle. Based on the bounds obtained, a graphical method for determination of the optimal values of the basic dimensions is proposed. A numerical example is presented for the purpose of illustration.

Rack-pinion-type steering device

Abstract: PROBLEM TO BE SOLVED: To provide a rack-pinion-type steering device constituting pinion teeth properly set with other tooth specifications under a large pressure angle and capable of stabilizing smooth and excellent steering feeling for a long period. SOLUTION: In this device, the pinion teeth 4 are constituted so that a module m of the pinion teeth 4, the number z of the teeth 4, the tooth height h and a twist angle β may be set in the following ranges under the pressure angle α set within the range of 24°≤α≤30° and an imparted stroke ratio. In this case, the module m of the pinion teeth 4 is taken 1.8≤m≤2.0, the number z of the teeth 4 is taken 7≤z≤13, the tooth height h is taken 2m≤h≤2.5m, and the twist angle βis taken β≤35°. COPYRIGHT: (C)2005,JPO&NCIPI

Zero degree operating pressure angle clearing

Abstract: A zero degree operating pressure angle gearing system includes an external gear and a mating gear. The external gear has a plurality of teeth disposed along a periphery of the gear, each of the teeth having a convex profile. The mating gear has a plurality of teeth, each of the teeth having a concave profile. The gears are mated to one another such that an operating pressure angle defined by the gears is substantially zero.

Asymmetrical tooth gear transmission composed of double arc and involute

Abstract: The present invention relates to mechanics, and is one kind of gear with different bearing capacity for forward and reverse force transmission. The gear is suitable for force transmission with basically fixed transmission direction and occasional reverse transmission. During force transmission in the forward direction, the main operating surfaces are contacted and the main operating surfaces are in stepped double-arc tooth form with lower bending stress and higher bearing capacity compared with standard double-arc tooth form. During force transmission in reverse direction, the subsidiary operating surfaces are contacted and the subsidiary operating surfaces are in great pressure angle involute tooth form with bearing capacity lower than that of double-arc tooth form but higher standardinvolute tooth form.

Automatic tool replacing device

Abstract: PROBLEM TO BE SOLVED: To prevent abrasion of a ball of a speed reducer and uneven distribution of pressing force in the shaft direction, by reducing a load when rotatingly driving a turret, in an automatic tool replacing device SOLUTION: The speed reducer for driving the turret in this automatic tool replacing device, is constituted by superposing a driving plate 5a, a cage 5b and a driven plate 5c in this order A recess-projection-shaped ball groove 6c of a frequency equivalent to a tool number is formed on the driven plate 5c attached with a tool The driving plate 5a is provided with the ball groove 6a for transferring a two period quantity by expanding the ball groove 6c of the driven plate 5c in the angle direction A plurality of guide holes 6b are arranged in the radial direction in the cage 5b, to respectively hold balls 5d The driving plate 5a is rotated by rotation of a main spindle, and the driven plate 5c is driven by reducing a speed to (the tool number/2) via the balls 5d The ball groove 5c of the driven plate 5c is set to an optimal pressure angle, and the load can be reduced The balls 5d are dispersed, and pressure in the shaft direction is uniformized, and the abrasion of the balls and the ball groove can be reduced COPYRIGHT: (C)2006,JPO&NCIPI

Optimum Design of the Involute-Cycloid Composite Tooth Profile Helical Gear

Abstract: The tooth bending and tooth contact strengths of the involute-cycloid composite tooth profile helical gear, which was developed as a non-involute tooth profile gear based on cycloid tooth profile, are directly affected by its tooth profile. The involute-cycloid composite tooth profile curve changes with some design parameters such as pressure angle and radius of rolling circle. In this study, we developed a method to calculate the tooth root stress and the tooth contact stress of the involute-cycloid composite tooth profile helical gear. Then we compared the tooth root and tooth contact stresses calculated by this method with the experimentally measured data, and the validity of the present calculation method was certified by the good agreement of the calculated values with the measured data. Furthermore, we discussed the effects of the design parameters on the tooth bending and tooth contact strengths of the involute-cycloid composite tooth profile helical gear considering the results of the tooth root and the tooth contact stresses calculated in the case of various values of the design parameters.

Motor-driven power steering apparatus

Abstract: The invention provides a motor-driven power steering apparatus which can achieve a predetermined speed reduction ratio even in the case that the motor-driven power steering apparatus is constituted by a pair of spur gears or helical gears, and can secure a sufficient gear strength on the basis of a simple structure. In a motor-driven power steering apparatus in which a rotating torque of an electric motor ( 7 ) is transmitted to a steering shaft by a drive gear ( 6 ) provided in an output shaft of the electric motor ( 7 ) and a driven gear ( 5 ) provided in the steering shaft, and a speed reduction ratio is equal to or more than 3, the steering shaft and the output shaft of the electric motor ( 7 ) are arranged in almost parallel, a center distance between both the shafts is equal to or more than 35 mm and equal to or less than 90 mm, and the drive gear ( 6 ) is configured such that a number of teeth is equal to or more than 6 and equal to or less than 15, a module is equal to or more than 0.8 and equal to or less than 1.5, a tooth depth is equal to or less than 2.4 times of the module, and a pressure angle is equal to or more than 14.5 degrees and equal to or less than 30 degrees, and a torsion angle is equal to or more than 0 degrees and equal to or less than 40 degrees.

Gear Geometry and Applied Theory: Face-Gear Drives

Abstract: INTRODUCTION A conventional face-gear drive is formed by an involute spur pinion and a conjugated face-gear (Fig. 18.1.1). Such a gear drive may be applied for transformation of rotation between intersected and crossed axes. An important example of application of a face-gear drive with intersected axes is in the helicopter transmission (Fig. 18.1.2). The manufacturing of face-gears by a shaper was invented by the Fellow Corporation. The basic idea of generation is based on simulation of meshing of the generating shaper with the face-gear being generated as the meshing of the pinion of the drive with the face-gear. In the process of generation, the surfaces of the teeth of the shaper and the face-gear are in line contact at every instant. However, when the shaper is exactly identical to the pinion of the face-gear drive, the generated face-gear drive becomes sensitive to misalignment. This causes an undesirable shift of the bearing contact and even separation of the surfaces. Therefore, it is necessary to provide an instantaneous point contact between the tooth surfaces of the pinion and the face-gear instead of a line contact. Then, the bearing contact will be localized and the face-gear drive will be less sensitive to misalignment. Point contact between the pinion and face-gear tooth surfaces is provided by application of a shaper of number of teeth N s > N p where N p is the number of teeth of the pinion of the drive (see Section 18.4).

Broaching tool for spline, and broaching method

Abstract: PROBLEM TO BE SOLVED: To provide a broaching tool for a spline, and a machining method having high tooth trace accuracy even in a thin-walled workpiece without chipping in spline punching of high hardness of 45-65 HRC. SOLUTION: The material of a cutting edge part of a tooth face finishing part 1 of a large number of cutting edges 2, 3 around an axis and in an axial direction is hard metal, and the entering direction of the cutting edges 2, 3 is only upward on the tooth face. Hard coating is applied to the flank 4 of the cutting edge, and a rake angle θ is set to -35°≤θ≤-5° or 5°≤θ≤15°. The depth of cut quantity W per cutting edge is to be 5 μm to 15 μm, and the total depth of cut or a finishing margin H is to be 0.02 mm to 0.2 mm. Preliminary machining is performed by such a broach while leaving the finishing margin to the involute tooth face with a pressure angle of 15° to 45°, and after heat treatment, a cut material with a high hardness of 45 to 65 HRC is finished into the machined dimensions of a finished product. COPYRIGHT: (C)2005,JPO&NCIPI

Correlation of Spray Cone Angle and Fuel Line Pressure in a Pressure-Swirl Injector Spray

Abstract: The transient cone angle of a pressure swirl spray from an injector for gasoline direct injection engines was measured from 2D Mie scattering images Iso-octane was used as the fluid that was delivered at room temperature for two different static pressures, 5MPa and 85MPa The iso-octane was injected into a chamber at room temperature and ambient pressure After a rapid initial increase, the cone angle oscillates before stabilizing to a steady-state value very close to the nominal cone angle The period of the oscillation was found to correlate well with oscillations measured in the fuel line pressure

New typed combination mechanism of linking rod and cam

Abstract: A kind of linking rod and cam combination mechanism, which could achieve a transmission of stable drive ratio, has been innovated. The transmission principle and calculation of drive ratio of this mechanism was analyzed. The mathematical equations of theoretical contour of cam and its tangent line and normal line were derived. Coordinates value of intersection point of common normal at each high paired contacting point were found by the use of analytical method, and the concept of pitch circle was presented. The expression of pressure angle of an arbitrary point on the theoretical contour of cam was established, and the moment relationship of driving and driven components was deduced. A kind of new typed linking rod and cam reducer was successfully developed based on this kind of mechanism.

Device for formation by bending

Abstract: PROBLEM TO BE SOLVED: To provide a device for formation by bending, a device capable of accurately and easily adjusting the optimum pressing force of a punch applied to a blank. SOLUTION: In the bending formation device that forms a metallic plate into a prescribed shape by moving a punch along a cam curve, a prescribed rotary angle range for one rotation of cam 200 is at least provided with a first cam pressure angle range 213 and an adjacent second cam pressure angle range 214 which is connected to the first. The increment of operation quantity of the punch 201 is fixed in the range in which the pressure angle of the second cam is smaller than that of the first cam and also in the range of the second cam pressure angle. COPYRIGHT: (C)2004,JPO

The Influence of the Gears Geometry on Value of the Force Acting on Tooth of HCR Gears

Abstract: High transverse contact ratio gears (abbr. HCR gears) are non-standard spur gears with a transverse contact ratio 2

A parametric study of planar cam-roller speed reducers

Abstract: Speed-o-Cam, a family of speed-reduction mechanisms based on cams and pure-rolling contact, is currently under development at McGill University’s Centre for Intelligent Machines. It is intended to replace gears and harmonic drives in applications where backlash, friction, and flexibility cannot be tolerated. We focus on the pressure angle and the machinability of internal and external planar Speedo-Cam layouts. In particular, this paper regards the pressure angle and the machinability as design constraints, while focusing on the Speed-o-Cam parameter optimization. A total of three design parameters, is investigated, so as to find the relationships between these parameters and the pressure angle, and the machinability of the cam plate. Optimum parameter values are thus obtained.

Piston type cyclotomic internal combustion engine

Abstract: The present invention relates to a piston cyclotomic internal combustion engine, including cylinder, piston, connecting bar and crank, etc. The described connecting bar is connected with swing bar, the included angle formed between them is a pressured angle (by shape angle), the initial state pressure angle can be selected from 0-90 deg., another end of said swing bar is coaxial with another swing bar, the included angle between two swing bars is any fixed angle, another end of the above-mentioned another swing bar is connected with another connecting bar, and the included angle formed between said two components is a stressing angle (by sharp angle), the initial state stressing angle can be selected from 0-90 deg. and another end of the above-mentioned another connecting bar is connected with crank to drive crank and make it implement circumferential motion to output power.

Mechanism for converting reciprocating motion into rotation

Abstract: FIELD: mechanical engineering; transport engineering. SUBSTANCE: invention relates to gear mechanisms designed for converting reciprocating motion into rotation and it can be used in drives of bicycles. Proposed mechanism contains post, driven gear wheel (ratchet), driving member executing reciprocating motion (slider or rocker) and intermediate member (pawl) hinge fastened on driving member to form gear meshing with ratchet. Pawl toothed rim designed for engaging with ratchet is made with pitch surface whose profile is logarithmic spiral with pole in pawl hinge joint. Pawl of mechanism can have lantern wheel gearing for engagement with ratchet, and pressure angle of alpha = 35°±5°. EFFECT: provision of constant pressure angle at working stroke of mechanism, improved quality of operation. 2 cl, 3 dwg

Double screw compressor for supplying gas

Abstract: A double-screw compressor for supplying gas, such as air, to a gas consumer, is provided. The double-screw compressor includes two interacting rotors for compressing the gas and a toothed gearing. The toothed gearing includes a gearing housing with two opposite end walls made of a first material. Two gearwheels made of a second material which has a thermal expansion coefficient different from the thermal expansion coefficient of the first material are mounted in the end walls. In order to reduce the effect of the temperature on the backlash, both gearwheels are designed with one and the same pressure angle which is smaller than 15°.

Design of a new type of radial piston pump without delivery microseism

Abstract: This paper discusses the differences of different hydraulic pumps in characteristics and introduces a new type of radial piston pump with inner curve stator in order to reduce the vibration and noise of the pump. By designing the inner surface curve of the stator, the delivery microseism of pump can be reduced to zero theoretically. Some measures are taken to reduce the pressure angle along the surface of the stator in order to increase the working life of the pump. The surface curve and pressure angle of the stator are calculated by means of Matlab software. The results of analysis are useful to the design and manufacture of hydraulic piston pumps with low noise.

Coupling element in a motor vehicle gearbox and a method to manufacture such coupling element

Abstract: A coupling element, for example a coupling sleeve (1), having coupling teeth (2) which, over a part (2a) of their length, have a gradually diminishing cross-sectional profile, a so-called back rake. Over said part, the coupling teeth have a portion (7b) nearest the tooth root having a first pressure angle, which portion connects to a portion (7b) extending to the tooth tip and having a greater pressure angle than the former portion.