Showing papers on "Pressure angle published in 1988"

Determination of Settings of a Tilted Head-Cutter for Generation of Hypoid and Spiral Bevel Gears.

Abstract: Kinematics of Gleason mechanisms of hypoid and spiral bevel cutting machines are considered. These mechanisms are designated to install the position and tilt of the head cutter. The tilt of the head cutter with standard blades provides the required pressure angle. The authors have developed the matrix presentation of kinematics of these meachanisms and basic equations for the required settings. An example is presented based on the developed computation procedure.

Method for machining gearwheels

Abstract: A method is described for hob grinding helical gearwheels by continuous diagonal hobbing using a tool in the form of a substantially involute worm whose active length is greater than the length of the working area and whose center distance from the gearwheel is changed during its feed motion in the diagonal direction from the axial and tangential directions to generate lateral crowning. The pressure angle of the right or left flanks decreases continuously from a maximum value starting at one end of the worm toward the other end, whereby the maximum pressure angle of the right flanks at one end of the worm coincides with the minimum pressure angle of the left flanks, and vice versa.

Laser-assisted contact angle measurements.

Abstract: A laser beam, aimed at the solid-liquid-air interface of a sessile drop on a contact lens, produces two lines of diffraction which are theoretically normal to the profile of the fluid and solid surfaces at the point of contact. In the present experiments, the beam and the diffraction patterns were projected on a flat screen perpendicular to the beam, and the angle was measured as a contact angle. The angle was measured on curved surfaces (contact lenses) of 6.5 to 8.9 mm radius and for each material studied, the angle: (1) was independent of the front surface radius, (2) was independent of droplet volume at 2 and 10 microliter, and (3) decreased with time after drop placement. The laser-derived measurements correlated well with contact angles measured by goniometry on contact lenses and a variety of other materials (r = 0.86; p less than 0.0001). Because the diffraction lines are straight and are generated at the point of contact, the angle formed by them is measured easily with a protractor, yielding a convenient and reproducible contact angle measurement. An application of the method was demonstrated by measuring contact angles for saline-containing 0 to 2% bovine serum albumin or bovine submaxillary mucin on Silafocon-A (Polycon II), Pasifocon C (Paragon EW), and polymethyl methacrylate (generic PMMA and Paragon 18) lenses. On each material, physiological concentrations of mucin, but not of albumin, significantly (p greater than 0.01) decreased contact angles by 8 to 15 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)

Profile modified gear

Abstract: PURPOSE:To reduce gear noise still more, by applying bias correction in which the amount of pressure angle correction in the direction of tooth width gradually changes, so that the engaging part of a pair of gears engaging each other can be lengthened along the advancing direction. CONSTITUTION:The amount of correction in a bias correction is expressed by the difference in the pressure angle correction amounts at both ends of an inspection tooth width or the difference between the pressure angle correction amount P1 at one end in the tooth width direction as shown in the figure and that P2 at the other end. Then, the target correction amount of the bias correction is set to a value in which chiefly the primary and secondary components, out of order components of engaging error obtained by developing the engaging error wave form into Fourier series, become small. In the gear to which this bias correction has been applied, consequently, the engaging part of a pair of gears engaging each other is lengthened along the advancing direction of engaging. In this profile modified gear, since the bias correction is applied as a correction element for a reference tooth surface 10, the engaging error of gear is reduced, and the gear noise can be still more reduced.

Control of ignition timing of internal combustion engine

Abstract: PURPOSE:To control ignition timing with high precision by detecting the actual top dead center position of a piston and correcting the standard crank angle position according to the actual top dead center position and obtaining the max. pressure angle on the basis of the corrected standard crank position angle and controlling the ignition timing. CONSTITUTION:A piezoelectric type pressure sensor 22 for detecting the cylinder internal pressure is arranged in each cylinder of an internal combustion engine 20, and the max. pressure value is obtained by measuring the interval between each standard crank position and the max. pressure value generating position by a peak hold circuit 28, comparison circuit 32, etc. on the basis of the output of each pressure sensor 22. In this case, the actual top dead center position of a piston is detected on the basis of the output signal of each crank sensor 36 installed in the vicinity of the revolution part of the internal combustion engine, and the standard crank angle position is corrected according to the actual top dead center position. The max. pressure angle is obtained on the basis of the standard crank angle position after correction is obtained, and the ignition timing is controlled by a control unit 24 according to the max. pressure angle.

Image carrying body unit

Abstract: PURPOSE:To assure sure contact of a developing sleeve and photosensitive drum at two points by providing two degrees of turning freedom to a developing unit CONSTITUTION:The developing unit 2 is supported freely tiltably in a radiation direction of the drum 5 on a straight line 6 parallel with the engaging pressure angle direction past a pitch point 13 of a driving gear 17 at the end of the developing sleeve 4 The developing unit 2 is supported freely rotatably around the engaging pressure angle direction in the place nearest the centroid of the developing unit 2 on the tilting axial line 6 thereof The developing unit is constituted to be supported substantially at one point by imparting said two degrees of freedom thereto The developing unit is supported at three points by two pieces of members for maintaining the spacing from a photosensitive drum at both ends of the developing sleeve The developing sleeve is thereby brought into sure contact at two points with the drum

Effect of Standard Pressure Angle on the Bending Fatigue Strength of Helical Gears

Abstract: This paper presents a study on the effect of standard pressure angle on the bending fatigue strength of helical gears. The root stresses of meshing helical gears with various pressure angles, helix angles and whole tooth depths were calculated by using the approximate equations for deflection and bending moment due to a concentrated load on gear teeth of full depth and long teeth with various pressure angles and Kubo and Umezawa's method. Bending fatigue tests were performed on helical gears of full depth teeth with various pressure angles and helix angles. On the basis of these results, the effects of pressure angle, helix angle, and whole tooth depth on the root stresses and bending fatigue strength of helical gears were clarified to a considerable extent.

Mechanical reduction gear system

Abstract: of EP0161072A mechanical reduction gear system is of the type comprising an external gear (16) which is rotatable about an eccentric revolving shaft (14) and an internal gear (18) which is engaged with the external gear (16). The contact ratio and operating contact during the actual loading operation are improved by constructing the system so that an external gear (16) has a tooth profile curve which is an addendum tooth profile curve at the outside of a pitch circle and an epicycloid curve, for example, such as that generated on the basis of a rolling circle or generating circle having a tooth number slightly fewer than the pitch circle and has a predetermined pressure angle on the pitch circle, and an internal gear has a tooth profile curve, for example, such as that generated on the basis of the tooth profile of the external gear.

Plastic working machine provided with rotation control mechanism for cam shaft

Abstract: PURPOSE:To make an advance end position of a working tool variable, and also, to make it unnecessary to change a cam one by one even if an object to be worked is changed, by controlling a rotating speed of a cam shaft of a single cam having plural different pressure angle patterns, so as to be variable in one cycle, and moving the tool. CONSTITUTION:A working tool, namely, a roller 2 is fixed to a main shaft base 11 in an advance end position of a rotary forming machine 1 in order to work an object to be worked. The advance end position of the roller 2 can be adjusted by a roller advance end adjusting screw 3 provided on the main shaft base 11, and by a gear box 5 and a pulse motor, the advance end position of the roller 2 is adjusted freely to a set position. The screw 3 receives a pressing force from a cam follower 9 for abutting on a cam 7 and moves the roller 2. A pressure angle pattern of the cam 7 consists of a cam pattern having plural different radiuses of curvature, and by controlling a rotating speed of a cam shaft 8 by a servo-motor 10 so as to be variable in one cycle, it is unnecessary to replace the cam even if the object to be worked is changed.

Flexible meshing type gear device

Abstract: PURPOSE:To permit the working with high precision and high productivity at a low cost by forming each tooth face of the internal and external gears from the standard rack consisting of the tooth form having a tooth face part equipped with an arcuate part and a straight line part smoothly connected with the arcuate part. CONSTITUTION:On the tooth face of the standard rack of the internal and external gears, the main part of the tooth face is formed into a curved circle, and the part to the datum point M of the standard rack is formed in straight line form having a pressure angle (alpha). In this case, the connection between the curved circle and the straight line is formed into smooth form. MC is the straight line part of the tooth face of the flexible external gear, and CD is the arcuate part of the tooth face, and MA is the straight line part of the tooth face of the rigid internal gear, and AB is the arcuate part of the tooth face, and a flexible external gear is the deepest intruded state to the tooth groove of the rigid internal gear. The tooth shape is substantially a continuous contact tooth form. In other words, since a tooth form which can realize the continuous contact can be realized by using the arcuate form and the straight line, the high productivity can be obtained, and low cost can be realized.

Finite-element analysis of ring gear/casing spline contact

Abstract: The speed reduction from turbine to propeller is achieved in the Pratt and Whitney PT6 turbo propeller engines through a two-stage epicyclic gear train. In this arrangement, the ring gear is locked to the casing through external splines. The orbitting of the planet gears generate cyclic stresses in the teeth fillets of the ring gear and the casing. The sliding contact between the steel ring gear and the casing splines generates wear. A two-dimensional finite-element computer program was extended to iteratively solve the problem of load-dependent contact between the splines. Using this program, the nonuniform distribution of the reactive load and the relative sliding on the loaded splines are calculated for any planet gear load position. The analysis predicts that the relative sliding reduces through a change in the spline pressure angle from 20-30 deg. Spline wear is practically eliminated in field engine gearboxes through this design change. The cyclic variation of the fillet stresses are also determined due to the orbitting planet load using a detailed network and by imposing boundary displacements. Qualitative comparison of the stress prediction is made using instrumented test results. The paper demonstrates the analysis procedure using a typical ring gear and casing combination.

Rotor of apparatus for changing pressure of fluid medium

Abstract: The invention concerns helical- or screw-type driving and driven rotors having lands and intervening grooves for coacting engagement, within a housing of a machine, such as a gas compressor or expander, the rotors having improved, more efficient, profiles. The profiles are defined with contiguous elliptic and involute sections to improve the pressure angle, and the profiles are configured to define rotor-to-rotor sealing surfaces in closure of a compressed gas pocket in which, the pocket gas pressure always urges or torques the driven rotor in the positive or forward-rotary direction.

Pressure Angle in Loom Shedding Cam Design

Abstract: A method for calculating the shedding cam pressure angle in cam-driven looms has been developed. The main advantage of this method over the conventional drawing method is that, because of the mathematical treatment and the use of computers, the numerous mechanical factors involved can easily be taken into account and the precision significantly improved. There is also an analysis of the influence of the treadle pivot location and the harness movement on the pressure angle and the lateral force.

Finishing method of gear tooth surface

Abstract: PURPOSE: To uniformize a tooth surface in super high accuracy without deforming a gear as well as to finish it smoothly along the tool form direction by rocking a work gear and a master gear relatively so as to slidingly contact with each other on an involute curve of the tooth surface of the work gear without entailing any interference with the underside CONSTITUTION: A work gear 1 and a finishing gear 2 are engaged with each other at a contact point C, rotataing the gear 1 in an A direction and the gear 2 in a B direction, respectively, and at this time braking force is applied to a turning shaft of the gear 2, whereby proper load is made so as to act on the contact point C Then, a tooth surface 30 of the gear 1 and a tooth surface 30' of the gear 2 are made slidingly contact with each other and thereby the tooth surface 30 is finished up At this time, there is produced an angle α between a center line X passing a turning shaft 5 of the gear 1 and the turning shaft 4 of the gear 2 and an operating pressure angle line P passing the contact point C, so that the turning shaft 4 is slidden along a line S in parallel with the pressure angle line P Sliding motion of the gear 2 may be done along any direction between the line P and involute curves I, I' In this connection, it may be done along curves R, R' COPYRIGHT: (C)1990,JPO&Japio

Effect of Standard Pressure Angle on the Fatigue Strength of Nitrided Gears

Abstract: Nitrided steel gears having three kinds of standard pressure angles were fatigue-tested using a power circulating gear testing machine, in order to elucidate the effect of standard pressure angle on the load carrying capacity and the failure mode of the nitrided gears. The relation between the tooth profile change and the dynamic performance of the gear in the fatigue process was also investigated. The failure modes were tooth breakage at the fillet or grinding notch under a lower pressure angle and higher load and spalling or tooth breakage due to spalling under a higher pressure angle and 10wer load. The fatigue strength for a normal load increased with an increasing pressure angle. The changes in the tooth profile and the dynamic characteristics during the fatigue process were slight.

Minimisation of error on the effective profile of pinion type gear shaping cutters

Abstract: Gear shaping cutters are provided with top-relief and rake angles to facilitate effective cutting. Due to this, the profile representing the cutting edge (effective profile) is altered. This paper outlines a method of obtaining the effective profile and its deviations from the theoretical involute form required. This paper also deals with a method that modifies the pressure angle, while maintaining zero deviation at the reference circle, so that the effective profile closer to the theoretical form is obtained after grinding the rake face. The Golden section optimization method is used to get the optimum value of the modified pressure angle. The effect of regrinding on the profile error of the cutting edge is also brought out. The method suggested in this paper will be useful to the designers and manufacturers of gear shaping cutters.

Gear unit for acceleration/deceleration driving device

Abstract: PURPOSE:To make the creation of a tooth form easy and to improve the operational property of a wave motion gear unit by approximating the tooth form of a soft gear of the wave motion gear unit to an involute tooth form which is the closest to the tooth form depending on an exact gearing theory of teeth CONSTITUTION:In this acceleration/deceleration driving device (the wave motion gear unit, henceforth), one side of a hard gear 1 or a soft gear 2 is made into an involute tooth form, and the tooth form of the other side which is to gear properly theoretically to the preceding gear is created into an involute tooth form with a different module and different standard pressure angle That is, the hard gear (inner teeth) 1 and the soft gear (outer teeth) 2 with a little different numbers of teeth are furnished in a wave motion gear unit, for example And by gearing the hard gear 1 and the soft gear 2 while deforming twisted the soft gear 2 in the radical direction by rollers 4 of a wave motion generator 3, and by moving the gearing part by the rotation of the wave motion generator 3, the soft gear 2 is rotated in the direction inverse to the rotation of the wave motion generator 3

Belt with teeth

Abstract: PURPOSE:To lessen transformation at the time of load operation, reduce sliding between teeth and make an irregular occlusion hardly brought about by forming a tooth-form with a tooth-tip straight line or a tooth-tip curved line, a cycloidal projecting curve connecting thereto and a circular arc connecting smoothly to a tooth-bottom. CONSTITUTION:Adopted is a tooth-form which is formed with a tooth-tip straight line or a tooth-tip curved line deflecting in the direction toward increasing a tooth-height, a cycloidal projecting curve connecting thereto and a circular arc 7 connecting smoothly to a tooth-bottom 8. Accordingly, the tooth-form of a belt with teeth 1 is unlikely to produce sliding between teeth because of a pressure angle being small through the adoption of the cycloidal projecting curve, and is unlikely to produce the floating-up of the tooth even if a high load acts upon because of a ratio of the tooth-height H to a tooth-width W being great. Furthermore, in case of the high load having acted upon, the load is dispersed over the whole of the tooth and is transmitted equally to the side of a load-taking-on member 3, therefore the transformation of the tooth itself is little, and durability is good and making it hard for an irregular occlusion to be brought about is made possible.