Showing papers on "Pressure angle published in 1999"

Method of and apparatus for using an alternate pressure to measure mach number at high probe angles of attack

Abstract: A method of and apparatus for obtaining angle of attack, local static pressure and local pitot pressure from measured pressure values at ports of a probe having angle measuring ports with angle measuring axes lying in a plane and a pitot port having an axis lying along an axis in the plane bisecting the angle between the measuring ports. A table of known values of angle of attack relative to measured pressure ratio at measured Mach numbers determined by P 1 /P m is stored in memory and used when P 1 is greater than the pressure sensed at the pitot port (P t′m ), P 1 is the pressure measured at the one of the angle measuring ports that is higher than the pressure measured at the other angle measuring port, and P m is an average of the pressures at the angle measuring ports. The correlation of the ratio of measured pressures on the probe relative to angle of attack is determined using the known values P 1 /P m at different angles of attack either in wind tunnel tests or by computer simulation. The known values are stored in a look-up table in an onboard air data computer. The values that have been stored then can be retrieved to solve for the correct angle of attack, using the measured pressures P 1 , P 2 and P t′m . The angle of attack values are used with an algorithm to determine local pitot and static pressure.

Geometric Design of Roller Gear Cam Reducers

Abstract: A roller gear cam reducer, composed of a turret with rollers and a globoidal cam, is often used to provide high positioning precision at low cost. In this study, a simple procedure is given to generate the surface of the cam without solving any contact equations. The method is based on rigid body transformations between the cam and the turret roller. Analyses of the pressure angle and the principal curvature of the surface geometry are also accomplished. In addition, contact forces between the roller and cam, input torque, and the reducer efficiency are evaluated. An example of the procedure is given.

Face gear set, manufacture of face gear wheel, and machining device thereof

Abstract: PROBLEM TO BE SOLVED: To reduce cost of a speed change device of high speed and high load by executing topological cutting while adjusting so that face gear wheel pressure angle becomes a correct value, by the use of a milling cutter having tooth profile of straight line or similar to a straight line. SOLUTION: In a face gear, a straight tooth profile changing pressure angle at respective positions in the radial direction, a small bow shaped curved tooth profile, or a curved tooth profile curved inside and outside against a reference straight line is formed by topological cutting. When the straight tooth profile or the tooth profile similar to a straight line is manufactured by a face gear machining device 10, a milling cutter having the straight tooth profile or the tooth profile similar to a straight line is used, and cutting is executed so that the pressure angle of the face gear wheel becomes a correct value by adjusting the angle of a C1 axis according to the respective positions of the Z-axis. COPYRIGHT: (C)2000,JPO

Method for measuring vibration characteristic of power transmission device

Abstract: PROBLEM TO BE SOLVED: To enable the accurate measurement of vibration characteristics by maintaining a spline fitted shaft and a sleeve in a predetermined coupled state without using a dedicated master. SOLUTION: At the time of calibration adjustment by measuring the vibration characteristics of a propeller shaft 14 in which a shaft 10 is spline-fitted into a sleeve 12, the propeller shaft 14 is driven to rotate by a driving electric motor 34 and is given rotation load by a driven side electric motor 38. By this, the shaft 10 and the sleeve 12 are automatically aligned on the basis of a pressure angle provided for the teeth of the spline.

Conjugate screw rotor profile

Abstract: The point of tangency of the tip circle (TM) of the male rotor (16) and the root circle (TF) of the female rotor (14) is used as a starting point in generating the series of curves defining the male and female conjugate rotor profiles. The present invention provides: reduced viscous drag through the use of a departure angle (Δ1,Δ2); strengthened female lobes (14-1) by controlling thickness along the pitch circle (PF); opened root of male rotor (16) to enhance manufacturability and tool life; a tortuous leakage path for gas traveling from a high pressure thread to a low pressure thread; better control of root diameter; and control of the pressure angle independently of the other variables.

Harmonic tooth differential gear

Abstract: The utility model relates to a harmonic tooth difference retarding mechanism, composed of a rotating arm bearing, a flexible gear wheel which is composed of a sliding tooth and a sheave, an annular wheel, a shell body, etc. The rotating arm bearing makes a harmonic motion formed between the flexible gear wheel and internal teeth, and a sheave is driven to do the differential tooth rotation of the definite proportion and orientation. The tooth form of the sliding tooth adopts a triangular tooth whose profile angle is equal to a pressure angle alpha. When a module is smaller, the range of a transmission ratio is large and can achieve above 1000. the inner tooth form of the pressure angle adopts slotting processing, and the process precision is high. The inner tooth form can be produced on a large scale and in a standardization mode, and the meshing of the teeth is surface contact. The carrying capacity is strong, and the utility model is inserted in a mounting structure in a coaxial mode and positioned through a key groove. The utility model can be used as conventional mechanical speed change and dividing mechanisms and also be arranged in devices.

On The Optimization Of Spatial Cam Mechanisms Considering Mechanical Errors

Abstract: In this paper, an optimal spatial cam mechanism design is modelled and studied considering the influences of two mainly mechanical error sources, manufacturing and assembly, on output functions and contact conditions in three-dimensional space. A cylindrical roller follower with a crowned surface is investigated using surface contact analysis (SCA). Optimization design is conducted by using an interface coupler to integrate and automate interactive processing of the commercial software Mathematica, and multifunctional optimization system tool, MOST, on a personal computer. The optimization problem for the spatial cam mechanism is formulated to include constraints on pressure angle, displacement error, and contact path bias, all of which should fall within the desirable bounds. The objective function is the maximum absolute value of the displacement error that is to be minimized. Results show that the process reported in this paper can make spatial cam mechanism motion more accurate without increasing manufacturing cost. A sensitivity analysis is also conducted to show how design variables affect the performance of a spatial cam mechanism.

Rotary type zoom lens

Abstract: PROBLEM TO BE SOLVED: To smoothly and highly accurately perform zoom operation with small operating power by providing a cam component with a non-linear rotation transmission groove and a lens group moving cam groove and decreasing the cam pressure angle of the lens group moving can groove rather than the case of making the rotation transmission groove linear. SOLUTION: A first lens group frame groove 41A to engage a first lens group frame provided on a first lens group moving frame and a third magnification cam cylinder groove to engage a second magnification cam output frame are provided. Then, the cam pressure angle at a wide side terminal part, namely, the angle formed with an optical axis direction 0 and a first lens group frame groove center line 41BC such as so-called cam pressure angle is reduced so that the cam pressure angle can be reduced smaller than a fixed value over all the first lens group frame groove at least. Namely, offset amounts α, β...between the center line 41BC of a first lens group frame groove 41B and a center line 41AC of the smoothly operable first lens group frame groove 41A are operated at each rotation angle position of the third magnification cylinder.

Studies on Friction Loss of Spur Gears. Effect of Viscosity of Lubricating Oils and Tooth Forms.

Abstract: The study of friction loss of spur gears was carried out, using test gears with a center distance a=183 mm. The load for the test gears was comparatively high, i.e.the load was applied up to about 60% of the Hertzian pressure of tooth surface strength in endurance strength range and the range of circumferential velocity was extended up to about 120 m / s. Generally speaking, we obtained that, the higher the lubricating oil viscosity, the lower the friction loss. Further we found that a most suitable oil viscosity in order to reduce the friction loss exists for the gear unit, including not only the test gears but also the bearings and the gear box. As far as tooth form is concerned, the cutter pressure angle α0=25° gives the lowest friction loss for the gear unit.

Fundamental Analysis of Linear Type Trochoidal Gear. (2nd Report). Motion Principle for Roller Rack Type Trochoidal Gear.

Abstract: Roller rack type trochoidal gear assembly has been developed which consists of a series of roller train and a mating cam pinion. Motion principle for the mechanism has been analyzed. To avoid undercut which occurs at the dedendum, we applied some amount of "profile shifting". The optimum value of the profile shifting coefficient is discussed in relation to contact factor and pressure angle. Roller diameter and tooth height also affects to the mechanism design. A prototype of roller rack trochoidal gear assembly was constructed using the optimal values. The accuracy and the smoothness of the motion proved to be sufficient for practical applications.

Tape cassette and cassette half

Abstract: PROBLEM TO BE SOLVED: To provide a tape cassette having a stable lid mechanism for performing a smooth opening operation even if dust is stuck to an exposed cam groove. SOLUTION: A cam groove 45 for guiding a cam pin 38b is composed of three different guiding parts, i.e., a first horizontal guiding part, a second horizontal guiding part and a slope guiding part, this slope guiding part is composed of a singular circular-arc shape, and a straight line connecting the center position of the circular arc with the rotational center of a front lid 37 is formed to pass through a middle position between a shaft position 38a at the start of opening a top lid 38 and a position after 30 degrees opening. Thus, an absolute value for a pressure angle is lowered as a whole, little change occurs from the 0 degree to 30 degrees opening angle of the front lid 37, and a pressure angle at the start of opening is lowest.

Throw-away hob and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To realize highly accurate and highly efficient machining and low tool cost and manufacture a throw-away hob without trial manufacture according to the properties of the gear to be cut by prescribing the dimensions and shape of the throw-away tip and the dimensions and shape of the tip securing seat face to a hob body. SOLUTION: A seat face 6 formed by electric discharge machining in the front face of a blade chip supporting section 4 in the rotation direction is formed in such a way that the angle between the center line 5c of a throw-away tip and a the shaft 11 orthogonal to a hob shaft becomes a pressure angle difference (ΔPA2), and in the throw-away tip secured on this seat face 6, the right and left pressure angles are set equal viewed from the tangential direction of a hob PCD.

Precise Design of Cylindrical Cams with Oscillating Cylindrical Roller Followers

Abstract: A novel understanding of theoretic profiles was discussed based on a full study of forming principle of theoretic profiles of the clindrical cams with oscillating roller followers Analytical equations in cylindrical coordinate system were derived Also contour surface equations were developed by utilizing the theory of envelopes for one parameter family of surfaces Furthermore, formulas of pressure angle at the contact point between rollers and contour surfaces were given

Automatic speed change gear

Abstract: PROBLEM TO BE SOLVED: To solve a problem having fear which causes engine stall by delay of a speed change gear when the speed change gear operates based on detected load and further having bad feeling, though automatic speed change gear detects load applied to wheels and decreases the speed when the load increases to prevent overload of engine. SOLUTION: This automatic speed change gear is equipped with an angle sensor 30 (or angular velocity sensor) for detecting angle of obliquity (or angular velocity) in longitudinal direction of a machine body and a traveling load sensor for detecting load of wheel and the speed change gear is provided so that a controller 29 is output by input from the angle sensor (or the angular velocity sensor) and a traveling load sensor 34 to accelerate and decelerate rotation of wheels.

Intermediate shaft coupling for steering device

Abstract: PROBLEM TO BE SOLVED: To improve the effect of fastening force by lessening the component force of transmission torque. SOLUTION: In this shaft coupling, a vehicle intermediate shaft coupling 8 having a variable length in an axial direction is provided with a pipe 11, provided with a slit 11a on one end part and formed of an involute serration 15 on the inner peripheral surface, and a shaft member 12 formed of an involute serration 16, slidable in the axial direction within the pipe 11 and engaging the involute serration 15 of the pipe 11, on the outer peripheral surface. In this case, a pressure angle α0 , on the standard pitch circle of the involute serrations 15 and 16 engaging with each other, is set smaller than a standard value.

Variable speed gear arrangement for a bicycle

Abstract: A variable speed gear arrangement comprises a disc member 12, rotatable about a first axis 14, having rings 16 of gear teeth 18 which mesh with teeth 24 on a gear, eg spur gear 20, that is rotatable about a second axis 22. The gear 20 has a splined shaft 30, which engage with spines in a bush 36, which allows it to be slid along the second axis 22, whilst remaining in mesh with teeth 24, in order to change the transmission ratio. Between each gear ring 16 there is a gap, wider than the width of gear 20, which ensures that the gear 20 unmeshes from one ring 16 before engaging another. To facilitate meshing/unmeshing, the teeth 18 have tapers of opposite senses (see fig 5) wherein a top face (66, fig 5) narrows away from axis 14 and a base (70, fig 5) widens away from axis 14. At a datum level the teeth 18 have the same tooth thickness, pitch and pressure angle as the gear teeth 24. Taper angle # is calculated by dividing number of teeth n by 360‹.