Showing papers on "Pressure angle published in 1998"

Pressure Oscillations in a Subsonic Cavity at Yaw

Abstract: An experimental investigation was undertaken to examine the effect of yaw angle on flow oscillations that occur in an open cavity placed within a subsonic boundary layer. A rectangular cavity with a length-to-depth ratio of unity and a planform aspect ratio of 8.7 was placed within a thick turbulent boundary layer with a corresponding Reynolds number based on the momentum thickness of 10.5 × 10 3 . Pressure time histories were acquired at 15 separate yaw angles using microphone-type pressure transducers. The spectral character of these signals was analyzed, and the pressure levels and dominant frequencies were determined. This study indicates that large changes in the pressure level occur as the yaw angle is changed from 0 to 70 deg. A state of resonance was observed at an angle of 60 deg. Relative sound pressure level calculations indicate that the energy within the cavity increased more than seven times at this orientation. Evidence suggesting a critical angle of approximately 60 deg, as well as mode switching from a fluid dynamic mode to a fluid acoustic mode, is also presented.

Worm gear assembly for drive axle

Abstract: A drive axle assembly for a vehicle receives input torque from an engine via an input shaft. The input shaft drives a worm which in turn drives a worm gear. The worm gear includes teeth which engage and drive an axle shaft which in turn drives a vehicle wheel. The teeth of the worm gear are defined by a tooth profile which has two pressure angles, one on each side of the tooth. The worm includes a thread with a thread profile that also has two pressure angles, one on each side of the thread. One of the pressure angles on the thread of the worm is greater than its other pressure angle and one of the pressure angles on the worm gear teeth is greater than its other pressure angle.

Synthesis of the internal parallel cam mechanism

Abstract: Parallel cam mechanisms have been studied in different ways. In this paper, a parametric formulation which can cover every configuration of the parallel cam mechanism is derived. As a result of parametric analysis, a new, last mechanism was found. This cam is essentially an internal cam mechanism. Based on the assumption of an equally distributed roller follower, the basic configurations of the mechanism are derived from both the pressure angle and the undercutting constraints. As a result, the possible number of rollers per spider plate is two. Thus the feasible area of the design parameters of the mechanisms are obtained. The advantages of the mechanism over the conventional parallel mechanism are the saving of space and a larger angular stroke of output.

Chamfering method for tip of toothed gear and tool for chamfering tip

Abstract: PROBLEM TO BE SOLVED: To enable efficient, good accuracy chamfer, using general devices in a method for chamfering the tip of each tooth in a toothed gear at an edge along the tooth trace of its tip SOLUTION: A tool for chamfering the tip of a toothed gear employs a mating toothed gear engaging with a toothed gear 10 to be chamfered, a module, and a toothed gear 12 having the number of teeth, and a helix angle equal to those of the mating toothed gear and a pressure angle greater than that of the mating toothed gear, where, the tooth flank 16 of each tooth 14 is used as a grinding surface The tool 12 for chamfering its tip is engaged with the toothed gear 10 and is rotated Thus, the tip 20 of each tooth 18 in the toothed gear 10 is chamfered at a predetermined chamfering part 22, an edge along the tooth trace in its tip 20

Profile forming method for oblique hob grinding worm, disk profile forming tool for executing this method and device for executing this method

Abstract: PROBLEM TO BE SOLVED: To provide a large grinding amount in a short time and form a corrected tooth flank in the range of μm on the other hand by providing, for the flank of a grinding worm screw, deviation from a normal pressure angle and a pressure angle steadily changed at least in the region of a grinding worm width. SOLUTION: In the cross direction position of a corresponding grinding worm, the pressure angle of a correction reference profile has deviation of an angle ΔF from the pressure angle of a non-correction reference profile 7. Further, if the flank profile 6 of a profile forming tool 1 is used considering profile dressing, the sum of gradient values of a correction function provides a guide value for the constant rotation of the profile forming tool regarding the rotation of rotary shaft vertical to a rotary shaft E of the profile forming tool 1 over a grinding worm width bs.

Design of Antibacklash Pin-Gearing

Abstract: This paper draws attention to pin gearing for its antibaiklash gear property. The gear tooth curve derived from a cycloidal curve furnishes the pin gearing with kinematic antibacklash, low pressure angle, and no interference among other features. The pins on one side of a centerline are contacting the forward faces of the mating tooth gear. Simultaneously the pins on the other side of the centerline are contacting the backward faces of the gear. The correct center distance can be maintained by appling a force directed to each other center for multiple contacts. A generating method of gear manufacture is also suggested. Contact and bending deformations as well as the gear stress are analyzed to help its engineering design.

Cleaning device for image forming device

Abstract: PROBLEM TO BE SOLVED: To obtain a cleaning device capable of preventing the occurrence of a jitter without increasing the load exerted on a photoreceptor drum even when a cleaning roller is in a torque-up state due to a secular change and the force in a pressure angle direction increases SOLUTION: In this cleaning device, rotational driving is transmitted to the gear 601 of a cleaning roller 6 by meshing the gear 100 of a photoreceptor drum 1 with the gear 601 of the roller 6 and making the force act in the pressure angle direction A at the meshing point B An arm member 61 turning with a supporting point 62 as a center is arranged at one end of the roller 6, the roller 6 is connected to the point of application of the member 61 and a load imparting means 63 imparting the specified load to the roller 6 is connected to the point of force

A Study on Diagnosis of Tooth Surface Failure by Wavelet Transform of Dynamic Characteristics

Abstract: This paper deals with a diagnosis of the tooth surface failure by the wavelet transform. A gear fatigue test was performed and the dynamic characteristics were analysed in a time-frequency domain using the wavelet transform. The vibration acceleration of the gear box and the tooth root strain were measured and the tooth surfaces were observed during the fatigue test. The test gear had some tooth profile error due to the pressure angle before the fatigue test. At the initial stage of the fatigue test, this profile error closed to zero by moderate wear. Therefore, the wavelet intensity at each harmonic frequency of the tooth mesh frequency was considerably decreased at the initial stage of the fatigue test. A tooth surface of the gear was damaged by spalling failure with the progress of the fatigue test. The wavelet intensity at each harmonic frequency showed a high value when the spalled gear tooth meshed. It could be understood that a failed tooth can be diagnosed by this analysis when one tooth failed. However, in the case of adjoining plural failed teeth, it was difficult to diagnose each failed tooth.

Paired gears made of abrasion reducing resin

Abstract: PROBLEM TO BE SOLVED: To satisfy various mechanical characteristic needs and further reduce abrasion in meshing gears made of resin by providing the gear having the less number of teeth with a specified number of teeth, and arranging the gears such that meshing pressure angle is within specified multiples of that of a tool. SOLUTION: Number of teeth of a gear which having less number of teeth in the pair may be not more than 30, preferably 25, and more prepferably 23. Two involute or substantially involute gears are so meshed with each other that the meshing pressure angle is within a range from 103 to 180% of that of a tool. It is thus possible to remarkably reduce abrasion of both of the gears composing the pair by highly controlling number of theeth, material, shapes and assembling (arrangement) of the paired gears made of abrasion reducing resin.

Improved worm gear assembly for drive axle

Abstract: A drive axle assembly (10) for a vehicle receives input torque from an engine (30) via an input shaft (22). The input shaft (22) drives a worm (20) which in turn drives a worm gear (18). The worm gear includes teeth (34) which engage and drive an axle shaft (14) which in turn drives a vehicle wheel (12). The teeth of the worm gear are defined by a tooth profile which has two pressure angles, one on each side of the tooth. The worm includes a thread with a thread profile that also has two pressure angles, one on each side of the thread. One of the pressure angles on the thread of the worm is greater than its other pressure angle and one of the pressure angles on the worm gear teeth is greater than its other pressure angle.

Gear train of screw compressor

Abstract: FIELD: compressor engineering. SUBSTANCE: gear train has profile of tooth 3 in cross section which is asymmetric relative to straight line running through point of tooth 3 and center of rotation of rotor 1. Rotor 1 with lesser number of starts on side of low pressure from tip circle to pitch circle is formed by conjugated curves located in succession from point of tooth 3 to its root. Sections of rotor 2 with larger number of starts are the envelopes corresponding to respective sections of rotor with lesser number of starts. EFFECT: enhanced efficiency and loading capacity of gear train due to increased length of throttling path at tooth point and increased pressure angle on side of low pressure at simultaneous increase of relative length of contact line. 3 dwg ooo1

Recliner for vehicle seat

Abstract: PROBLEM TO BE SOLVED: To smooth and ensure the rocking operation of a seat recliner in an inner tooth system by making the pressure angle of a valley part formed by the respective starting and finishing ends of the tooth part of a tooth plate and a toothless part on the inner peripheral surface of the circular arc part of a recessed part larger than the pressure angle of the other teeth. SOLUTION: A tooth member 11 forming a tooth part 10 to mesh with tooth parts 7 at an upper tip edge is held between a base plate 1 and a tooth plate 3 and housed within the recessed part 6 of the plate 3. In addition, guide parts 12 and 13 consisting of a projecting part or a recessed part having guide surfaces 12a and 13a holding the member 11 to slide-guide it in the radial direction are formed on the base plate 1. Then, at the tooth parts 7, the relation between a mountain angle and a valley (pressure) angle is constant at each of the tooth parts 7 nearly similarly to conventional one. However, the angle of a valley part formed between each of the starting or finishing ends of the parts 7 and a toothless part on the circular arc shaped inner peripheral surface of the recessed part 6 is formed larger than the valley angles of the other tooth parts 7.

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 a0=25°gives the lowest friction loss for the gear unit.

Crown wheel shaping machine

Abstract: The machine shapes crown wheels, where the flanks of the crown-wheel teeth have minimum (~amin) and maximum pressure angles respectively at the innermost and outermost portions, and work with a cylindrical pinion whose tooth-pitch angle (~f) is equal to 360 deg divided by the number of pinion teeth. The machine has a tool (12) with a working surface (9), which in a cross-section through its rotation axis has a profile incorporating several teeth of the same shape as those of the pinion, and is moved to and fro along the rotation axis of the pinion when meshing with the finished crown-wheel. On reversal of movement, the work is indexed round its axis, and the tool is rocked through an angle to either side of a centre line (V), so that tool and work turn for distances corresponding to the ratio between the numbers of pinion and crown-wheel teeth. The rocking angle is greater than half the tooth-pitch angle of the pinion and less than the minimum pressure angle of the crown-wheel teeth.

Axode Synthesis of Cam-Follower Mechanisms with Hyperboloidal Rollers

Abstract: The surface geometry of the roller-follower cam mechanisms are derived as the cam makes contact with the roller on their instantaneous screw axis.These surfaces, such as cam surface, follower surface, surface of action, and pitch surface, are ruled surfaces.With the restrictions of the geometric characteristics of a hyperboloidal roller, the relative locations of the axes of these cam mechanisms have to satisfy certain relation and the kinds of roller-follower cam mechanisms synthesized in axode contact are verified.The angular velocity of the roller and the screw pitch of the cam pair are derived, and the types of the contact surfaces, the pressure angle, and the purerolling cam pait are also discussed.