Hourglass Worm Research Articles

113 高性能小型鼓形ウォームギヤの研究(第 1 報)

Theory and production method of Hourglass worm gear of small size with a high performance are proposed. Wheel tooth is involute helical gear of this worm gear and pinion cutter generates worm tooth. This worm gear set is produced and contact mark is coinciding well with the theory.

115 高性能小型鼓形ウォームギヤの研究(第 3 報)

Theory and calculating method of axial section of Hourglass worm are introduced. Axial section of worm tooth is measured by 3 dimensional measuring machine. Profile errors of worm tooth are determined by comparing theoretical values and measured values of tooth profile.

114 高性能小型鼓形ウォームギヤの研究(第 2 報)

Tooth Contact Analysis of hourglass worm gearing of this study is reported in this report. Contact lines and radius of relative curvatures of mating teeth surface are obtained by T. C. A. The displacement of tooth contact mark caused by axial errors is represented by 3D contours.

Hourglass Worm Gearing with Worm Teeth Generated by High-Speed Screw Cutting Method. Manufacturing of High-Speed Hourglass Worm Screw Cutting Machine and Performance Test Results of the Worm Gear Generated by this New Machine.

Authors reported theory of hourglass worm gearing whose worm is generated by high speed screw generating method, on previous report. CNC high speed hourglass worm generating machine has been developed according to the theory. And worm cutting test and performance test of worm gearing was made. The test results are as follows: (1) Newly developed machine has high speed cutting ability same as mach type screw generating apparatus. (2) Surface roughness of worm tooth surface generated by the CNC high speed hourglass worm generating machine has same order of roughness of screw surface cut by mach type screw generating apparatus. (3) Hourglass worm gearing generated by the newly developed machine showed high efficiency and ran 1000 hours without trouble.

GDS-9 A STUDY ON THE MANUFACTURING OF THE HOURGLASS WORM GEAR SET(GEAR DESIGN AND SYNTHESIS)

GDS-9 A STUDY ON THE MANUFACTURING OF THE HOURGLASS WORM GEAR SET(GEAR DESIGN AND SYNTHESIS)

Three-dimensional mesh generation using principles of finite element method

The present work deals with the development of a three-dimensional mesh generation algorithm using the principles of FEM with special emphasis on the computational efficiency and the memory requirement. The algorithm makes use of a basic mesh that defines the total number of elements and nodes. Wavefront technique is used to renumber the nodes in order to reduce the bandwidth. By elastic distortion of the basic mesh, it is redefined to map onto actual geometry to be discretized. Later a finer distribution of mesh is done in the zones of interest to suit the nature of the problem. The same Finite Element code meant for stress analysis is adopted with necessary modifications. The algorithm has been extended to three-dimensional geometries. The current methodology is used to discretize a straight bevel gear and an hourglass worm to study their stress patterns.

Hourglass Worm Gearing with Worm Teeth Generated by High-Speed Screw Cutting Method. 2nd Report. Manufacturing of High-Speed Hourglass Worm Screw Cutting Machine and Performance Test Result of the Worm Gear Generated by this New Machine.

Authors reported theory of hourglass worm gearing whose worm is generated by high speed screw generating method, on 1 st report. CNC high speed hourglass worm generating machine has been developed according to the theory. And worm cutting test and performance test of worm gearing was made. The test results are as follows: (1) Newly developed machine has high speed cutting ability same as mach type screw generating apparatus. (2) Surface roughness of worm tooth surface generated by the CNC high speed hourglass worm generating machine has same order of roughness of screw surface cut by mach type screw generating apparatus. (3) Hourglass worm gearing generated by the newly developed machine showed high efficiency and ran 1000 hours without trouble.

A Study on Hob for Hourglass Worm Wheel. 3rd Report. Hob Design for Hourglass Worm Wheel with Crowned Teeth.

A new concept of a new type hob for hourglass worm wheel has been proposed. The hob can be used repeatedly when the cutting edges become worn. In this paper, the authors try to design the hob generating the crowned wheel tooth surface. In this purpose, the tooth profile data are modified to be desirable crowned form using the B-spline curve fitting method. The concept was applied to the design of a hob for wheel tooth generation of the hourglass worm gear generated by a tool with a conical surface. Numerical calculations show that both the crowned form and the amount of crowning are exactly controlled using the hob.

A Study on the Grinding of the Hourglass Worm Wheel.

The high performance of the hourglass worm gearing is well known among all types of worm gearings, especially after the developement of HEDCON【○!R】 worm gear reducer. Despite its high performance, the difficulty in manufacturing the hob is one of the obstacles of production and it has been one of the themes of study. Worm wheel grinding means not only teeth surface grinding but also teeth generating using the electro deposited diamond wheel which shapes the worm thread. This type of grinding wheel has the possibility of being an easy method for producing the worm wheel.

Accuracy Control of Hourglass Worm Gearing. Analysis of Tooth Shape and Tooth Contact.

Feeding under-cutting of Lorentz wheel cutting method of Hindley hourglass worm gearing is analyzed at first. And the shape of the wheel tooth surface is made clear by the analysis and the measuring method of the wheel by 3-dimensional coordinate measuring machine is proposed. Statical and dynamical tooth contact are analyzed to control the accuracy of manufacturing a pair of Hindley hourglass worm gearing.

Study on Hob for Hourglass Worm Wheel. 2nd Report. Design with Shaft Angle between Hob and Tool axes Added.

A concept for a new type of hob for an hourglass worm wheel has been proposed. The hob can be used repeatedly when the cutting edges become worn. This concept was applied to the design of a hob cutter for the principal part of the wheel tooth surface generation of the hourglass worm gear generated by use of a tool with a conical surface. In this paper, the authors, increasing design elasticity, describe design of such a hob to generate the whole tooth surface. Numerical calculation results show that the hob generates not only the secondary part of the wheel tooth surface but also the primary part of it with high accuracy after regrinding of its face surface.

Study on Hob for Hourglass Worm Wheel. 1st Report. Basic Principles for Hob Design.

This paper describes the concept of a new hob for an hourglass worm wheel. The hob can be used repeatedly when the cutting edges become worn. The basic cutter surface of the hob is generated by the relative motion of the tool and the work different from that of the wheel and the worm. This concept was applied to the design of a hob for wheel tooth generation of the hourglass worm gear generated by a tool with a conical surface. Numerical calculations show that the hob has sufficient relief angles and that it generates the principal part of the wheel tooth surface with high accuracy after regrinding its face surface.

Hourglass Worm Tooth Modification Using CNC-Hobbing Machine.

This paper describes a new method for hourglass worm tooth modification using a CNC-hobbing machine. In the hourglass worm gear modified by this method, the worm tooth surface never contacts the mating wheel tooth surface at the end of worm tooth thread when the wheel tooth surface becomes worn. This modification method was applied to the design of an hourglass worm gear with arcuate tooth profile. In the case of tooth surface generation, the hobbing machine was controlled with an external control unit connected to a personal computer by using a manual handle interrupter attached to the hobbing machine.

Hourglass Worm Gearing With Worm Teeth Generated by High-Speed Screw Cutting Method. 1st Report. Proposal of High-Speed Worm Cutting Method and Performance Analysis.

Hourglass Worm Gearing With Worm Teeth Generated by High-Speed Screw Cutting Method. 1st Report. Proposal of High-Speed Worm Cutting Method and Performance Analysis.

A study on the Hourglass Worm Gearing whose Wheel has the Helical Teeth. (2nd Report).

The authors proposed the hourglass worm gearing with helical Involute gear wheel, and made the numerical simulation and the experiment and confirmed the usefulness of the proposed gearing in the 1st report. The authors tryed to get the initial tooth contact mark at any point on the middle plane on this worm gearing. The authors tryed to analyze the contact marks appears on the wheel tooth, when the both teeth were attached with each other during the rotation of the gearing. This contact marks are so colled the moving tooth contact. The authors developed the soft wear of this moving tooth contact containing the cutting and the assembling errors. This soft wear can also analyze the rotation angle errors.

A Study on the Hourglass Worm Gearing whose Wheel has the Helical Teeth. (1st Report).

A Study on the Hourglass Worm Gearing whose Wheel has the Helical Teeth. (1st Report).

Hourglass Worm Gears Designed to Concentrate Surface Normals. Design for Worm Gears with Large Lead Angles.

Hourglass Worm Gears Designed to Concentrate Surface Normals. Design for Worm Gears with Large Lead Angles.

Point-Contact Hourglass Worm Gears. (Crowning Method, the Analysis of Tooth Contact and Kinematic Precision of the Gearing).

In this paper, a method of crowning is proposed for hourglass worm gears to obtain the manner of point-contact with the aim of controling the sensitivity to various errors. In the studied worm gears, the worm is generated from a basic member with a plane or a spherical surface. The basic surface of the hob is also generated from a basic member with a spherical surface, but the radius of curvature is lesser than the former to some degree. Errors of center distence and shaft angle were introduced in the tooth contact analysis (TCA). The contact pattern and kinematic error curves were presented. The results showed that the method of crowning proposed can be employed for Practical use.

Hourglass Worm Gears Designed to Concentrate Surface Normals. Experimental Investigation on Load Capacity.

To reduce the edge contact of gear tooth surfaces on load, the authors have already proposed a new concept of gear design. Based on this idea, a few methods of tooth surface generation for hourglass worm gears have been devised. Also, taking advantage of one of the methods, an hourglass worm gear has been made and its characteristics for tooth bearing tested. In this research, the authors investigate the effect of a slight change of tooth bearing on the ability of the newly designed worm gear, by showing the experimental results on load-carrying capacity and efficiency, and temperature of the lubricating oil. As a result, the validity of the design concept is proven.

Hourglass Worm Gears Designed to Concentrate Surface Normals. Manufacturing and Experimental Investigation on Tooth Bearing.

To avoid the influence from the small displacement of gear axes under load, the authors propose that all contact normals of a tooth surface be at right angles to the direction of the small displacement induced at each contact point under load. On the basis of this state of surface normals, a few methods for tooth surface generation have been devised for realizing this concept. In this research, an hourglass worm gear having the above geometrical characteristics was made using the conventional methods of tooth surface generation and tooth bearing of the worm gear was experimentally tested. As a result, the validity of this design concept was proven.