DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
A SYSTEM AND METHOD TO PRODUCE TAPERED FLANK ON A SHOULDERED EXTERNAL GEAR TEETH

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having Address As:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present invention claims priority from Indian patent application numbered IN 202241047379 filed on 19th August, 2022.

FIELD OF THE INVENTION
[002] The present subject matter described herein, in general, relates to a system and method to produce tapered flank on gear teeth with shoulder and more particularly relates to a cold forming process for chipless generation of tapered flank external gear teeth with shoulder.
BACKGROUND OF THE INVENTION
[003] Numerous machining systems like milling and cutting are used for generating a gear. However, machining process needs special work holding fixtures and customized machines to produce the taper flank external gear tooth with shoulder. The machining cost is very high, due to use of special cutters and higher cycle time. Moreover, in machining operation the tool has to be resharpened after periodic time interval.
[004] Producing taper flank on external gear tooth with shoulder requires special machines with complex operation. The machining of gear while producing taper flank generates chip, requires high cycle time and is very costly. Hence, there is necessity of a process, which will manufacture gear in lesser time, with reduced cost and without chipping the material.
OBJECT OF THE INVENTION
[005] The main object of the invention is to provide a system and method to produce tapered flank on external gear tooth with shoulder by cold-forming process.
[006] Another object of the invention is to provide a forming tool/cutter to produce tapered flank on gear teeth.
[007] Yet another object of the invention is to produce a tapered flank on a shouldered external gear tooth by chipless operation.
[008] Yet another object of the invention is to reduce a cost and cycle time to generate taper flank on shouldered external gear tooth.
[009] Yet another object of the invention is to facilitate forming of bi-directional tapered flank on external gear teeth for synchromesh transmissions. Yet another object of the invention is to eliminate the development of customized machinery to generate taper flank on shouldered external gear tooth.

STATEMENT OF THE INVENTION
[0010] Accordingly, the present invention relates to a system to produce tapered flank on shouldered external gear teeth comprising of a drive spindle configured for mounting of a component, a driven spindle configured for mounting of a forming tool, a gear holding fixture configured to adapt the component wherein said gear holding fixture is provided with a height adjustment mechanism, a cutter holding fixture configured for mounting the forming tool and wherein the component and the forming tool are configured to be synchromesh while machining. The system is configured to produce tapered flank by a cold forming. The component is configured to be a gear with external gear teeth and a shoulder. The forming tool is configured to be an inverted replica of a required gear with tapered flank. The forming tool is configured to be provided with an inverted taper angle. The component is configured to be provided with a single tapered flank or a double tapered flank. The forming tool is configured to produce inside or outside tapered flank on the component. The forming tool is configured to apply direct pressure on the component for producing tapered flank on the component.
[0011] Further, a method to produce tapered flank on shouldered external gear teeth comprising steps of: i. mounting a forming tool on a driven spindle, ii. mounting a gear holding fixture on a drive spindle, iii. mounting a component with external gear teeth on said gear holding fixture, iv. adjusting a height and operating position of the forming tool and the component to be synchromesh with each other, v. locking the forming tool and the component on said spindles respectively, vi. setting a speed, feed, direction of operation and number of cycles to be performed, vii. operating a system for cold forming of the component, viii. inspecting the formed component for ensuring overall required dimensions and ix. unloading the machined component from said system.

SUMMARY
[0012] Before the present system and method are described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a system and method to produce tapered flank on external gear teeth with shoulder, and the aspects are further elaborated below in the detail description.
[0013] The present invention discloses a system and method to produce tapered flank on a shouldered external gear teeth wherein said system and method uses cold forming process for generation of taper flank on said gear teeth. The system mainly comprises of a drive spindle on which a component/gear to be machine is mounted, a driven spindle on which a forming tool/cutter is mounted, a gear holding fixture for mounting the gear and a cutter holding fixture for mounting the forming tool/cutter. The forming cutter is configured to be an inverted replica of the gear to be formed. Further, the above-mentioned fixtures are provided with a locking mechanism to prevent displacement of the gear and the cutter while machining. Furthermore, said fixtures are provided with mechanism to adjust the height and operating position of the forming cutter and gear. .In the system, the specifically made cutter is configured to apply direct pressure on the component/gear for chipless generation of taper flank on gear teeth while machining.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing summary, as well as the following detailed description of embodiment, is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing.
[0015] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0016] Figure 1 illustrates a side view of a system to produce tapered flank on shouldered gear teeth, in accordance with the present invention.
[0017] Figure 2 illustrates an isometric view of a system showing a forming tool/cutter to produce tapered flank on shouldered gear teeth, in accordance with the present invention.
[0018] Figure 3 illustrates a forming tool/cutter of a system to produce tapered flank on shouldered gear teeth, in accordance with the present invention.
[0019] Figure 4 illustrates a gear holding fixture of a system to produce tapered flank on shouldered gear teeth, in accordance with the present invention.
[0020] Figure 5 illustrates a cutter holding fixture of a system to produce tapered flank on shouldered gear teeth, in accordance with the present invention.
[0021] Figure 6 illustrates a formed/processed gear of a system to produce tapered flank on shouldered gear teeth, in accordance with the present invention.
[0022] Figure 7 illustrates a flowchart of a method to generate tapered flank on shouldered external gear teeth, in accordance with the present invention.
[0023] Figures depicts various embodiments of the present disclosure for purpose of illustration only. Only skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0024] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words “comprising”, “having”, and “including,” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0025] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to another embodiment. However, one of the ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated but is to be accorded the widest scope consistent with the principles and features described herein.
[0026] The present invention describes a system and method to produce tapered flank on an external gear tooth with shoulder by a cold-forming process. A forming cutter is configured such that it is an inverted replica of a gear to be produced. The gear to be machined is configured to be mounted on provided fixture such that it can be machined through the cutter to produce the gear tooth flank (inside or outside taper) with tapered angle.
[0027] Figure 1 and figure 2 shows a system (100) to produce tapered flank on the shouldered external gear. Said system (100) is configured for cold forming of the shouldered external gear to produce tapered flank. The system comprises a drive spindle (102), a driven spindle (104), a forming tool (108), a gear holding fixture (110) and a cutter holding fixture (112). A component (106) to be machined is mounted on the drive spindle (102) and the forming tool (108) is mounted on the driven spindle (104). The gear holding fixture (110) is configured to hold the component (106) and the cutter holding fixture (112) is configured to hold the forming tool (108) wherein said fixtures (110 & 112) are such that it provides height adjustment of the component (106) and the forming tool (108). Also, the fixtures (110 & 112) is provided with a locking mechanism which prevents displacement of the component (106) and the forming tool (108) while machining. The fixtures (110 & 112) illustrated in the present embodiment is not restricted to the disclosed fixture only and it may include other types of fixtures which provide proper holding and locking mechanism to the component and the forming tool. Further, said forming tool (108) is also known as cutter hereinafter. Moreover, the system (100) of the present invention eliminates the use of external pressure rollers for cold forming of the external gear tooth of the component or gear (106). Further, the cutter tooth is specifically made as inverted replica of the required tapered flank gear tooth wherein a flank angle is provided on the cutter to form an inverted taper angle on the flanks of the shouldered gear tooth of the gear (106).
[0028] Referring to Figure 3, the cutter (108), which is an inverted replica of the required gear (106) is shown. Said cutter (108) is configured to apply direct pressure on the component (106) for chipless generation of taper flank on the shouldered external gear tooth (601). In one of the embodiments of the present invention, the dimensions of the cutter are module: 4, pressure angle: 30O, cutter bore: 80mm, tip diameter: 257.4mm, PCD: 248, side clearance angle: 3O (inverted), material: HCHC, D+F: 4.36. Further, the dimensions of the cutter are based on the required dimensions of the gear.
[0029] Figure 4 and figure 5 shows the gear holding fixture (110) and cutter holding fixture (112) of the present invention. The gear holding fixture (110) is mounted on the drive spindle (102) through fastening members such as bolts or alike. Further, the component (106) is clamped on the center of the spindle (102) with a center top clamp. In one of the embodiments of the present invention, the gear holding fixture (110) is mounted on the drive spindle (102) by four M12 bolts and gear is clamped on center of spindle with M24 thread center top clamp. Moreover, the cutter (108) is mounted on the driven spindle (104) through key and is clamped on the spindle (104) through fastening member such as nut. In one of the embodiments of the present invention, the cutter (108) is mounted on the driven spindle with 8 mm key and clamped with M42 nut.
[0030] Referring to figure 6, a final product of machining or the gear with tapered flank (106) is shown. Said gear (106) comprises of a gear tooth (601), a tapered flank (602) and a shoulder (603). In one of the embodiments of the present invention, the gear tooth (601) is formed with 30 inverted taper angle on both the flanks.
[0031] Figure 7 shows a flowchart for generating tapered flank on an external gear tooth with shoulder by cold forming process. According to the flowchart, the cutter (108) is mounted on the driven spindle (104), the gear holding fixture (110) is mounted on the drive spindle (102), the gear or the component (106) to be machined is mounted on said fixture (110), the height and the operating position of the cutter (108) and the component (106) is adjusted such that both are synchromesh to each other, the component (106) and the cutter (108) are locked on the respective spindles (102 & 104), the machining parameters including speed, feed, direction of operation and number of cycles are set and then the cycle is started or the system (100) is operated. Finally, after completion of the operation, the gear (106) is inspected for ensuring the required overall dimensions and then the gear (106) or a machined component is unloaded from the system (100).
[0032] Moreover, the present invention relates to a system (100) to produce tapered flank on shouldered external gear teeth comprising of a drive spindle (102) configured for mounting of a component (106), a driven spindle (104) configured for mounting of a forming tool (108), a gear holding fixture (110) configured to adapt the component (106) wherein said gear holding fixture (110) is provided with a height adjustment mechanism, a cutter holding fixture (112) configured for mounting the forming tool (108) and wherein the component (106) and the forming tool (108) are configured to be synchromesh while machining. The system is configured to produce tapered flank by a cold forming. The component (106) is configured to be a gear with external gear teeth and a shoulder. The forming tool (108) is configured to be an inverted replica of a required gear with tapered flank. The forming tool (108) is configured to be provided with an inverted taper angle. The component (106) is configured to be provided with a single tapered flank or a double tapered flank. The forming tool (108) is configured to produce inside or outside tapered flank on the component (106). The forming tool (108) is configured to apply direct pressure on the component (106) for producing tapered flank on the component (106).
[0033] Further, a method to produce tapered flank on shouldered external gear teeth comprising steps of: i. mounting a forming tool (108) on a driven spindle (104), ii. mounting a gear holding fixture (110) on a drive spindle (102), iii. mounting a component with external gear teeth (106) on said gear holding fixture (110), iv. adjusting a height and operating position of the forming tool (108) and the component (106) to be synchromesh with each other, v. locking the forming tool (108) and the component (106) on said spindles (104 & 102) respectively, vi. setting a speed, feed, direction of operation and number of cycles to be performed, vii. operating a system (100) for cold forming of the component (106), viii. inspecting the formed component (106) for ensuring overall required dimensions and ix. unloading the machined component (106) from said system (100).
[0034] Further, the invention can be used, but not limited to, in the following applications.
[0035] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0036] Some embodiments of the present invention provides a simple process for producing taper flank on a shouldered external gear tooth.
[0037] Some embodiments of the present invention eliminate use of external pressure rollers for forming of gear.
[0038] Some embodiments of the present invention eliminate import of gear with tapered flank on gear tooth.
[0039] Some embodiments of the present invention produce a gear with tapered flank on gear tooth indigenously.
[0040] Some embodiments of the present invention provides a forming of bi-directional taper flank on gear tooth required for synchromesh transmissions.
[0041] Some embodiments of the present invention eliminate intricate machining of tapered flank and a root surface on a gear tooth.
[0042] Some embodiments of the present invention reduces high machining cost.
[0043] Some embodiments of the present invention avoids investment on customized machinery.

[0044] REFERENCE NUMERALS
Element Description Reference Numerals
System to produce a Taper flank on shouldered external gear teeth 100
Drive spindle 102
Driven spindle 104
Gear/ Component 106
Forming tool/cutter 108
Gear holding fixture 110
Cutter holding fixture 112
Gear tooth 601
Tapered flank 602
Shoulder 603

,CLAIMS:
1. A system (100) to produce tapered flank on shouldered external gear teeth comprising:
a drive spindle (102) configured for mounting of a component (106);
a driven spindle (104) configured for mounting of a forming tool (108);
a gear holding fixture (110) configured to adapt the component (106) wherein said gear holding fixture (110) is provided with a height adjustment mechanism;
a cutter holding fixture (112) configured for mounting the forming tool (108); and
wherein the component (106) and the forming tool (108) are configured to be synchromesh while machining.
2. The system to produce tapered flank on shouldered external gear teeth as claimed in claim 1, wherein the system is configured to produce tapered flank by a cold forming.
3. The system to produce tapered flank on shouldered external gear teeth as claimed in claim 1, wherein the component (106) is configured to be a gear with external gear teeth and a shoulder.
4. The system to produce tapered flank on shouldered external gear teeth as claimed in claim 1, wherein the forming tool (108) is configured to be an inverted replica of a required gear with tapered flank.
5. The system to produce tapered flank on shouldered external gear teeth as claimed in claim 1, wherein the forming tool (108) is configured to be provided with an inverted taper angle.
6. The system to produce tapered flank on shouldered external gear teeth as claimed in claim 1, wherein the component (106) is configured to be provided with a single tapered flank or a double tapered flank.
7. The system to produce tapered flank on shouldered external gear teeth as claimed in claim 1, wherein the forming tool (108) is configured to produce inside or outside tapered flank on the component (106).
8. The system to produce tapered flank on shouldered external gear teeth as claimed in claim 1, wherein the forming tool (108) is configured to apply direct pressure on the component (106) for producing tapered flank on the component (106).
9. A method to produce tapered flank on shouldered external gear teeth comprising steps of:
i. mounting a forming tool (108) on a driven spindle (104);
ii. mounting a gear holding fixture (110) on a drive spindle (102);
iii. mounting a component with external gear teeth (106) on said gear holding fixture (110);
iv. adjusting a height and operating position of the forming tool (108) and the component (106) to be synchromesh with each other;
v. locking the forming tool (108) and the component (106) on said spindles (104 & 102) respectively;
vi. setting a speed, feed, direction of operation and number of cycles to be performed;
vii. operating a system (100) for cold forming of the component (106);
viii. inspecting the formed component (106) for ensuring overall required dimensions; and
ix. unloading the machined component (106) from said system (100).