KR-20260066053-A - Monoblock gear for transmission and method of manufacturing the same

Abstract

A method for manufacturing a monoblock gear (200) having a dog tooth (208) comprises the step of pre-machining a forged blank to obtain an outer profile, wherein the outer profile comprises a first profile associated with a set of splines of the monoblock gear (200) and a second profile associated with a set of gear teeth (206) of the monoblock gear (200). The method comprises the step of forming a set of straight splines on the first profile by either cold forging or machining, and the step of performing a cold forging operation to provide a loop angle and a back taper to the dog tooth. During the cold forging operation, a force is applied radially to form the spline at a specific loop angle.

Inventors

• 마크와나 비샬

Assignees

• 텍스핀 베어링스 리미티드

Dates

Publication Date

20260512

Application Date

20240112

Priority Date

20230804

Claims (4)

1. A method (100) for manufacturing a monoblock gear (200) having a set of dog teeth (208), A step of pre-processing a forged blank to obtain an external profile, wherein the external profile comprises a first profile associated with a spline set of the monoblock gear (200) and a second profile associated with a set of gear teeth (208) of the monoblock gear (200); The step of forming the spline set on the first profile; and The method includes the step of performing a cold forging operation to form a dog tooth (208) by providing a roof angle (202) and a back taper (204) to the spline (208), and In the above cold forging operation, the cold forging force is applied in the radial direction, method (100).
2. In claim 1, The step of forming the above spline set is performed by either a machining operation or a cold forging operation, in a method (100).
3. In claim 1, A method (100) comprising the step of performing the above cold forging process, using a die set configured to enable simultaneous cold forming of the loop angle (202) and the back taper (204) of all the above dog teeth (208) in a single operation.
4. In claim 1, A method (100) comprising the step of performing the above cold forging process, wherein one or more tools are used, but fewer than the number of splines in the spline set, and the step of indexing the blank by rotation to align each of the splines with the one or more tools before moving the one or more tools radially inward to form the loop angle and the back taper on the corresponding splines.

Description

Monoblock gear for transmission and method of manufacturing the same The present invention relates to the field of transmission gears. More specifically, the present invention relates to a method for manufacturing a monoblock gear for a transmission. Transmission gears are essential components in various mechanical systems, such as transmission assemblies and other industrial machinery used in diverse applications. They play a role in maintaining the required speed ratio, ensuring smooth power transmission, and controlling the speed of driven components. Monoblock gears are a critical part of transmission assemblies, facilitating the engagement and interaction of gear teeth, which directly impacts the efficiency, reliability, and overall performance of the transmission system. The formation of teeth on monoblock gears is a critical manufacturing process that significantly impacts the performance of transmission gears. The accuracy and precision of gear teeth directly affect the efficiency, reliability, and smooth operation of various mechanical systems, including automotive transmissions and industrial machinery. Properly formed teeth ensure smooth engagement, reduce noise and vibration, and optimize power transmission, thereby contributing to the overall performance and durability of transmission gears. Since teeth play a vital role in transmitting power and torque between components, achieving high-quality tooth geometry is essential to ensure optimal gear function and the smooth operation of the mechanical systems in which they are integrated. The process of forming teeth on a monoblock gear involves multiple steps. Initially, following a first hot forging process of blanking, a second hot forging process creates a straight spline shape and a rough roof angle on the dog teeth. Subsequently, the final roof angle of the teeth is achieved through cold forging. Another cold forging step is used to create the tooth back taper. Finally, the gear teeth are formed during the gear cutting process. However, in conventional methods, creating the roof angle and back taper involves separate processes that require significant effort and time, making it inefficient in terms of cost. Furthermore, in all conventional technologies, the tooth roof angle is formed by the axial force of the tool. Therefore, a manufacturing process is required that provides forging operations efficient in terms of both time and cost. The attached drawings are incorporated herein to provide further understanding of the invention and constitute part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, explain the principles of the invention. The drawings are for illustrative purposes only and do not limit the invention. Similar components and/or features may have the same reference numeral in the drawings. Additionally, various components of the same type may be distinguished by appending a second reference numeral following the reference numeral to distinguish similar components. It is assumed that only the first reference numeral is used in this specification. In this case, the description applies to any similar component having the same first reference numeral, regardless of the second reference numeral. FIG. 1 illustrates an exemplary flowchart of a method for manufacturing a monoblock gear for a transmission according to an embodiment of the present invention. FIGS. 2a to 2i illustrate a schematic diagram of a stepwise expansion of a monoblock gear for a transmission according to an embodiment of the present invention. FIGS. 3a to 3c illustrate schematic diagrams of a cold forging operation according to an embodiment of the present invention. FIG. 4a illustrates a schematic diagram of the overall tool arrangement for creating a desired tooth profile according to an embodiment of the present invention. FIG. 4b illustrates a schematic diagram of individual profiles of a tool used for cold forming of a loop angle and a back taper on a single spline according to an embodiment of the present invention. FIG. 4c illustrates a schematic diagram of the overall profile of a generated dog tooth according to an embodiment of the present invention. FIGS. 5a to 5c illustrate schematic diagrams of alternative tool arrangements for generating a desired tooth profile according to an embodiment of the present invention. In the following description, various specific details are presented for illustrative purposes to provide a complete understanding of the embodiments of the present invention. However, it will be apparent that the embodiments of the present invention can be practiced without these specific details. Some features described below may be used independently of each other or in any combination of other features. Individual features may not solve all of the problems discussed above, or may solve only some of the problems discussed above. Some of the problems discussed above may n