Patent Application
20220097159
The present disclosure relates to forming metal gears for motor vehicles. More particularly, the present disclosure relates to forming metal gears scattered tooth-to-tooth topography.
A typical motor vehicle is made of many different components. Many of these components incorporate a set of gears to operate the component. During the operation of these components, the noise, vibration and harshness (NVH) generated by these components may not be suitable in certain situations. To reduce NVH in various components, manufacturing of the gears for these components requires multiple processes.
Thus, while current systems and process to form gears achieve their intended purpose, there is a need for a new and improved system and method for forming gears to reduce NVH while being cost effective.
According to several aspects, a method to form a gear for motor vehicles includes one or more of the following: placing a blank between a first tool member and a second tool member, each of the first tool member and the second tool member having a set of teeth; and moving the first tool member and the second tool member towards the blank while rotating the first tool member and the second tool member to form a gear with a set of teeth from the blank. Each tooth of the set of teeth has a topography that varies tooth-to-tooth.
In an additional aspect of the present disclosure, the blank is made of powered metal.
In another aspect of the present disclosure, the surface of each tooth of the set of teeth is densified to increase the hardness and strength of the surface of each tooth.
In another aspect of the present disclosure, the Young's modulus decreases as a distance from an edge of the surface increases.
In another aspect of the present disclosure, the topography results in random excitation during an operation of the gear.
In another aspect of the present disclosure, the surface of a gear tooth is densified and the set of teeth have a random tooth-to-tooth topography.
In another aspect of the present disclosure, the surface of a gear tooth is densified and the set of teeth have a pre-determined variable tooth-to-tooth topography.
According to several aspects, a method to form a gear for motor vehicles includes one or more of the following: placing a blank between a first tool member and a second tool member, the blank being made of powered metal, each of the first tool member and the second tool member having a set of teeth; and moving the first tool member and the second tool member towards the blank while rotating the first tool member and the second tool member to form a gear with a set of teeth from the blank by cold rolling. The set of teeth of the gear has a scattered tooth-to-tooth topography.
In another aspect of the present disclosure, the surface of each tooth of the set of teeth is densified to increase the hardness and strength of the surface of each tooth.
In another aspect of the present disclosure, the Young's modulus decreases as a distance from an edge of the surface increases.
In another aspect of the present disclosure, the topography results in random excitation during an operation of the gear.
In another aspect of the present disclosure, the surface of a gear tooth is densified and the set of teeth have a random tooth-to-tooth topography.
In another aspect of the present disclosure, the surface of a gear tooth is densified and the set of teeth have a pre-determined variable tooth-to-tooth topography.
In another aspect of the present disclosure, the tooth-to-tooth topography has varying micro-geometry parameters.
In another aspect of the present disclosure, the micro-geometry parameters include variations in at least one of tooth-to-to spacing error, profile crown, lead crown, profile slope, lead slope, or profile tip relief.
According to several aspects, a gear for a motor vehicle includes a set of teeth formed from a blank by cold rolling. The set of teeth has a random tooth-to-tooth topography.
In another aspect of the present disclosure, the tooth-to-tooth topography has varying micro-geometry parameters.
In another aspect of the present disclosure, the micro-geometry parameters include variations in at least one of tooth-to-to spacing error, profile crown, lead crown, profile slope, lead slope, or profile tip relief.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
Referring to
The gear 12 is mounted initially as a blank to a platform 18. The gear 12 is mounted in a manner to the platform 18 to allow the gear 12 to rotate relative to the platform 18 during the forming process to make the gear 12. During the forming process the platform 18 is stationary while the platforms 20 and 22 are linearly movable. As such, the platforms 20 and 22 move inwardly during the during the cold rolling process to apply pressure to the blank to form the teeth on the gear 12 by the teeth on the first tool 14 and the second tool 16. In some arrangements, the cold rolling of the gear 12 proceeds by cold rolling a cylindrical blank without any teeth. In other arrangements, the cold rolling of the gear 12 proceeds by cold rolling a blank that has a set of teeth.
As the gear 12 is formed, the surface density of the gear 12 increases to increase the hardness and strength of material at the surface of the teeth of the gear 12.
Referring to
Referring now to
A gear with scattered topography of the present disclosure offers several advantages. These include a convergence of multiple processes in a single process. Namely, the strengthening of the surface of the teeth of the gear and the application of a varying micro geometry on the surface of the teeth is accomplished in a single process. Moreover, the process provides NVH improvement by decreasing the tonality of the noise generated by a set of gears.
The description of the present disclosure is merely exemplary in nature and variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure.
