CN-122003555-A - Power transmission mechanism and method for manufacturing gear

Abstract

The power transmission mechanism 3 includes a drive gear 10 fixed to the drive shaft 1 and a driven gear 20 fixed to the driven shaft 2 and meshed with the drive gear 10, and outputs power input to the drive shaft 1 to the driven shaft 2, wherein at least one of the drive gear 10 and the driven gear 20 has a tooth group in which a torsion angle and/or a pressure angle of teeth are varied in a circumferential direction. The change in the torsion angle and/or the pressure angle of the teeth in the circumferential direction is shaped to correspond to the waveform of a sine wave in the circumferential direction, for example.

Inventors

• J. KAZAMI
• YAMADA SHOGO
• Ling Hexing
• NAKAMURA TAKASHI

Assignees

• 丰田自动车九州株式会社
• 丰田自动车株式会社

Dates

Publication Date

20260508

Application Date

20241008

Priority Date

20231011

Claims (9)

1. 1. A power transmission mechanism having a drive gear fixed to a drive shaft and a driven gear fixed to a driven shaft and meshed with the drive gear, the power transmission mechanism outputting power input to the drive shaft to the driven shaft, characterized in that, At least one of the drive gear and the driven gear has a tooth group in which a torsion angle and/or a pressure angle of the tooth is varied in a circumferential direction.
2. 2. The power transmission mechanism according to claim 1, wherein, The change in the torsion angle and/or the pressure angle of the teeth in the circumferential direction is shaped to correspond to the waveform of a sine wave in the circumferential direction.
3. 3. The power transmission mechanism according to claim 1, wherein, The change in the torsion angle and/or the pressure angle of the teeth in the circumferential direction is shaped to correspond to a prescribed randomly varying waveform in the circumferential direction.
4. 4. The power transmission mechanism according to claim 1, wherein, The change in the torsion angle and/or the pressure angle of the teeth along the circumferential direction is shaped to correspond to a monotonically increasing and/or monotonically decreasing waveform along the circumferential direction.
5. 5. The power transmission mechanism according to any one of claim 2 to 4, wherein, The torsion angle and/or the pressure angle of the teeth along the circumferential direction are such that the waveform varies periodically over the circumference.
6. 6. The power transmission mechanism according to any one of claims 1 to 4, characterized in that, The driving gear and the driven gear are helical gears.
7. 7. A method of manufacturing a gear in which a torsion angle and/or a pressure angle of teeth are varied in a circumferential direction, the method comprising: A gear cutting process for forming a set of teeth in which a torsion angle and/or a pressure angle are varied along a circumferential direction of a gear member to be processed, and And a tooth surface machining step of grinding the set of teeth formed by the tooth cutting step to form a tooth surface.
8. 8. A method of manufacturing a gear in which a torsion angle and/or a pressure angle of teeth are varied in a circumferential direction, the method comprising: a gear cutting process in which a set of teeth having a uniform torsion angle and/or pressure angle along the circumferential direction of a gear member to be machined is formed, and And a tooth surface machining step of performing tooth surface machining in which a torsion angle and/or a pressure angle is varied in a circumferential direction for each tooth formed by the tooth cutting machining step.
9. 9. The method for manufacturing a gear according to claim 7 or 8, wherein, In the gear cutting process, the gear cutting process is performed by any one of gear hobbing process, gear scraping process, milling process, end mill process, and gear shaping process, In the tooth surface machining process, the tooth surface machining is performed by any one of grinding machining, shaving machining, honing machining, shaving machining, milling machining, end mill machining, and gear shaping machining.

Description

Power transmission mechanism and method for manufacturing gear Technical Field The present disclosure relates to a power transmission mechanism capable of suppressing gear noise while maintaining original power transmission performance and durability required for a gear, and a method for manufacturing a gear. Background With recent vehicle electric power generation, engine utilization is disabled and engine start time is reduced. As a result, since the engine sound that conceals the gear noise disappears, it is desirable to further reduce the gear noise than before from the viewpoint of quietness. Patent document 1 discloses a technique for suppressing gear noise by having periodically changing teeth in which the tooth width is periodically changed in the circumferential direction. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2012-122504 Disclosure of Invention Problems to be solved by the invention In patent document 1, gear noise caused by a meshing transmission error is suppressed by periodically varying the tooth width and randomizing, that is, making the meshing transmission error irregular. However, if the tooth width is periodically changed, the mass in the circumferential direction may become unbalanced, and the gear may be eccentric. If the eccentricity occurs, vibration and noise associated with the vibration are generated. In addition, in the processing for periodically changing the tooth width, the processing of a portion where the tooth width is reduced is also required. Further, if the tooth width is periodically changed, the width of the tooth contact varies greatly, and therefore, the engagement transmission error varies greatly, and improvement of the power transmission performance is demanded. The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power transmission mechanism and a method for manufacturing a gear, which can suppress gear noise while maintaining the original power transmission performance and durability required for the gear. Means for solving the problems In order to solve the above-described problems and achieve the object, a power transmission mechanism according to the present invention includes a drive gear fixed to a drive shaft and a driven gear fixed to a driven shaft and engaged with the drive gear, and outputs power input to the drive shaft to the driven shaft, wherein at least one of a tooth group of the drive gear and the driven gear changes a torsion angle and/or a pressure angle of a tooth in a circumferential direction. In addition to the above, in the power transmission mechanism according to the present invention, the change in the torsion angle and/or the pressure angle of the teeth along the circumferential direction is shaped to correspond to the waveform of the sine wave along the circumferential direction. In addition to the above, in the power transmission mechanism according to the present invention, the change in the torsion angle and/or the pressure angle of the teeth in the circumferential direction is shaped to correspond to a predetermined randomly-varying waveform in the circumferential direction. In addition, in the power transmission mechanism according to the present invention, the change in the torsion angle and/or the pressure angle of the teeth in the circumferential direction is shaped so as to correspond to a monotonically increasing and/or monotonically decreasing waveform in the circumferential direction. In addition, in the power transmission mechanism according to the present invention, the waveform is periodically changed within a circumference of the circumference by a torsion angle and/or a pressure angle of the teeth along the circumference. In the power transmission mechanism according to the present invention, the driving gear and the driven gear are helical gears. The method for manufacturing a gear according to the present invention is characterized by comprising a tooth cutting process for forming a tooth group in which the torsion angle and/or the pressure angle are varied in the circumferential direction of a gear to be machined, and a tooth surface machining process for grinding the tooth group formed by the tooth cutting process and forming a tooth surface. The method for manufacturing a gear according to the present invention is characterized by comprising a tooth cutting process for forming a set of teeth having a uniform torsion angle and/or pressure angle in the circumferential direction of a gear to be machined, and a tooth surface processing process for performing tooth surface processing for each tooth formed by the tooth cutting process, wherein the torsion angle and/or pressure angle of each tooth is varied in the circumferential direction. In addition, in the above-described aspect, in the gear manufacturing method according to the present invention, the gear cutting process is perfo