Automatic transmission power transmission device

Patent metadata

Field	Value
Publication number	US-11149847-B2
Application number	US-201816768864-A
Country	US
Kind code	B2
Filing date	Nov 13, 2018
Priority date	Dec 8, 2017
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

A power transmission device in an automatic transmission includes a friction tightening element (a second brake) having a drum member, and a transmission path constituent member (a third ring gear) coupled to the drum member via a coupling part extending circumferentially along the drum member, the drum member having low-rigidity parts (long holes) provided at a plurality of circumferential positions on the drum member in at least one of portions radially outside and inside the coupling part.

First claim

The invention claimed is:

1. A power transmission device in an automatic transmission, the power transmission device comprising:
a friction tightening element including a drum member having a bottomed cylindrical shape; and
a transmission path constituent member coupled to a bottom of the drum member via a coupling part extending circumferentially along the drum member, and constituting part of a power transmission path of the automatic transmission, wherein
the bottom of the drum member has low-rigidity parts that are provided at a plurality of circumferential positions on the drum member in respective portions radially outside and inside the coupling part, the low-rigidity parts being configured to reduce vibration of the drum member, and
the low-rigidity parts are configured as long holes that extend circumferentially along the drum member and penetrate the bottom.

2. The power transmission device of claim 1 , wherein
the friction tightening element is a brake configured to fix the transmission path constituent member to a transmission case when the friction tightening element is tightened.

3. The power transmission device of claim 2 , wherein
the transmission path constituent member is a ring gear in a planetary gear set, and the coupling part is a welding coupling part.

4. The power transmission device of claim 1 , wherein
the automatic transmission is directly connected to a driving source, not via any torque converter, and
the friction tightening element is a vehicle start friction tightening element configured to be tightened when a vehicle mounting the automatic transmission starts.

5. The power transmission device of claim 1 , wherein
outer long holes that are long holes provided radially outside the coupling part are equal in length circumferentially and equal in width radially,
inner long holes that are long holes provided radially inside the coupling part are equal in length circumferentially and equal in width radially, and
the outer long holes are circumferentially longer than the inner long holes.

6. The power transmission device of claim 5 , wherein
the outer long holes are disposed circumferentially so as to be equally spaced apart from each other,
the inner long holes are disposed circumferentially so as to be equally spaced apart from each other, and
the outer long holes and the inner long holes are equally positioned circumferentially.

Assignees

• Mazda Motor

Inventors

• Sasaki Masanori
• Fujikawa Masamichi
• Yamada Kazuhiro
• Ueda Kensuke
• Katayama Sayaka
• Miura Yasuo
• Tanaka Takeyuki
• Kouno Hirokazu
• Miyamoto Takashi
• HANAMURE Ryohei
• Tao Siyuan

Classifications

• F16H2200/2043

  with five engaging means · CPC title

• F16H2200/2023

  using a Ravigneaux set with 4 connections · CPC title

• F16H2200/2012

  with four sets of orbital gears · CPC title

• F16H2200/006

  the gear ratios comprising eight forward speeds · CPC title

• F16H3/663

  with conveying rotary motion between axially spaced orbital gears, e.g. a stepped orbital gear or Ravigneaux · CPC title