Automatic transmission

Patent metadata

Field	Value
Publication number	US-9353843-B2
Application number	US-201214345220-A
Country	US
Kind code	B2
Filing date	Sep 5, 2012
Priority date	Sep 26, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Automatic transmission 1 includes second friction plates 17 connecting a second drum 27 to a second hub 37 , a second engagement hydraulic chamber 67 , a second centrifugal balance chamber 77 , and a second piston 47 engaging and disengaging the second friction plates 17 . The second centrifugal balance chamber 77 overlaps the second friction plates 17 in the axial direction in the automatic transmission 1 . The automatic transmission 1 further includes a second oil passage 9 for discharging hydraulic oil in the second centrifugal balance chamber 77 to a position not overlapping the second friction plates 17 in the axial direction.

First claim

The invention claimed is:

1. An automatic transmission comprising:
a frictional engagement element for transmitting power input from a drive source via an input shaft, the frictional engagement element including
friction plates for connecting a drum to a hub,
an engagement hydraulic chamber and a centrifugal balance chamber located more inward than the friction plates in a radial direction,
a piston segmenting the engagement hydraulic chamber from the centrifugal balance chamber in an axial direction, and engaging and disengaging the friction plates based on a pressure difference between hydraulic oil in the chambers, and
the centrifugal balance chamber overlapping the friction plates in the axial direction;

a discharge section for discharging the hydraulic oil in the centrifugal balance chamber to a position not overlapping the friction plates in the axial direction; and
a cylindrical member supporting the input shaft inserted thereinto, wherein
the discharge section is located more inward than the centrifugal balance chamber in the radial direction, and includes an oil passage formed in the cylindrical member and extending in the axial direction,
an end of the oil passage at a non-drive source side in the axial direction communicates with the centrifugal balance chamber, and
an end of the oil passage at a drive source side in the axial direction communicates with a discharge oil passage provided in a position not overlapping the friction plates in the axial direction to extend in the radial direction.

2. The automatic transmission of claim 1 , wherein
the frictional engagement element includes a plurality of frictional engagement elements, and
the discharge oil passage is, in the axial direction, closer to the drive source side than a drum of the one of the frictional engagement elements, which is the closest to a front cover blocking an end of a transmission case at the drive source side in the axial direction.

3. The automatic transmission of claim 2 , wherein
the input shaft is transversely mounted in a vehicle along a width of the vehicle.

4. The automatic transmission of claim 1 , further comprising:
a seal plate faces the piston in the axial direction such that the centrifugal balance chamber is located between the seal plate and the piston; and
a sleeve externally fitted to the cylindrical member, connected to the input shaft, and supporting an inner circumference of the seal plate at an outer circumference thereof, wherein
a substantially annular space is formed at an end of the cylindrical member at the non-drive source side in the axial direction to be surrounded by the end of the cylindrical member, the input shaft, and the sleeve, and to communicate with the oil passage,
a through-hole is formed in the sleeve to connect the space to the centrifugal balance chamber, and to extend in the radial direction, and
the sleeve is welded to the input shaft to reduce leakage of the hydraulic oil toward the friction plates, which flows from the centrifugal balance chamber to the oil passage via the space.

5. The automatic transmission of claim 4 , wherein
the input shaft is transversely mounted in a vehicle along a width of the vehicle.

6. The automatic transmission of claim 1 , wherein
the input shaft is transversely mounted in a vehicle along a width of the vehicle.

7. An automatic transmission comprising:
a frictional engagement element for transmitting power input from a torque converter via an input shaft, the frictional engagement element including
friction plates for connecting a drum to a hub,
an engagement hydraulic chamber and a centrifugal balance chamber located more inward than the friction plates in a radial direction,
a piston segmenting the engagement hydraulic chamber from the centrifugal balance chamber in an axial direction, and engaging and disengaging the friction plates based on a pressure difference between hydraulic oil in the chambers, and
the centrifugal balance chamber overlapping the friction plates in the axial direction;

a discharge section for discharging the hydraulic oil in the centrifugal balance chamber to a position not overlapping the friction plates in the axial direction and being closer to the torque converter than the friction plates in the axial direction; and
a cylindrical member supporting the input shaft inserted thereinto, and extending in the axial direction, wherein
the drum is in a bottomed cylindrical shape,
a bottom of the drum is located closer to the torque converter than the friction plates in the axial direction, and
the discharge section includes an oil passage formed in the cylindrical member and extending in the axial direction, and discharges the hydraulic oil in the centrifugal balance chamber from the centrifugal balance chamber to a space between the bottom of the drum and the torque converter in a transmission case via the oil passage.

8. The automatic transmission of claim 7 , wherein
another drum different from the drum is provided between the drum and the torque converter, and constitutes another frictional engagement element different from the frictional engagement element,
said another drum is in a bottomed cylindrical shape,
a bottom of said another drum is located closer to the torque converter than friction plates of said another frictional engagement element in the axial direction, and
the discharge section discharges the hydraulic oil in the centrifugal balance chamber from the centrifugal balance chamber to a space between the bottom of said another drum and the torque converter in the transmission case via the oil passage.

9. The automatic transmission of claim 8 , further comprising:
a seal plate facing the piston in the axial direction such that the centrifugal balance chamber is located between the seal plate and the piston; and
a sleeve externally fitted to the cylindrical member, connected to the input shaft, and supporting an inner circumference of the seal plate at an outer circumference thereof, wherein
a substantially annular space is formed at an end of the cylindrical member at a non-torque converter side in the axial direction to be surrounded by the end of the cylindrical member, the input shaft, and the sleeve, and to communicate with the oil passage,
a through-hole is formed in the sleeve to connect the substantially annular space to the centrifugal balance chamber, and to extend in the radial direction, and
the sleeve is welded to the input shaft to reduce leakage of the hydraulic oil toward the friction plates, which flows from the centrifugal balance chamber to the oil passage via the substantially annular space.

10. The automatic transmission of claim 7 , wherein
a cover member and another drum are provided between the drum and the torque converter such that the cover member is closer to the torque converter than said another drum,
the cover member is adjacent to an end of the transmission case at the torque converter in the axial direction,
said another drum is different from the drum, and constitutes another frictional engagement element different from the frictional engagement element,
said another drum is in a bottomed cylindrical shape,
a bottom of said another drum is located closer to the torque converter than friction plates of said another frictional engagement element in the axial direction, and
the discharge section discharges the hydraulic oil in the centrifugal balance chamber from the centrifugal balance chamber to a space between the bottom of said another drum and the cover member in the transmission case via the oil passage.

11. The automatic transmission of claim 10 , further comprising:
a seal plate facing the pisto

Assignees

• Nakashima Kyosei
• Marusue Toshihisa
• Ueda Kensuke
• Sasaki Masanori
• Fujikawa Masamichi
• Mazda Motor

Inventors

• Nakashima Kyosei
• Marusue Toshihisa
• Ueda Kensuke
• Sasaki Masanori
• Fujikawa Masamichi

Classifications

• F16D25/12

  Details not specific to one of the before-mentioned types · CPC title

• F16D2048/0224

  Details of conduits, connectors or the adaptors therefor specially adapted for clutch control · CPC title

• F16D25/123

  in view of cooling and lubrication · CPC title

• Y02T10/76

  Cross-Sectional Technologies · mapped topic

• F16D2500/5104

  Preventing failures · CPC title