Abstract: In a transmission case mounted on a FF type vehicle, the transmission case includes a resin side cover formed at a front side of the vehicle. The resin side cover constitutes a vehicle front side surface section of an oil storage section configured to store oil in the transmission case, and includes a protrusion disposed above an oil surface of the oil stored in the oil storage section and protruding toward the front side of the vehicle to constitute the foremost section of the transmission case and a fragile section disposed between the protrusion and the oil surface of the oil and extending transversely in a lateral direction.

Abstract: In a transmission case mounted on a FF type vehicle, the transmission case includes a resin side cover formed at a front side of the vehicle. The resin side cover constitutes a vehicle front side surface section of an oil storage section configured to store oil in the transmission case, and includes a protrusion disposed above an oil surface of the oil stored in the oil storage section and protruding toward the front side of the vehicle to constitute the foremost section of the transmission case and a fragile section disposed between the protrusion and the oil surface of the oil and extending transversely in a lateral direction.

Abstract: A sealing device that hermetically seals a gap between a first member and a second member that is reciprocally movable with respect to the first member. The sealing device seals liquid supplied into a pressurizing chamber surrounded by the first member and the second member. The sealing device includes a seal member that is attached to the second member. The seal member slides relative to the first member while being in contact with the first member. The seal member includes a base portion and a protruding portion. The protruding portion protrudes from the base portion toward the first member to separate the first member from the base portion. After the liquid is supplied into the pressurizing chamber to fill the pressurizing chamber with the liquid, the protruding portion elastically deforms to bring the base portion into close contact with the first member.

Abstract: In an embodiment of the present invention, a piston apparatus of an automatic transmission includes a piston member capable of moving in the axial direction of the rotation shaft, and a hydraulic chamber, and has been configured so that the piston member moves in the axial direction due to pressure in the hydraulic chamber. The piston member includes a cylinder part that extends in the axial direction and to which pressure in the hydraulic chamber is transmitted, a pressing part that extends in the radial direction and presses against a friction engaging element of the automatic transmission, and a connecting part that connects the cylinder part and the pressing part and, with respect to the axial direction, is offset from the pressing part in a direction of separation from the friction engaging element. Also, the axial direction offset amount of the connecting part from the pressing part of the piston member has been set larger than the stroke amount of the piston member.

Abstract: The friction engagement apparatus comprises a case forming part of a power transmission apparatus, a plurality of friction plates splined to the case, a plurality of friction plates splined to a rotation element, an annular piston having a cylindrical wall portion imparting the urging pressure to the friction plates, an urging device having a return spring intervening between the case and the piston to urge the piston in one axial direction, the cylindrical wall portion having a first pressure receiving section formed with a cut-off recession, and a second pressure receiving section formed with no cut-off recession, and the return spring being coaxially arranged with the piston and having a bending stiffness in the axial direction with respect to a circumferential unit length, the bending stiffness in the first pressure receiving section being larger than the bending stiffness in the second pressure receiving section.

Abstract: In an embodiment of the present invention, a piston apparatus of an automatic transmission includes a piston member capable of moving in the axial direction of the rotation shaft, and a hydraulic chamber, and has been configured so that the piston member moves in the axial direction due to pressure in the hydraulic chamber. The piston member includes a cylinder part that extends in the axial direction and to which pressure in the hydraulic chamber is transmitted, a pressing part that extends in the radial direction and presses against a friction engaging element of the automatic transmission, and a connecting part that connects the cylinder part and the pressing part and, with respect to the axial direction, is offset from the pressing part in a direction of separation from the friction engaging element. Also, the axial direction offset amount of the connecting part from the pressing part of the piston member has been set larger than the stroke amount of the piston member.

Abstract: {Problem} To provide a friction engagement apparatus for effectively restraining a piston from being deformed with a cut-off recession formed in the piston to prevent the piston from interfering with other neighboring members {Problem Solving Means} The friction engagement apparatus comprises a case 11 forming part of a power transmission apparatus, a plurality of friction plates 12 splined to the case 11, a plurality of friction plates 14 splined to a rotation element 13, an annular piston 15 having a cylindrical wall portion 15b imparting the urging pressure to the friction plates 12, 14, urging means 17 having a return spring 18 intervening between the case 11 and the piston 15 to urge the piston 15 in one axial direction, the cylindrical wall portion 15b having a first pressure receiving section A1 formed with a cut-off recession, and a second pressure receiving section A2 formed with no cut-off recession, and the return spring 18 being coaxially arranged with the piston 15 and having a bending stiffness

Abstract: A sealing device that hermetically seals a gap between a first member and a second member that is reciprocally movable with respect to the first member. The sealing device seals liquid supplied into a pressurizing chamber surrounded by the first member and the second member. The sealing device includes a seal member that is attached to the second member. The seal member slides relative to the first member while being in contact with the first member. The seal member includes a base portion and a protruding portion. The protruding portion protrudes from the base portion toward the first member to separate the first member from the base portion. After the liquid is supplied into the pressurizing chamber to fill the pressurizing chamber with the liquid, the protruding portion elastically deforms to bring the base portion into close contact with the first member.