Abstract: An automatic transmission that includes an input shaft; an output shaft; and a speed change mechanism portion that shifts a rotation of the input shaft to be transmitted to the output shaft, wherein: the output shaft has a spline formed in a range in which the output shaft fits in a power transmission shaft included in a vehicle, and n-stage (n is an integer of at least 2) chamfering is performed on a larger diameter portion of the spline.

Abstract: An automatic transmission in which first to third clutches which can couple an input shaft to a first element of a first multiple planetary gear set and second and fourth elements of the second multiple planetary gear set, respectively, are arranged on a front side of the first multiple planetary gear set. Thus, it is possible to prevent a situation in which disengaging of the third clutch in the first speed causes the fourth element of the first multiple planetary gear set to rotate in reverse and generate a large relative rotation with the first element.

Abstract: An automatic transmission is provided having appropriately spaced gear ratios for eight forward speeds to be capable of obtaining a shift feeling in all of the eight speeds, and is reduced in size and weight. Rotation of an input shaft is transmitted to an output shaft at a speed selected from a plurality of shift speeds by first and second clutches selectively transmitting the rotation of the input shaft to first and second compound planetary gears, and by first to fourth brakes selectively fixing each element of the first and second compound planetary gears, the first compound planetary gear includes first and second sun gears, a common carrier rotatably supporting a long pinion and a pinion, and a common ring gear that meshes with the first sun gear through the long pinion or the pinion and also meshes with the second sun gear through the long pinion and the pinion.

Abstract: In single pinion planetary gear mechanisms, a second sun gear is linked to an input shaft in a power-transmissible manner, a first sun gear is linked to a third control brake, and a first carrier and a second ring gear which are linked to each other are linked to a first control brake. In single pinion planetary gear mechanisms, a third sun gear and a fourth sun gear which are linked to each other are linked to the input shaft disengageably by a first control clutch, and a third ring gear and a fourth ring gear are linked to a second control brake and a fourth control brake, respectively. Furthermore, in the single pinion planetary gear mechanisms, a third carrier is linked to the input shaft disengageably by a second control clutch and a fourth carrier is linked to an output shaft.

Abstract: To provide an automatic transmission apparatus for forward 8-speed, which keeps a transmission gear ratio step in good balance. The apparatus includes: a first planetary gear device PG0 having a ring gear R0 connected to an input shaft; a second planetary gear device PG1 having a carrier C1 connected to a carrier C0 of the first planetary gear device, and a sun gear S1 connected to R0; a third planetary gear device PG2 having a ring gear R2 connected to C1; a fourth planetary gear device PG3 having a sun gear S3 connected to a sun gear S2 of the third planetary gear device; a first clutch C-1 that selectively connects S2 to the input shaft; a second clutch C-2 that selectively connects C2 to the input shaft; a first brake B-1 that selectively regulates the rotation of R0; a second brake B-2 that selectively regulates the rotation of R2; a third brake B-3 that selectively regulates the rotation of S0; and a fourth brake B-4 that selectively regulates the rotation of R3.

Abstract: An automatic transmission is provided that has appropriately spaced gear ratios for eight forward speeds to be capable of obtaining a shift feeling in all of the eight speeds, and that can be reduced in size and weight. In the automatic transmission that transmits rotation of an input shaft to an output shaft at a speed selected from a plurality of shift speeds by first and second clutches selectively transmitting the rotation of the input shaft to first and second compound planetary gears, and by first to fourth brakes selectively fixing each element of the first and second compound planetary gears, the first compound planetary gear includes first and second sun gears, a common carrier rotatably supporting a long pinion and a pinion, and a common ring gear that meshes with the first sun gear through the long pinion or the pinion and also meshes with the second sun gear through the long pinion and the pinion.

Abstract: An automatic transmission in which first to third clutches which can couple an input shaft to a first element of a first multiple planetary gear set and second and fourth elements of the second multiple planetary gear set, respectively, are arranged on a front side of the first multiple planetary gear set. Thus, it is possible to prevent a situation in which disengaging of the third clutch in the first speed causes the fourth element of the first multiple planetary gear set to rotate in reverse and generate a large relative rotation with the first element.

Abstract: An oil pump includes a pump cover covering a recess in a side face of a pump body to form a gear compartment therebetween. A drive gear and a rotatably driven gear are meshed and mounted in the gear compartment. Working spaces R are formed by the engagement of the meshed gear teeth. Discharge ports are formed in both the pump body and the pump cover in communication with the gear compartment. A notch is formed in the pump body at the bottom of the gear compartment and extends from the front end of the discharge port in the pump body to the rear end of a discharge area for the working spaces. Another notch is formed in the inner side face of the pump cover, and extends from the front end of the discharge port in the cover to the rear end of the discharge area.

Abstract: An oil pump includes a pump cover covering a recess in a side face of a pump body to form a gear compartment therebetween. A drive gear and a rotatably driven gear are meshed and mounted in the gear compartment. Working spaces R are formed by the engagement of the meshed gear teeth. Discharge ports are formed in both the pump body and the pump cover in communication with the gear compartment. A notch is formed in the pump body at the bottom of the gear compartment and extends from the front end of the discharge port in the pump body to the rear end of a discharge area for the working spaces. Another notch is formed in the inner side face of the pump cover, and extends from the front end of the discharge port in the cover to the rear end of the discharge area.

Abstract: An automatic transmission that includes an input shaft; an output shaft; and a speed change mechanism portion that shifts a rotation of the input shaft to be transmitted to the output shaft, wherein: the output shaft has a spline formed in a range in which the output shaft fits in a power transmission shaft included in a vehicle, and n-stage (n is an integer of at least 2) chamfering is performed on a larger diameter portion of the spline.

Abstract: An automatic transmission having a second ring gear of planetary gear mechanisms and is connected to an input shaft so as to be able to transmit power thereto, and a first sun gear and a second sun gear, and a first carrier that are connected to each other are in turn connected to a third control brake and a first control brake, respectively. A third sun gear and a fourth sun gear of the planetary gear mechanisms are connected to each other, and are in turn detachably connected to the input shaft 14 by a first control clutch. A third ring gear R2 and a fourth ring gear R3 are connected to a second control brake and a fourth control brake, respectively. Furthermore, a third carriers is detachably connected to the input shaft by a second control clutch, and a fourth carrier is connected to an output shaft.

Abstract: [Object] To provide an automatic transmission capable of providing a sufficient feeling of acceleration with a clear shift feeling at the time of shifting with acceleration by properly allocating step ratios between shift stages. [Means for Solution] In single pinion planetary gear mechanisms 21 and 22, a second sun gear S1 is linked to an input shaft 14 in a power-transmissible manner, a first sun gear S0 is linked to a third control brake B-3, and a first carrier C0 and a second ring gear R1 which are linked to each other are linked to a first control brake B-1. In single pinion planetary gear mechanisms 23 and 24, a third sun gear S2 and a fourth sun gear S3 which are linked to each other are linked to the input shaft 14 disengageably by a first control clutch C-1, and a third ring gear R2 and a fourth ring gear R3 are linked to a second control brake B-2 and a fourth control brake B-4, respectively.

Abstract: [Task] To provide an automatic transmission apparatus for forward 8-speed, which keeps a transmission gear ratio step in good balance. [Solution] The apparatus includes: a first planetary gear device PG0 having a ring gear R0 connected to an input shaft; a second planetary gear device PG1 having a carrier C1 connected to a carrier C0 of the first planetary gear device, and a sun gear S1 connected to R0; a third planetary gear device PG2 having a ring gear R2 connected to C1; a fourth planetary gear device PG3 having a sun gear S3 connected to a sun gear S2 of the third planetary gear device; a first clutch C-1 that selectively connects S2 to the input shaft; a second clutch C-2 that selectively connects C2 to the input shaft; a first brake B-1 that selectively regulates the rotation of R0; a second brake B-2 that selectively regulates the rotation of R2; a third brake B-3 that selectively regulates the rotation of S0; and a fourth brake B-4 that selectively regulates the rotation of R3.

Abstract: A parking control mechanism to prevent generation of noise and shock when a parking range is released after a vehicle has been parked so that a driver does not feel uncomfortable. A parking apparatus of an automatic transmission has a parking gear; a parking pole swingably disposed and provided with a claw arranged to selectively be engaged with a tooth space of the parking gear; an engagement inhibition device movably disposed and arranged to be moved to an inhibition position for inhibiting engagement between the claw and the tooth space and to an inhibition release position for releasing the inhibition of the engagement; and an engagement inhibition release device for moving the engagement inhibition device to the inhibition release position in synchronization with the rotation of the parking gear. After a residual torque existing between the parking gear and drive wheels has been released, the claw and the tooth space are engaged with each other.

Abstract: An automatic transmission including at least one rotary member; a rotary member enclosure enclosing the rotary member; and an oil reservoir arranged below the rotary member enclosure for collecting and reserving the oil. An oil separator is located facing the outer circumference of the rotary member for separating the oil adhering to the rotary member. Because the amount of oil left on the surface of the rotary member is reduced, the amount of oil recovered in the oil reservoir is accordingly increased and the level of the oil surface in the oil reservoir is prevented from falling.