Mazda Motor Corporation

Yasuhiro Ogauchi

Shinya Kamada

Tatsuhiko Iwasaki

Masaru Nakagishi

Akihiro Uchida

A power transmission system for a hybrid vehicle includes planetary gear mechanisms that couple an internal combustion engine, an electric motor, and a transmission, and has a brake that engages and disengages the internal combustion engine with and from a housing. The planetary gear mechanisms have a first rotary element, a second rotary element, a third rotary element, and a fourth rotary element. Any one of the internal combustion engine, the electric motor, and the transmission is connected to a respective one of the first rotary element, the second rotary element, and the third rotary element. The fourth rotary element is configured as an inertial member for suppressing transmission of a torque fluctuation of the internal combustion engine to the transmission side.

Power transmission system for hybrid vehicle

To provide a drive system for a hybrid vehicle capable of suppressing energy loss by slip control at a start of an internal combustion engine during electric vehicle (EV) travel, a power transmission system for the hybrid vehicle is configured to couple an internal combustion engine, an electric motor, and a transmission by planetary gear mechanisms, has a brake that engages and disengages the internal combustion engine with and from a case, engages the brake during EV travel in which only the electric motor is used as a drive source, and is configured to start the internal combustion engine by disengaging the brake at the time of switching from the EV travel to hybrid vehicle (HEV) travel in which the internal combustion engine and the electric motor are used as drive sources.

A transmission brake device includes: a friction plate set configured such that a plurality of rotation-side friction plates; an engaging piston disposed on an axial side of the friction plate set; a clearance adjustment piston disposed on a side of the engaging piston opposite to the friction plate set; a clearance adjustment hydraulic chamber configured to move the clearance adjustment piston; and an engaging hydraulic chamber configured to move the engaging piston; a biasing member disposed between each adjacent pair of the fixed-side friction plates, the biasing member being configured to bias each adjacent pair of the fixed-side friction plates in directions away from each other. The biasing member distributes the clutch clearance in a gap between each adjacent pair of the fixed-side friction plates when a hydraulic pressure is supplied only to the clearance adjustment hydraulic chamber.

Transmission brake device

Disclosed is an automatic transmission () in which, of four planetary gear sets (PG, PG, PG, and PG), two planetary gear sets (PG, PG) are arranged such that one of the two planetary gear sets (PG, PG) is disposed radially inward from the other to form a two-stage planetary gear set (PGt). One planetary gear set (PG) of the other two planetary gear sets functions as a specified planetary gear set disposed adjacent to the two-stage planetary gear set in a transmission axial direction. A carrier (C) of the radially outer planetary gear set (PG) of the two-stage planetary gear set, a carrier (C) of the specified planetary gear set, and an output section (an output gear ()) are always engaged together.

Automatic transmission

A brake device of a transmission is provided. The brake device includes a friction plate set including fixed friction plates and rotatable friction plates alternately disposed with each other, an engaging piston, and a clearance adjusting piston. A clearance adjusting hydraulic chamber is formed on a side of the clearance adjusting piston opposite to the friction plate set, and a concave portion is formed in a surface of the clearance adjusting piston on a friction plate set side. A base part of the engaging piston on a side opposite to the friction plate set is slidably fitted into the concave portion of the clearance adjusting piston and an engaging hydraulic chamber is formed by the base part and the concave part.

Brake device of transmission

Disclosed herein is an automatic transmission () including first and second planetary gear sets (PL) and (PL). The first planetary gear set (PL) has a first sun gear (S) to which power from a power source () is input via an input shaft (), and a first ring gear (R) engaged with a first brake (B). The second planetary gear set (PL) has a second ring gear (R) always engaged with a first carrier (C), a second sun gear (S) engaged with a second brake (B), and a second carrier (C) engaged with an output (output gear ()). The automatic transmission is configured to engage the first and second brakes in a first gear to allow the power from the power source to be transmitted to the output via the input shaft and the first and second planetary gear sets.

An automatic transmission is provided. The transmission includes clutches coaxially arranged in layers in a radial direction of the transmission. The transmission includes a piston provided to each clutch, the pistons being aligned in the radial direction on a same plane perpendicular to an axis of the transmission, without overlapping with each other in an axial view. The transmission includes a common rotational member having a wall, commonly used for the clutches, and disposed at a predetermined position of the transmission in an axial direction, wherein the wall is formed along the plane. The transmission includes operational hydraulic passages parallely arranged in the wall of the common rotational member in a circumferential direction of the transmission on the same plane perpendicular to the axis, each of the operational hydraulic passages communicating with one of operational hydraulic chambers of the respective clutches.

An automatic transmission () includes, in a transmission case (), an input shaft (), first to third planetary gear sets (PL-PL) of a single pinion type, a fourth planetary gear set (PL) of a double pinion type, five frictional engagement elements (CL, CL, and B-B), and outputs (). The outputs () are always engaged with a fourth ring gear (R).

An automatic transmission () includes a first planetary gear set (PL) of a double pinion type, second to fourth planetary gear sets (PL-PL) of a single pinion type, first to third clutches (CL-CL), and first and second brakes (Band B). A third carrier (C) and a fourth sun gear (S) are always coupled to an input (i.e., an input shaft ()). An output (i.e., an output gear ()) is always coupled to a fourth ring gear (R). A first carrier (C) is always coupled to a third sun gear (S). A second sun gear (S) is always coupled to a third ring gear (R). A first ring gear (R) is always coupled to a second ring gear (R).

An automatic transmission includes: an input shaft connected to a driving source; an output shaft provided coaxially with the input shaft and connected to a differential mechanism; double pinion type first and second planetary gear sets; single pinion type third and fourth planetary gear sets; first to third clutches each configured to connect and disconnect predetermined rotational elements of the planetary gear sets to and from each other; and first and second brakes configured to connect and disconnect a predetermined rotational element of the planetary gear set to and from a transmission case. When the first to third clutches are engaged, and the first and second brakes are released, an eighth gear stage whose reduction ratio is 1 is formed.

To simplify the hydraulic pressure supply passage to each clutch, an multistage automatic transmission comprises an input part and output part, three clutches, two brakes, and four planetary gear sets, where the first and fourth sets are of a single pinion type and the second and third of a double pinion type. The input and output parts and the planetary gear sets connect to each other and the clutches and brakes decouple components in such a way that enlargement as a whole of the transmission and the deterioration of the responsiveness of the shift control are controlled.

An automatic transmission () includes in a transmission case (), an input (an input shaft), an output (an output shaft), first to fourth planetary gear sets (PG, PG, PG, and PG) of a single pinion type, first to third clutches (CL-CL) engaging and disengaging predetermined rotating elements of the first to fourth planetary gear sets, a first brake (BR) engaging and disengaging a third ring gear (R) with and from the transmission case, and a second brake (BR) engaging and disengaging a first sun gear (S) and a fourth sun gear (S) with and from the transmission case. The input, the output, the planetary gear sets, the clutches, and the brakes are arranged coaxially with each other. The first, second, third, and fourth planetary gear sets are arranged in this order from one axial end to the other axial end of the automatic transmission.

An automatic transmission () includes an input shaft (), an output (an output shaft) arranged coaxially with the input shaft and engaged with a differential mechanism, first and second planetary gear sets (PGand PG) of a double pinion type, third and fourth planetary gear sets (PGand PG) of a single pinion type, first to third clutches (CL-CL) engaging and disengaging predetermined rotating elements of the first to fourth planetary gear sets, and first and second brakes (BRand BR) engaging and disengaging a second carrier (C) and a first carrier (C) from a transmission case (). A gear ratio of the automatic transmission is 1 in a sixth gear.

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Higashihiroshima, Japan

Yasuhiro Ogauchi