JPH062066Y2 - Gear train structure of automatic transmission - Google Patents

Description

The present invention relates to a gear train structure of an automatic transmission having a planetary gear.

2. Description of the Related Art Generally, an automatic transmission is provided with two sets of planetary gears, and the coupling relationship between the constituent gears of these planetary gears is a clutch or band brake that is engaged and released by hydraulic pressure supplied from a hydraulic pressure control circuit. Various gears can be obtained by switching the friction elements. For example, as a conventional automatic transmission, NISSAN Service Weekly Report No. 49
No. 1 (issued in October 1983), page III-7. In this automatic transmission, an input shaft and an output shaft are arranged coaxially, and a front planetary gear and a rear planetary gear are arranged as the two sets of planetary gears on the outer circumference of the output shaft. Then, examples of the friction element include a low clutch and a low and reverse brake. The low clutch is provided between the planet carrier of the front planetary gears and the internal gear of the rear planetary gears. Specifically, the low clutch is surrounded by the outer circumferences of the front and rear planetary gears. The housing is provided with a drum whose one end is rotatably supported in a cantilever manner, and the planet carrier is spline-fitted to the drum so that the rotation of the planet carrier is transmitted to the drum. The clutch plate of the low clutch is provided between the inner periphery and the outer periphery of the internal gear of the rear planetary gear. At the 1st, 2nd, and 3rd speeds, the low clutch is engaged so that the planet carrier and the internal gear are integrally coupled.

Further, the low and reverse brake is used at the time of reverse and at the time of fixing the first speed of the "I" range, and fixes the planet carrier of the front planetary gear to the mission housing side. In the first gear, the rotation of the internal gear of the rear planetary gear is restricted in one direction to reduce the rotation of the planet carrier of the rear planetary gear and output the rotation. The one-way restriction of the rotation of the ring gear is performed by a one-way clutch.

However, in the conventional gear train of the automatic transmission, the clutch plate of the low-and-reverse brake for fixing the planet carrier of the front planetary gear to the mission housing side has a low clutch inside. The one-way clutch, which is provided between the outer periphery of the drum provided with the clutch plate and the mission housing, and which regulates the direction of rotation of the internal gear of the rear planetary gear at the first speed, is connected to the outer periphery of the planet carrier of the front planetary gear. It is designed to be provided between the transmission and the housing.

Therefore, the drum is supported in a cantilevered manner on the transmission housing as described above, and the clutch plate of the low and reverse brake is provided on the outer periphery of the drum, so that the peripheral weight associated with the drum is increased. I will end up.
Therefore, the rotation stability of the drum is deteriorated, and particularly in recent years, in a vehicle equipped with an engine having an increased output function such as a twin cam, the rotation of the gear train is further increased and the rotation stability of the drum is improved. It becomes a problem. Further, the clutch plate of the low and reverse brake is provided on the outer periphery of the drum, and the one-way clutch is also provided on the outer peripheral portion of the planet carrier of the front planetary gear. Therefore, these clutch plates and the one-way clutch have a significantly large diameter. Inevitably, the clutch piston for engaging and disengaging the clutch plate is increased in diameter, and the weight of the automatic transmission is increased.

Therefore, in the present invention, a friction element or a one-way clutch disposed on the outer peripheral portion of a gear train constituent member such as a drum or a planet carrier can be laid out in series in the axial direction with respect to the drum to thereby realize the friction. An object of the present invention is to provide a gear train structure of an automatic transmission that can reduce the diameter of an element or a one-way clutch.

In order to achieve such an object, in the gear train structure of the automatic transmission according to the present invention, an axial direction is provided on the outer periphery of a rotary shaft composed of an input shaft and an output shaft arranged coaxially. It is provided between two sets of planet gears arranged side by side, a drum arranged so as to surround the planet gears from the planet carrier of one of the planet gears, and the inside of the drum and the internal gear of the other planet gear. First to be
In an automatic transmission including a friction element, a second friction element and a one-way clutch that are provided between the drum and the mission housing, a tubular fixing that is fixed to the mission housing and surrounds the rotary shaft. With a shaft,
One end of the drum is rotatably supported on the fixed shaft, and an annular projecting member is integrally provided from the outside of the drum between the fixed shaft and the mission housing, and between the projecting member and the mission housing. Is provided with either the second friction element or the one-way clutch, and the other of the second friction element or the one-way clutch is provided between the protruding member and the fixed shaft.

In the gear train structure of the automatic transmission according to the present invention having the above-described structure, the protruding member integrally provided from the drum is arranged between the fixed shaft surrounding the rotating shaft and the transmission housing. The space between the installation member and the transmission housing and the space between the projection member and the fixed shaft that is integral with the transmission housing are arranged in series in the axial direction with respect to the drum. Therefore, the second friction element and The one-way clutch is similarly arranged in series in the axial direction with respect to the drum. Therefore, it is not necessary to provide the second friction element and the one-way clutch on the outer circumference of the drum, and it is possible to reduce the diameters of these friction element and one-way clutch.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

That is, FIG. 1 shows an embodiment of an automatic transmission 10 using the gear train structure of the present invention, in which 12 is a mission housing, 14 is a rotation shaft composed of an input shaft 2 and an output shaft 6 arranged coaxially with each other. It is an axis. Two sets of planetary gears, a front planetary gear 4 and a rear planetary gear 5, are provided on the outer circumference of the input shaft 2 in the axial front-rear direction (left-right direction in the drawing), and the meshing relationship of these planetary gears is fastened by various friction elements. ，
By appropriately combining by releasing, the changed engine rotation is transmitted to the output shaft 6.

FIG. 2 shows a schematic diagram of a gear train of the automatic transmission, which includes a torque converter 3 for transmitting rotation from the engine output shaft 1 to an input shaft 2, a front planetary gear 4, a rear planetary gear 5, an output shaft 6, And the various friction elements.

The torque converter 3 is driven by the engine output shaft 1 and is also used for driving the oil pump 0 / P. A pump impeller 3P, which is fluid-driven by an internal working fluid by the pump impeller, and transmits power to the input shaft 2. Runner 3T and one-way clutch 7
A stator 3S that is placed on a fixed shaft via the stator 3S to increase the torque to the turbine runner 3T, and a lockup clutch 3L is added to the stator 3S to form a normal lockup torque converter.

The front planetary gear 4 includes a sun gear 4S, an internal gear 4I, a pinion 4P meshing with these, and a planet carrier 4C rotatably supporting the pinion 4P.
And the rear planetary gear 5 is also a simple planetary gear set including a sun gear 5S, an internal gear 5I, a pinion 5P and a planet carrier 5C.

Next, the various friction elements will be described. The carrier 4C can be appropriately connected to the input shaft 2 through the high clutch H / C, the sun gear 4S can be appropriately fixed by the band brake B / B, and can be appropriately connected to the input shaft 2 by the reverse clutch R / C. To do. Carrier 4C is a multi-plate low reverse brake LR / B.
It is possible to fix it properly by using the low one way clutch LO / C and reverse rotation (rotation in the opposite direction to the engine)
Prevent. The internal gear 4I is integrally coupled to the carrier 5C and drivingly coupled to the output shaft 6, and the sun gear 5S is coupled to the input shaft 2. The internal gear 5I is appropriately connected to the carrier 4 via the overrun clutch OR / C.
Besides being connectable to C, it is correlated with the carrier 4C via the forward one-way clutch FO / C and the forward clutch F / C. Forward one-way clutch F
O / C is the reverse direction of the internal gear 5I when the forward clutch F / C is engaged (direction opposite to engine rotation).
In, the carrier 4C is bound.

High clutch H / C, reverse clutch R / C, low reverse brake LR / B, overrun clutch OR /
C, forward clutch F / C and band brake B
Each / B is actuated by the supply of hydraulic pressure to perform the above-mentioned appropriate coupling and fixing.

The gear train includes friction elements B / B, H / C, F /
By operating C, OR / C, LR / C, and R / C in various combinations as shown in the following table, the friction element FO /
Coupled with the appropriate operation of C and LO / C, the planetary gear sets 4, 5
The rotational speed of the output side 6 with respect to the rotational speed of the input shaft 2 can be changed by changing the rotational states of the elements constituting the above, and as shown in the following table, it is possible to obtain a forward speed 4 speed reverse 1 speed gear stage. You can do it. In the table below, ○ indicates the operation (hydraulic inflow), while ☆ indicates the friction element that should be activated when engine braking is required.
Then, while the overrun clutch OR / C is operated as indicated by a star, the forward one-way clutch FO / C juxtaposed thereto is deactivated, and the parallel one-way clutch FO / C is juxtaposed thereto while the low reverse brake LR / B is operated. Of course, the row one way clutch LO / C is deactivated.

By the way, in FIG. 1, 16 is a forward clutch as a first friction element, 18 is an overrun clutch, and 19
Is a low reverse brake as a second friction element.
The forward clutch 16 includes a drum 22 that is spline-coupled with the planet carrier 4C of the front planetary gear 4 and rotates integrally with the planet carrier 4 and a rear planetary gear 5.
It is provided between the internal gear 5I and the first shell 26 which is connected via the forward one-way clutch 24. On the other hand, the overrun clutch 18 is
It is provided between the drum 20 and a second shell 28 connected to the internal gear 5I of the rear planetary gear 5. The drum 20 is formed in a tubular shape surrounding the outer sides of the front and rear planetary gears 4 and 5, and is fitted and supported by a fixed shaft 30 described later. That is,
Reference numeral 30 denotes a fixed shaft, which is formed in a cylindrical shape surrounding the outer circumference of the output shaft 14b of the fixed shaft 30, and is fixedly mounted on the mission housing 12 via a rear end (right end in the drawing) bolt B. The drum 20 is provided around the fixed shaft 30.
The boss portion 32 is rotatably fitted through the first bearing 34, and the first piston 36 of the forward clutch 16 and the second piston 38 of the overrun clutch 18 slide on the outer periphery of the boss portion 32. It is movably fitted. The first piston 36 is fitted to the inner circumference of the drum 20, and the first piston 36 is fitted between the drum 20 and the first piston 36 to form a first
A cylinder chamber 40 is formed, the second piston 38 is fitted to the inner circumference of the first piston 36, and a second cylinder chamber 42 is formed between the first and second pistons 36, 38. Has become. The first cylinder chamber 40
Is supplied with hydraulic fluid from a first passage 44 formed inside the fixed shaft 30 via a communication hole 46, and the second cylinder chamber 42 is also similarly supplied with the fixed shaft 30. The hydraulic fluid is supplied from the second passage 48 formed in the above through the communication hole 50.

By the way, on the outside of the right end of the drum 20, an annular projecting member 52 surrounding the outer periphery of the fixed shaft 30 is provided.
It is extended in the central axis extension direction of 0. A low reverse brake 19 as the second friction element is provided between the outer circumference of the projecting member 52 and the inner circumference of the transmission housing 12, and the low reverse brake 19 is provided between the projecting member 52 and the fixed shaft 30. Is provided with a rowan way clutch 54. The piston 56 of the low reverse brake 19
Is a cylinder 5 formed in the mission housing 12.
8 is slidably fitted into the third cylinder chamber 60 formed between the cylinder 58 and the piston 56, and the working fluid is supplied through a passage (not shown) formed in the transmission housing 12. It is supposed to be done. On the other hand, the low one-way clutch 54 is configured by using the fixed shaft 30 also as an inner race and the protruding member 52 also as an outer race, and disposing a roller 54a between the fixed shaft 30 and the protruding member 52. ing.

In the gear train structure of the automatic transmission according to the present embodiment having the above structure, the drum 20 is replaced by the transmission housing 1.
The low reverse brake 19 for connecting and disconnecting to the second side is provided between the projecting member 52 extending from the rear end of the drum 20 and the mission housing 12, and the diameter of the projecting member 52 is the same as the above. Since it can be determined regardless of the diameter of the drum 20, the diameter of the low reverse brake 19 can be reduced by forming the outer diameter of the protruding member 52 to be smaller than the outer diameter of the drum 20 as shown in this embodiment. . Further, since the diameter of the low reverse brake 19 can be reduced, the diameter of the transmission housing 12 can be reduced. Further, by providing the rowan way clutch 54 on the inner diameter side of the projecting member 52, the rowan way clutch 54 can be further reduced in diameter. Therefore, the diameters of the low reverse brake 19 and the low one-way clutch 54 are reduced, and the diameter of the transmission housing 12 itself can be reduced, whereby the weight of the automatic transmission 10 can be reduced.

Since the low reverse brake 19 and the low one-way clutch 54 can be arranged in series in the axial direction with respect to the drum 20 by providing the projecting member 52 in this manner, other inevitable substances are attached to the outer periphery of the drum 20. Can be prevented, and the peripheral weight of the drum 20 can be reduced. Therefore, the rotation stability of the drum 20 can be significantly improved.

By the way, in the present embodiment, a large diameter portion 30a is formed at the end of the fixed shaft 30 on the side where it is attached to the mission housing 12, and the low one way clutch 54 is provided in this large diameter portion 30a. The projecting member 52 is supported on the large diameter portion 30a via a second bearing 62. Further, a step portion 30b formed between the tip portion of the fixed shaft 30 and the large diameter portion 30a, and a boss portion 32 of the drum 20.
A thrust bearing 64 is provided between the ends. Therefore,
The fall of the drum 20 is caused by the boss portion 32 and the fixed shaft 30.
It is supported by the first bearing 34 provided therebetween, the second bearing 62 between the protruding member 52 and the large diameter portion 30a, and the thrust bearing 64. In addition to this, the rotational stability of the drum 20 is further increased.

In this embodiment, the low reverse brake 19 is provided between the projecting member 52 and the transmission housing 12, and the low one-way clutch 54 is provided between the projecting member 52 and the fixed shaft 30. However, the present invention is not limited to this, and the row-one-way clutch 54 is provided between the projecting member 52 and the transmission housing 12 with the locking direction of rotation reversed, and further, the projecting member 52 and the fixed shaft. Three
A low reverse brake 19 may be provided between the low reverse brake 19 and zero.

According to the gear train structure of the automatic transmission of the present invention having the above-described configuration, the fixed shaft fixed to the mission housing surrounding the rotary shaft and the mission housing are integrally formed from the outside of the drum. The second friction element and the one-way clutch are provided between the projecting member and the transmission housing and between the projecting member and the fixed shaft. The element and the one-way clutch can be arranged axially in series with respect to the drum. Therefore, it is possible to prevent the inclusion of frictional elements and the like on the outer periphery of the drum, and it is possible to significantly improve the rotational stability by reducing the weight of the peripheral portion of the drum. Also, the second
By reducing the diameter of the friction element and the projecting member provided with the one-way clutch, the diameter of the second friction element and the one-way clutch, and thus the mission housing itself, can be reduced, and the weight of the automatic transmission is significantly reduced. It has various excellent effects.

[Brief description of drawings]

FIG. 1 is a fragmentary sectional view showing an embodiment of an automatic transmission using a gear train structure of the present invention, and FIG. 2 is a schematic view showing an entire gear train of the automatic transmission of FIG. 2 ... Input shaft, 3 ... Torque converter, 4 ...
Front planetary gear, 5 ... Rear planetary gear, 6 ... Output shaft, 10 ... Automatic transmission, 1
2 ... Mission housing, 14 ... Rotating shaft, 16 ... Forward clutch (first friction element), 18 ... Overrun clutch, 19 ... Low reverse brake (second friction element), 20 ... Drum, 30 ... Fixed shaft, 52 ... Projecting member,
54 ... Low one-way clutch (one-way clutch).

Claims (1)

[Scope of utility model registration request] 1. A set of two planetary gears axially juxtaposed on the outer periphery of a rotary shaft composed of an input shaft and an output shaft coaxially arranged, and a planet carrier of one planetary gear from the outside of the planetary gear. A drum arranged surrounding the drum, a first friction element provided between the inside of the drum and the internal gear of the other planetary gear, a second friction element provided between the drum and the mission housing, and In an automatic transmission including a one-way clutch, a cylindrical fixed shaft that surrounds the rotary shaft and is fixedly installed in a transmission housing is provided, and one end of the drum is rotatably supported by the fixed shaft, An annular projecting member is integrally provided from the outside of the drum between the fixed shaft and the mission housing. Wherein between the ring second
One of a friction element and the one-way clutch is provided, and the other of the second friction element and the one-way clutch is provided between the protruding member and the fixed shaft. Construction.