JPH10103384A - Automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the low oil temperature operation period of an automatic transmission. SOLUTION: An automatic transmission comprises frictional engaging elements 50 and 60 coupled to a rotary member 53 (63) on the drive side and a rotary member 56 (66) on the driven side; a hydraulic servo 3 and 4 to press the frictional engaging elements; and a circulation route for lubricating oil to lubricate the frictional engaging elements. Hydraulic servo cylinders 30 and 40 'are formed at a transmission case 10 to wrap a shifting mechanism M and comprises bearings 32 and 42 to transmit the press forces of the pistons 31 and 41 of the hydraulic servo as an axial force to a frictional engaging element; and reaction force members 56, 71, 16, S1 , 74, C1 , 75, S3 , 76, C3 , 19, 24, 25, 66, 14, and 59 are provided to transmit an axial force, transmitted to the frictional engaging element, to a transmission case 10. The coefficient of thermal expansion of a transmission case is set to a value higher than that of a reaction force member. During low oil temperature operation, the transmission case has an axial contraction amount higher than that of the reaction force member. This constitution decreases a clearance during release of the frictional engaging element, increases an amount of heat generated due to drag of lubrication oil, and promotes the increase of an oil temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, and more particularly to an automatic transmission in which a friction engagement element in a transmission mechanism is controlled by a stationary cylinder type non-rotating hydraulic servo provided in an automatic transmission case. .

[0002]

2. Description of the Related Art In general, an automatic transmission is provided with an automatic transmission hydraulic oil (A) that passes through various parts of the transmission mechanism for lubrication and cooling of the parts and transmission of torque in a torque converter.
TF). Hydraulic oil flowing through this circulation path prevents wear due to direct contact of the rotating members that constitute the mechanism, and increases in temperature due to the relative rotation of the rotating member boundaries of each part of the mechanism and the shear load caused by co-rotation with the member. Cooled by an oil cooler disposed in the return circuit of the circulation path, the cooling medium plays a role of a cooling medium for releasing heat in the transmission to the atmosphere. By such a circulation, the hydraulic oil is maintained within a predetermined temperature range (hereinafter, the oil temperature in this range is referred to as normal oil temperature), whereby the inside of the transmission is also maintained within the predetermined temperature range.

[0003]

Incidentally, the characteristics of the automatic transmission change under the influence of the temperature of the hydraulic oil. Therefore, as described above, the operating oil is maintained at the normal oil temperature, and assuming that the operating oil operates at the normal oil temperature, the desired lubrication and cooling effects can be obtained with the smallest possible amount of oil. In addition, each part of the mechanism that suppresses dragging and stirring of the oil is set. In particular, with respect to the friction engagement element in the transmission mechanism, by maintaining a predetermined clearance between the friction material disk and the separator plate at the time of disengagement in order to prevent a delay in engagement, the lubricating oil is reduced. A setting is made to suppress a decrease in transmission efficiency due to dragging.

[0004] However, at the beginning of the operation of the automatic transmission, the operating oil has dropped to about the outside air temperature, so that it must be operated at a temperature lower than the normal oil temperature. At such a low oil temperature, the viscosity of the oil becomes larger than at the normal oil temperature, and the flow resistance increases. Therefore, the responsiveness to the hydraulic control is reduced, which causes a shift shock due to an operation delay. In addition, the high viscosity increases the resistance caused by dragging and stirring of the oil by the rotating member, and lowers the transmission efficiency of the transmission mechanism.

[0005] Therefore, how to raise the operating oil temperature to the normal oil temperature at first becomes a problem. for that purpose,
Contrary to the above-mentioned suppression of oil temperature rise, dragging and stirring should be increased, but simply doing so would result in a breather due to a further increase in oil temperature after reaching normal oil temperature. As a new countermeasure to prevent the occurrence of blowing etc., measures such as increasing the oil cooler capacity are necessary, as well as measures for low oil temperature when the operating period is usually short, which is often short. Therefore, the transmission efficiency at the time of normal oil temperature is reduced. Therefore, to properly address these issues, low oil temperature and normal oil temperature
It is necessary to take measures to change the drag and agitation of the oil,
Such a measure requires an additional mechanism and control means for the mechanism, which leads to a complicated and large-sized mechanism, and thus is not always an effective measure.

[0006] The present invention has been devised in view of the above-mentioned circumstances, and without using any special additional mechanism or control means,
Utilizing the characteristics of the stationary cylinder type hydraulic servo configuration, by performing clearance management according to the temperature of the friction engagement element in the transmission mechanism, the oil temperature is quickly raised at low oil temperature,
A first general object is to provide an automatic transmission that can suppress an increase in oil temperature when the oil temperature reaches a normal oil temperature.

In the case of the above-described stationary cylinder type hydraulic servo configuration, a thrust force that changes the clearance of the friction engagement element may act depending on the configuration of the transmission mechanism. In that case, the effect of the clearance management based on the oil temperature as described above is weakened. Therefore, it is a second object of the present invention to eliminate the influence of such a thrust force even when the thrust force acts, and to obtain a configuration that makes the effect of the clearance management of the friction engagement element effective.

A third object of the present invention is to ensure the maximum amount of change in the clearance managed as described above.

When performing the above-described clearance management, the smaller the number of parts to be managed, the smaller the error. Accordingly, the present invention is directed to improving the management accuracy by reducing the number of members to be managed for clearance.
The purpose of.

A fifth object of the present invention is to further increase the oil temperature more quickly by associating the friction engagement element for performing the clearance management with a specific shift speed of the transmission mechanism. I do.

It is a sixth object of the present invention to realize the above clearance management without changing the material of each member constituting the automatic transmission to a special material.

Further, in order to effectively utilize the heat generated in the friction engagement element portion to raise the oil temperature of the entire lubricating oil, it is important to circulate the heated lubricating oil promptly throughout the transmission.
Therefore, a seventh object of the present invention is to further enhance the effect of the clearance management by promoting the circulation of the lubricating oil heated by the clearance management.

[0013]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention provides a frictional engagement element connected to a driving-side rotating member and a driven-side rotating member, and pressing the frictional engagement element. And a hydraulic servo that connects the two rotating members via a frictional engagement element and a circulation path for lubricating oil that lubricates the frictional engagement element, wherein the hydraulic servo cylinder includes a transmission mechanism. A bearing that is formed on a transmission case that is a fixed member that transmits the pressing force of the piston of the hydraulic servo to the friction engagement element as an axial force, and a transmission case that transmits the axial force transmitted to the friction engagement element. , And the thermal expansion coefficient of the transmission case is set to be larger than the thermal expansion coefficient of the reaction force member.

In order to achieve the second object, a pressing member is provided between the bearing and the frictional engagement element, and a return spring for pushing back the hydraulic servo piston is provided between the reaction force member and the pressing member. Configuration.

In order to achieve the third object, the transmission case has end walls at both ends sandwiching the transmission mechanism, a cylinder of the hydraulic servo is formed at one end wall, and a reaction member is provided with a frictional member. It is configured to be provided from the engagement element to the other end wall.

In order to achieve the fourth object, the reaction member is an input shaft of a transmission extending between both end walls of the transmission case.

In order to achieve the fifth object, the speed change mechanism achieves a plurality of shift speeds, and the frictional engagement element engages to achieve a low speed among the plurality of shift speeds. When the high-speed gear is achieved, it is released.

In order to achieve the sixth object, the automatic transmission case is made of an aluminum alloy, and the reaction member, the piston and the pressing member are made of steel.

In order to achieve the seventh object, the circulation path has a structure in which a lubricating oil passing through the friction engagement element is discharged to the outside of the friction engagement element.

[0020]

According to the present invention having the above structure,
When the frictional engagement element is released, the lubricating oil that lubricates the frictional engagement element is dragged by the relative rotation through a clearance formed between the frictional engagement elements that relatively rotate on the driving side and the driven side. At the time of low oil temperature, the transmission case side contracts more than the reaction member at a low oil temperature due to the thermal expansion coefficient between the transmission case and the reaction member. Narrow the clearance compared to times. This narrowing of the clearance increases the shearing force due to drag on the lubricating oil passing through it, increasing the calorific value and heating it at room temperature, and this heated lubricating oil circulates through the lubrication path of the transmission. By doing so, the oil temperature of the transmission as a whole also quickly rises. When the oil temperature rises, the temperature of the transmission case and the reaction force member also rises accordingly, so that the clearance in the friction engagement element becomes the desired clearance at normal oil temperature, and the friction engagement element The calorific value in the section also becomes a steady state value, and the rise in oil temperature can be suppressed. Thus, according to the present invention, the oil temperature can be quickly raised at a low oil temperature and an abnormal increase in the oil temperature can be suppressed at a normal oil temperature. The period of the warm state can be shortened, and the blowing of the breather due to overheating can be prevented.

Further, according to the second aspect of the present invention, the return spring is provided between the reaction member and the pressing member. As a result, it is possible to obtain a clearance change depending on the oil temperature change excluding the clearance change due to the action of the thrust force.

According to the third aspect of the present invention, the magnitude of the change in the clearance of the frictional engagement element due to the change in the oil temperature is such that the reaction force member is moved from the piston of the hydraulic servo to the transmission case by the axial force. The change in the distance between both end walls of the transmission case, which is the largest distance in the transmission, is reflected in the change in the clearance of the frictional engagement element in accordance with the distance to the contacting portion for transmitting the force. Thereby, the maximum clearance change can be secured, and the effect of the present invention can be maximized.

According to the fourth aspect of the present invention,
Since the reaction force member is an input shaft extending between both end walls of the case, the clearance can be controlled with high accuracy by a minimum number of members, so that the effect of the clearance change due to the oil temperature change can be sufficiently exerted. .

Further, according to the fifth aspect of the present invention, a clearance state in which the clearance of the friction engagement element is small when a high speed stage having a higher traveling frequency than the low speed stage is achieved can be obtained.
The heating period of the lubricating oil during low oil temperature running can be lengthened, whereby a rapid increase in oil temperature can be obtained.

Further, according to the configuration of the sixth aspect, the relationship of the coefficient of thermal expansion required for the clearance management is obtained from the same material as that of the conventional transmission, so that the transmission mechanism accompanying the clearance management is performed. It is possible to avoid the restriction on the material of each component.

Further, according to the structure of the seventh aspect, the lubricating oil heated in the friction engagement element portion can be positively discharged from the discharge passage and returned to the outside without staying in the portion. Therefore, the circulation of the heated lubricating oil can be promoted and the entire transmission can be quickly and uniformly warmed, whereby the temperature can be quickly raised to the normal oil temperature and the low oil temperature traveling period can be shortened. it can.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing embodiments. 1 to 3 show a first embodiment. First, a schematic configuration will be described. As shown by a skeleton in FIG. 2, the device according to this embodiment is a transaxle combining a laterally-mounted automatic transmission for a front-engine front-drive vehicle and a differential device. I have. This device includes a torque converter 12 having a lock-up clutch 11 connected to a crankshaft of an engine (not shown), an input shaft 14 integrated with the shaft 13 to which power is transmitted from a turbine output shaft 13, and an input shaft 14. The three planetary gear sets M ₁ , which shift the power entering the gear 14 to the fifth forward speed and the first reverse speed and output to the output gear 19.
A transmission mechanism M mainly composed of M ₂ and M ₃ , a counter gear device 20 for reducing the output from the transmission mechanism M and transmitting the output to the differential device 21, and a power transmitted from the counter gear device 20 to the left and right of the vehicle. And a differential device 21 for transmitting to the wheel.

The transmission mechanism M is included in the transmission case 10 and includes three-stage planetary gear sets M ₁ , M ₂ , and M ₃ , and the brakes (B-1 _, B-B) are associated therewith.
2, B-3, BR) and clutch (C-1, C-2)
Are arranged. Both planetary gear sets M ₁ , M ₃
Are the sun gears S ₁ , S ₃ and the ring gears R ₁ ,
R ₃ and carriers C ₁ , C ₃ rotatably supporting the pinion gears P ₁ , P ₃ meshing therewith. The planetary gear set M ₂ includes a sun gear S ₂ and the pinion gear P ₁ meshing therewith. more and a pinion P ₂ of the small-diameter pinion gear P ₂ is rotatably supported on carrier C _1, it is relatively non-rotatably coupled to the pinion gear P _1. Each of the ring gear R _1, R ₃ and the carrier C _3, C ₁ of the two gear sets M _1, M ₃ is connected to each other, the sun gear S ₁ and the carrier C ₁ of the gear set M _1, in order to an input element , Respectively, are connected to the input shaft 14 via clutches (C-1, C-2). The ring gear R ₁ and the carrier C coupled to each other
₃ is connected to the output gear 19.

[0029] In addition, the sun gear S ₁ of the gear set M ₁ is,
Can be retained on the transmission case 10 by the brake (B-1), the sun gear S ₂ of the gear set M _2, like can be retained on the transmission case 10 by the brake (B-2), the carrier C ₁ connected ring gear R ₃ are is can be retained relative to the transmission case 10 by the brake (B-R). The sun gear S ₁ is connected to the clutch (C-1) via a sun gear shaft 16 fitted on the outer periphery of the input shaft 14, and the carrier C ₁ is connected via a carrier shaft 17 fitted on the outer periphery of the input shaft 14. is connected to the clutch (C-2), the sun gear S ₃ is connected to the brake (B-3) through a full sun gear shaft 18 fitted on the outer periphery of the carrier shaft 17. Also, although not limited thereto, the brake (B
Each of the brakes except -R) has a band brake configuration, and the brake (BR) has a meshing brake configuration.

The two input clutches (C-1 and C-2) disposed at both ends of the transmission mechanism M are engaged with each other.
Two hydraulic servos 3 and 4 for releasing operation are provided. According to the present invention, the cylinder 3 of each hydraulic servo 3, 4
Numerals 0 and 40 are formed on the respective end walls 10a and 10b of the transmission case 10, which are fixed members containing the transmission mechanism M, so as to face each other, and are stationary cylinders.
Two pistons 3 which are slidably fitted into the cylinders 30 and 40, respectively, and define oil chambers 3C and 4C to which hydraulic pressure is supplied in cooperation with the cylinders 30 and 40, respectively.
1, 41 are provided.

Between the pistons 31, 41 of the hydraulic servos 3, 4 and the frictional engagement elements 50, 60 of the clutches (C-1, C-2), the pistons 31, 41, Each of the pistons 3 allows relative rotation between the friction engagement elements 50 and 60 and supplies hydraulic pressure.
Respective bearings 32, 42 are provided for transmitting the servo force from the components 1, 41 to the friction engagement elements 50, 60, respectively. Further, between the bearings 32 and 42 and the friction engagement elements 50 and 60, pressing members 33 and 43 are provided.

Further, the configuration of each part will be described in more detail with reference to FIG. 1 showing a detailed cross section. The transmission case 10 is integrated with a case body made of an aluminum alloy and bolted to one end thereof, and is also integrated with a cover made of the same aluminum alloy forming one end wall 10a and bolted to the other end. Steel oil pump case 10d
And is indirectly fixed to the case body by a bolt and fixed to the case main body, and is formed of a partition wall 10b made of the same aluminum alloy as the other end wall 10b. Further, the transmission case 1
0, the end walls 10a, between 10b, is provided with an aluminum alloy of the intermediate wall 10c of the center support for supporting the output gear 19 which is connected to the carrier C ₃ as an output element.

A steel input shaft 14 for inputting power to the speed change mechanism M (hereinafter, all members which are not described in detail except for bearing bushings and elastic seals are steel members).
Extends from one end of the transmission case 10 to the other end through _three planetary gear sets M ₁ , M ₂ , and M ₃ , and has one end fitted and fixed to the inner peripheral portion of the partition wall 10b. The shaft is radially supported on the cover 10a via a bearing bush and the other end via a needle bearing. The input shaft 14 has a partition 1
0b is integrally formed with a radial flange adjacent to the end wall 1b.
A step 14a is formed on the side adjacent to 0a, and the race 59a of the bearing 59 is in contact with the step 14a.

Each of the frictional engagement elements 50 and 60 of both clutches (C-1 and C-2) serves as a drive-side rotating member.
Carrier and each hub 53, 63 is connected via the reaction force flange 56 and 66 respectively, via the sun gear shaft 16 to the sun gear S ₁ of the planetary gear set M ₁ as a driven side rotating member, also to the carrier C ₁ to The hub 53 is connected via the shaft 17 and sandwiches the friction engagement elements 50 and 60.
The drum 63 has drums 54 and 64 arranged on the outer peripheral side.
Each friction engagement element 50, 60 is composed of a plurality of friction material disks 52, 62 having facings applied to both surfaces thereof, and a plurality of separator plates 5 alternately arranged in the axial direction.
1,61. Each of the friction material disks 52, 62
The outer peripheral side is spline-fitted to the inner peripheral surface of each drum 54, 64, and each separator plate 51, 61 is connected to the hub 53,
63 is spline-fitted to the outer peripheral surface on the inner peripheral side. Therefore, the respective friction engagement elements 50 and 60 are pressed by the respective hydraulic servos 3 and 4 and the respective clutch hubs 53 and 63 are pressed.
And the clutch drums 54 and 64 are connected.

The bearings 32, 42 for transmitting the pressing force of the pistons 31, 41 to the friction engagement elements 50, 60 via the pressing members 33, 43, respectively, apply the thick plate race to the inner diameters of the pistons 31, 41. It is constituted by a thrust roller bearing which is brought into contact with a side portion and is arranged by fitting a thin plate race on the inner periphery of the pressing members 33 and 43.

Both bearings 32, 42 and friction engagement element 5
Press members 33, 43 are spline-fitted to the outer peripheral surfaces of the hubs 53, 63 so as to be relatively non-rotatable and slidable in the axial direction, respectively. Both pressing members 3
Reference numerals 3 and 43 face the respective bearings 32 and 42 on the inner peripheral side, and face the frictional engagement elements 50 and 60 on the outer peripheral side. The pressing members 33 and 43 have, on one side of the outer diameter side thereof, a contact portion for the friction material disks 52 and 62, and the inner peripheral surface of the contact portion has the input shaft 14 similar to the separator plates 51 and 61. Are spline-engaged with the hubs 53 and 63 connected via reaction force flanges 56 and 66 so as to be relatively non-rotatable and slidable in the axial direction.

Each of the pressing members 33 and 43 and the friction engagement element 5
0 and 60, return springs 58 and 68 are provided to the pistons 31 and 41 to apply a pressing force against the movement of the pistons 31 and 41 due to the supply of the hydraulic pressure to the oil chambers 3C and 4C, respectively. Return spring 58,
Numeral 68 is fitted into the positioning holes of the pressing members 33, 43 and the hubs 53, 63 via spring retainers, and comes into contact with reaction flanges 56, 66 as reaction members.

In connection with the _three planetary gear sets M ₁ , M ₂ , M ₃ of the transmission mechanism M, their sun gears S ₁ , M ₂
A plurality of thrust bearings 7 at the same diameter position as S ₂ and S ₃
1, 74, 75, and 76 are provided, and the input clutch (C-
The axial force of 1) is generated by these thrust bearings 71,
The structure which transmits to the intermediate | middle wall 10c via 74,75,76 is employ | adopted.

In this case, the reaction member receives the axial force from each of the input clutches (C-1 and C-2) and applies the rotational force from the input shaft 14 to each of the input clutches (C- and C-2).
1, C-2) two reaction force flanges 56, 66
And a reaction flange 66 on the input clutch (C-2) side where the axial force is transmitted to the end wall 10a via the input shaft 14.
Is fixed to the flange of the input shaft 14 by welding or the like so as to be immobile in the axial direction, and the axial force is transmitted through the speed change mechanism M to the intermediate wall 10.
The reaction force flange 56 on the input clutch (C-1) side transmitted to the input shaft c is connected to the input shaft 14 by spline engagement so as to be movable in the axial direction.

The center support constituting the intermediate wall 10c is formed separately from the main body of the transmission case 10, and has a radial flange portion extending from the inner periphery of the case main body to the vicinity of the outer periphery of the sun gear shaft 18, and one end thereof. It has a cylindrical portion 10a "extending in the axial direction, and the outer peripheral side of the radial flange portion is brought into contact with the inner peripheral step portion of the case main body to be integrated with the main body by bolting. The cylindrical shape of the intermediate wall 10c. A counter drive gear 19 is supported on the outer periphery of the portion 10a ″ via a pair of angular ball bearings 24 and 25.
Is to be able to transmit the axial force from the first input clutch (C-1) to the intermediate wall 10c, is engaged with the output elements or comb-shaped engaging portion with a play in the carrier C ₃ of the speed change mechanism It is connected so that it can self-center.

The output gear 19 is constituted by a helical gear having teeth twisted with respect to the axis, and meshes with a counter driven gear 23 constituted by a similar helical gear.
The direction of the thrust force generated at the time of driving by the helical gear is set to a direction (leftward in the drawing) facing the axial force from the input clutch (C-1).

Although the circuit configuration is not shown in the figure, the oil pan is an oil reservoir, the oil pump 8 driven by the rotation of the case of the torque converter 12 is used as a hydraulic source, and a valve constituting a hydraulic control device is provided. Lubricating oil for supplying hydraulic fluid to the hydraulic servos 3 and 4 of the clutch, the hydraulic servos of the brakes, the torque converter 12 and the lubricating oil passage via the body to lubricate each section of the transmission mechanism including the friction engagement elements 50 and 60. Circulation path is provided. The lubricating oil passages for the friction engagement elements 50 and 60 are an oil passage in the stator support shaft, an axial oil passage and the radial oil passage in the input shaft 14 that communicate with a lubricating pressure output oil passage of a valve body (not shown). It is composed of

In the device configured as described above, the reaction force member for transmitting the axial force transmitted to each of the friction engagement elements 50 and 60 to the transmission case 10 includes: reaction force flange 56, bearing 71, the sun gear shaft 16, the sun gear S _1, the bearing 74, the carrier C _1, bearing 75, the sun gear S _3, the bearing 7
6, the carrier C ₃ , the counter drive gear 19, and the bearings 24, 25, and the frictional engagement element 60 side is constituted by the reaction force flange 66, the input shaft 14, and the bearing 59 including the bearing race 59a.
These members are all made of steel, and have a smaller coefficient of thermal expansion than the coefficient of thermal expansion of the transmission case 10 made of an aluminum alloy.

The automatic transmission T configured as described above supplies hydraulic pressure to hydraulic servos corresponding to each clutch and brake under the control of a hydraulic control device (not shown), and the operation is graphically shown in FIG. Next, each shift speed is achieved by engaging (shown by a circle in the drawing) and releasing (showing no mark in the drawing) each clutch and brake. That is, the first speed (1S
T) is achieved when the clutch (C-1) and the brake (B-3) are engaged. At this time, the rotation of the input shaft 14 enters the sun gear S ₁ through the clutch (C-1),
Is output to the counter drive gear 19 as an engagement rotation of the carrier C ₃ which is most reduced at the locking of the sun gear S ₃ by the brake (B-3).

On the other hand, the second speed (2ND) is achieved by engagement of the clutch (C-2) and the brake (B-3). At this time, the carrier shaft 1 is connected via the clutch (C-2).
7 enters the ring gear R _{3 as} it is via the carrier C ₁ , as a differential rotation of the carrier C ₃ having the sun gear S ₃ locked by the engagement of the brake (B-3) as a reaction element. Output to counter drive gear 19. Third
Speed (3RD) is achieved by engagement direct connection of the planetary gear set M ₁ according to the two clutches (C-1, C-2 ).
At this time the rotation of the input shaft 14 is output to the counter drive gear 19 as the rotation of the carrier C _3.

4th speed (4TH) due to overdrive
The engaging of the clutch (C-2), is achieved by the engagement of the brake (B-1) for locking the sun gear S _1. At this time, the rotation of the input shaft 14 is transmitted from the carrier C ₃ to the counter drive gear 19 as the rotation of the rotation component acceleration has been ring gear R ₁ of the pinion gears P ₁ relative to the rotation of the carrier C _1. On the other hand, in the fifth speed, the clutch (C-
2) and the engagement of the brake (B-2).
At this time, the rotation of the input shaft 14 is larger than the rotation of the carrier C _{1 by} the rotation of the small-diameter pinion gear P ₂ that takes a reaction force to the larger-diameter sun gear S ₂ than when the fourth speed is achieved. It is transmitted from the carrier C ₃ to the counter drive gear 19 as the rotation of _one.

The reverse (REV) is controlled by the clutch (C-
1) and the engagement of the brake (BR). At this time, the rotation of the decelerated ring gear R ₁ , which is reversed by the engagement of the carrier C ₁ with respect to the input of the sun gear S ₁ , is rotated by the carrier C
It is output from the counter drive gear 19 via ₃ .

To achieve each of the above-mentioned shift speeds, each clutch (C-1, C-2) is provided with a piston 3 when oil pressure is supplied to the respective oil chambers 3C, 4C from an oil passage in the transmission case.
1, 41 are pushed out, but bearings 32, 42 are provided between the pistons 31, 41 and the clutches (C-1, C-2).
And the pressing members 33 and 43, the servo force from the pistons 31 and 41 is applied while allowing the relative rotation between the clutches (C-1 and C-2) and the pistons 31 and 41. , 60, and the clutches (C-1, C-2) can be engaged.

In such an operation, the servo force from the piston 31 of the hydraulic servo 3 is applied to the bearing 32 and the pressing member 3.
Via the frictional engagement element 50 of the third and first clutches (C-1) is transmitted to the reaction force the flange 56 and the bearing 71 from the reaction force the flange 56, the sun gear shaft 16, the sun gear S _1, the bearing 74, the carrier C ₁ , bearing 7
5, the sun gear S _3, bearings 76, the carrier C _3, is transmitted to the center support 10c via the counter drive gear 19 and the bearing 24, 25. In addition, a hydraulic reaction force in a direction opposite to the servo force of the piston 31 acts on the case end wall 10a on the side where the hydraulic servo 3 is provided. As a result, the servo force of the piston 31 and the hydraulic pressure in the opposite direction are transmitted to the case end wall 10a and the intermediate wall 10c, that is, to the transmission case 10, and are balanced.

On the other hand, the piston 4 of the hydraulic servo 4
1 is transmitted to the reaction flange 66 via the bearing 42, the pressing member 43, and the friction engagement element 60 of the second clutch (C-2), and the input shaft 14,
Cover 10a via bearing 59 including race 59a
Is transmitted to In addition, a hydraulic reaction force in a direction opposite to the servo force of the piston 41 acts on the case end wall 10b on the side where the hydraulic servo 4 is provided. As a result, piston 4
The servo force of 1 and the oil pressure in the opposite direction are transmitted to the case end walls 10a and 10b, that is, the transmission case 10, and are balanced.

Since the transmission path of the axial force through the transmission case 10 is thus formed, in the transmission mechanism M, the expansion and contraction of the transmission case 10 due to the heat are caused by the respective reaction flanges 56 and 66. And the pressing members 33 and 43 affect the clearance when the frictional engagement elements 50 and 60 are released. When the clearance is set to a predetermined value at a normal oil temperature, the clearance is narrower than the predetermined value at a low oil temperature. That is, the clutch (C-1)
On the side, the friction engagement element of the pressing member 33 from the inner race contact surface to the contraction amount of the steel at the distance from the inner race end surface of the bearing 25 to the contact surface of the reaction force flange 56 with the friction engagement element 50. The distance to the contact surface with respect to 50 appears substantially as the amount of shrinkage of the aluminum alloy,
Since the coefficient of thermal expansion of aluminum alloy is larger than that of steel,
Clearance is reduced.

On the other hand, on the clutch (C-2) side,
The friction of the pressing member 43 from the bearing contact surface with respect to the contraction amount of steel at the distance from the contact surface of the bearing 59 to the transmission case end wall 10a to the contact surface of the reaction force flange 66 with the friction engagement element 50. The distance to the contact surface with respect to the engagement element 60 substantially appears as the amount of contraction of the aluminum alloy,
Also in this case, since the coefficient of thermal expansion of the aluminum alloy is larger than that of steel, the clearance is reduced.

In such a reduced state of the clear rinse, the lubricating oil for lubricating the friction engagement elements 50 and 60 is released when the friction engagement elements 50 and 60 are released, that is, in this embodiment, the friction engagement element 50 , The second speed, the fourth speed and the fifth speed, and the frictional engagement element 60 between the frictional engagement elements 50 and 60 that relatively rotate between the driving side and the driven side in the first speed and the reverse direction. It is dragged by the relative rotation through the clearance formed and is released outward in the engagement direction and circulates, but such a narrow clearance increases the shearing force due to drag on the lubricating oil passing therethrough, The calorific value is increased and the lubricating oil is heated from normal temperature, and the heated lubricating oil circulates through the lubrication path of the transmission, so that the oil temperature of the entire transmission quickly rises.

Further, the friction engagement element 5 caused by a change in oil temperature
The magnitude of the clearance change of 0, 60 is determined by the reaction force members 33, 43 from the pistons 31, 41 of the hydraulic servos 3, 4.
Is determined by the distance to a portion that is in contact with the transmission case 10 in order to transmit the axial force, and especially on the frictional engagement element 60 side, the transmission that has the largest distance in the transmission. By reflecting the change in the distance between both end walls 10a and 10b of the machine case 10 in the change in the clearance of the friction engagement element 60, the maximum change in the clearance can be ensured. Moreover, in this case, by using the input shaft 14 extending between both end walls of the case as the reaction force member 43, the clearance management can be performed with high accuracy by using a minimum number of members. On the frictional engagement element 50 side, a clearance state in which the clearance of the frictional engagement element 50 is small when the second, fourth, and fifth speeds, which are higher in the traveling frequency than the first speed, is achieved. The lubricating oil heating period during oil temperature traveling can be lengthened. Further, the reaction force flange 56 and the pressing member 33
By providing the return spring 58 between the first and second members, the clearance at the frictional engagement element 50 can be maintained at a desired width against the thrust force by the expanding force, so that the clearance change due to the action of the thrust force can be maintained. And a clearance change depending on the oil temperature change can be obtained.

For any of the above frictional engagement elements, the relationship of the coefficient of thermal expansion required for clearance management is obtained from the same material as that of the conventional transmission. It is possible to avoid restrictions on the material of each component. Further, the friction engagement elements 50,
The lubricating oil heated in the 60 parts can be positively discharged from the discharge path between the pressing members 33, 43 and the clutch drums 54, 64 without being retained in the part, and can be refluxed. By promoting the circulation of the lubricating oil, the entire transmission can be quickly and uniformly heated, whereby the temperature can be quickly raised to the normal oil temperature and the low oil temperature running period can be shortened.

FIG. 4 shows a second embodiment of the present invention. This embodiment differs from the first embodiment in that the reaction force members of both clutches (C-1, C-2) include the input shaft 14. According to this configuration, as shown in FIG.
The bearing 69 is attached to the case end wall 10b, specifically, the end surface of the stator support shaft that comes into contact with the case end wall 10b, on the reaction force flange 66 side. Specifically, the reaction force flange 6 on the friction engagement element 60 side
6 is fixed to the input shaft 14 in the same manner as in the first embodiment, and the reaction force flange 56 on the frictional engagement element 50 side is different from the first embodiment in the step portion 14a of the input shaft 14. The input shaft 14 is inserted through a flange member 56a that is spline-fitted to the input shaft 14 having a flange formed thereon.
It is fixed to. The other points are substantially the same as those in the first embodiment, and a detailed description thereof will be omitted. Of course, the shift speed achieved in this embodiment is the same as that in the first embodiment.

In the case of the second embodiment having such a configuration,
The servo force from the piston 31 of the hydraulic servo 3 is applied to the bearing 32, the pressing member 33, and the first clutch (C-1).
Is transmitted to the reaction force flange 56 through the friction engagement element 50 of the input shaft 14 and the bearing 6 from the flange member 56a.
9 and to the partition 10b via the stator support shaft.
The case end wall 1 on the side where the hydraulic servo 3 is provided
On 0a, a hydraulic reaction force acts in the opposite direction to the servo force of the piston 31. As a result, the servo force of the piston 31 and the hydraulic pressure in the opposite direction are applied to both case end walls 10a, 10a.
b, that is, transmitted to the transmission case 10 and balanced. Note that the balance of the axial force on the hydraulic servo 4 side is the same as in the first embodiment.

In this case, the change of the clearance due to the thermal expansion and contraction of the transmission case 10 is, of course, substantially the same for both friction engagement elements.

As described above, the present invention has been described based on the two embodiments. However, the present invention is not limited to the structure exemplified in the above-described embodiment, but various concrete examples are possible within the scope of the claims. By changing the configuration, the present invention can be applied to various transmission mechanisms.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of an automatic transmission to which the present invention is applied.

FIG. 2 is a skeleton diagram showing a schematic configuration of an entire transaxle including the automatic transmission.

FIG. 3 is an operation chart of the automatic transmission according to the first embodiment.

FIG. 4 is a sectional view showing only a reaction force member of an automatic transmission according to a second embodiment of the present invention.

[Explanation of symbols]

 M Transmission mechanism 3, 4 Hydraulic servo 10 Transmission case 10a, 10b End wall 14 Input shaft 30, 40 Cylinder 31, 41 Piston 32, 42 Bearing 33, 43 Pressing member 50, 60 Friction engagement element 53, 63 Clutch hub ( Driving-side rotating member) 54, 64 Clutch drum (driven-side rotating member) 56, 66 Reaction flange 58, 68 Return spring

Claims (7)

[Claims] A friction engagement element connected to the driving-side rotation member and the driven-side rotation member; and a hydraulic servo for pressing the friction engagement element to connect the two rotation members via the friction engagement element. And an automatic transmission including a lubricating oil circulation path for lubricating the frictional engagement element, wherein a cylinder of the hydraulic servo is formed in a transmission case which is a fixed member including a transmission mechanism. A bearing for transmitting the pressing force as an axial force to the frictional engagement element, and a reaction force member for transmitting the axial force transmitted to the frictional engagement element to the transmission case are provided. An automatic transmission characterized in that the coefficient of thermal expansion of the reaction force member is set large. 2. The automatic transmission according to claim 1, wherein a pressing member is provided between the bearing and the frictional engagement element, and a return spring that pushes back the piston of the hydraulic servo is provided between the reaction force member and the pressing member. Machine. 3. The transmission case has end walls at both ends sandwiching a transmission mechanism, a hydraulic servo cylinder is formed on one end wall, and a reaction force member is provided between the friction engagement element and the other end wall. The automatic transmission according to claim 1, wherein the automatic transmission is provided over the range. 4. The automatic transmission according to claim 3, wherein the reaction member is an input shaft of a transmission extending between both end walls of the transmission case. 5. The speed change mechanism achieves a plurality of shift speeds, and the friction engagement element is engaged to achieve a low speed shift among the plurality of shift speeds, and is released when a high speed shift is achieved. The automatic transmission according to claim 1 or 2, wherein the automatic transmission is provided. 6. The automatic transmission according to claim 1, wherein the automatic transmission case is made of an aluminum alloy, and the reaction member, the piston, and the pressing member are made of steel. 7. The circulation path has a discharge path for lubricating oil passing through the friction engagement element to the outside of the friction engagement element.
The automatic transmission according to any one of claims 1 to 6, wherein