DE112006002160B4 - automatic transmission - Google Patents

Abstract

An automatic transmission (10) disposed at a rear side of an engine relative to a traveling direction of a vehicle, comprising a speed change mechanism (13) for shifting between a plurality of gears by engaging and disengaging a plurality of clutches (C-1, C-2 , C-3, C-4) and brakes (B-1, B-2), characterized in that the speed change mechanism (13) comprises:
a cylindrical support portion (27a);
a first hydraulic servo having a first drum (31) and a first piston (44) forming a first cylinder chamber (43) together with the first drum (31) for making one of the plurality of clutches operable; and
a main bearing (36) disposed on an inner periphery of a boss portion (31a) of the first drum (31) and an outer circumference of the cylindrical support portion (27a) for rotatably supporting the first drum (31); wherein the speed change mechanism (13) is characterized by
an auxiliary bearing (37) pressed into one end of the inner circumference of the boss portion (31a) of the first drum (31) and fitted to the cylindrical support portion (27a) with clearance therebetween, and only the cylindrical support portion (27a) touches when the first drum (31) tilts in the direction of travel of the vehicle, and which has a shorter axial length than the main bearing (36).

Description

Technical part

The present invention relates to an automatic transmission, and more particularly to an automatic transmission in which a drum is normally supported only by a bearing and causing another bearing to function only when an external force is applied. An automatic transmission with the features of the preamble of claim 1 is made US 2005/0183925 A1 known. Other automatic transmissions are in US Pat. No. 5,069,657 A and US 4945782 A described.

In an automatic transmission having a speed change mechanism for shifting between a plurality of gears by engaging and disengaging a clutch and a brake, the clutch is constituted by a drum, a piston, a canceler, and so forth. Furthermore, the automatic transmission is typically provided with two or more clutches.

DISCLOSURE OF THE INVENTION

Problems to be solved by the invention

In this type of automatic transmission, rotational support of the clutch drum is performed using a bearing so that the clutch drum is rotatably supported at one point or at both ends, particularly at two points. If the support is provided at one point, the axial length of the bearing must be increased considerably to ensure that the first drum is not caused to over tilt by an external force. On the other hand, if the support is provided at two points, the two bearings must be durable and therefore a sufficient axial length must be ensured to provide certainty that sufficient durability can be provided.

Therefore, in a conventional automatic transmission, a bearing having a large axial dimension is disposed at the end portion of a passage for supplying pressurized oil irrespective of whether support is provided at one point or two points, and as a result, the axial length of the drum increases. whereby extending the automatic transmission makes it difficult to reduce the weight and to improve the compactness of the drum.

The present invention has been made in consideration of these conventional problems, and it is an object of the invention to provide an automatic transmission, the weight of which can be reduced and which can be made compact by minimizing the axial length of an auxiliary bearing.

Means for solving the problem

To achieve the object described above, an invention described in claim 1, an automatic transmission, which is arranged at the rear of an engine relative to a direction of travel of a vehicle, the speed change mechanism for switching between a plurality of gears by engaging and disengaging a plurality of clutches and Brakes, characterized in that the speed change mechanism comprises: a cylindrical support portion; a first hydraulic servo having a first drum and a first piston which, together with the first drum, form a first cylinder chamber to operate one of the plurality of clutches; a main bearing disposed at an inner circumference of a boss portion of the first drum and an outer circumference of the cylindrical support portion to rotatably support the first drum; and an auxiliary bearing that is pressed into one end of the inner circumference of the boss portion of the first drum and fitted to the cylindrical support portion with a clearance therebetween that contacts the cylindrical support portion only when the first drum tilts in the traveling direction of the vehicle and has a shorter axial length than the main bearing.

An invention described in claim 2 is the automatic transmission according to claim 1, characterized in that the cylindrical support portion is a hub portion extending from a transmission housing, wherein the speed change mechanism comprises a first working oil supply passage formed in the hub portion of the transmission housing, and a first Working oil supply hole formed in the hub portion of the first drum, and wherein working oil is supplied to the first cylinder chamber through the first working oil supply passage and the first working oil supply hole via a pair of sealing rings, which are arranged on the hub portion of the transmission housing.

An invention described in claim 3 is the automatic transmission according to claim 2, characterized in that the speed change mechanism further comprises: a second hydraulic servo having a second drum and a second piston, which is slidably disposed on a hub portion of the second drum and a second Cylinder chamber forms together with the second drum; and one a second working oil supply passage formed in the boss portion of the transmission case, a second working oil supply hole formed in the boss portion of the first drum, and a third working oil supply hole formed in the boss portion of the second drum, the first drum being rearward of the traveling direction of the second drum Vehicle is open, wherein the first drum and the second drum are engaged so that they can perform a rotation as a unit, namely by a key engagement portion, the first spline, on an outer peripheral surface of a rear end portion of the hub portion of the first drum is formed in the traveling direction of the vehicle, and has a second spline formed on an inner circumferential surface of the hub portion of the second drum, wherein the main bearing on an inner peripheral side of the rear end portion of the hub portion of the first drum in FIG is arranged in the direction of the vehicle, and wherein the working oil to the second cylinder chamber through the second working oil supply passage and the second working oil supply hole via the pair of sealing rings, which are arranged on the hub portion of the transmission housing, and through the second working oil supply hole and the third working oil supply hole via a pair of sealing rings, which are arranged between the hub portion of the first drum and the hub portion of the second drum is supplied.

An invention described in claim 4 is the automatic transmission according to one of claims 1 to 3, characterized in that the main bearing is formed of a metal sleeve.

According to the invention of claim 1, the main bearing disposed on the inner circumference of the boss portion of the first drum and the outer circumference of the cylindrical support portion for rotatably supporting the first drum and the auxiliary bearing provided in one end of the inner circumference of the boss portion the first drum is pressed and fitted to the cylindrical support portion with a clearance therebetween, which contacts the cylindrical support portion only when the first drum tilts in the direction of travel of the vehicle, and which has a shorter axial length than the main bearing. Since the auxiliary bearing supports the first drum only when it is necessary when z. B. tilts the first drum in the direction of travel of the vehicle, it does not have to be durable and can be performed with a minimum axial length. As a result, the axial dimension of the first drum can be reduced.

According to the invention of claim 2, the speed change mechanism includes the first working oil supply passage formed in the hub portion of the transmission case and the first working oil supply hole formed in the hub portion, and becomes working oil to the first cylinder chamber through the first working oil supply passage and the first working oil supply hole supplied via the pair of sealing rings, which are arranged on the hub portion of the transmission housing. Since the first drum is supported by the auxiliary bearing when the first drum tilts in the traveling direction of the vehicle, a situation in which the sealing rings forming the working oil supply passage to the first cylinder chamber are broken by the tilting of the first drum can be prevented. As a result, pressure oil leakage through the broken portion of the seal rings can be prevented, and reduction in controllability of the first hydraulic servo can be prevented.

According to the invention of claim 3, in a case that the first drum is open to the rear of the traveling direction of the vehicle, the first drum and the second drum are engaged so as to be able to rotate as a unit through the wedging engagement portion the first spline formed on the outer circumferential surface of the rear end portion of the boss portion of the first drum in the traveling direction of the vehicle and the second spline formed on the inner peripheral surface of the boss portion of the second drum, and the working oil becomes the second Cylinder chamber through the second working oil supply passage and the second working oil supply hole via the pair of sealing rings, which are arranged on the hub portion of the transmission housing, and supplied through the second working oil supply hole and the third working oil supply hole via the pair of sealing rings, which is between the hub portion of the first Dromm el and the hub portion of the second drum, wherein the working oil must be supplied to the second cylinder chamber via the first drum, which means that the dimension of the first drum must be increased. Therefore, in a case that the size of the first drum is increased in this way, the first drum is supported by the main bearing, and when the first drum tilts in the traveling direction of the vehicle, the first drum is simultaneously supported by the auxiliary bearing. As a result, improvement in compactness can be excellently achieved.

According to the invention of claim 4, the main bearing is formed of a metal sleeve. Thereby, a sufficient axial length for rotatably supporting the drum can be easily realized.

BRIEF DESCRIPTION OF THE DRAWINGS

1 FIG. 10 is a grid diagram showing an automatic transmission according to the present invention. FIG.

2 is a view showing the engagement states of brakes and clutches in the respective gear of the in 1 shown automatic transmission shows.

3 Fig. 10 is a sectional view showing a lubricating device of the automatic transmission according to an embodiment of the present invention;

4 is a view that is a partial magnification of 3 shows.

LIST OF REFERENCE NUMBERS

10

AUTOMATIC TRANSMISSION

11

GETRIEBEGEHÄUSE

13

SPEED CHANGE MECHANISM

15

INPUT SHAFT

16

OUTPUT SHAFT

20

REDUCE SPEED PLANETARY

21

PLANETARY GEAR SET

27

OIL PUMP BODY

27a

CYLINDRICAL SUPPORT SECTION (NOSE SECTION)

31

FIRST DRUM

32

SECOND DRUM

33

SLEEVE ELEMENT

35

fixing sleeve

36

HAUPTLAGER

37

AUXILIARY BEARING

43, 53, 73

CYLINDER CHAMBER

44, 54, 74

PISTON

46, 65, 66

LABOR OIL SUPPLY HOLE

95

KEIL INTERVENTION SECTION

99, 100

SEAL

S1, S2, S3

sun

C1, C2, C3

CARRIER

R1, R2

RING GEAR

C-1

FIRST COUPLING

C-2

SECOND COUPLING

C-3

THIRD CLUTCH

C-4

FOURTH COUPLING

B-1

FIRST BRAKE

B-2

SECOND BRAKE

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below on the basis of the following drawings.

1 shows an automatic transmission 10 , which can be preferably used for example in a front-mounted engine and rear-wheel drive vehicle. The automatic transmission 10 is with a torque converter 12 and a speed change mechanism 13 in a gearbox 11 provided, which is attached to a vehicle body. A delivery of the engine becomes an input shaft 15 of the automatic transmission 10 via a pump impeller and a turbine runner of the torque converter 12 initiated. The speed change mechanism 13 Switches the speed of rotation of the input shaft 15 is initiated, and gives the rotation to an output shaft 16 which is connected to a driven wheel. The torque converter 12 is with a lockup clutch 17 Mistake. Further, the input shaft 15 and the output shaft 16 of the automatic transmission 10 coaxial relative to a direction of travel of the vehicle. The torque converter 12 is arranged on the front side in the vehicle running direction, while the output shaft 16 is arranged at the rear in the vehicle travel direction. It should be noted that in this embodiment, the torque converter side 12 (the front in the vehicle running direction) in the axial direction of the automatic transmission 10 will be referred to as "front", and the side of the output shaft 16 (Rear in vehicle travel direction) will be referred to as "rear".

The speed change mechanism 13 is through the input shaft 15 , a speed reduction planetary gearbox 20 , a planetary gear set 21 formed with a plurality of planetary gears, first to fourth clutches C-1 to C-4 and first and second brakes B-1, B-2, the coaxially successive in the transmission housing 11 are supported.

The speed reduction planetary gearbox 16 that is the speed of the input shaft 15 is reduced and transmits the rotation to a rotating element at a reduced speed, by a sun gear S1, which is connected to the gear housing 11 is fixed at all times and its rotation is restricted by a carrier C1 directly connected to the input shaft 15 coupled, a first pinion 23A , which is supported by the carrier C1 and meshes with the sun gear S1, a second pinion 23B supported by the carrier C1 and meshing with the first pinion 23A engages, and a ring gear R1 formed with the second pinion 22B combing intervenes.

The planetary gear set 21 is formed, for example, from a Ravigneaux gear set that combines a single pinion planetary gear and a double pinion planetary gear.

A small diameter first sun gear S2 of the planetary gear set 21 is disengageable by the first clutch C-1 with the ring gear R1 of the speed reduction planetary gear 20 connected. A large-diameter second sun gear S3 is disengageable by the third clutch C-3 with the ring gear R1 of the speed reduction planetary gear 20 connected and via the carrier C1 of the speed reduction planetary gear 20 through the fourth clutch C-4 disengageable with the input shaft 15 connected. A short sprocket 25 meshes with the first sun gear S2. A long pinion 26 meshes with the second sun gear S3 and the short pinion 25 one. The short sprocket 25 and the long pinion 26 are each rotatably supported by directly coupled carrier C2, C3. A ring gear R2 meshes with the long pinion 26 one and is with the output shaft 16 connected as output element.

The second sun gear S3 is disengageable by the first brake B-1 with the transmission housing 11 connected. The carrier C2 (C3) is disengageable by the second clutch C-2 with the input shaft 15 connected. The carrier C2 (C3) is also disengageable by the second brake B-2 with the transmission case 11 connected and can be locked by a one-way clutch F-1.

The automatic transmission 10 , which is constructed in the manner described above, can ratios for eight forward gears and two reverse gears by selectively engaging and disengaging the first to fourth clutches C-1 to C-4 and the first and second brakes B-1, B-2 and selective Connecting or fixing the input shaft 15 , the output shaft 16 and the various elements of the speed reduction planetary gear 20 and the planetary gear set 21 form. In 2 The circles marked in the columns of the clutch and brake corresponding to the respective gear indicate that the clutch or brake is in the engaged state, and if no circle is marked, this indicates the disengaged state.

An operation of each gear will now be described. When a shift range corresponds to a P range (parking range) and an N range (neutral range), all the clutches C-1 to C-4 and brakes B-1, B-2 are disengaged, and therefore, the power transmission between the input shaft 15 and the output shaft 16 interrupted.

In the first forward, as in 2 1, the first clutch C-1 is engaged and the one-way clutch F-1 is engaged. As a result, the reduced speed rotation of the ring gear R1 becomes in the speed reduction planetary gear 20 in the first sun gear S2 of the planetary gear set 21 initiated via the first clutch C-1. The speed of rotation of the reduced speed of the first sun gear S2 is then further reduced via the carrier C2 (C3) whose rotation is restricted in a single direction by the one-way clutch F-1, and is introduced into the ring gear R2, whereby the output shaft 16 is positively rotated at a reduced speed corresponding to the gear ratio of the first gear. It should be noted that during engine braking, the second brake B-2 is engaged instead of the one-way clutch F-1 and the rotation of the carrier C1 (C3) is kept stationary.

In the second forward speed, the first clutch C-1 and the first brake B-1 are engaged. As a result, the reduced speed rotation of the ring gear R1 becomes in the speed reduction planetary gear 20 is input to the first sun gear S2 via the first clutch C-1, and since the second sun gear S3 is fixed by the first brake B-1, the ring gear R2 becomes, and therefore, the output shaft 16 positively rotated at a reduced speed corresponding to a gear ratio of the second gear.

In the third forward speed, the first and third clutches C-1, C-3 are engaged. As a result, the reduced speed rotation of the ring gear R1 becomes in the speed reduction planetary gear 20 introduced into the first sun gear S2 via the first clutch C-1 and introduced into the second sun gear S3 via the third clutch C-3. Accordingly, the planetary gear set rotates 21 as a unit and becomes the Ring gear R2 and therefore the output shaft 16 rotated at a reduced speed according to the gear ratio of the third gear, wherein the rotational speed of the rotation of the input shaft 15 through the speed reduction planetary gear 20 is reduced.

In the fourth forward speed, the first and fourth clutches C-1, C-4 are engaged. As a result, the reduced speed rotation of the ring gear R1 becomes in the speed reduction planetary gear 20 is introduced into the first sun gear S2 via the first clutch C-1, and the rotation of the carrier C-1 in the speed reduction planetary gear 20 introduced into the second sun gear S3 via the fourth clutch C-4. Thus, the ring gear R2 and therefore the output shaft 16 positively turned with a gear ratio of the fourth gear.

In the fifth forward speed, the first and second clutches C-1, C-2 are engaged. As a result, the reduced speed rotation of the ring gear R1 becomes in the speed reduction planetary gear 20 is introduced into the first sun gear S2 via the first clutch C-1 and becomes the rotation of the input shaft 15 introduced into the first and second carrier C2, C3, which are directly coupled via the second clutch C-2. Thus, the ring gear R2 and therefore the output shaft 16 positively rotated at a reduced speed corresponding to a gear ratio of the fifth gear.

In the sixth forward speed, the second and fourth clutches C-2, C-4 are engaged. As a result, the rotation is reflected in the input shaft 15 is introduced into the fourth clutch C-4 via the carrier C1 of the speed reduction planetary gear 20 initiated, and the rotation is then introduced into the second sun gear S3. The rotation of the input shaft 15 is also introduced into the first and second carrier C2, C3, which are directly coupled via the second clutch C-2. Thus, the planetary gear set rotates 21 as a unit with the input shaft 15 and becomes the ring gear R2 and therefore the output shaft 16 positively turned with a gear ratio of the sixth gear.

In the seventh forward speed, the second and third clutches C-2, C-3 are engaged. As a result, the rotation of the input shaft 15 are introduced into the first and second carriers C2, C3 directly coupled via the second clutch C-2, and the reduced speed rotation of the ring gear R1 in the speed reduction planetary gear 20 introduced into the second sun gear S3 via the third clutch C-3. Thus, the ring gear R2 and therefore the output shaft 16 positively rotated at an increased speed corresponding to a gear ratio of the seventh gear.

At the eighth forward speed, the second clutch C-2 and the first brake B-1 are engaged. As a result, the rotation of the input shaft 15 are introduced into the first and second carriers C2, C3 directly coupled via the second clutch C-2, and the second sun gear S3 is fixed by the first brake B-1. Thus, the ring gear R2 and therefore the output shaft 16 positively rotated at an increased speed corresponding to a gear ratio of the eighth gear.

In the first reverse gear, the third clutch C-3 and the second brake B-2 are engaged. As a result, the rotation of the input shaft 15 into the second sun gear S3 via the third clutch C-3, and the first and second carriers C2, C3, which are directly coupled, are fixed by the second brake B-2. Thus, the ring gear R2 and therefore the output shaft 16 rotated backward at a reduced speed corresponding to a gear ratio of the first reverse gear.

In the second reverse gear, the fourth clutch C-4 and the second brake B-2 are engaged. As a result, the rotation of the input shaft 15 in the fourth clutch C-4 via the carrier C1 of the speed reduction mechanism 20 and the rotation is then introduced into the second sun gear S3, while the first and second carriers C2, C3, which are directly coupled, are fixed by the second brake B-2. Thus, the ring gear R2 and therefore the output shaft 16 rotated backward at a reduced speed corresponding to a gear ratio of the second reverse gear.

The 3 and 4 are structural diagrams showing the specific structure of the speed reduction planetary gearbox 20 showing third and fourth clutches C-3, C-4 and first brake B-1. In the diagrams, the input shaft 15 through the gearbox 11 , an oil pump body 27 that with the gearbox 11 is fixed, and a stator shaft 30 rotatably supported. The stator shaft 30 is at the inner periphery of a hub portion 27a of the oil pump body 27 press-fit. The speed reduction planetary gearbox 20 is on the outer peripheral side of a rear side end portion of the stator shaft 30 arranged and the rotation of the sun gear S1 of the speed reduction planetary gear 20 is overridden by a wedging action.

The third clutch C-3, which is the first drum 31 which assumes a cylindrical shape with a closed end, and the fourth clutch C-4, which is a second drum 32 which also assumes a cylindrical-like shape with a closed end are in the gearbox 11 accommodated. The fourth clutch C-4 is on the inner peripheral side of the first drum 31 added. The first drum 31 is on the outer periphery of a sleeve member 33 rotatably supported, in the outer periphery of the hub portion 27a of the oil pump body 27 pressed. The second drum 32 is through a hub section 31a which is arranged so that it extends along the inner peripheral side of the first drum 31 extends, and thus engages by a wedging engagement portion 95 so that it is capable of uniform rotation with it.

A plurality of sealing elements are between the inner periphery of the hub portion 31a the first drum 31 and the outer circumference of the sleeve member 33 set. A rear end of the hub portion 31a the first drum 31 is through a sleeve-shaped metallic main bearing 36 rotatably supported, that on a fixing sleeve 35 disposed on the outer periphery of the rear end portion of the hub portion 27a of the oil pump body 27 is fit. The main camp 36 alone has a sufficient axial length for rotatably supporting the first drum 31 ,

Further, a metallic sleeve-shaped auxiliary bearing 37 with a shorter axial length than the main bearing 36 in the inner circumference of the other end (the front end portion in the traveling direction of the vehicle) of the hub portion 31a pressed. The auxiliary warehouse 37 is in the outer circumference of the sleeve member 33 with a gap in between and usually does not work as a bearing. The auxiliary warehouse 37 touches the outer circumference of the sleeve member 33 so that it only works as a bearing when a slope-related force such. B. a gyroscopic moment on the first drum 31 is applied, so that the first drum 31 tilts, or beyond a predetermined inclination in the direction of travel of the vehicle. Thus, the volume of the auxiliary bearing 37 be reduced below that in a case where the drum is constantly supported at two points, and accordingly, its axial length can be minimized. Therefore, the pressing surface of the first drum 31 for pressing the auxiliary bearing 37 be shortened, thereby the axial dimension of the first drum 31 to reduce.

One end of an outer peripheral portion 31b on the open side of the first drum 31 is disengageable via the third clutch C-3 with the ring gear R1 of the speed reduction planetary gear 20 connected. The third clutch C-3 is composed of a frictional engagement element having a partition plate connected to the outer peripheral portion 31b is in wedge engagement, and a friction plate, which is in spline engagement with the ring gear R1, and a first hydraulic servo formed. The first hydraulic servo is a first piston 44 , which is slidable in a first cylinder chamber 43 is received in the bottom portion of the first drum 31 is formed, a Aufhebungsplatte 91 at the hub section 31a the first drum 31 is arranged, and a return spring 45 formed the first piston 44 biases.

An inner peripheral portion of the cancellation plate 91 is with the outer circumference of the hub portion 31a the first drum 31 latched, allowing its movement in an axial direction through a clamping ring 90 is limited. The outer peripheral portion of the cancellation plate 91 is in the inner circumferential surface of the first piston 44 fitted leak-proof and a first repeal chamber 92 is between the suspension plate 91 and the first piston 44 educated. The return spring 45 that the first piston 44 in the axial direction to open the third clutch C-3 is between the cancellation plate 91 and the first piston 44 arranged.

The first suspension chamber 92 Clearing oil (lubricating oil) becomes through a cancellation oil supply hole 93 supplied in a radial direction in the hub portion 27a of the oil pump body 27 , the sleeve element 33 and the first drum 31 is trained. The repealing oil that goes to the first repeal chamber 92 is supplied to the outside by a cancellation oil discharge well 91a ejected in the inner peripheral portion of the cancellation plate 91 is trained. The first suspension chamber 92 acts to cancel the centrifugal oil pressure caused by the oil in the first cylinder chamber 43 is generated, cancel. The first piston 44 extends along the inner circumference of the outer peripheral portion 31b the first drum 31 and a tip end portion thereof is disposed along the frictional engagement element of the third clutch C-3. The first cylinder chamber 43 The hydraulic servo is in communication with an oil passage in the hub portion 27a of the oil pump body 27 is formed, via a feed passage 47 formed by oil holes formed in the hub portion 31a the first drum 31 and the sleeve member 33 are formed. The oil passage in the hub section 27a is formed, is connected to an oil pressure control device, which is not shown in the drawings, and as a result of an oil pressure, which is supplied by the oil pressure control device, the first piston moves 44 against the spring force of the return spring 45 to frictionally engage the frictional engagement element of the third clutch C-3. When the supply of the pressure oil is stopped, the frictional engagement with the frictional engagement element by the spring force of the return spring 45 solved.

The second drum 32 is inside the first piston 44 the third clutch C-3 arranged. A hub section 32a in the hub section 31a the first drum 31 is disposed on the inner peripheral side of the second drum 32 provided, and an outer peripheral portion 32b is provided on the outer peripheral side. As in 4 is shown is an inner wedge 32c on an inner periphery of the rear end portion of the boss portion 32a in the second drum 32 educated. The inner wedge 32c is in wedging engagement with an outer wedge 31c at the outer periphery of the front end portion of the boss portion 31a in the first drum 31 is trained. A first spline, through the outer wedge 31c is formed, and a second Spline through the inner wedge 32c is formed, form the wedges engaging portion 95 out.

The open (back) end portion of the outer peripheral portion 32b the second drum 32 is releasably connected to the carrier C1 of the speed reduction planetary gear 20 via the fourth clutch C-4. The fourth clutch C-4 is formed by a frictional engagement element with a partition plate 51 , which wedges with the inner circumference of the outer peripheral portion 32b is, and a friction plate 52 , which wedges with the outer circumference of a clutch hub 56 which is coupled to the carrier C1, and formed by a second hydraulic servo. The second hydraulic servo is through a second piston 54 , which is slidable in the second cylinder chamber 53 is received, which at the bottom portion of the second drum 32 is formed, a Aufhebungsplatte 97 at the hub section 31a the first drum 31 is arranged, and a return spring 55 formed the second piston 54 biases. One end of the second piston 54 is in wedging engagement with the inner circumference of the outer peripheral portion 32b the second drum 32 and is disposed on the rear side of the frictional engagement element of the fourth clutch C-3. The second piston 54 is on the outer peripheral side of the hub portion 32a the second drum 32 arranged with the wedges engaging portion 95 is trained.

The suspension plate 97 is on the outer periphery of the rear end portion of the boss portion 31a at the first drum 31 arranged so that their movement in an axial direction through a clamping ring 96 is limited. The outer peripheral side of the cancellation plate 97 is in the inner circumferential surface of the second piston 54 fitted and a second repeal chamber 98 is between the suspension plate 97 and the second piston 54 educated. The return spring 55 that the second piston 54 in the axial direction board to open the fourth clutch C-4 is between the Aufhebungsplatte 97 and the second piston 54 arranged.

The third clutch C-3 is through the third drum 31 , the frictional engagement element, which passes through a partition plate 41 and a friction plate 22 is formed, the first cylinder chamber 43 , the first piston 44 , the return spring 45 and the hydraulic servo fluid-tight through the first drum 31 and the first piston 44 is executed. The friction engagement element, the first piston 44 and the return spring 45 are in the first drum 31 accommodated.

Similarly, the fourth clutch C-4 is through the second drum 32 , the frictional engagement element passing through the partition plate 51 and the friction plate 52 is formed, the second piston 54 , the return spring 55 and the hydraulic servo fluid-tight through the second drum 32 and the second piston 54 is executed. The friction engagement element, the second piston 54 and the return spring 55 are inside the second drum 32 added. A pressure oil supply passage 60 is through a variety of second working oil supply holes 56 in the hub section 31a the first drum 31 are formed in circumferentially equiangular positions in the radial direction, a plurality of third working oil supply holes 66 in the hub section 32a the second drum 32 are formed in circumferentially equiangular positions in the radial direction, and an annular oil passage 67 formed between the two hub sections 31a . 32a is trained. The second and third working oil supply hole 65 . 66 stand together over the annular oil passage 67 in connection. A pair of sealing rings 99 is on the sleeve element 33 on each side of the second working oil supply holes 65 arranged in the axial direction. Likewise, a sealing ring (O-ring) 100 at the hub portion 31a the first drum 31 on each side of the second and third working oil supply holes 65 . 66 arranged in the axial direction thereof, around the annular oil passage 67 train.

The outer circumference of the outer diameter section 31b the first drum 31 is disengaged via the first brake B-1 with the gear housing 11 connected. The first brake B-1 is engaged by a frictional engagement element with a partition plate 71 , which wedges with the inner circumference of the transmission housing 11 is, and a friction plate 72 that wedges with the outer circumference of the outer diameter section 31b the first drum 31 , and formed a hydraulic servo. The hydraulic servo is from a piston 74 , which is displaceable in an oil chamber 73 housed in the gearbox 11 is formed, and a return spring 75 formed the piston 74 biases.

The supporting end of the piston 74 extends to the side of the frictional engagement element of the first brake B-1. The oil chamber 73 the hydraulic servo is connected to the oil pressure control device via an oil passage or the like, which is not shown in the drawing, in the transmission housing 11 is formed, and as a result of the oil pressure supplied by the oil pressure control device, the piston shifts 74 against the spring force of the return spring 75 to frictionally engage the frictional engagement element of the first brake B-1. When the supply of the pressure oil is stopped, the frictional engagement with the frictional engagement element by the spring force of the return spring 75 solved.

A lubricant supply passage 81 is in the input shaft 15 and lubricating oil discharged by an oil pump not shown in the drawing becomes the supply passage 81 via the oil pressure control device and a supply hole 83 fed. A variety of rows of feed holes 84 . 85 communicates with the feed holes 81 and the lubricating oil becomes each portion in the interior of the transmission case 11 through these feed holes 84 . 85 fed. The lubricating oil that goes to the inside of the gearbox 11 is distributed radially outward by the action of the centrifugal force and thereby to various locations including the speed reduction planetary gear 20 , the clutches C-3, C-4, the brake B-1 and the bearings supplied.

When the third clutch C-3 is engaged, the first drum rotates 31 as a unit with the ring gear R1 of the speed reduction planetary gear 20 , Further, when the fourth clutch C-4 is engaged, the first drum rotates 31 with the second drum 32 , acting as a unit with the carrier C-1 of the speed reduction planetary gear 20 rotates. Usually the first drum 31 at the hub portion 27a of the oil pump body 27 over the fixing sleeve through the main bearing 36 rotatable alone. The auxiliary warehouse 37 is on the outer circumference of the sleeve member 33 with a gap in between, and therefore does not work as a bearing.

However, if the vehicle turns right or left while the first drum 31 As a result, a phenomenon occurs whereby the first drum tilts in the axial direction (the traveling direction of the vehicle) due to generation of a gyroscopic moment. When the external force of an axial inclination, such as gyroscopic moment on the first drum 31 works that way, so the first drum 31 tilts by a predetermined angle, the auxiliary bearing touches 37 the outer circumference of the sleeve member 33 so it works as a warehouse. Because the auxiliary camp 37 functioning as an emergency warehouse, it does not need to be durable and can therefore be set to a minimum axial length. Since also the auxiliary storage 37 the axial inclination of the first drum receives, a situation can be prevented in which the first drum, the sealing rings, on the oil passage for supplying the working oil to the first cylinder chamber 43 are set, breaks up, so that the pressurized oil leading to the first cylinder chamber 43 is supplied, which causes a reduction in the controllability of the first hydraulic servo.

According to the embodiment described above, the inner periphery becomes at one end of the boss portion 31a the first drum 31 at the fixing sleeve 35 rotatably supported at the tip end portion of the outer periphery of the boss portion 27a of the oil pump body 27 fitted over the metallic sleeve-shaped main bearing 36 , and the main camp 36 has a sufficient axial length to the first drum 31 to be supported alone. Therefore, usually the first drum 31 at the hub portion 27a of the oil pump body 27 only through the main camp 36 be supported rotatably. Furthermore, the metallic sleeve-shaped auxiliary bearing 37 having a short axial length at the inner periphery at the other end of the boss portion 31a fit and is the auxiliary camp 37 on the outer circumference of the sleeve member 33 with a gap in between, so normally the auxiliary bearing 37 not working as a warehouse. Therefore, the auxiliary warehouse needs 37 not durable and can be set to the minimum axial length. As a result, although the plurality of supply passages for supplying the pressurized oil to the first and second cylinder chambers 43 . 53 the respective hydraulic servo of the third and fourth clutches C-3, C-4 at the mating surface between the boss portion 31a and the sleeve member 33 are provided, increases the axial length of the first drum 31 and the support device for supporting the first drum 31 can be suppressed and accordingly the weight of the automatic transmission can be reduced and this can be made more compact.

In the embodiment described above, an automatic transmission capable of obtaining gear ratios for eight forward speeds and two reverse speeds is described, but the present invention is not limited thereto and can be applied to any automatic transmission in which lubricating oil is supplied via a clutch to another clutch ,

Further, in the above-described embodiment, the planetary gear set 21 a Ravigneaux gear set that combines a single pinion planetary gearbox and a double pinion planetary gearbox, but is the planetary gear set 21 of the present invention is not limited to a Ravigneaux gear set, and any planetary gear set may be employed as long as it has a plurality of (two or more) planetary gears.

Moreover, in the embodiment described above, the sleeve member 33 and the fitting sleeve 35 each at the outer periphery of the hub portion 27a of the oil pump body 27 fitted, leaving one end of the first drum 31 at the fixing sleeve 35 about the main camp 36 is rotatably supported and the other end of the first drum 31 with the auxiliary camp 37 is provided on the sleeve member 33 with a game in between. Here form the sleeve element 33 and the fixing sleeve 35 a part of the cylindrical support portion in the claims. It should be noted that the sleeve element 33 and the fixing sleeve 35 can be omitted and the first drum 31 on the cylindrical support portion (the hub portion 27a ) can be directly supported. The specific structure of the above-described embodiment is just one example of the present invention. The present invention is not limited to this specific structure and, of course, may employ various aspects within the scope that does not depart from the spirit.

Industrial applicability

The automatic transmission according to the present invention is disposed at the rear of the engine relative to the direction of travel of the vehicle, and is suitable for an application suitable for a speed change mechanism for shifting between a plurality of gears by engaging and disengaging a plurality of clutches and brakes.

Claims (4)

Automatic transmission ( 10 ) disposed relative to a direction of travel of a vehicle on the rear side of an engine, which includes a speed change mechanism ( 13 ) for shifting between a plurality of gears by engaging and disengaging a plurality of clutches (C-1, C-2, C-3, C-4) and brakes (B-1, B-2), characterized in that the speed change mechanism ( 13 ) Comprises: a cylindrical support section ( 27a ); a first hydraulic servo having a first drum ( 31 ) and a first piston ( 44 ), which has a first cylinder chamber ( 43 ) together with the first drum ( 31 ) to make one of the plurality of clutches operable; and a main camp ( 36 ), which on an inner circumference of a hub portion ( 31a ) of the first drum ( 31 ) and an outer periphery of the cylindrical support portion (FIG. 27a ) is arranged to the first drum ( 31 ) rotatably support; wherein the speed change mechanism ( 13 ) is characterized by an auxiliary bearing ( 37 ), which in one end of the inner circumference of the hub portion ( 31a ) of the first drum ( 31 ) is pressed and to the cylindrical support portion ( 27a ) is fitted with a play therebetween, the cylindrical support section ( 27a ) only touches when the first drum ( 31 ) tilts in the direction of travel of the vehicle, and that has a shorter axial length than the main bearing ( 36 ) Has. Automatic transmission ( 10 ) according to claim 1, characterized in that the cylindrical support section ( 27a ) is a hub portion extending from a transmission housing ( 11 ), wherein the speed change mechanism ( 13 ) a first working oil feed passage ( 47 ), which in the hub portion of the transmission housing ( 11 ), and having a first working oil supply hole in the hub portion (FIG. 31a ) of the first drum ( 31 ), and wherein the working oil to the first cylinder chamber ( 43 ) is supplied through the first working oil supply passage and the first working oil supply hole via a pair of seal rings attached to the hub portion of the transmission case (FIGS. 11 ) are arranged. Automatic transmission ( 10 ) according to claim 2, characterized in that the speed change mechanism ( 13 ) further comprises: a second hydraulic servo with a second drum ( 32 ) and a second piston ( 54 ) slidably mounted on a hub portion ( 32a ) of the second drum ( 32 ) is arranged and a second cylinder chamber ( 53 ) together with the second drum ( 32 ) trains; and a second working oil feed passage ( 60 ), which in the hub portion of the transmission housing ( 11 ) is formed, a second working oil supply hole ( 65 ) located in the hub section ( 31a ) of the first drum ( 31 ), and a third working oil supply hole ( 66 ) located in the hub section ( 32a ) of the second drum ( 32 ), wherein the first drum ( 31 ) is open to the rear in the direction of travel of the vehicle, the first drum ( 31 ) and the second drum ( 32 ) by a wedging engagement section ( 95 ), a first spline ( 31c ), which on an outer peripheral surface of a rearward in the direction of travel of the vehicle end portion of the hub portion ( 31a ) of the first drum ( 31 ) is formed, and a second spline ( 32c ), which on an inner peripheral surface of the hub portion ( 32a ) of the second drum ( 32 ) are engaged, so that they are capable of rotation as a unit, wherein the main bearing ( 36 ) on an inner peripheral side of the vehicle rear end portion of the hub portion (FIG. 31a ) of the first drum ( 31 ), and wherein the working oil to the second cylinder chamber ( 53 ) through the second working oil feed passage ( 60 ) and the second working oil supply hole ( 65 ) over the pair of sealing rings ( 99 ), which at the hub portion of the transmission housing ( 11 ) and through the second working oil supply hole (FIG. 65 ) and the third working oil supply hole ( 66 ) via a pair of sealing rings ( 100 ) is fed between the hub portion ( 31a ) of the first drum ( 31 ) and the hub portion ( 32a ) of the second drum ( 32 ) are arranged. Automatic transmission ( 10 ) according to one of claims 1 to 3, characterized in that the main bearing ( 36 ) is formed of a metal sleeve.

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