JPS62288753A - Multi-disc type brake lubricating construction of automatic transmission - Google Patents

Abstract

PURPOSE:To make an oil pump compact by providing an oil passage which introduces working oil leaked from a hydraulic receiving part supplying the working oil pressure to a clutch into multi-disc type brake friction plates and lubricates the plates between a clutch drum of the hydraulic working clutch and a drum supporting member thereof. CONSTITUTION:Working oil pressure is supplied through a hydraulic receiving part 44 to actuate a hydraulic working clutch F/C, and respective forward speeds can be selected. This time, a portion of working oil is leaked from a seal ring 46 and gone into friction plates 48, 49 from a hole 55 through a cavity 53 and an oil gallery 54 to lubricate the plates. A multi-disc type brake LR/B and a reverse clutch R/C are actuated to select back speed. This time, the clutch F/C is not operated and no oil is leaked from the seal ring 46 and the friction plates 48, 49 are not lubricated. Then, drive load of an oil pump can be reduced and compactness of the pump can be realized.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a lubrication structure for a multi-disc brake that is operated when reverse is selected in an automatic transmission.

(Prior Art) Automatic transmissions are normally configured so that forward gears can be selected by operating a hydraulically operated clutch, and reverse gears can be selected by operating a multi-disc brake.

By the way, when it comes to lubrication of multi-disc brakes, that is, lubrication of their friction plates, conventionally the low reverse method shown in Figure 19 of page 16 of "Nirasan Full Automatic 3N71 Type B Maintenance Manual" published by Nissan Motor Co., Ltd. in 1976 has been used. As seen in the lubrication structure of the brake, the lubrication is performed using a portion of the lubricating oil that is constantly guided from the shift control hydraulic circuit to the center hole of the transmission output shaft.

(Problems to be Solved by the Invention) However, in such a conventional configuration, the multi-disc brake is constantly lubricated regardless of whether the forward gear is selected or the reverse gear is selected, resulting in the following problems. .

That is, lubrication of a multi-disc brake is not required during operation when there is no relative rotation between its friction plates, and is only necessary during non-operation when relative rotation is occurring between the V-plates. However, in the conventional configuration in which lubrication is performed even though it is not necessary during reverse gear selection when the multi-disc brake is activated, the oil pump must discharge excess hydraulic oil.In addition, Since it is necessary to increase the hydraulic pressure of the multi-disc brake while selecting the reverse gear, the amount of lubricating oil is increased even though it is not necessary, and the oil pump capacity is even insufficient.

In addition, there are many automatic transmission components between the hollow hole of the transmission output shaft and the friction plates of the multi-disc brake, and forming a lubricating oil passage that penetrates these components requires a large number of oil holes. The problem of increased costs also arises.

(Means for Solving the Problems) The present invention proposes a multi-disc brake lubrication structure that does not cause these problems. It is characterized by a structure in which a lubricating oil passage is provided to guide hydraulic oil leaking from a hydraulic pressure transfer section that transfers hydraulic pressure to the clutch between the drum support member and the friction plate that is inactive during forward gear selection. .

(Function) The automatic transmission selects each forward gear by operating a hydraulically operated clutch, and selects a reverse gear by operating a multi-disc brake.

During selection of each forward gear stage, the hydraulically operated clutch is actuated by hydraulic pressure supplied via a hydraulic transfer section between the clutch drum and the clutch drum support member.

During this time, the hydraulic oil leaking from the hydraulic transfer section is guided by the lubricating oil path to the friction plates of the multi-disc brake, so that the friction plates that rotate relative to each other during selection of the forward gear stage can be lubricated as required.

During selection of reverse gear, the hydraulically actuated clutch is deactivated;
Therefore, the hydraulic pressure does not pass through the hydraulic pressure transfer section, and the hydraulic fluid does not leak from this and reach the friction plates of the multi-disc brake. However, while the lever is selecting the reverse gear, the friction plate is not rotating relative to the other and does not require lubrication, so there is no problem.

Therefore, the multi-disc brake is not lubricated when unnecessary reverse movement is selected, and the amount of hydraulic oil discharged from the oil pump can be reduced accordingly, thereby reducing the driving load. Furthermore, even if the operating hydraulic clutch of the multi-disc brake is increased when the reverse gear is selected, operating hydraulic pressure is not supplied to the hydraulically operating clutch at this time, so the amount of hydraulic oil leaking from the hydraulic pressure transfer section is O, and the oil pump has a capacity of The oil pump can be downsized without causing shortages.

(Example) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is an internal configuration diagram of an automatic transmission showing one embodiment of the present invention, and FIG. 2 is a skeleton diagram showing the same outline.

First, the outline will be explained with reference to FIG. 2. The human power shaft 1 and the output shaft 2 are arranged coaxially, a first planetary gear set 4 and a second planetary gear set 5 are provided on the common axis, and further explained below. The transmission train of an automatic transmission is constructed by adding various friction elements.

The first planetary gear set 4 includes a sun gear 4S and a ring gear 4R.

A normal simple planetary gear set consisting of a pinion 4P meshing with these and a carrier 4C rotatably supporting the pinion 4P is used, and the second planetary gear set 5 is also a sun gear 5S.

A simple planetary gear set consisting of a ring gear 5R, a pinion 5P, and a carrier 5C.

Next, the various friction elements mentioned above will be explained. The carrier 4C can be appropriately connected to the input shaft 1 via a high clutch H/C, the sun gear 4S can be appropriately fixed by a band brake B/B, and the input shaft 1 can be connected to the input shaft 1 by a reverse clutch R/C.
It can be combined as appropriate. Further, the carrier 4C can be appropriately fixed by a multi-plate low reverse brake LR/B, and is prevented from being reversed (rotation in the opposite direction to the engine) via a row one-way clutch LO/C. The ring gear 4R is integrally coupled to the carrier 5C and drivingly coupled to the output shaft 2, and the sun gear 5S is coupled to the input shaft 1. Ring gear 5R is connected to carrier 4C as appropriate via overrun crank OR/C.
In addition to being able to connect to the forward one-way clutch F
It is correlated to the carrier 4C via the O/C and forward clutch F/C. Forward one-way clutch FO
/C is assumed to connect the ring gear 5R to the carrier 4C in the reverse direction (direction opposite to the engine rotation) with the forward clutch F/C engaged.

High clutch II/C, reverse clutch R/C, low reverse brake LR/B, overrun clutch OR
The forward clutch F/C and the forward clutch F/C are each operated by the supply of hydraulic pressure to perform the above-mentioned appropriate coupling and fixing, but the band brake B/B is particularly constructed as shown in FIG. 3. That is, the stepped piston 8 and the piston 9 are slidably fitted into the housing 10 to form the second speed servo apply chamber 2.
Set S/A, 3rd speed servo release chamber 3S/R, and 4th speed servo apply chamber 4S/A.

A spring 11 is compressed between both pistons 8.9 to restrain them to the farthest position from each other as shown in the figure, and while maintaining this relative position, both pistons 8.9 are urged to the non-operating position by a spring 12. support In this configuration, when the second speed selection pressure P2 is supplied to the second speed servo apply chamber 2S/A, the piston 8 moves to the left in the figure together with the piston 9, and the band brake B/B is tightened by tightening the brake band 13. Operate. In this state, 3 is also placed in the 3rd speed servo release chamber 3S/R.
When the speed selection pressure P is supplied, the piston 8 moves to the right in the figure depending on the magnitude of the pressure receiving area, and the band brake B/B becomes inoperable due to the relaxation of the brake band 13. Thereafter, when the 4th speed selection pressure P4 is also supplied to the 4th speed servo apply chamber 4S/A, the piston 9 is moved to the left in the figure independently, and the band brake B/B is activated by tightening the brake band 13.

The power transmission train in Figure 2 consists of friction elements B/B, H/C, F.
/C.

By operating OR/C, LR/B, and R/C in various combinations as shown in the table below, the friction elements FO/C, L
Together with the appropriate operation of the O/C, it is possible to change the rotational state of the elements constituting the planetary gear set 4.5, thereby changing the rotational speed of the output shaft 2 relative to the rotational speed of the input shaft 1,
As shown in the following table, it is possible to obtain four forward speeds and one reverse speed. In the table below, the ○ mark indicates operation (hydraulic inflow), and the ∆ mark indicates a friction element that should be activated when engine braking is required. Then, while the overrun clutch OR/C is operated as indicated by Δ, the forward one-way clutch FO/C placed in parallel with these becomes inactive, and while the low reverse brake LR/B is operated, the forward one-way clutch FO/C is placed in parallel with it. Of course, the row one-way clutch LO/C becomes inoperative.

As is clear from Table 1, in the power transmission train, the low reverse brake LR/B corresponds to the multi-disc brake, and the forward clutch F/C corresponds to the hydraulically operated clutch.

FIG. 1 embodies the above-mentioned power transmission train and shows the lubrication structure of the present invention configured for low reverse brake LR/B applied thereto. Reference numeral 20 in the figure indicates a transmission case, and an oil pump 21 for discharging hydraulic oil is provided at the open left end in the figure, and the input shaft 1 is installed through the center of the oil pump to be rotatably supported. The output shaft 2 is installed rotatably through the closed right end of the transmission case 20 in the figure, and the input/output shaft 1
．． 2 are butted together so that they can rotate relative to each other on the same axis.

First and second planetary gear sets 4 and 5 are provided on the input shaft 1, and a reverse clutch R/C, high clutch H/C, and band brake B/B are installed between the planetary gear set 4 and the oil pump 21.
Place. A member 22 that serves as the clutch drum of the high clutch H/C and the clutch hub of the reverse clutch R/C is drivingly connected to the input shaft l, and the clutch hub 23 and drum 24 of the high clutch H/C are arranged inside and outside the member 22. do. The clutch hub 23 is drivingly coupled to the carrier 4C,
The drum 24 is connected to the sun gear 4S and serves as the clutch drum of the reverse clutch R/C and the brake drum of the band brake B/H. Hydraulic piston 2 within member 22
5 is slidably fitted, and this piston operates the high clutch H/C by the hydraulic pressure applied to the chamber 26.

Further, a hydraulic piston 27 is slidably fitted into the drum 24, and this piston operates the reverse clutch R/C by applying hydraulic pressure to the chamber 28.

Ring gear 4R is connected to carrier 5C, and carrier 5C
is drive-coupled to the output shaft 2, and the sun gear 5S is drive-coupled to the input shaft 1. A clutch drum 29 is fixedly attached to the carrier 4C, and extends to near the right end of the transmission case 20 in the drawing, and serves as a clutch drum for the forward clutch F/C and overrun clutch OR/C. The forward clutch F/C is arranged on the outer periphery of the ring gear 5R, and the overrun clutch is arranged on the right side of the forward clutch F/C in the figure, and the overrun clutch OR/C is arranged on the outer periphery of the ring gear 5R.
A forward one-way clutch FO/C is placed on the inner circumference of the clutch.

The clutch hub 30 of the forward clutch F/C is rotatably supported on the outer periphery of the ring gear 5R and connected to the outer race 31 of the forward one-way clutch FO/C, and the inner race 32 of the forward one-way clutch FO/C is connected to the output shaft 2. The ring gear 5R is rotatably supported and connected to the ring gear 5R. The right end of the clutch drum 29 in the figure is rotatably supported on a clutch drum support member 34 connected to the transmission case 20 with bolts 33, and the rightward thrust in the figure applied to the clutch drum 29 is transmitted between this and the clutch drum support member 34. It is supported by a thrust bearing 35 interposed between the step portion 34a and the step portion 34a.

A hydraulic piston 36 is slidably fitted into the right end of the clutch drum 29 in the figure, and this piston operates the forward clutch F/C by applying hydraulic pressure to a chamber 37. Overrun clutch OR/C clutch hub 38
is arranged to surround the outer race 31 of the forward one-way clutch FO/C, and is connected to the inner race 32 of the one-way clutch. Another hydraulic piston 39 is slidably fitted into the hydraulic piston 36, and this piston operates the overrun clutch OR/C by applying hydraulic pressure to the chamber 40.

To explain the oil path leading to the operating hydraulic chamber 37 of the forward clutch F/C related to the present invention, this is the oil path leading to the hydraulic pressure chamber 37 of the forward clutch F/C.
0 and the vertical hole 41 formed in the clutch drum support member 34
, a groove 42 formed on the outer periphery of the clutch drum support member 34 in communication with the groove 42 , and a radial hole 43 in the clutch drum 29 . The groove 42 and the radial hole 43 constitute a hydraulic pressure transfer section 44 that transfers the working pressure to the forward clutch F/C between the clutch drum 29 and the member 34 that rotatably supports it. Seal rings 45, 46 are provided on both sides of the thread s42 to prevent leakage of hydraulic oil from the parts. However, the seal rings 45 and 46 are split at one place in the circumferential direction so that they can be expanded and installed when installed, and hydraulic oil leaks through this area when hydraulic pressure passes through the seal ring. 45.
There are some cases where the seal ring 46 is not broken, and in the present invention, the oil leaking from the seal ring 46 is utilized for lubrication of the low reverse brake LR/H by the following configuration.

The low reverse brake LR/B and the row one-way clutch LO/C are arranged inside the right end of the transmission case 20 in the figure, and the row one-way clutch LO/C is located on the inner periphery of the low reverse brake LR/B. The inner race of the row one-way clutch LO/C is formed by the clutch drum support member 34, and the outer race 47 also functions as the hub of the low reverse brake LR/B. This outer race 47 is butted against and welded to the right end of the clutch drum 29 in the figure, and a friction plate 48 is spline-fitted to the outer periphery of the outer race 47. A friction plate 49 is spline-fitted to the inner periphery of the transmission case 20. A low reverse brake LR/B is constituted by a hydraulic piston 50 that frictionally engages the plates. The piston 50 is slidably fitted into the corresponding end of the transmission case 20, and the above-mentioned frictional engagement is performed by the hydraulic pressure applied to the chamber 51, so that the low reverse brake LR is activated.
/B shall be activated.

Low reverse brake LR/B, friction plate 48.4
9 is lubricated by oil leaking from the seal ring 46, the outer race 4 is butted against the clutch drum 29.
A cutout groove 52 is formed in the end face of the outer race 47 of the outer race 47, and a through hole 55 is formed in the outer race 47 to allow communication between the storage space 53 of the thrust bearing 35 and the oil gear lary 54, and to allow the oil gear lary 54 to communicate with the friction plate 48,49. , these constitute a lubricating oil passage 56 that guides leaked oil from the seal ring 46 to the friction plates 48, 49.

The operation of the above embodiment will be explained next.

The hydraulic pressure flows from the vertical hole 41 to the chamber 37 via the hydraulic pressure transfer section 44.
While the piston 36 moves to the left in the figure and operates the forward clutch F/C, other friction elements B/B, H/C, FO/C, LO/ By selecting C, the first to fourth forward speeds can be selected. Hydraulic pressure delivery unit 44 during selection of each of these forward gears
A portion of the hydraulic oil that continues to be supplied through the seal ring 46
leaks into the cavity 53 through the thrust bearing 35.
Lubricate. The leaked oil then passes through the notched groove 53 and is stored in the oil gear lary 54, and is passed through the hole 55 to the friction plate 48, 49.
be guided by By the way, the forward gear selection middle-reverse brake LR/B is deactivated, and the friction plate 48.
Since there is relative rotation between the two parts, lubrication is essential, and this lubrication can be reliably performed using the leaked oil.

The piston 50 moves to the left in the figure due to the hydraulic pressure applied to the chamber 51, actuating the low reverse brake LR/B, and at the same time
When the piston 27 moves to the right in the drawing due to the working oil pressure to 8 and operates the reverse clutch R/C, the reverse gear stage can be selected as is clear from Table 1 above. During this time, the forward clutch F/C is inactive, and no hydraulic pressure passes through the hydraulic pressure transfer section 44. Therefore, seal ring 4
There is no oil leaking from 6, low reverse brake 1. R/
Fl's 1\rub 4Fl, 49 are not lubricated. However, while selecting the reverse gear, the low reverse brake LR/B
continues to be operated and no relative rotation occurs between the friction plates 48 and 49, so lubrication of the low reverse brake LR/B is unnecessary and no problem occurs.

In this way, by not lubricating the low reverse brake LR/B when unnecessary reverse gear is selected, the amount of hydraulic oil discharged from the oil pump 21 can be reduced accordingly, and the driving load thereof can be reduced. Furthermore, even if the hydraulic pressure of the low reverse brake LR/B is increased when the reverse gear is selected, the hydraulic pressure is not supplied to the forward clutch F/C and the leakage oil from the hydraulic pressure transfer section 44 is zero. The oil pump 21 does not become insufficient in capacity due to increased leakage oil, and the oil pump can be downsized.

Furthermore, a hydraulic transfer section 44 and a friction plate 48 of a multi-disc brake.
49, there are very few automatic transmission components present between them (in the illustrated example, only the outer race 47 of the row one-way clutch LO/C), and the oil that needs to be formed when forming the lubricating oil path is The number of holes 52 and 55 is small, and the processing cost does not increase.

As is clear from Table 1 above, the low reverse brake LR/B is also operated during engine braking in the first forward speed and does not require lubrication. /B is lubricated by leaking oil from the hydraulic pressure transfer section 44. However, such engine braking time is extremely short and does not pose a problem.

In addition, in this embodiment, the forward clutch F/C and low reverse brake LR/B are constructed to be adjacent to each other, or even if they are separated from each other, the oil leaked from the forward clutch F/C operation can be removed. It goes without saying that the same effect can be achieved even if the low reverse brake LR/B is supplied through a separate oil path.

(Effects of the Invention) As described above, the structure of the present invention provides a hydraulically operated clutch (forward clutch F/C) operated at each forward gear.
The multi-disc brake (
Since the configuration is such that the low reverse brake (LR/B) is lubricated, the multi-disc brake is lubricated only when a necessary forward gear is selected, and not when an unnecessary reverse gear is selected. The driving load can be reduced by reducing the amount. In addition, even if the hydraulic pressure of the multi-disc bouquet is increased when reverse gear is selected, the leaked oil is kept at O because the hydraulically operated clutch is not activated, and the oil pump does not run out of capacity in the reverse gear. The pump can be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view showing a power transmission section of an automatic transmission according to an embodiment of the present invention, Fig. 2 is a skeleton diagram thereof, and Fig. 3 is a sectional view of a band brake in this power transmission section. . 1... Input shaft 2... Output shaft 4... 1st planetary gear set 5... 2nd 't1 star gear set B/B.
・・Band brake R/C・・Reverse clutch)
1/C...High clutch F/C...Forward clutch (hydraulic operated clutch)
FO/C...Forward one-way clutch OR/C
...Overrun clutch LR/B...Low reverse brake (multi-plate brake)
LO/C... Row one-way clutch 20... Transmission case 2nd work... Oil pump 44... Hydraulic pressure transfer part 45.46... Seal ring 48.4
9...Friction plate 5G...Lubricating oil path Patent applicant: Nissan Motor Co., Ltd. Representative Patent Attorney Akatsuki Sugimura Shudo Patent Attorney Kosaku Sugimura

Claims (1)

[Claims] 1. A multi-disc brake that is deactivated during each forward gear selection and activated when a reverse gear is selected, and a multi-disc brake that continues to be activated during each forward gear selection and selects a reverse gear. In an automatic transmission equipped with a hydraulically actuated clutch that is deactivated when the hydraulically actuated clutch is turned off, hydraulic pressure is transferred to the hydraulically actuated clutch between a clutch drum of the hydraulically actuated clutch and a clutch drum support member that supports the clutch drum. A multi-disc brake lubrication structure for an automatic transmission, characterized in that a lubricating oil path is provided to guide hydraulic oil leaking from a hydraulic pressure transfer section to a friction plate of the multi-disc brake.