JPH0221055A - Transmission with auxiliary transmission - Google Patents

Abstract

PURPOSE:To form easily a drain passage of an auxiliary transmission side by forming a drain passage for communicating a lube oil reservoir with the opposite side of a lube oil reservoir of the friction element, between the outer surface lower part of a piston drum and an auxiliary transmission case. CONSTITUTION:The second piston drum 152 of a reduction brake composing an auxiliary epicycle transmission gear 114 is formed separately from an auxiliary transmission case 134. Owing to this reason, a drain passage 170 for communicating the chamber 162 side of a reduction brake with the oil pan 133 side of the reduction brake can be formed by the forming of a channel part 168 simultaneously with the molding of the auxiliary transmission case 134, without any machine work when the second piston drum 152 is attached. Consequently, the processing of the drain 170 is remarkably simplified in cooperation with the integral forming of the auxiliary transmission case 134 so that the productivity of the auxiliary transmission is improved and a large cost down can be aimed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transmission equipped with an auxiliary transmission for multi-stage output rotation.

BACKGROUND OF THE INVENTION Conventional transmissions with sub-transmissions include, for example, the one disclosed in Japanese Patent Application Laid-Open No. 6141067.
In the transmission disclosed in the same publication, an automatic transmission is used as a main transmission, and the output rotation that has been shifted to a plurality of gears by the automatic transmission is further transmitted by an auxiliary transmission provided on the output side of the automatic transmission. It is now multi-staged.

The sub-transmission disclosed in the above publication is constituted by a sub-gear transmission mechanism using one set of planetary gears, and the coupling relationship of each component of the planetary gear set is appropriately set in the sub-gear transmission mechanism. Two sets of piston-type friction elements are provided for switching.

In addition, in the same publication, since the transmission is used as a four-wheel drive device, a transfer device is provided in the sub-transmission, in addition to the two sets of friction elements, and the output is distributed to the transfer device. A set of friction elements is provided for this purpose.

Problems to be Solved by the Invention However, in such a conventional transmission with an auxiliary transmission, the auxiliary transmission case that houses the auxiliary gear transmission mechanism has a structure that separates each of the three friction elements provided in the auxiliary transmission. The auxiliary transmission is assembled into these divided cases by sometimes using fastening members such as bolts to connect them together.

However, although it is more reasonable to separately process and assemble each friction element that has different functions as required for its function, the case itself has the function of protecting what is inside, so each divided case are the same function,
It is preferable to form at least the sub-transmission case entirely by integral molding in terms of man-hours.

For this reason, in the above-mentioned conventional transmission with an auxiliary transmission, the auxiliary transmission case is divided into three parts, which increases the number of man-hours for assembly due to the increase in the number of parts, resulting in a decline in productivity. Put it away.

Furthermore, in the transmission with an auxiliary transmission disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 61-41067, although an oil pan (lubricating oil reservoir) is provided on the main transmission side,
An oil pan is also provided on the sub-transmission side, which also increases the number of parts and increases the size of the transmission.

In other words, it is desirable that the oil pan be unified into one oil pan in order to simplify the configuration and facilitate liquid level management using a level gauge or the like.

Therefore, as shown in FIG. 3, an auxiliary transmission case 2 that houses the auxiliary transmission gear mechanism 1 is formed by integral molding, and the integrally molded auxiliary transmission case 2 is used as a main transmission case that houses the main transmission gear mechanism 3. A unified oil pan 5 is provided at the lower part of the main transmission case 4 while being connected to the transmission case 4,
It is possible to imagine a transmission M with a sub-transmission in which the lubricating oil used in the main transmission 6 and the sub-transmission 7 is stored in the oil pan 5, respectively.

8 is an input shaft that introduces engine power to the main transmission 6;
9 is an intermediate shaft connecting the main transmission 6 and the sub-transmission 7; 10
is an output shaft that transmits the output of the sub-transmission 7 to the driving wheels.

By the way, when such a transmission M with an auxiliary transmission is assumed, it is necessary to flow lubricating oil from the auxiliary transmission 7 to the oil pan 5, as shown in the following A) and C). Various issues arise.

That is, since a planetary gear set is used in the auxiliary transmission gear mechanism l of the auxiliary transmission 7, its friction element is disposed coaxially with the output shaft 10 of the auxiliary transmission 7, and the friction element is arranged coaxially with the output shaft 10 of the auxiliary transmission 7. A multi-plate club using a chi type is used,
It is disposed in a substantially circular shape within the inner cross section of the sub-transmission case 2.

b) In FIG. 4, the outer periphery of the annular piston I2 of the friction element 11 is slidably fitted inside the sub-transmission case 2, and the inner periphery of the annular piston 12 is fitted to the outer periphery of the output shaft 8. The sub-transmission case 2 and the drum support 13 are slidably fitted into the inner cylinder 13a of the drum support 13.
A piston drum 14 is shown in which a piston drum 14 is constructed, and a chamber 15 on the right side of the friction element 11 in the figure (on the opposite side from the oil pan 5) is provided with a tampon drum for lubricating the outlet portion of the output shaft 10. Lubricating oil needs to be supplied.

In such a case, a drain passage 16 is required to allow the lubricating oil in the right side chamber 15 to flow into the oil pan 5.

However, since the rear end portion (the right end in the figure) of the sub-transmission case 2 is largely constricted, the drain passage 16 should be formed when the sub-transmission case 2 is manufactured by casting. In part A in the figure, casting scum remains, and in order to communicate with the drain passage 16,
It is necessary to machine the parts, and the process of removing these residual slag and machining work is increased,
Case material is wasted and costs increase.

Furthermore, if a blowhole is formed in the above-mentioned portion A, the machined surfaces will be communicated with each other by the blowhole when processing the inner surface of the piston drum 14 and machining the drain passage 16, and the hydraulic pressure chamber 17 of the friction element 11 will be Leaks may occur.

Therefore, as shown in FIG. 5, an opening 18 is set in advance at the rear end of the auxiliary transmission case 2, and the opening 18 is formed at the time of casting.
It is conceivable that the drain passage 16 is communicated by inserting a casting mold through the forming part of the opening 18, and then the opening 18 is closed. In this case, i19. Bolts 20 and sealing material 21 are required, which not only increases the number of parts and weight, but also increases the number of locations where lubricating oil may leak.

C) Furthermore, as a method to solve the above disadvantages, it is possible to use a sand mold core, but in this case, the drain passage 16 can be easily communicated, but the productivity decreases, which is a disadvantage of sand molds. Also, the weight increases significantly due to thickening of the casting wall.

In view of such conventional problems, the present invention has a structure in which the auxiliary transmission case is integrally molded, one lubricating oil reservoir is provided on the main transmission case side, and a drain on the auxiliary transmission side is provided. It is an object of the present invention to provide a transmission with an auxiliary transmission in which a passage can be easily formed.

Means for Solving the Problems In order to achieve the object, the present invention provides a main transmission in which a plurality of gears can be obtained by a main gear transmission mechanism, and a main transmission disposed on the output side of the main transmission. a sub-transmission that multi-stages the output rotation of the sub-gear by a sub-gear transmission mechanism; a lubricating oil reservoir provided in a main transmission case that houses the main gear transmission mechanism; and a sub-transmission case that houses the sub-gear transmission mechanism. and a friction element of the auxiliary gear transmission mechanism, which is disposed between the inner periphery of the auxiliary gear transmission and the outer periphery of the output shaft of the auxiliary gear transmission, and is engaged and released by movement of the annular piston, the lubricating oil of the friction element. In a transmission with an auxiliary transmission in which lubricating oil is actively supplied to the side opposite to the reservoir, the auxiliary transmission case is formed by integral molding, and the piston drum into which the annular piston is fitted is provided. The inner cylinder and the outer cylinder of the piston drum are formed separately from the auxiliary transmission case, and the inner and outer cylinders of the piston drum are integrally molded to slidably fit the inner and outer peripheries of the annular piston, respectively. A drain passage communicating with the lubricating oil reservoir and the opposite side of the lubricating oil reservoir of the friction element is formed between the outer peripheral lower end of the drum and the auxiliary transmission case.

Effect With the above configuration, in the transmission with a sub-transmission of the present invention, the piston drum into which the annular piston of the friction element is fitted is formed separately from the sub-transmission case, and the sub-transmission Since a drain passage is formed between the case and the piston drum, when casting the auxiliary transmission case as one piece,
By simultaneously forming a groove portion in advance in a portion corresponding to the drain passage, the groove portion becomes a drain passage when the piston drum is assembled, and the lubricating oil reservoir portion provided in the main transmission case. The friction element is easily communicated with the opposite side of the lubricating oil reservoir.

Further, since the inner cylinder and the outer cylinder of the piston drum are integrally formed, the piston drum can be manufactured by casting, and productivity can be improved.

EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

That is, FIG. 1 is a sectional view of a main part of a transmission with an auxiliary transmission 100 showing one embodiment of the present invention, and the overall configuration of the transmission with an auxiliary transmission 100 is shown in a schematic configuration diagram of FIG.

First, the transmission with sub-transmission R100 will be explained using the above-mentioned FIG. ) 1 is equipped with a main planetary gear transmission mechanism 112, and the sub-transmission 113 is equipped with a sub-planetary gear transmission mechanism 114.

The transmission 100 with a sub-transmission also includes an input shaft 118 connected to an engine (not shown) via a torque converter (not shown), and an output shaft 120 disposed on a coaxial extension of the input shaft 118. The output shaft 120 is connected to a rear wheel final reduction gear (not shown) via a propeller shaft (not shown).

The main planetary gear transmission mechanism 112 is attached to the input shaft 118, and the sub planetary gear transmission mechanism 114 is disposed on the output shaft 120.

The main planetary gear transmission mechanism 112 has basically the same structure as the variable transmission disclosed in Japanese Patent Application Laid-Open No. 62-62047, which has already been filed by the present applicant, and has two first and second planetary gears. The first . 2nd planetary gear set 1
22 and 124 are each configured as a simple planetary gear set, and each gear set has a first . 2nd sun gear 122s, 1
24S.

1st. Second ring gear 122. ．． 12411. 1st degree second pinion gear 122P, 124. , and 1st ° 2nd
It includes carriers 122c and 124c.

"28's 1st sun gear 122s is a band brake l (/
can be fixed to the housing ■ (side) through B, and
It can be coupled to the input shaft 118 via reverse clutch R/C.

The first carrier 122c can be coupled to the input shaft 118 via a high clutch H/C, and is prevented from rotating in the opposite direction to the input shaft 118 via a low one-way clutch L10YC, and the low reverse brake L R
/ B allows it to be fixed to the housing H side.

Further, the first carrier 122c is connected to the second ring gear 1248 via a forward clutch F/C and a forward r one-way clutch F10YC which are arranged in series with each other.
The first carrier 122C and the second ring gear 124R are further coupled to an overrun clutch OR.
It is possible to connect via /C.

(11) The second sun gear 124s is coupled to the input shaft 118, and the second carrier 124c is connected to the second sun gear 124s.
The rotation of the second carrier 124c is connected to the ring gear 122II, and the rotation of the second carrier 124c becomes the output rotation of the main planetary gear transmission mechanism 112.

1. The auxiliary planetary gear transmission mechanism +14 is a third idler 4-t4'IIfi wheel set 126 configured as a simple planetary gear set.
The third planetary gear set 126 includes a third sun gear 126
8, 3rd ring gear 126R, m3 pinion Kia 126
, and a third carrier 126c.

The third ring gear 1263 is coupled to the second carrier 124c, which is the output element of the main planetary gear transmission mechanism 112, via the intermediate shaft 128, and is connected to the third carrier 126c via the intermediate shaft 128.
c is coupled to the output shaft 120, and the third carrier 126c
The rotation becomes the output rotation of the sub-planetary gear transmission mechanism 114, and is transmitted from the output shaft 120 to the rear wheel side final reduction gear (not shown).

Further, the third carrier 126c can be coupled to a third sun gear 1268 via a direct clutch D/C, and the third sun gear 1269 can be fixed to the housing H side via a reduction brake RD/Is. Moreover, the third sun gear 1268 is prevented from rotating in the opposite direction to the human power shaft 118 via the reduction one-way clutch RD10YC.

Incidentally, the parking gear 130 is the third carrier 126c.
and the housing H.

In the transmission 100 with an auxiliary transmission configured as above, by operating the forward clutch F/C, high clutch II/C, and band brake 117B provided in the main planetary gear transmission mechanism 112, the main planetary gear transmission mechanism 112 is operated. Four forward speeds are obtained by the planetary gear transmission mechanism 112, and a reverse gear (L speed) is obtained by further operating the reverse clutch latch R/C and low reverse brake LR/B.

That is, when the forward clutch F/C is engaged, the second
Ring gear 124. is forward one-way clutch F
10YC and the row one-way clutch L10VC prevent rotation in the opposite direction to the human power shaft 118, so when 118 rotations of the human power shaft are input to the second sun gear 245,
2nd pinion gear 124 pi;! The second ring gear 1248, which is in a fixed state, rolls within the second ring gear 1248 and is an output element.
The carrier 124c is greatly decelerated in the same direction as the input shaft 118 and rotates forward, reaching the first forward speed state.

Next, when the forward clutch F/C and the band brake B/B are engaged, the first sun gear 122s is fixed by the band brake +1/B, and the second carrier 122s is fixed by the band brake +1/B.
When the first ring gear 1228 is rotated with the revolution of the sun gear 122, the first pinion gear 122P
The revolution when rolling on 2S is the first carrier 122. ,
Second ring gear 124. via forward clutch F/C and forward one-way clutch P10YC.
1 as a rotational force in the same direction as the input shaft 118, the second carrier 124c is rotated faster than the 1 speed state, and enters the 2nd forward speed state.

Next, forward clutch F/C and high clutch 1
1/C, the second ring gear I 2411 is integrally connected to the input shaft 118 via the forward clutch F/C, the first carrier 122c, and the high clutch H/C, and the second ring gear 124□ and the second sun gear 1248 are rotated together with the input shaft 118, so that the second carrier 12/1. rotates the same as the human power shaft 118, and is in the third forward speed state.

Next, high clutch H/C and band brake 13/
When B is fastened, the rotation of the input shaft 118 is input to the first carrier 122C with the first sun gear 1225 fixed, and the first ring gear 122. is rotated at increased speed. At this time, since no rotation blocking force is acting on the second ring gears 124, 1, the accelerated rotation of the first ring gear 1241I becomes the rotation of the second carrier 12/IC, and the state is in 4th forward speed. becomes.

Furthermore, reverse clutch R/C and low reverse brake 1. l? /B, the first sun gear 122
8 is integrally coupled to the input shaft 118, and the first carrier 122c is fixed to the housing I (side), so the rotation of the human shaft 118 input to the first sun gear 1225 is
It is transmitted to the first ring gear 122R in a reverse and decelerated state with only the rotation of the first pinion gear 122P. At this time, since no rotation preventing force is acting on the second ring gears 12/l, l, the rotation of the first ring gear 122R, which has been reversed and decelerated in 1-, becomes the rotation of the second carrier 124c, The vehicle will move backwards.

The overrun clutch OR/C is engaged when the engine brake is activated, and the overrun clutch OR/C and low reverse brakes 1 and R/B are engaged during the first forward speed, and the overrun clutch OR/C is engaged when the engine is in the first forward speed. Only the run clutch OR/C is engaged.

As described above, the forward 1, 2, and 3 forward speeds are obtained by the main planetary gear transmission mechanism 112.

The rotations of the fourth gear and the reverse gear are input to the sub-light star gear transmission mechanism 114 via the intermediate shaft 128, and the sub-light star gear transmission mechanism 114 multiplies each gear stage.

That is, the secondary light star gear transmission mechanism 114 has the same speed as deceleration.
The third sun gear 126S is fixed to the housing FI side by engaging the reduction brake RD/B, and the extension member 1
28, when the rotation of the main planetary gear transmission mechanism 112 is input to the third ring gear 1268, the third pinion gear! 26. is rolled along the third sun gear 1263,
The third pinion gear 126 is in a deceleration state at this time.
The revolution of p is transmitted to the output shaft 12 via the third carrier 126c.
It is manually powered to 0 and enters a deceleration state.

Next, when the reduction brake RD/B is released and the direct clutch D/C is engaged, the third sun gear 126S and the third carrier 126c are integrally coupled, and the third i! The star gear set +26 is in a locked state, that is, a directly connected state, and the rotation of the third ring gear 126R is directly outputted via the third carrier 126o, resulting in the same speed state.

Note that the reduction one-way clutch RD10YC reduces the switching shock when the reduction brake RD/B is released.

In this way, the secondary planetary gear transmission mechanism 114 has two-step switching capability, and the main planetary gear transmission mechanism 112
Each of the four forward gears and one reverse gear can be switched in two ways to obtain eight forward gears and two reverse gears.

By the way, as shown in FIG. 1, the main planetary gear transmission mechanism 112 is housed in a main transmission case 132 (partially shown in the figure), and the auxiliary planetary gear transmission mechanism 114 is housed in a main transmission case 132 (partially shown in the figure). The main transmission case 132 and the sub-transmission case 134 are housed in an auxiliary transmission case 134, and the main transmission case 132 and the auxiliary transmission case 134 are integrally connected via bolts (not shown).

An oil pan 133 serving as a lubricating oil reservoir is attached to the lower side of the main transmission case 132, and the lubricating oil stored in the oil pan 133 is circulated within the main transmission 111 and the sub-transmission 113. be done.

1-2 Direct clutch D/C and reduction brake RD/ incorporated in sub-planetary gear transmission mechanism 114
B is configured as a multi-disc clutch-type friction element that is engaged and released by a piston, respectively, and the former direct clutch D/C is a first annular friction element in a first piston drum 136 fixed to a third sun gear 126. piston 138
are fitted, and the first annular piston 138 is connected to the first hydraulic chamber 1
40, the first piston drum 136 and the third carrier 1
A large number of clutch plates 144 disposed between the cylinder body 142 fixed to the third sun gear 126s
The third carrier 126c is coupled (fastened) to the third carrier 126c.

In addition, the latter glue reduction brake RD/13 is the second
Due to the movement of the annular piston 146 to the left in the drawing, a large number of clutch plates 150 disposed between the cylindrical body 148 fixed to the first piston drum 136 and the auxiliary transmission case 134 are brought into pressure contact with each other. A third sun gear 126s is coupled to the sub-transmission case 134.

By the way, the second annular piston 146 is fitted into the second piston drum 152, and the second annular piston 146 is fitted into the second piston drum 152.
The inner periphery and outer periphery of the second piston drum 152 are slid on the inner periphery 152a of the second piston drum 152 and the inner periphery of the outer cylinder 152b in the C axis direction with a liquid-tight function.

Note 11. R152a of the second piston drum 152
is extended to a location where the first piston drum 136 is arranged, and the first piston drum 136 is rotatably fitted and supported by the inner cylinder 152a.

By the way, 1. Rear end of L output shaft 120 (right end in the figure)
A spline 154 is formed on the spline 15.
A propeller shaft (not shown) is fitted into part 1, and the rear end of the sub-transmission case 134 is conically narrowed, and a sliding bearing rotatably supports the propeller shaft.
56 is formed.

Then, the above-mentioned daccon brake RD
Right side in the figure of /H (the opposite side from the oil pan 133 marked with "-")
Lubricating oil is actively supplied to the chamber 162, and this lubricating oil lubricates the sliding bearing portion 156 and the oil seal 164 provided at the outer end of the sliding bearing portion 156.

Here, in this embodiment, the sub-transmission case 134
The whole is integrally molded by casting, and the -F2 sub-planetary gear transmission mechanism 114 is attached to the sub-transmission case 134 made of cedar.
is stored.

By the way, the second piston drum 152 of the reduction brake RD/B is provided separately from the auxiliary transmission case 134, and includes the inner cylinder 152a, the outer cylinder 152b, and the bottom connecting the inner and outer cylinders 152a and 152b. wall 15
2C is integrally molded by casting or the like.

The second piston drum 152 is closely fitted and positioned inside the sub-transmission case 134 and fixed to the sub-transmission case 134 via bolts 166.

At this time, the chamber 162 is separated by the second piston drum 152, but in this embodiment, when the auxiliary transmission case 134 is molded, the chamber 162 and the main transmission case are formed at the bottom of the case 134. A groove 168 connecting the inside of the case 132 is formed in advance, and the groove 168 serves as a drain passage 170.

The lubricating oil supplied to the chamber 162 through the drain passage 170 is then transferred to the oil pan 133 on the main transmission Ill side.
will be returned to.

As described above, in the transmission 100 with an auxiliary transmission of this embodiment, the auxiliary transmission case 134 is not divided, but is formed as a whole by integral molding. Since the entire auxiliary light star gear transmission mechanism 114 is assembled within the auxiliary transmission case 134, the auxiliary transmission case 13/
By unifying I, we achieved a significant reduction in the number of parts.
Assembling work efficiency is improved.

In addition, the second piston drum 152 of the auxiliary idler h1 gear transmission mechanism 114 and the transmission brake RD/H are as follows:
Since it is formed separately from the sub-transmission case 134,
When integrally casting the auxiliary transmission case 134, the groove portion 168
By simultaneously forming a drain passage that communicates the chamber 162 side of the reduction brake RD/H with the oil pan 133 side without requiring any machining when the second piston drum 152 is assembled. 170 can be formed.

Further, since the second piston drum 152 has the inner cylinder 152a, the outer cylinder 152b, and the bottom wall 152c integrally formed by casting, the work of forming the second piston drum 152 is extremely simple, and the piston drum 1
An oil passage or the like can be formed within the wall thickness of 52.

In this embodiment, a passage 172 for supplying the differential hydraulic pressure of the direct clutch D/C is formed within the thickness of the second piston drum 152.

By the way, the transmission with sub-transmission 100 of this embodiment has a main planetary gear transmission mechanism 11 which is an automatic transmission as a main transmission.
2 has been described as an example, but it goes without saying that the present invention is not limited to this automatic transmission type, but can also be applied to systems in which a manual transmission is used as the main transmission. .

As described in detail, in the transmission with an auxiliary transmission of the present invention, the auxiliary transmission case is integrally molded to improve productivity, and the lubricating oil reservoir is located on the main transmission side. The piston drum of the friction element of the sub-transmission is formed separately from the sub-transmission case, and the above-mentioned lubrication is provided between the outer peripheral lower end of the piston drum and the sub-transmission case. Since a drain passage leading to the oil sump has been formed, by forming a groove in advance in the part corresponding to the drain passage when integrally molding the auxiliary transmission case, it is possible to assemble the piston drum after molding the auxiliary transmission case. At the same time, the groove can be configured as a drain passage without any subsequent machining required to form the drain passage.

Therefore, by integrally molding the auxiliary transmission case and greatly simplifying the machining of the drain passage, the productivity of the auxiliary transmission is significantly improved, and the cost of the product can be significantly reduced. At the same time, the drain passage can be formed without increasing the weight of the sub-transmission case (and without increasing the weight of the sub-transmission case) and minimizing the leakage area of excess lubricating oil.

In addition, since the inner cylinder and the outer part of the piston drum are integrally formed, the piston drum can be manufactured by casting, which also has the advantage of improving productivity. It has a great effect.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts showing one embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing the overall configuration of the present invention, FIGS. 3 and 4,
FIG. 5 is a supplementary explanatory diagram of a conventional transmission with an auxiliary transmission. 100... Transmission with sub-transmission, Ill... Main transmission, 112... Main planetary gear transmission mechanism (main gear transmission mechanism), 113... Sub-transmission, 114... Sub-light star Gear transmission mechanism (auxiliary gear transmission mechanism), 118... human power shaft, 12
0... Output shaft, 122... First planetary gear set, 124
...Second planetary gear set, 126...Third planetary gear set,
132... Main transmission case, 133... Oil pan (lubricating oil reservoir), 134... Sub-transmission case, 14
6... Annular piston, 152... Piston drum,
152a...inner cylinder, 152b...outer cylinder, 168...
Rice part 4, 170...Drain passage. 2 people Figure 3 Figure 4

Claims (1)

[Claims] (1) A main transmission that provides a plurality of gears using a main gear transmission mechanism, and a sub-transmission that is arranged on the output side of the main transmission and that multi-stages the output rotation of the main transmission using a sub-gear transmission mechanism. and a lubricating oil reservoir provided in the main transmission case that houses the main gear transmission mechanism, between the inner periphery of the auxiliary transmission case that houses the auxiliary gear transmission mechanism, and the outer periphery of the output shaft of the auxiliary transmission. and a friction element of the auxiliary gear transmission mechanism, which is disposed in the auxiliary gear transmission mechanism and is engaged and released by movement of the annular piston, and lubricating oil is actively supplied to a side of the friction element opposite to the lubricating oil reservoir. In the transmission with an auxiliary transmission, the auxiliary transmission case is formed by integral molding, and the piston drum into which the annular piston is fitted is formed separately from the auxiliary transmission case, and the annular An inner cylinder and an outer cylinder of the piston drum that slidably fit the inner and outer peripheries of the piston, respectively, are formed by integral molding, and between the lower end of the outer periphery of the piston drum and the sub-transmission case, A transmission with an auxiliary transmission, characterized in that a drain passage is formed that communicates with the lubricating oil reservoir and a side of the friction element opposite to the lubricating oil reservoir.