JPS6242185B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic transmission in which an overdrive device is disposed between a hydraulic torque converter and an underdrive device.

BACKGROUND OF THE INVENTION Automatic transmissions automatically switch reduction ratios in relation to vehicle speed and engine load. The automatic transmission is
It usually consists of a torque converter and an underdrive device connected to the torque converter to obtain a plurality of reduction ratios of 1 or more, in other words, an underdrive device equipped with a plurality of gears with a reduction ratio of 1 or 1 or more. In recent years, the demand for automatic transmissions that can also provide overdrive (speed-increasing drive) has been increasing from the viewpoint of fuel savings and reduction of harmful components in exhaust gas. When an overdrive device is added to an automatic transmission consisting of a torque converter and an underdrive device, the required strength of the overdrive device's gears and the required capacity of the friction material are reduced, which is advantageous in terms of durability and cost. In order to Connect to the input side of (prefix type)
It is preferable (for example, Japanese Patent Application Laid-Open No. 52-52067).

Problems to be Solved by the Invention An underdrive device consisting of a planetary gear device having a plurality of gear stages with a reduction ratio of 1 or more is provided with a direct coupling ratio of a reduction ratio of 1 and an overdrive ratio of a reduction ratio of less than 1. When constructing an automatic transmission by incorporating a planetary gear device with It is necessary to configure and attach the stationary side member of the brake device that is to be locked to the transmission case, which requires the transmission case to be significantly extended in the axial direction of the planetary gear set, and in some cases, In order to house the overdrive device in the transmission case coaxially with the underdrive device, each configuration of the underdrive device is different from each configuration of the planetary gear device used in conventional automatic transmissions without overdrive. Unable to standardize parts,
Furthermore, it is often difficult to use common parts for the planetary gear device itself of the overdrive device in combination with other underdrive devices.

In addition, by adding an overdrive device to the underdrive device, a breather circuit for compensating for pressure changes in the space of the transmission case that houses the overdrive device can compensate for pressure changes in the space that houses the underdrive device. In addition to a breather circuit to compensate for the change, this also requires a major design change to the transmission case. For this reason, when an overdrive device is added to a conventional automatic transmission consisting of a torque converter and an underdrive device to configure an automatic transmission with overdrive ratio gears, significant changes are made to the transmission case. In addition, it is difficult to commonly use the parts of the underdrive device, and the assembly of an automatic transmission consisting of an underdrive device and an overdrive device is different from the conventional automatic transmission with only an underdrive device. In addition, the overdrive device itself is extremely difficult to standardize work methods or standardize parts when assembling various types of underdrive devices. This causes problems such as:

Therefore, the present invention provides a case in which the overdrive device is housed separately from the transmission case that houses the underdrive device to strengthen the connection between the overdrive device and the underdrive device. and standardization of automatic transmission components.
The purpose is to standardize the assembly work, and as part of that effort, prevent damage to seals and oil leaks by using a single breather port instead of providing a breather port for each overdrive device and underdrive device. It is.

Means for Solving the Problems The present invention is characterized in that the case housing the overdrive device is constructed separately from the transmission case housing the underdrive device, and the underdrive device is The overdrive device is housed in a transmission case that has almost the same shape and dimensions as the transmission case in an automatic transmission without overdrive, and the overdrive device is housed in a dedicated overdrive case to provide input to the underdrive device. The design aims to standardize the underdrive device, overdrive device, other parts, and assembly work by positioning the device between the side and the output side of the torque converter, ensuring concentricity of both devices, and strong connection between both cases. be.

In order to achieve the above object, in the present invention,
The power on the input side is connected directly to the reduction ratio of 1 and the reduction ratio of 1.
An overdrive device consisting of a planetary gear device that selectively transmits power to the output side with an overdrive ratio of less than The input side of the overdrive device is connected to the output part of the torque converter, and the output side is connected to the underdrive device, which is a planetary gear device that transmits transmission to the output side at a plurality of reduction ratios of 1 or more. A transmission case that is connected to the input shaft of the drive device, supports the input shaft of the underdrive device by a portion of the overdrive case extending between the overdrive device and the underdrive device, and houses the underdrive device. The overdrive case is connected to the overdrive case by a spigot, and the oil pump body and oil pump cover of an oil pump that generates hydraulic pressure are extended between the hydraulic torque converter and the overdrive device, and the oil pump body and oil pump cover are extended between the hydraulic torque converter and the overdrive device. an oil pump body, an oil pump cover, an overdrive case, and a transmission case are connected to each other by a through bolt that passes through the overdrive case and reaches the transmission case, and a flow hole is formed in the overdrive case; The communication hole allows the internal space of the overdrive device and the underdrive device to communicate with each other, and a breather passage is formed in the overdrive case, and the breather passage formed in the transmission case is connected to the overdrive case. It is connected to the internal space of the drive device or underdrive device.

Effect of the Invention In the automatic transmission of the present invention, the power of the crankshaft of the engine is transmitted to the overdrive device via the hydraulic torque converter, and is transmitted to the underdrive device at a reduction ratio selected by the overdrive device, To the output side of the underdrive device,
It is output at a reduced directivity ratio obtained by multiplying the reduction ratio of the overdrive device by the reduction ratio of the underdrive device. The underdrive device has a reduction ratio of 1, while the overdrive device has a reduction ratio of 1.
When an overdrive ratio of less than 1 is selected, the rotation speed is increased in the same direction as when a direct coupling ratio of reduction ratio 1 is selected. The internal space of the transmission case in which the underdrive device is housed is separated from the internal space of the overdrive case in which the overdrive device is housed by a portion of the overdrive case that supports the input shaft of the underdrive device;
Even if a pressure change occurs in the space inside the transmission case due to the underdrive device itself being rotated at an increased speed, the pressure in the space inside the overdrive case is balanced with the pressure in the space inside the overdrive case through the communication hole formed in the overdrive case, and Because it communicates with outside air through the breather passage and breather port,
The pressure difference with atmospheric pressure is eliminated.

Example The present invention will be described with reference to the embodiments shown in the drawings.

FIG. 2 shows an automatic transmission that is commercially available before the application is filed and does not include an overdrive device. The hydraulic torque converter 1 includes a pump impeller 5, a turbine runner 6, and a stator 7. The pump impeller 5 is connected to a crankshaft 8 of an engine (not shown), and the turbine runner 6 is connected to a turbine shaft 9a. There is. The torque converter 1 is
The turbine shaft 9a is circumferentially surrounded by the housing 17a.

Rear of torque converter 1 (hereinafter, the side closer to the engine is referred to as "front", and the side farther from the engine is referred to as "rear")
are partitioned by an oil pump body 20. The oil pump cover 21 is arranged adjacent to the oil pump body 20 and defines a pump chamber of the oil pump 71 together with the oil pump body 20. The oil pump gear 50 of the oil pump 71 is connected to the pump impeller 5. Passage 7 formed in oil pump body 20
2 is connected to the suction side of the oil pump 71 at one end, and is connected to the oil pump cover 21 at the other end.
and is connected to the inside of the oil pan 75a via a passage in the transmission case 18.

An underdrive device 3 with three forward speeds and one reverse speed is installed coaxially with the torque converter 1 behind the oil pump 71 and adjacent to the oil pump cover 21 . The turbine shaft 9a serves as an input shaft of the underdrive device 3. The underdrive device 3 has its front portion covered by an oil pump cover 21 and a transmission case 18. Oil pump body 20, oil pump cover 21, and transmission case 18 are connected to each other by a plurality of bolts 22a.

The turbine shaft 9a is connected to a clutch cylinder 65, and a multi-plate clutch 24 is provided between the clutch cylinder 65 and the intermediate shaft 29. The hub 66 is fitted with a clutch cylinder 65, and a multi-plate clutch 25 is provided between the hub 66 and the sun gear shaft 30. sun gear shaft 3
0 and a support 31 fixed to the transmission case 18, a multi-disc brake 26 is provided.
Furthermore, a series connection of a one-way clutch 61 and a multi-disc brake 60 is provided. A sun gear 32 is formed on the sun gear shaft 30. Sun gear 32 is planetary pinion 34 and 37
One planetary pinion 34 meshes with a ring gear 35, and the other planetary pinion 37 meshes with a ring gear 38. That is, the sun gear 32, the planetary pinion 34,
A two-row planetary gear device including a ring gear 35, a sun gear 32, a planetary pinion 37, and a ring gear 38 is configured. Ring gear 35 is connected to intermediate shaft 29 via flange 67. Further, the planetary pinion 34 is rotatably supported on a pinion shaft 69 of the carrier 33, and the planetary pinion 37 is rotatably supported on a pinion shaft 68 of the carrier 36.
An output shaft 39 of the underdrive device 3 is connected to a ring gear 38 and a carrier 33. A multi-disc brake 27 and a one-way clutch 28 are provided between the carrier 36 and the transmission case 18.

Below the underdrive device is the oil pan 75a.
covered by. Inside the oil pan 75a is a hydraulic control device 4a that controls the hydraulic pressure supplied to the hydraulic servo (cylinder) of the underdrive device.
(only a portion shown) is placed.

A breather port 103 is provided at the front upper end of the transmission case 18, and a plug 104 is provided.
is installed at this breather port. A passage 1 is provided above the oil pump cover 21 in the axial direction.
05 is formed, and a passage 106 is formed below in the axial direction. A passage 107 is bent and formed between the oil pump body 20 and the oil pump cover 21 to connect the passages 105 and 106. In this way, the atmospheric pressure is the breather port 103.
It is guided from the axial direction into the lower part of the underdrive device 3 via passages 105, 107, and 106.
Such a configuration of the breather circuit is advantageous for preventing oil leakage.

FIG. 1 is a longitudinal sectional view of an automatic transmission when an overdrive device is added. Portions corresponding to those in FIG. 2 are designated by the same reference numerals as in FIG. 2, and description thereof will be omitted.

The overdrive device 2 includes a sun gear 11 and a planetary pinion 1 in an overdrive case 16.
4, ring gear 15, the planetary pinion 1
A clutch device that accommodates a carrier 10 that supports an overdrive case 16 and engages the sun gear 11 and the carrier 10 to enable integral rotation, and a clutch device that locks the sun gear 11 to an overdrive case 16 and makes it stationary. A planetary gear system consisting of a brake device is housed in an overdrive case 16, and the overdrive case 16 is assembled to a transmission case 18 with a spigot, and is attached to an oil pump body 20, with a through bolt 22. It is coupled to the transmission case 18 together with the oil pump cover 21.

The turbine shaft 9 plays the role of an output shaft of the torque converter 1 as well as an input shaft of the overdrive device 2, and is connected to a carrier 10 of a planetary gear device in the overdrive device. The carrier 10 has a pinion shaft 49, and needle bearings 43, 44 are provided in two rows in the axial direction on the outer periphery of the pinion shaft 49. The planetary pinion 14 is connected to these two needle bearings 4.
3 and 44, and is rotatably supported by a pinion shaft 49, and meshes with sun gear 11 and ring gear 15. A thrust washer 5 is provided between the planetary pinion 14 and the carrier 10, respectively.
1,52 are provided. A sun gear shaft 78, on which the sun gear 11 is formed, is connected to the clutch cylinder 63. The hub 64 is spline fitted to the clutch cylinder 63. A multi-plate clutch 12 is provided between the clutch cylinder 63 and the carrier 10, and a sun gear shaft 78 and the carrier 10 are connected to each other.
A clutch 13 is provided between the hub 6 and the hub 6.
4 and an overdrive case 16 containing an overdrive device, a multi-disc brake 19 is provided. The housing 17 covers the periphery of the torque converter 1 and has an extension portion 77 having an inner surface shaped like a cylindrical side surface. The overdrive case 16 has a cylindrical side surface, and is disposed such that the side surface fits into the inner surface of the extension portion 77 .
Further, the overdrive case 16 is assembled to the transmission case 18 by a spigot, which facilitates alignment of the overdrive device 2 and the underdrive device. ring gear 15
The flange 53 connected to the underdrive device 3 is spline connected to the input shaft 23 of the underdrive device 3.
The input shaft 23 is arranged coaxially with the turbine shaft 9 and is connected to the aforementioned clutch cylinder 65 of the underdrive device 3. The overdrive case 16 has a radially extending portion 120 for supporting the input shaft, and this portion 12 partitions the internal space of the overdrive device 2 from the internal space of the underdrive device 3. turbine shaft 9
A bearing 54 is arranged between the input shaft 23 and the input shaft 23.
A washer 56 is provided between the carrier 10 and the flange 53. Multiple through bolts 22
passes through the oil pump body 20, oil pump cover 21, and overdrive case 16 in order to reach the transmission case 18,
These are coupled together in the axial direction.

In such an automatic transmission, the relationship between the shift position and gear position and the operating state of each clutch and brake is shown in the diagram of FIG. In Figure 3, P is the parking range, R is the reverse range, N is the neutral range, D is the drive range, 2 is the second range, L is the low range, 〇 is the engaged state, × is the released state, and RC is the locked state. situation,
OR indicates an overrun state, and * indicates a state where no power is being transmitted. Also,
OD means overdrive.

Next, lubrication and cooling of each element constituting the overdrive device 2 and the underdrive device 3 will be explained.

The oil pressurized by the oil pump 71 is adjusted to a predetermined pressure in the hydraulic control device 4. The regulated oil flows through the oil passage 45 of the transmission case 18 and the oil passage 46 of the intermediate shaft 29.
It is supplied to each element of the overdrive device 2 and the underdrive device 3 via the pump to lubricate and cool them. Special oil passages are formed in the overdrive device 2 for lubrication and cooling in the vicinity of the needle bearings 43, 44. That is, a space defined by the input shaft 23 and the turbine shaft 9 forms an oil chamber 55. Oil chamber 5
5 is a hole 42 provided in the side wall of the input shaft 23.
It is connected to the inner hole of the input shaft 23 via. The oil passage 40 extends within the carrier 10 in its radial direction,
It is connected to the oil chamber 55 at one end and is closed off by a plug 58 at the other end. An oil passage 41 extending in the axial direction is provided inside the pinion shaft 49 . The oil passage 41 is connected to the oil passage 40 at one end.
and is closed at the other end by a plug 57. An oil passage 48 is formed in the radial direction approximately at the longitudinal center of the pinion shaft, and this oil passage 48 is connected to the oil passage 41 at one end and reaches an intermediate point between the needle bearings 43 and 44 at the other end. In this way, the needle bearings 43, 4
Elements near 4 are lubricated and cooled by oil at a predetermined pressure supplied through the hole 42, the oil chamber 55, and the oil passages 40, 41, and 48.

4 is a left side view (torque converter 1 side) of the overdrive case 16, FIG. 5 is a sectional view taken along the - line in FIG. Device 3
side) respectively. In FIGS. 4 and 6, the vertical direction corresponds to the vertical direction, and in FIG. 5, the left end corresponds to the torque converter 1 side, and the right end corresponds to the underdrive device 3 side. 81 is
This is a hole for the bolt 22 to pass through. 82 is
Breather port 103 at the upper front end of transmission case 18 and passage 10 in oil pump cover 21
This is a breather passage that connects 5 to 5. 83 is an oil return passage provided below the breather passage 82 in order to prevent oil from leaking from the breather port 103 via the breather passage 82. The oil return passage 83 is connected to the breather passage 82 at the rear end via a groove 88 formed in the cross section of the overdrive case 16 on the underdrive device 3 side, and is connected to the passage 107 at the front end. . In this way, oil that may accumulate in the breather passage 82 is returned via the oil return passage 83 without leaking from the breather port 103. 84 is a supply passage for supplying oil from the hydraulic control device 4 to the torque converter 1; 85 is a supply passage for supplying oil to the torque converter 1;
This is a discharge passage for returning the water from the hydraulic pressure control device 4 to the hydraulic control device 4. 86 and 87 are suction passages that guide oil in the oil pan 75 installed at the bottom of the underdrive device 3 to the oil pump 71; 91 is a suction passage that guides the oil pressurized by the oil pump 71 to the underdrive device 3; This is a discharge passage leading to the hydraulic control device 4 at the bottom of the . The suction passage 87 is connected at the front end to the passage 72 via the oil passage of the oil pump cover 21, and at the rear end to the oil passage 76 and an oil passage (not shown) provided through the side wall. There is. In order to be properly connected to the oil passage of the oil pump cover 21, the suction passage 87 is formed at the lowermost end of the overdrive case and has an enlarged portion 92 at the front end. The discharge passage 93 is formed at the lowest end of the periphery of the overdrive case 16 along with the suction passage 87, and communicates with the lower part of the space inside the overdrive case 16, and is connected to the inside of the oil pan 75 at the rear end. has been done. At least the lower part of the discharge passage 39 is located below the lowermost rotating element of the overdrive device 2, in this case the clutch cylinder 63. The rotation of the rotating element of the overdrive device 2 stirs the oil and becomes a factor that inhibits the discharge of oil through the discharge passage 93. At least part of the oil accumulated in the lower part of the internal space of the overdrive device 2 is discharged without being agitated by the rotating elements of the overdrive device 2, and as a result, the oil can be smoothly discharged from the overdrive device 2. The suction passage 87 and the discharge passage 93 are separated by a wall 98. 101 more
102 is a passage connecting the hydraulic control device 4 and the clutch cylinder 63 and guiding the hydraulic pressure, and 102 is a passage connecting the hydraulic control device 4 and the clutch cylinder 65 and guiding the hydraulic pressure. Passage 82, 83, 84, 85,
86, 87, 91, and 101 all penetrate in the axial direction around the overdrive case 16.

As can be seen from the left side view and right side view of FIGS. 4 and 6, the angular intervals of the bolt through holes 81 in the circumferential direction of the overdrive case 16 are different, and a plurality of bolts 22 are inserted into the holes 81.
through the oil pump body 20, oil pump cover 21, overdrive case 16,
When the transmission case 18 is assembled, the passages 82 to 87 on both sides of the overdrive case 16 in the axial direction are automatically connected to their corresponding passages.

Furthermore, the overdrive case 16 has a plurality of communication holes 111, passages 82, 83, 84, 86, 8.
7, 91, 93, and 101 are formed concentrically on the inner side in the radial direction from the peripheral portion where the portions 7, 91, 93, and 101 are formed. As a result, the input shaft 2 of the underdrive device 3
Overdrive case 16 as a support member of No. 3
The internal spaces of the overdrive device 2 and the underdrive device 3, which are partitioned from each other by the portion 120, communicate with each other through the communication hole 111, and the air pressures of both internal spaces are maintained equal to each other.

Effects of the Invention According to the present invention, the power on the input side is reduced to a reduction ratio of 1
An overdrive device consisting of a planetary gear device that selectively transmits data to the output side with a direct coupling ratio of an input side and an output side of the overdrive device are respectively connected to an output part of a hydraulic torque converter and an input shaft of an underdrive device, and a transmission case that accommodates the underdrive device accommodates the overdrive device. Because they are connected to the overdrive case by the spigot, the planetary gear set of the underdrive device and the planetary gear set of the overdrive device do not interfere with each other. Therefore, the planetary gear set of the underdrive device does not have the conventional overdrive. The gears used in automatic transmissions can be used as they are, and the assembly work can be done in the same way as for conventional automatic transmissions, and the planetary gears of the overdrive device can be replaced with the planetary gears of the underdrive device. Since it can be designed regardless of the type and structure of the device, it is possible to provide a common device that can be shared by multiple types and structures of underdrive devices having the same or similar power transmission capacity. In addition, the overdrive device is housed in an overdrive case separate from the transmission case, and the overdrive case is connected to the transmission case housing the underdrive device by a spigot. Even when adding an overdrive device to an automatic transmission that combines a formula torque converter and an underdrive device,
There is no need to change the length of the transmission case that accommodates the underdrive device along the axial direction of the underdrive device, and it is sufficient to change the design of the spigot joint with the overdrive case as necessary. In the case where the transmission case of a conventionally manufactured automatic transmission has an oil pump body and an oil pump cover engaged at the end on the hydraulic torque converter side at a step and connected with bolts, these When used for the structure of the spigot joint between the step part of the transmission case that engages the oil pump body and oil pump cover and the overdrive case,
The transmission case can also be used in common for an automatic transmission without an overdrive and an automatic transmission to which an overdrive device is added according to the present invention. Furthermore, since the underdrive device can be assembled into the transmission case separately from the overdrive device, the underdrive device can be installed in a conventional automatic transmission without an overdrive. It can be easily assembled using the following assembly procedure.

Moreover, the pump body and oil pump cover of the oil pump that generates the working hydraulic pressure for the operation of the automatic transmission are arranged to extend between the hydraulic torque converter and the overdrive device, and the through bolts are arranged to extend between the hydraulic torque converter and the overdrive device. The oil passes through the oil pump body, the oil pump cover, and the overdrive case to reach the transmission case, and connects the oil pump body, oil pump cover, overdrive case, and transmission case. Assembly is easier than connecting the pump and overdrive case and the overdrive case and transmission case with separate bolts, and each connection part is connected with an average bonding force to prevent local oil leakage. The joint strength of the overdrive case and the transmission case is ensured by the joint between the overdrive case and the transmission case through the socket, and the joint between the overdrive case and the transmission case through the socket and the support of the input shaft of the underdrive device by the overdrive case. , it is possible to improve the concentric arrangement of each planetary gear device of the overdrive device and the underdrive device. Since the oil pump is installed on the side of the hydraulic torque converter in the overdrive case, it can be driven by being connected to the pump impeller of the hydraulic torque converter, similar to conventional automatic transmissions without overdrive, so its drive is stable and In the automatic transmission of the present invention, in which an overdrive device is added to the transmission by using a screw hole provided in the transmission in order to mount the oil pump with a screw in an automatic transmission without an overdrive, the oil pump body This can be a threaded hole for a through bolt that passes through the oil pump cover and overdrive case and is screwed into the transmission case.

In addition, in the present invention, since the overdrive device is disposed in front of the input side of the underdrive device, when the overdrive device is selected for an overdrive ratio of less than 1, the overdrive device is automatically The planetary gear of the underdrive device is rotated at a higher rotational speed than the underdrive device of the transmission, but the input shaft of the underdrive device is a part of the overdrive case extending between the overdrive device and the underdrive device. Since the input shaft is supported by the input shaft, the input shaft is strongly supported, and the underdrive device is stabilized during high speed rotation due to the overdrive ratio. Furthermore, as mentioned above, the strength of the part of the overdrive case that supports the input shaft of the underdrive device is increased, so that this part is divided into a space for accommodating the overdrive device in the overdrive case and an underdrive part in the transmission case. The underdrive device is tightly separated from the space accommodating the device, and the underdrive device is rotated at high speed according to the overdrive ratio, so that the pressure in the tight space accommodating the underdrive device of the transmission case is increased. Even if there is a flow hole formed in the overdrive case, it communicates with the space that houses the overdrive device in the overdrive case, and furthermore, the space is connected to the breather port or the overdrive case by the breather passage. Because it communicates with the breather port through the space that accommodates the overdrive device, the pressure difference with atmospheric pressure can be eliminated or minimized, and the pressure increase causes the oil seal of the automatic transmission to This can prevent the risk of damaging the oil or causing oil leakage.

The breather port and breather passage are designed to prevent pressure changes inside the transmission case.
Depending on the difference between the atmospheric pressure outside the case and the pressure inside the case, atmospheric air is taken into the case or the pressurized air inside the case is released outside the case. When releasing air out of the case, lubricating and cooling oil may also be released from the breather port along with the air, so the oil must be separated from the released air in the breather passage that communicates with the breather port and returned to the case. Since it is difficult to form this breather passage in the transmission case, in conventional automatic transmissions without overdrive, a breather passage is formed in the oil pump and the passage is formed in the transmission case. It is customary to communicate with the breather port. In the present invention, the breather passage is formed in the overdrive case coupled to the transmission case, and is communicated with the breather port to connect the breather port to the internal space of the overdrive device or the underdrive device. The breather port formed in the case can be used as is to connect the internal space of the underdrive device or the overdrive device to the breather port.

In summary, the present invention provides an automatic transmission in which an overdrive device having a direct coupling ratio of a reduction ratio of 1 and an overdrive ratio of less than 1 is added between a hydraulic torque converter and an underdrive device. The planetary gear device constituting the overdrive device is housed in an overdrive case and disposed between the hydraulic torque converter and the underdrive device, and the overdrive case has one end connected to the hydraulic torque converter and the overdrive device. It is connected to the oil pump body and oil pump cover of the oil pump that extend between the drive device, and the other end is connected to the transmission case that houses the planetary gear device that constitutes the underdrive device by a spigot, and the bolts that pass through these. The overdrive device to be added is housed in the overdrive case, and is separate from the underdrive device, the transmission case housing it, the oil pump body and oil pump cover of the oil pump. In this case, a breather passage for the internal space of the overdrive device is formed in the overdrive case without the need to provide a breather port in the overdrive case, and this is connected to the breather port provided in the transmission case. At the same time, since the internal space of the overdrive device is communicated with the internal space of the underdrive device through the communication hole formed in the overdrive case, it is possible to make slight changes to conventionally manufactured automatic transmissions without overdrive. It is possible to construct an automatic transmission equipped with an overdrive device by using the above-mentioned automatic transmission without adding or changing it, thereby making it possible to standardize parts and improve the efficiency of assembly.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an automatic transmission of the present invention when an overdrive device is added, FIG. 2 is a longitudinal sectional view of a known automatic transmission without an overdrive device, and FIG. Diagram showing the relationship between the gear stage and the operating state of each frictional engagement device, No. 4
The figure is a left side view of the overdrive case, FIG. 5 is a sectional view taken along the line - in FIG. 4, and FIG. 6 is a right side view of the overdrive case. DESCRIPTION OF SYMBOLS 1...Hydraulic torque converter, 2...Overdrive device, 3...Underdrive device, 6...
...Turbine runner, 8...Crankshaft, 16...
Overdrive case, 18... Transmission case, 20... Oil pump body, 21
...Oil pump cover, 22...Bolt, 23
...Input shaft, 63...Clutch cylinder, 71...
... Oil pump, 82 ... Breather passage, 103
... Breather port, 111 ... Communication hole, 120 ...
part.

Claims (1)

[Claims] 1 A hydraulic torque converter driven by the crankshaft of the engine, which is connected to the output part of the hydraulic torque converter on the input side and selectively transfers the power on the input side with a direct coupling ratio of a reduction ratio of 1 and an overdrive ratio of less than 1. an overdrive device consisting of a planetary gear unit that transmits the power to the output side and is housed in an overdrive case; an oil pump body and an oil pump cover extending between the hydraulic torque converter and the overdrive device; An oil pump that generates a an underdrive device comprising a planetary gear device connected to an overdrive case by a spigot; a portion of the overdrive case extending between the overdrive device and the underdrive device and supporting an input shaft of the underdrive device; a communication hole formed in the overdrive case to communicate the internal space of the overdrive device and the internal space of the underdrive device; a breather port provided in the transmission case;
A breather passage formed in the overdrive case and connecting the breather port to an internal space of the overdrive device or the underdrive device, and a breather passage that passes through the oil pump body, the oil pump cover, and the overdrive case to connect the transmission. An automatic transmission characterized in that it has a through bolt that reaches the case and connects the oil pump body, the oil pump cover, the overdrive case, and the transmission case.