JPS6234978B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a gear transmission that achieves overdrive, and particularly to a gear transmission that is suitable for use in combination with a torque converter used in automobiles and the like. Planetary gear mechanisms are often used as gear transmissions in combination with torque converters, and for automobiles, two sets of planetary gear mechanisms are usually arranged concentrically, and a carrier or ring gear that supports a sun gear or planetary pinion is selected. By selectively engaging the clutch or applying the brake, a gear train with three forward speeds and one reverse speed is obtained. The gear ratios of these gear transmission trains are conventionally set to 1 or greater than 1. This type of gear transmission, especially automatic transmission devices used in automobiles, requires low torque and high-speed rotation of the driven shaft, such as when a car runs at high speed on a flat road for a long time. In this case, in order to save the energy consumed by the prime mover, a transmission gear train with a transmission ratio of less than 1, in other words an overdrive, is required. The present invention uses one of the planetary gear mechanisms to be incorporated in a gear transmission to have a gear ratio smaller than 1, and is intended to achieve overdrive without adversely affecting other transmission gear trains of the gear transmission. The present invention is particularly suitable for application to a gear transmission of a conventional automatic transmission which is composed of a planetary gear mechanism and is used in combination with a torque converter. That is, the present invention provides a planetary gear mechanism including a housing, a sun gear, a planetary pinion, a ring gear, and a carrier supporting the planetary pinion, an input shaft concentrically connected to the carrier, and an output concentrically connected to the ring gear. a shaft, a friction type clutch that removably connects the sun gear and the ring gear, a friction type brake that brakes the sun gear, and a friction type brake connected between the sun gear and the ring gear when the sun gear is braked. The friction type clutch is comprised of a one-way clutch that causes the ring gear to overrun, and the friction type clutch is disposed between one clutch hub concentrically connected to the ring gear and the other clutch hub that is rotated integrally with the sun gear. a friction plate and a pressure plate, the friction brake being configured between the other clutch hub and the housing, and the one-way clutch comprising:
The clutch includes an inner race connected to the other clutch hub, an outer race spline connected to the one clutch hub, and a clutch member disposed between the outer race and the inner relay, and the inner race has an inner race connected to the inner race. This relates to an overdrive gear transmission in which a small hole communicating with the sliding surface of the race and the clutch member is bored, and the one-way clutch is formed between the sun gear and the ring gear, so that the one-way clutch is formed between the sun gear and the ring gear. Provided in close proximity to the planetary gear mechanism, the axial dimension is not increased, and the torque transmitted by the one-way clutch is reduced, allowing the use of a small one-way clutch and effectively utilizing the space within the housing. It is an object of the present invention to provide a compact overdrive gear transmission in which a one-way clutch is not adversely affected by accuracy errors in a planetary gear mechanism, and to facilitate lubricating the one-way clutch and increase the durability of the one-way clutch. That is. FIG. 1 shows a torque converter in which an overdrive transmission of the present invention is coupled to an output shaft 1 of a prime mover, and a transmission gear system 100 with three forward speeds and one reverse speed, in which two sets of planetary gear mechanisms are arranged concentrically. 2 is a schematic diagram of an automatic transmission inserted as an auxiliary transmission 200 between the torque converter 2 and the transmission gear device 100 in the automatic transmission connected to the transmission gear 2. FIG. In FIG. 1, the input shaft 3 and output shaft 4 of the sub-transmission 200 are concentric with a planetary gear mechanism 8 consisting of a sun gear 21, a planetary pinion 22, a ring gear 23, and a planetary carrier 24 that rotatably supports the planetary pinion 22. The input shaft 3 is connected to a planetary carrier 24, the output shaft 4 is connected to a ring gear 23, and the sun gear 21 and the ring gear 23 are detachably connected by a clutch 11. A one-way clutch 20 is provided between the ring gear 23 and the sun gear 21, and the ring gear 23 is configured to overrun the sun gear 21 when the sun gear 21 is braked by the brake 14. There is. The variable speed gear device 100 includes two sets of planetary gear mechanisms 9 and 10 arranged concentrically with the planetary gear mechanism 8, with the output shaft (intermediate shaft) 4 serving as its input shaft,
Friction plate type clutches 12, 13, friction plate type brakes 15, 16, 17, and one-way clutch 1
This is a conventionally known mechanism for selectively outputting to the output shaft 7 at a gear ratio of 3 forward speeds and 1 reverse speed by means of 8 and 19. A shaft 6 that is detachable and is common to the shaft 4 and the sun gear 81 of one planetary gear mechanism 9 and the sun gear 91 of the other planetary gear mechanism 10.
The shaft 6 is braked by a brake 15, and the outer race of a one-way clutch 18 provided on the shaft 6 is braked by a brake 16. Planetary pinion 8 of gear mechanism 9
The second carrier 84 is braked by a brake 17 and a one-way clutch 19 is formed between it and a fixed part, and its ring gear 83 is connected to a planetary pinion 92 of the other planetary gear mechanism 10.
The ring gear 93 of the planetary gear mechanism 10 is connected to the intermediate shaft 5. FIG. 2 shows the above sub-transmission 200 implementing the present invention.
2 is a cross-sectional view of a main part of the input shaft 3, in which a flange 42 is formed in the radial direction at the rear end of the input shaft 3 to fix the carrier 24 of the planetary pinion 22, and the clutch 11 is fixed to the front end of the ring gear 23 in the axial direction. One clutch hub 26 constituting the clutch hub 26 is integrally formed with the sun gear 21, and the inner race 38 of the one-way clutch 20 is integrally formed with the sun gear 21, and is connected to a cylinder body 25 constituting the other clutch hub of the clutch 11. A piston 34 for actuating the clutch 11 is disposed inside the cylinder body 25, and the outer circumferential edges of the pressure plate 28 of the clutch 11 and the brake hub 29 are splined on the outer circumferential edge of the cylinder body 25. The friction plate 27, which is spline-fitted to the clutch hub 26, is connected to the piston 34 and the pressure plate 28, and its movement is prevented by fitting and fastening members 43 and 44.
The clutch 11 is inserted between the piston 34 and the piston 34 so that the clutch 11 can be engaged and disengaged by moving the piston 34 back and forth. Further, the cylindrical portion at the other end of the brake hub 29 has a friction plate 30 of the brake 14 on its outer periphery.
Fit the spline to the transmission case 32.
The friction plate 30 is inserted between the movable pressure plate 31 and the pressure plate 46 which is spline-fitted to the inner periphery of the cylinder 31 and is locked by the fastening member 45. The brake 14 is activated or released by moving the provided piston 35 forward or backward. The outer race 37 of the one-way clutch 20 is spline-fitted to the inner periphery of the clutch hub 26, and
A clutch member (sprag) 39 is disposed between the outer race 37 and the inner race 38 to allow overrun rotation of the ring gear 23 when the sun gear 21 is braked by the brake 14.
Also, it is intended to prevent overrun rotation of the sun gear 21. A thrust bearing 40 is provided in front of the outer race 37 in the axial direction by being spline-fitted to the clutch hub 26, and is supported in the axial direction by a snap spring 41, so that the thrust force applied to the one-way clutch 20 is transferred by the thrust bearing 40. It is configured to receive. The ring gear 23 of the planetary gear mechanism 8 is connected to the outer periphery of a flange 36 spline-coupled to the output shaft 4 whose tip is supported in the shaft hole 48 of the input shaft 3, and is connected to the output shaft 4. Note that the small hole 49 bored in the inner race 38 of the one-way clutch 20 is similar to that of a normal planetary gear device 8,
9, 10, the oil supply passages 50, 5 are connected from the oil supply pump driven by the prime mover by the same means.
This hole was drilled to supply oil to the one-way clutch 20 through the first engine. In the automatic transmission configured as described above, the rotation of the input shaft 1 transmitted to the input shaft 3 via the torque converter 2 is transmitted to the planetary pinion 22.
is transmitted to the carrier 24 of the clutch 11.
When operating the sun gear 21 and ring gear 23 to connect them together, the planetary gear unit 8 rotates integrally and does not perform a speed change action, and the input shaft 3 rotates at a gear ratio of 1 through the ring gear 23. It is transmitted to the output shaft (intermediate shaft) 4. Therefore clutch 11
The output shaft 4 and the intermediate shaft 6 are connected by actuating the clutches 12, 13 and the brakes 15, 16, 17.
By selectively engaging and disengaging, it is possible to obtain a transmission gear train with three forward speeds and one reverse speed, similar to the conventional one. When the clutch 11 is released and the brake 14 is engaged to brake the sun gear 21, the gear train Since the rotational drive by the input shaft 3 of 24 drives the ring gear 23 and the output shaft (intermediate shaft) 4 that connects the ring gear 23 at higher speed than the rotation of the input shaft 3, the sub-transmission 200 obtains a reduction ratio smaller than 1, Overdrive of the output shaft 7 can be achieved. The operation of the automatic transmission configured as shown in FIG. 1 is as shown in the following table.

[Table] In this table, the ◯ mark indicates that the clutch and brake are operating by the hydraulic oil operating mechanism. The △ mark indicates that the brake is being operated by the pressure oil operating mechanism during engine braking. The * mark indicates that the one-way clutch is locked only when the engine is driving. Note that the explanation of the operation for each gear stage is well known and therefore does not need to be explained. The present invention connects a planetary carrier constituting a planetary gear mechanism to an input shaft and its ring gear to an output shaft, and connects the sun gear and ring gear of the planetary gear mechanism in a detachable manner by a friction plate type clutch. , a one-way clutch is formed between these that causes the ring gear to overrun when the sun gear is braked, and the sun gear can be freely locked to the housing of the gear transmission using a friction type brake, so that when the sun gear is braked by the brake, the housing is When the input shaft is locked, the rotation of the input shaft causes the planetary pinion to revolve through the planetary carrier, and the planetary pinion meshes with the sun gear and rotates, causing the ring gear to rotate in the same direction as the input shaft and at an increased speed. Rotation is transmitted to the output shaft. Furthermore, when the brake is released, the one-way clutch is locked and the sun gear and ring gear are locked, allowing a smooth transition to direct coupling operation.When the clutch is engaged, each element of the planetary gear mechanism is connected as one, and the input shaft and the output shaft are directly connected, and torque is transmitted without using gears. In the present invention, when the one-way clutch is connected between the sun gear and the ring gear, the outer race of the one-way clutch is connected to one of the two clutch hubs connected to the sun gear and the ring gear, respectively. Because it is spline-fitted, it is concentric with the planetary gear mechanism that achieves the overdrive gear ratio.
Moreover, the one-way clutch can be arranged in a position very close to the axial direction, and the concentric arrangement with the planetary gear mechanism can be made very good. Generally, when a gear transmission is constructed by incorporating a clutch, a brake, and a one-way clutch into a planetary gear mechanism, when torque is transmitted between each element of the planetary gear mechanism, a forcing force is generated between the elements due to accuracy errors. If the race of a one-way clutch is directly connected between the elements, this force will cause a disadvantage in that it will deteriorate the operability and durability of the one-way clutch, but in the present invention, the outer race of the one-way clutch is spline-fitted to the clutch hub. Even if there is misalignment between the planetary gear mechanism and the one-way clutch due to dimensional errors in manufacturing or installation errors in each element of the planetary gear mechanism, the spline fitting portion can absorb the misalignment. In addition to suppressing the generation of vibration and heat, the inner race has a small hole that communicates with the sliding surface between the inner race and clutch members such as sprags. The oil can be supplied to the inside of the one-way clutch through the small hole, and the durability of the one-way clutch can be improved. Also, when a one-way clutch is connected between the sun gear and ring gear of a planetary gear mechanism, the torque transmitted by the one-way clutch is calculated by the formula: input torque x number of sun gear teeth / number of sun gear teeth + number of sun gear teeth, and the input torque A one-way clutch with a torque transmission capacity of approximately 1/3 of that is sufficient.
It has the advantage of being able to choose a small one-way clutch.
Moreover, the utilization rate of the internal space of the transmission housing is improved. However, on the other hand, when the input shaft is driven with the sun gear of the planetary gear mechanism being braked, the planetary pinion is driven via the carrier connected to the input shaft, and the planetary pinion rotates while meshing with the sun gear and the ring gear. Then, it revolves around the axis of the sun gear and tries to center around the axis of the sun gear. The torque that acts on the surface that meshes with the sun gear and ring gear is large, so if there is a dimensional error in each element of the planetary gear mechanism or an installation error in the assembly, it will act on the surface that meshes with the two gears. The angle may become excessive in some areas, causing the sun gear axis to swing, or
This produces vibrations that make the planetary pinion's revolution axis eccentric with respect to the sun gear's axis. Runout and eccentric vibration caused by such dimensional and installation errors greatly affect the ring gear, so if the outer race of the one-way clutch is fixed to the clutch hub,
The rotation of the outer race includes a relatively large eccentric runout with respect to the inner race, and this eccentric runout quickly damages the one-way clutch. In other words, clutch members such as sprags of a one-way clutch slide along with the outer race on the inner surface of the inner race in metal contact at the rotational speed of the output shaft, and when the relative eccentric runout occurs, the sprag moves against each race. This accelerates the wear of the cam surfaces that come in contact with each other. On the other hand, the engagement of the sprag with the inner race and the outer race is achieved by the shape of the cam surface at the contact point between the cam surface of the sprag and the inner surface of each race and the torque received by the sprag. Therefore, the wear of the cam surface causes the hopping phenomenon in which the sprag springs out of engagement, the hop-out phenomenon in which the sprag bites into the cage that holds it between both races, and the rollover phenomenon in which the sprag goes too far in the direction of engagement, causing the sprag to reverse. This can cause damage to the one-way clutch. However, in the present invention, since the outer race of the one-way clutch is spline-coupled to the clutch hub, if a relative eccentric runout occurs between the outer race and the inner race connected to the other clutch hub, Also, the eccentric runout is eliminated by the spline connection between the outer race of the one-way clutch and the clutch hub, and the concentricity of the outer race with respect to the inner race is maintained, so that the cam surface due to the eccentric runout is Since there is no risk of surface wear, the one-way clutch maintains accurate operation and increases its durability. The torque force that acts on the one-way clutch acts on the fitting surface of the outer race of the one-way clutch where it connects to the clutch hub, but since the outer diameter of the outer race can be made large and the fitting area can be large, it is durable. There is no risk of harm to sex. Therefore, good concentricity is provided between the inner race and the outer race, reducing the surface pressure between the inner race and the clutch member (sprag) of the one-way clutch, and the inner race has a good concentricity with the inner race. A small hole that communicates with the sliding surface of the clutch member is drilled in the sliding surface of the inner race and the clutch member such as a sprag that slides with large relative rotation in an overrun state during overdrive. It supplies lubricating oil stably to prevent oil film from running out, and this reduces the frictional resistance between both parts. This prevents wear on the inner race and clutch members of the one-way clutch, and also prevents wear on the inner race and clutch members of the one-way clutch. A clutch can be used, and the one-way clutch can be disposed between the sun gear and the ring gear of the overdrive device, even if a large relative rotation occurs when the one-way clutch overruns during overdrive.
The durability of the overdrive gear transmission can be improved. Further, one clutch hub spline-fitting the outer race of the one-way clutch is arranged concentrically with the other clutch hub connected to the inner race, and a clutch is configured between the two clutch hubs for engaging or disengaging the two, and A brake for locking or releasing the clutch hub from the housing is constructed between the other clutch hub and the inner wall of the housing, so these clutches and brakes can be constructed near the outer peripheral portion of the planetary gear mechanism, and are frictionally engaged. The outer diameter and engagement area of the part can be made large and efficient, and the space inside the housing can be effectively utilized without increasing the axial dimension of the overdrive gear transmission. Therefore, when the present invention is combined with a torque converter and a conventional gear transmission to form an automatic transmission, an overdrive gear train can be added without impairing the performance of the conventional gear transmission. The clutch and brake can be controlled using the control oil of the hydraulic control device of the automatic transmission, and the automatic transmission with an overdrive gear ratio can be controlled without significantly increasing the axial dimension of the automatic transmission. The transmission can be configured extremely easily, and since the clutch and brake are of friction type, the gears can be smoothly engaged and disengaged without making any noise when engaged, and switching between direct coupling and overdrive can be ensured. can be set. In constructing the brake, when the brake hub is connected to the outer peripheral wall of the cylinder body constituting the other brake hub and the brake is constructed between the brake hub and the inner wall of the housing, the cylinder body It is possible to have a simple structure without having to make a complex structure for installing a clutch and a brake together, and to increase the degree of freedom in the location where the brake can be installed.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an automatic transmission in which the present invention is implemented as a sub-transmission, and FIG. 2 is a partially cutaway sectional view of an embodiment of the present invention. In the figure, 1 is the output shaft of the prime mover, 2 is the torque converter, 100 is the gear transmission of the automatic transmission, 2
00 is the sub-transmission, 3 is the input shaft, 8, 9, 10 are planetary gear mechanisms, 21, 81, 91 are sun gears, 2
2, 82, 92 are planetary pinions, 24, 8
4, 94 are its carriers, 23, 83, 93 are ring gears, 11, 12, 13 are clutches, 14,
15, 16, 17 are brakes, 20, 18, 19
1 shows a one-way clutch, 37 an outer race, 38 an inner race, and 40 a thrust bearing.

Claims (1)

[Scope of Claims] 1. A planetary gear mechanism including a housing, a sun gear, a planetary pinion, a ring gear, and a carrier supporting the planetary pinion, an input shaft concentrically connected to the carrier, and a planetary gear mechanism concentrically connected to the ring gear. A friction type clutch that connects a connected output shaft, a friction type clutch that removably connects the sun gear and the ring gear, a friction type brake that brakes the sun gear, and a friction type brake that is connected between the sun gear and the ring gear and brakes the sun gear. The friction type clutch is a one-way clutch that causes the ring gear to overrun when the ring gear is turned. a friction plate and a pressure plate disposed, the friction brake being configured between the other clutch hub and the housing, and the one-way clutch having an inner race connected to the other clutch hub; , an outer race spline-connected to the one clutch hub, and a clutch member disposed between the outer race and the inner race,
An overdrive gear transmission characterized in that the inner race has a small hole that communicates with a sliding surface between the inner race and the clutch member. 2. The overdrive gear transmission according to claim 1, wherein the friction brake is configured between a brake hub connected to the other clutch hub and the inner wall of the housing.