JPH032097B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to an automatic transmission used in specially equipped vehicles such as mixer trucks, fire trucks, concrete pump trucks, etc., in which special machinery is attached to the vehicle and is driven by the motor of the vehicle. . (Prior art) As an automatic transmission equipped with a conventional power take-off drive gear, for example, "Automotive Engineering Complete Book Volume 9 Power Transmission Device" (published by Sankaido Co., Ltd. in November 1980)
The one shown in Figure 3.88 on page 195 of . This conventional automatic transmission includes an input shaft into which rotational driving force from a torque converter is input, and a transmission element (clutch, The system includes a planetary gear type gear train that changes speed by operating a brake, etc.), and a power take-off drive gear that extracts driving force from an input drive system to the gear train to outside the system. Furthermore, the conventional power take-off drive gear is
It is fixed on the outer periphery of the clutch drum of the forward clutch that is engaged during forward gear shifting. (Problems to be Solved by the Invention) However, in such conventional automatic transmissions, as mentioned above, the power take-off drive gear was fixed on the outer periphery of the clutch drum. I had a problem like this. Due to gear selection regulations that require the power take-off drive gear to have a gear diameter greater than the outer diameter of the clutch drum, the degree of freedom in setting the acceleration/deceleration ratio is low. In particular, when attempting to increase the reduction ratio, the power take-off unit incorporating the reduction gear is very large and protrudes from the transmission case, making it difficult to mount it on the vehicle. Since the power take-off drive gear is attached via a clutch drum having a cavity in which the clutch is installed, the support accuracy and rigidity of the power take-off drive gear are low. As a result, gear noise was large and durability was low. (Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and in order to achieve this purpose, the present invention has adopted the following solving means. . The solution of the present invention will be explained with reference to the conceptual diagram of the claim shown in FIG.
, a gear train 3 that changes the rotational speed from the input shaft 2 by operating a speed change element according to the gear position, and a power take-off drive gear 4 that extracts driving force from the input drive system to the gear train 3 to the outside of the system. In the automatic transmission, the power take-off drive gear 4 is provided on the input shaft 2 between the torque converter 1 and the gear train 3. (Function) Therefore, in the automatic transmission of the present invention, as described above, by providing the power take-off drive gear on the input shaft between the torque converter and the gear train, If the gear has a gear diameter of In addition, by installing the power take-off drive gear on the input shaft, which requires high support precision in the power transmission system, the gear support precision is high, and since it is not supported via a rotating member such as a clutch drum, , gear support rigidity is also high. (Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
In describing this embodiment, an automatic transmission with three forward speeds and one reverse speed, which is equipped with a torque converter with a lockup, will be taken as an example. First, the configuration of the first embodiment will be explained. FIG. 2 schematically shows the power transmission parts inside the automatic transmission A of the first embodiment. The main power transmission system of the automatic transmission A includes a crankshaft 10, a torque converter 11, Input shaft 12, front planetary gear 1
3. A rear planetary gear 14 and an output shaft 15 are provided. As the transmission elements, there are a front clutch 16 and a rear clutch 17 between the input shaft 12 and both planetary gears 13 and 14 (gear train).
A low and reverse brake 19, a brake band 20, and a one-way clutch 21 are provided between the planetary gears 13, 14 and the transmission case 18. As the power take-off device, a power take-off drive gear 22 and a power take-off unit 23 are provided. In addition, in Fig. 2, 24 is an oil pump, 25 is a connecting gear, 26 is a parking pole, 2
7 is an oil distributor, 28 is a secondary governor valve, and 29 is a primary governor valve. The torque converter 11 is of a type called a symmetrical three-element one-stage two-phase type, and the crankshaft 1
0 and the turbine runner 1 connected to the input shaft 12.
12, and a stator 114 fixed to the transmission case 18 via a one-way clutch 113. The torque converter 11 of the embodiment is provided with a lock-up clutch 30 that directly connects the crankshaft 10 and the input shaft 12 during predetermined operation. The front planetary gear 13 and the rear planetary gear 14 are both simple planetary gears (pinion is one type), and both planetary gears 1
3 and 14 are arranged in a Simpson gear train to form the gear train of the embodiment. The transmission element is operated according to the gear position by control pressure from a hydraulic control device (not shown) to change the gear combination of the planetary gears 13 and 14 to obtain a different transmission ratio (gear ratio). be. Incidentally, the shift elements at each shift position of the automatic transmission A of the first embodiment operate as shown in Table 1 below.

[Table] In the above table, ○ represents the hydraulic oil supply, and when the band servo is supplied with hydraulic oil to both the actuation and release chambers, it will be released due to the difference in piston area. The power take-off drive gear 22 is a gear for extracting driving force from the input drive system to the gear train by the planetary gears 13 and 14 to the outside of the system, and is an input between the torque converter 11 and the planetary gears 13 and 14. It is fixed on the shaft 12. In addition, in the embodiment, transmission case 1
A power take-off drive gear 22 is disposed between the oil pump 24 and the front clutch 16 in order to secure a space for arranging the power take-off unit 23, which is installed inside the engine 8. Specifically, as shown in FIG. 3, the large diameter portion 12a of the input shaft 12 is supported via thrust bearings 33 and 34 with respect to the pump-side power take-off housing 31 and the clutch-side power take-off housing 32. , the power take-off drive gear 22 is fixed to the unit mounting hole 3 opened in the transmission case 18.
5, a unit case 231 of the power take-off unit 23 is fixed. The power take-off unit 23 includes a unit case 231, a power take-off input shaft 232, and a power take-off input gear 23.
3. It is composed of support bearings 234, 235, an idler gear 236, etc. Although not shown, the power takeoff output shaft and output gear, or the output gear is engaged with the idler gear 236 by a switching operation, and the power takeoff is brought out of the inoperative state. It also includes a switching device that switches the power take-off to the operating state and vice versa. In addition, 36 in Fig. 3 is a converter housing, 3
7 is an oil pump housing, and 38 is a front clutch drum. Next, the operation of the first embodiment will be explained. First, when the power take-off is not in operation, the gears are shifted according to the shift position in the same way as in a normal automatic transmission. Furthermore, the gears of the power take-off unit 23 idle. Next, when the vehicle is stopped and the gear shift position is set to the neutral position (all gear shift elements are open) and the switching device of the power take-off unit 23 is switched to the power take-off operating side, the torque converter 1
1, the engine driving force input to the input shaft 12 is transferred to the input shaft 12 →
Power takeoff drive gear 22 → power takeoff input gear 233 → idler gear 23
6→Output gear→Power takeoff The output shaft can be taken out of the vehicle drive system. Incidentally, it is also possible to run the vehicle with the power takeoff operating state while the power transmission system is divided. The power take-off drive gear 22, which is a gear for extracting the driving force from the input shaft 12 during power take-off operation, is provided on the input shaft 12, so the gear has a diameter larger than the shaft diameter of the input shaft 12. As long as the gear has a diameter, a gear of any size can be selected, and the increase/deceleration ratio of the external driving force can be set freely. For example, when taking out the input shaft 12 without changing its speed as in the first embodiment, if the power take-off drive gear 22 with a small number of teeth is selected, the power take-off unit 2
The input gear 233 of No. 3 is almost housed inside the transmission case 18, so that the protrusion of the power take-off unit from the transmission case 18 to the outside can be reduced.
Vehicle mountability is improved. In addition, the power take-off drive gear 22,
It is provided on the input shaft 12 which requires high support accuracy in the power transmission system, and in the first embodiment, the input shaft 12 of the gear attachment part is supported in the axial direction via thrust bearings 33 and 34. This increases gear support accuracy and gear support rigidity, prevents gear noise, and improves durability. Furthermore, in the first embodiment, since the power take-off unit 23 is removable into the unit mounting hole 35 of the transmission case 18, it can be used instead of the power take-off unit 23 as an automatic transmission for a vehicle that does not require a power take-off. The present invention can be applied without any problem simply by providing a cover to cover the unit attachment hole 35, and the power take-off unit 23 can also be attached if necessary. Next, a second embodiment shown in FIG. 4 will be described. In this embodiment, the power take-off input gear 233 provided in the power take-off unit 23 in the first embodiment is connected to the transmission case 1 together with the power take-off drive gear 22'.
This is an example in which it is installed inside 8'. The power take-off drive gear 22' is spline-coupled to the input shaft 12', and is supported in the radial and axial directions by ball bearings 40 and 41 for the pump-side power take-off housing 31' and the clutch-side power take-off housing 32'. has been done. The input shaft 42 is a gear integrated with the power take-off input shaft, and is supported in the radial and axial directions by ball bearings 43 and 44 with respect to both power take-off housings 31' and 321'. The clutch case 45 has almost the same shape as an oil pump case in an automatic transmission without a power take-off mechanism, so that it can be equipped with a power take-off mechanism without requiring major design changes. Note that the other configurations are the same as in the first embodiment, so
The same reference numerals are given to the drawings, and the description thereof will be omitted. Furthermore, the operation is the same as in the first embodiment, and the difference is that up to the input gear 42 is mounted inside the transmission case 18', making the power take-off unit 23' even smaller than in the first embodiment. can do. Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included. For example, in the embodiment, an automatic transmission with three forward speeds and one reverse speed is shown as an example, but the automatic transmission may have different gears. Further, in the embodiment, a planetary gear type gear train is shown, but a gear train other than the embodiment may be used, such as a parallel shaft type using helical gears or the like. Further, in the embodiment, the power take-off drive gear is fixed on the input shaft, but the power take-off drive gear may be integrally formed with the input shaft. (Effects of the Invention) As explained above, the automatic transmission of the present invention has a configuration in which the power take-off drive gear is provided on the input shaft between the torque converter and the gear train. Therefore, if the gear has a gear diameter larger than the shaft diameter of the input shaft, it is not subject to gear selection regulations.
The advantage is that the increase/deceleration ratio of the external driving force can be selected with a high degree of freedom in setting, and it is also possible to downsize the power take-off unit. Furthermore, by providing the power take-off drive gear on the input shaft, gear support accuracy and gear support rigidity are high, thereby preventing gear noise and improving durability.

[Brief explanation of drawings]

Fig. 1 is a frame conceptual diagram showing the automatic transmission of the present invention, Fig. 2 is a schematic diagram showing the power transmission part of the automatic transmission of the first embodiment of the invention, and Fig. 3 is the automatic transmission of the first embodiment. FIG. 4 is a cross-sectional view showing the power take-off mechanism of the automatic transmission according to the second embodiment. 1...Torque converter, 2...Input shaft, 3...Gear train, 4...Power take-off drive gear.

Claims (1)

[Scope of Claims] 1. An input shaft into which the rotational driving force from the torque converter is input, a gear train that changes the rotational speed from the input shaft by operating a speed change element according to a gear position, and a gear train to which the rotation speed is input. and a power take-off drive gear for extracting driving force from an input drive system to the outside of the system, wherein the power take-off drive gear is provided on an input shaft between a torque converter and a gear train. Features an automatic transmission.