JPS6121296Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lubricating oil circulation pump in an ultra-low-speed transmission attached to an agricultural tractor, particularly a small tractor.

In the past, it has been desired to equip small tractors with ultra-low speed transmissions, but this has been difficult due to space limitations. Therefore, it has been proposed to attach a compact ultra-low-speed transmission consisting of a planetary gear mechanism to the top of the main transmission. By the way, since the ultra-low speed transmission is located above the main transmission and consists of complex gears and bearings like a planetary gear mechanism, the splash type lubrication method cannot provide sufficient lubrication.
Although it is necessary to install a lubricating oil circulation pump, it is difficult to mount the conventional circulation pump separately from the ultra-low speed transmission due to space constraints, and the shapes of the pipes on the suction and discharge sides are also complicated. Summer,
Further, there are drawbacks such as damage due to external force.

Therefore, the present invention connects a lubricating oil circulation pump to the input shaft of an ultra-low-speed transmission via a pump power shaft, and also houses the pump in an ultra-low-speed transmission case. The input shaft and the pump power shaft are rotatably supported concentrically, and the discharge port of the pump is communicated with the input shaft and the rotation support surface of the planetary gear mechanism, thereby supporting the rotation of the planetary gear mechanism. In addition to forcibly lubricating the surfaces and smoothly operating the planetary gear mechanism, which is prone to transmission problems, the ultra-low speed transmission has a compact structure, and can be easily attached to conventional tractors. The purpose of this invention is to provide an extremely low-speed transmission that operates reliably.

Embodiments based on the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the tractor 1 has an engine 3 supported by front wheels 2 at the front of the machine, and a main transmission case 6 supported by rear wheels 5 at the rear of the machine. The main transmission case 6 is connected by a clutch housing 7. Furthermore, at the top of the main transmission case 6, as shown in FIG.
is arranged, and the ultra-low speed transmission 9
A gear shift lever 10 is arranged adjacent to and in front of. As shown in FIG. 3, the ultra-low speed transmission 9 has a case 11 fixed to the main transmission case 6 and the clutch housing 7. Behind the case 11, there is a case 11 fixed to the case 11. The support shaft 1 is
3 is supported by a rotation stopper 12a.
Furthermore, a fixed sun gear 15 is fixed to the tip of the support shaft 13, and a rotary sun gear 16 is rotatably supported adjacent to the fixed sun gear 15. The boss portion of the rotating sun gear 16 is connected to the sleeve shaft 1 rotatably supported by the support shaft 13.
6a, and a shifter gear 17 is slidably supported on the sleeve shaft 16a. Further, a casing 19 is rotatably supported on the support shaft 13 and the sleeve shaft 16a so as to cover both sun gears 15 and 16, and a shaft 20 fixed and supported on the casing 19 has a planet with a wide tooth width. A gear 21 is rotatably supported. Planetary gear 2
1 meshes with both the fixed and rotating sun gears 15 and 16, but both sun gears 15 and 16 have a suitable amount of shift to mesh with the planetary gear 21 without strain, but there is a slight The number of teeth is different. Further, a gear 22 is fixed to a shaft portion 19a formed at one end of the casing 19, and the gear 22 is rotatably supported by an intermediate gear 25 that is rotatably supported by an intermediate shaft 23 fixedly supported by the case 11. It meshes with the Further, the gear 25 meshes with a gear 27 fixed to a transmission shaft 26 supported by the clutch housing 7, and the main transmission case 6 has a gear shift constituting the main transmission coaxially with the transmission shaft 26. A subshaft 28 is rotatably arranged. Shifter gears 29 and 30, which are operated by the speed change lever 10, are slidably supported on the subshaft 28, and the gear 30 is connected to the shifter gear via a gear set 31 loosely fitted to the intermediate shaft 23. 17 can be meshed.

On the other hand, inside the front end of the case 11 is a cylindrical portion 11a.
A pump body 32 of a lubricating oil circulation pump 31 is housed and fixed in the cylindrical portion 11a. One end of the pump body 32 holds a rolling bearing 33 that supports the outer periphery of the shaft 19a of the casing 19 of the planetary gear 21, and the tip of the shaft 19a is connected to the pump body 32 by a double shaft pin joint 35. It is connected to a pump power shaft 36 which is rotatably fitted into the center. Power shaft 36
As shown in FIGS. 4 and 5, the other end is connected to a rotor set inner 37, and the inner 37 cooperates with a rotor set outer 39 fixed to the body 32 to constitute a trochoid pump. ing. A discharge port 40 of the pump 31 passes through the body 32 and communicates with a lubricating oil chamber 41 constituted by the end surface of the casing 19, and a suction port 42 passes through the side surface of the body 32 and communicates with the case 11. It communicates with the formed filter chamber 11b. An oil filter 43 is housed in the filter chamber 11b, and an oil passage 45 is communicated above it as shown in FIG. It communicates with the oil sump below. Furthermore, the lubricating oil chamber 41 is connected to the casing 19.
The end of the shaft part 19a and the body 32 form a normal chamber sub-1.
It is narrowed down to about 1/5 and communicates with the rolling bearing 33, and also connects the support shaft 13 and the casing 1.
9, communicates with the fixed sun gear 15 and the sleeve shaft 16a, and further branches into a casing 19
The planetary gear 21 and the shaft 20 communicate with each other through an oil passage 47 bored in the shaft 20 and an oil passage 49 bored in the shaft 20 .

Since the present invention has the above configuration, the rotation of the engine 3 is transmitted to the gear 27 via the transmission shaft 26, and the casing 19 is further supported via the gears 25 and 22 by the rolling bearing 33, the support shaft 13, etc. and rotate. The rotation of the casing 19 also causes the planetary gear 21 to revolve, but at the same time, the planetary gear 21 meshes with the fixed sun gear 15 and rotates, whereby the rotating sun gear 16 is decelerated based on the difference in the number of teeth with the fixed sun gear 15. Rotates at extremely low speed. The extremely low speed rotation is caused by the shifter gear 17 via the sleeve shaft 16a.
When the speed change lever 10 is operated, the signal is further transmitted to the speed change subshaft 28 via the gears 31 and 30, thereby rotating the traveling shaft or the PTO shaft of the tractor 1 at an extremely low speed. On the other hand, the rotation of the casing 19 is transmitted to the pump power shaft 36 via the pin joint 35,
The lubricating oil circulation pump 31 is driven. This results in
The pump 31 has a suction pipe 46, an oil passage 45,
Lubricating oil is sucked in from the suction port 42 via the filter chamber 11b and the filter 43, and is discharged into the lubricating oil chamber 41 via the discharge port 40. Further, a portion of the lubricating oil in the chamber 41 flows out to the rolling bearing 33 depending on the aperture width, and most of the lubricating oil flows out to the support shaft 1.
3, lubricates the casing 19 and the needle bearings etc. that rotatably support the sleeve shaft 16a, and is discharged from the end of the sleeve shaft 16a. Furthermore, the lubricating oil around the support shaft 13 flows through the oil path 4 due to centrifugal force based on the rotation of the casing 19.
7, flows out to the support surface of the planetary gear 21 via the flow path 49, and is discharged from both sides of the gear 21. Further, the discharged lubricating oil lubricates the planetary gear 21 and both sun gears 15 and 16 together with the lubricating oil splashed by the lower gear and the lubricating oil flowing out between the two sun gears 15 and 16.

As explained above, according to the present invention, the lubricating oil circulation pump 31 is driven by the input shaft 19a of the ultra-low speed transmission 9, so that the pump 31 can be installed inside the case 11 of the ultra-low speed transmission. Therefore, the ultra-low speed transmission 9 can be compactly assembled and easily attached to the main transmission case 6 of a conventional tractor. Furthermore, since the ultra-low speed transmission 9 uses a planetary gear mechanism, it is possible to obtain a large reduction ratio with a compact configuration. However, in general, errors in gears etc. are superimposed on the planetary gear mechanism, making it difficult to distribute the load evenly to each gear. Although it is difficult to distribute, since the lubricating oil circulation pump 31 is connected to the input shaft 19a,
The planetary gear mechanism is supported by a large flow of lubricating oil based on the high-speed rotation of the planetary gear mechanism, and the planetary gear mechanism can absorb the above errors with a thick oil film caused by the lubricating oil, and can obtain smooth ultra-low speed rotation. . In addition, since the pump 31 sufficiently supplies lubricating oil to the inside of the casing 19 and sleeve shaft 16a, where lubricating oil is difficult to reach due to splashing, transmission troubles due to running out of lubricating oil can be prevented. Furthermore, the body 32 of the pump 31 allows
Since the input shaft 19a is rotatably supported and the pump power shaft 36 is rotatably supported concentrically, the lubricating oil circulation pump 31 is configured compactly and can be easily incorporated into the ultra-low speed transmission case 11. In addition, since the pump body 32 serves both of the above three roles, it can be manufactured at low cost. Furthermore, since the body 32 serves both as a rotational support for the input shaft 19a and a rotational support for the pump power shaft 36, the concentricity of both the shafts 19a and 36 can be set accurately. Concentricity can be set accurately, and transmission troubles such as at the joint 35 can be eliminated.

[Brief explanation of the drawing]

Fig. 1 is an overall side view showing a tractor according to the present invention, Fig. 2 is a partially sectional side view showing an ultra-low speed transmission portion, Fig. 3 is a partially enlarged view, and Fig. 4
The figure is a side sectional view showing the lubricating oil circulation pump.
The figure is a front view thereof, and FIG. 6 is a side view of the other side. 1...Tractor, 6...Main transmission case, 9...Super low speed transmission, 11...Case, 19a...Input shaft, 15, 16, 19, 21
... Planetary gear mechanism, 31 ... Lubricating oil circulation pump,
32...Pump body, 36...Pump power shaft,
40...Discharge port.

Claims (1)

[Scope of utility model registration request] In an ultra-low-speed transmission that is attached to the main transmission case of a tractor and is reduced based on a planetary gear mechanism, a lubricating oil circulation pump is connected to the input shaft of the ultra-low-speed transmission via a pump power shaft, and The input shaft and the pump power shaft are rotatably supported concentrically by the body of the pump, and the discharge port of the pump is communicated with the input shaft and the rotation support surface of the planetary gear mechanism. Mitssion's lubricating oil circulation pump for ultra-low speeds.