JP3602413B2 - Lubricators for tractor missions - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tractor transmission lubrication device.
[0002]
[Prior art]
In general, lubrication of a tractor transmission is performed by storing a lubricating oil that also serves as hydraulic oil in a transmission case, and immersing the transmission, particularly a gear, in the bath.
In so-called oil bath lubrication, the oil level fluctuates when traveling on an inclined road, etc., so that it may be difficult to sufficiently lubricate (cool) small lubricating parts such as bearings. There was a risk and there was a problem in durability.
[0003]
[Problems to be solved by the invention]
In addition to the oil bath immersed in the above-mentioned gear oil bath, means for lubricating the oil (lubricating oil) by scraping it up or scattering or means for lubricating using the return oil of a hydraulic lifting device provided in the tractor, etc. However, the former method has a problem that it is still difficult to refuel a narrow lubricating part because of the scattering method, and the latter method has multiple pipes and the like, which causes a pressure loss. .
Therefore, according to the present invention, since the return oil or excess oil from the control valve for controlling the hydraulic pack has pressure, it is possible to feed (blow out) even a narrow lubricated portion through a passage formed around the pressure oil. Thus, a lubricating device is provided.
[0004]
[Means for Solving the Problems]
The present invention provides a tractor transmission including a hydraulic pack that is turned on and off by a control valve in a traveling transmission system and a hydraulic pack that is turned on and off by a control valve in a PTO transmission system. Has taken technical measures. That is, according to the present invention, the return oil from the control valve of the PTO transmission system is used to lubricate bearings, clutch plates and the like through a passage formed in the drive shaft of the hydraulic pack in the transmission system in the axial direction. It is characterized by being blown out to a part.
[0005]
According to a second aspect of the present invention, a hydraulic pack for a traveling power transmission system is provided on a propulsion shaft interlocked with an engine, and a hydraulic passage for the hydraulic pack is formed in the propulsion shaft in an axial direction and a radial direction. The PTO drive shaft is coupled to the propulsion shaft, and a lubrication passage is formed in the PTO drive shaft and the propulsion shaft.
Further, in claim 2, it is recommended that an oil reservoir is formed at a joint portion between the propulsion shaft and the PTO drive shaft, and the oil is blown out to the lubricating portion via the oil reservoir (claim 3). ).
[0006]
Since such a configuration is employed, surplus oil from the control valve can be pressure-fed through a passage formed on the shaft, and reliable lubrication can be performed even in a narrow portion, and the number of piping members is reduced and pressure loss is reduced. I was able to hold it down.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a main transmission unit using a hydraulic shuttle transmission and a gear train. FIG. 2 shows a configuration in which a sub transmission unit using a gear train and / or a creep transmission unit using a gear train are provided on the output side of the main transmission unit. FIG. 3 schematically shows the entire traveling transmission system and PTO transmission system described above.
In FIGS. 1 to 3, a propulsion shaft 3 is interlocked to an engine (engine flywheel in the drawings) 1 via damper means 2.
[0008]
Since the damper means 2 reduces (absorbs) the torque of the engine or the load on the engine, the axial length of the coil spring 2A shown in FIG. 3 is provided in the circumferential direction.
A main transmission shaft 4 is provided behind the extension of the propulsion shaft 3 on the axial center thereof, and the main transmission shaft 4 is a cylindrical shaft.
A transmission sub-shaft 5 is installed parallel to the main transmission shaft 4, and in this example, a transmission sub-shaft 5 is installed above the main transmission shaft 4, and a main transmission unit is provided by a gear train 6 provided between the shafts 4 and 5. In the figure, the main transmission section 7 is a synchronous occlusion type, and the first shifter 8 and the second shifter 9 are slid forward and backward in the axial direction to perform a four-speed shift (first speed to fourth speed). It has been.
[0009]
A hydraulic shuttle transmission (hydraulic pack) 10 is provided on the propulsion shaft 3. The transmission 10 includes a reverse rotation 10A and a forward rotation 10B arranged in the axial direction. The transmission 10A is transmitted to the main shaft 4 via the main transmission unit 7, and the reverse rotation 10A is transmitted to the transmission sub-shaft 5 via the back gear train 11 to pass through the main transmission unit 7.
Referring to FIG. 1, a hydraulic shuttle transmission 10 has pistons 14A and 14B slidably fitted to front and rear cylinder portions of a clutch body 13 connected to a propulsion shaft 3 via a key 12. The clutch plates 16A, 16B arranged in the front-rear direction on the bowl-shaped clutch mounting plates 15A, 15B can be pressed against the pressure receiving plates 18A, 18B and the pistons 14A, 14B against the return springs 17A, 17B. The pressure oil from a pump (not shown) passes through the switching operation (on / off operation) of the control valve 19 through the passages 20A and 20B formed in the propulsion shaft 3 as the axial direction and the passages 21A and 21B formed in the radial direction. The liquid can be sent to the front and rear cylinders, respectively.
[0010]
The cylindrical boss of the clutch mounting board 15A of the reverse rotation 10A is fitted over the propulsion shaft 3 so as to be freely rotatable (idle freely), a reverse drive gear 11A is formed on the cylindrical boss, and the drive gear 11A is provided with an idle gear. The gear 11C is interlocked with the reverse driven gear 11C on the transmission countershaft 5 via 11B, and forms a back gear train 11 here, and is arranged on the front side of the hydraulic shuttle transmission 10.
The cylindrical boss of the clutch mounting board 15B of the forward rotation 10B is rotatably supported via a ball bearing and a sleeve bearing over the propulsion shaft 3 and the front portion of the main transmission shaft 4, respectively. The transmission gear 6B on the transmission countershaft 5 is engaged with the drive gear 6A.
[0011]
The propulsion shaft 3, the back gear train 6, and the hydraulic shuttle transmission 10 are supported by front and rear bearings 21A and 21B via an internal casing 20 built in a housing 19A of a transmission case 19 constituting a tractor body.
The inner casing 20 is formed by combining first and second bowl-shaped first and second casings 20A and 20B, and is assembled with bolts and the like (not shown), and the second casing 20B is attached to a partition wall 19B of the housing 19A with bolts and the like (not shown). (See FIG. 2).
As shown in FIG. 2, the main transmission portion 7 capable of performing four-speed shifting with the gear train 6 has a front and rear relative to a transmission gear 6B and a driving gear 6A fixed to the transmission sub shaft 5 meshing with the driving gear 6A. The transmission gear 6C is rotatable on the main transmission shaft 4 and the transmission gear 6D is fixed to the transmission sub shaft 5 that meshes with the gear 6C. The transmission gear 6D is fixedly arranged on the main transmission shaft 4 behind the transmission gear 6C. The transmission gears 6E and 6F are provided with transmission gears 6G and 6H supported on the transmission sub shaft 5 that meshes with the transmission gears 6E and 6F, respectively. 6D, the second shift is set. The first and second shifts including the neutral state can be switched by sliding the first shifter 8 of the synchronous occlusion type in the front-rear direction in the axial direction. 3 shifts, 4th shift in gear trains 6F, 6H, 2nd shift of synchronous occlusion type Switching of the third-4 shift is possible, including the neutral axial longitudinal sliding of 9.
[0012]
On the output side of the main transmission unit 7, a traveling transmission system for transmitting power to a rear wheel differential device 24 is provided with a two-stage auxiliary transmission unit 22 using a gear train and / or a creep transmission unit 23 using a gear train. The wheels can be driven via a final reduction gear (not shown).
As shown in FIG. 2, the auxiliary transmission portion 22 including the gear train includes two (high and low) gears 22 </ b> A and 22 </ b> B fixed on the main transmission shaft 4 at an axial interval, and the main transmission shaft 4. Two (high and low) gears 22C and 22D, which are engaged with the gears 22A and 22B so as to be freely rotatable on a transmission countershaft 25 provided in parallel in the transmission case 19, and the gears 22C. , 22D which can be freely engaged and disengaged, and a pinion type which is connected to a transmission sub shaft 25 by a coupling 26 by selecting the height by sliding the third shifter 22E in the axial direction. Is transmitted to the differential drive shaft 27.
[0013]
The large and small gears 23B and 23C are fixed to a creep shaft 23A provided on the transmission case 19 in parallel with the transmission sub shaft 25, and the large gear 23B is a small gear formed on the gear 22D. The small gear for creep 23C is engaged with a large gear 23E which is rotatably provided on the transmission countershaft 25, and is switched to an extremely low speed by engaging and disengaging the large gear 23E with a fourth shifter 23F. It is free.
The speed change sub-shaft 25 also serves as a front wheel drive system, and constitutes a front wheel drive gear train 27 extending between the front wheel propulsion shaft 26 and the sub-shaft 25. In the figure, switching operation of the fifth shifter 28 causes rear wheel drive. And front and rear wheel drive can be selected, and the front wheel propulsion shaft 26 can drive left and right front wheels in conjunction with a front wheel differential device (not shown).
[0014]
Referring to FIG. 1, a PTO drive shaft 29 is joined (directly connected) to the rear end of the propulsion shaft 3 by a spline connection or the like, and the PTO drive shaft 29 is slightly contained in the main transmission shaft 4 which is a traveling system having a cylindrical structure. As shown in FIG. 2, a hydraulic PTO is inserted through a gap 30, extends rearward beyond the rear end of the main transmission shaft 4, and is elastically embedded (incorporated) with rubber or the like. The clutch (hydraulic pack) 32 is interlocked and connected.
The PTO clutch 32 is operatively connected to a PTO transmission section 34 by gears via a transmission shaft 33 so as to drive the PTO shaft 35 (see FIG. 3).
[0015]
As shown in FIG. 4, the PTO clutch 32 fits the piston 32B into the cylinder chamber of the clutch body 32A, which is fitted over the transmission shaft 33 and is connected by a spline or the like, slidably by hydraulic pressure against the return spring 32C. The multi-plate clutch plate 32D interposed between the boss portion 31A of the coupling 31 and the boss portion 31A can be pressed (the piston shown in the upper part of FIG. 4 is in a pressed state, and the piston shown in the lower part is in a non-pressed state). When pressed, the inertia stopper plate (continuous rotation prevention plate) 32G is caused to accompany the spring 32H via the interlocking pin 32F, and when the oil pressure is released, the prevention plate 32G is pressed against the fixed plate 32I by the elastic restoring force of the spring 32H. By attaching it, continuous rotation is prevented.
[0016]
The hydraulic PTO clutch 32 is capable of introducing pressure oil from a PTO valve 36 for turning on and off the PTO transmission system shown in FIGS. 2 and 3 through a supply passage 36A. Oil is blown out to lubricated parts such as bearings, sliding parts, clutch plates and the like for lubrication or cooling.
For this reason, the return oil is received from the lubricating oil receiving port 37 shown in FIG. 4 and introduced into the passage 38 formed in the axial direction of the transmission shaft 33, and is used for cooling the clutch plate 32 </ b> D through the radial communication hole 39. While discharging, it is discharged to the front through a passage 40 formed in the PTO drive shaft 29 in the axial direction.
[0017]
As shown in FIG. 1, the passage 40 communicates with an oil reservoir 41 formed between the rear end of the propulsion shaft 3 and the oil in the oil reservoir 41. Cooling of the clutch plate 16B for the forward rotation 10B is blown out with a centrifugal force or the like as lubrication of a bearing or the like through a communication passage formed in the body, and formed on the propulsion shaft 3 through an oil reservoir 41. Through the axial passage 44 and the radial passage 45, the air is blown out with a centrifugal force and the like for cooling the reverse clutch plate 16A and for lubricating the bearings.
[0018]
Further, a passage 40 formed in the axis of the PTO drive shaft 29 communicates with the small gap 30 through a radial through hole 46 formed near the front end thereof, and a plurality of diameters formed in the main transmission shaft 4. The lubricating oil can be blown out by centrifugal force or the like into the gear engagement portion, the bearing, and the like of the main transmission portion 7 through the through hole 47 in the direction and the plurality of through holes 48 formed in the sleeve bearing. The fretting (rusting) of the joint is reliably prevented by supplying the spline to the spline joint between the shaft and the PTO drive shaft 29.
The passages 20A, 20B for the forward and reverse rotations 10A, 10B are closed by screw plugs 49, and a lubrication passage 44 is provided adjacent to the passages 20A, 20B in the axial direction of the propulsion shaft 3. It is formed with a bottom.
[0019]
In the embodiment of the present invention, the number of passages 40 formed in the PTO drive shaft 29 in the axial direction may be two or more. Return oil and excess oil for PTO are returned to the transmission case 19 after lubrication and cooling. Each gear is oil bathed in this bath.
[0020]
【The invention's effect】
As described in detail above, according to the present invention, the piping can be simplified (simplified) and the pressure loss can be suppressed. (Cooling).
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a hydraulic shuttle transmission (hydraulic pack) and a main transmission section, which are main parts in an embodiment of the present invention.
FIG. 2 is a sectional view showing a main part of the tractor transmission.
FIG. 3 is an overall configuration diagram of a tractor transmission.
FIG. 4 is a sectional view of a PTO hydraulic clutch device (hydraulic pack).
[Explanation of symbols]
10 Hydraulic pack 19 Control valve 29 PTO drive shaft 32 Hydraulic pack 36 Control valve 40 Passage

Claims (3)

A hydraulic shuttle transmission that is turned on and off by a control valve is provided on a propulsion shaft that is operatively connected to the engine, and is provided by a PTO valve at a rear end of a PTO drive shaft that is operatively connected to the rear end of the propulsion shaft. A PTO clutch to be disengaged is provided, and the propulsion shaft is formed with a passage capable of supplying the hydraulic shuttle transmission with hydraulic oil from the control valve for operation, and the PTO drive shaft and the propulsion shaft are formed. A lubrication system for a tractor transmission, characterized in that a passage is formed in a shaft to be blown out to the hydraulic shuttle transmission for lubricating return oil from the PTO valve . The tractor according to claim 1, wherein a passage for lubricating oil formed in the PTO drive shaft and the propulsion shaft communicates with an oil reservoir formed in a joint portion between the propulsion shaft and the PTO drive shaft. Mission lubrication device. A main transmission shaft is provided behind the extension of the propulsion shaft, and a subtransmission shaft is provided in parallel with the main transmission shaft, and a main transmission portion is provided by a gear train provided between these shafts. The main transmission shaft is formed as a cylindrical shaft, the PTO drive shaft is inserted therethrough, a passage for lubricating oil formed in the PTO drive shaft is communicated with the main transmission unit, and the the return oil lubrication system of the tractor transmission according to claim 1 or claim 2, characterized in that it is blown as lubricating main transmission section Te.

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