JPS6235983Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement of the dual shaft structure of a tractor drive system used, for example, in the transmission of an agricultural tractor. The purpose is to enable shaft support and sealing while making the gap between the shaft and the center shaft smaller.

In the transmission of agricultural tractors, a traveling propulsion shaft (cylindrical shaft) to which power is transmitted from the flywheel via a clutch is fitted to a PTO propulsion shaft (center shaft) connected to the flywheel.
It is configured to transmit engine power to the PTO shaft and wheels.

Since the cylindrical shaft is equipped with a clutch and a power transmission gear, and is also supported by a wall via a bearing, its outer diameter cannot be made too large; on the contrary, the central shaft must have an outer diameter sufficient to transmit the required torque. Therefore, it is preferable that the gap between both shafts be smaller.
However, a bearing must be installed between the two shafts, and since the bearing is lubricated with oil, a sealing member must also be placed, and if a general bearing and sealing member is used, the gap will be large. I don't get it. Moreover, if the lip portion of the sealing member is easily deformed when inserting the center shaft, problems such as the lip portion being caught and turned up may result in damage.

The present invention eliminates the drawbacks of the conventional structure and is characterized by the fact that the center shaft 16, through which power is transmitted from the engine, is equipped with a cylinder through which power is also transmitted from the engine via a dry clutch 5. The shaft 17 is fitted with a gap, and the cylindrical shaft 17 is attached to the wall 7 that divides the inside of the housing 2 into front and rear parts with a bearing 19.
A needle bearing 39 with a retainer and a collar are installed between the inner circumferential surface of the end of the cylinder shaft 17 on the side where the gear 29 is attached and the center shaft 16 from the cylinder shaft end surface 17a toward the rear. Part 4
5 and a seal member 40, the lip portion 42 of the seal member 40 protrudes from the metal ring 43 toward the axial collar member 45, and the collar member 45 is connected to the metal ring 43 and the needle bearing 39 at both ends thereof.
The retainer is in contact with the retainer, and its outer circumferential surface is in contact with the inner circumferential surface of the cylindrical shaft 17, and its inner circumferential surface overlaps the lip portion 42 at a position close to it.

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

In Figures 1 and 2, 1 is a tractor body, a clutch housing 2, a transmission case 3
4 is a flywheel attached to the crankshaft of the engine, 5 is a dry type running clutch attached to the flywheel 4, and has a release lever 6.

Reference numeral 7 denotes a support base, which is attached to a support wall 8 that partitions the clutch housing 2 and the transmission case 3, and serves as a wall that divides the housing 2 into front and rear parts, and the front part is a dry room where the clutch 5 is placed. ,
Behind it is a wet chamber in which a power transmission gear 29 and the like, which will be described later, are arranged. The support base 7 supports the release hub 9 in a cylindrical portion 7a so as to be slidable in the axial direction. This release hub 9 is slid by a release fork 11 provided on a fork shaft 10,
The release lever 6 is pushed through the release bearing 12 to connect and disconnect the clutch 5.

15 is a double shaft, with center shaft 1 serving as the PTO propulsion shaft.
6 and a cylindrical shaft 17 as a travel propulsion shaft. The center shaft 16 has a front end connected to the flywheel 4, a rear end pivotally supported to the transmission case 3, and drives the PTO shaft via a PTO clutch and a PTO transmission (not shown). The cylinder shaft 17 is the center shaft 16
The distal end thereof is pivotally supported by the flywheel 4 via a bearing 18, and the midway portion thereof is rotatably supported by the support base 7 via a bearing 19.

20 is a traveling transmission shaft, which is connected to the center shaft 1 behind the cylindrical shaft 17.
6 and is loosely fitted to the partition wall 2 through the bearing 21.
It is rotatably supported by the second class. 23 is a first deceleration shaft disposed below and parallel to the double shaft 15; 24;
is a second
The deceleration axes are shown respectively.

A high speed clutch portion 26 is provided at the rear end of the cylinder shaft 17.
A hydraulic clutch 28 in which a low-speed clutch portion 27 and a low-speed clutch portion 27 are integrated is keyed, and the low-speed clutch portion 27
A gear 29 having a passive portion 29a that receives power transmission from the gear 29 is loosely fitted therein.

A passive body 30 and a gear 31 to which power is transmitted from the high-speed clutch portion 26 are disposed at the tip of the traveling transmission shaft 20.
are spline fitted.

A gear 32 that meshes with the gear 29 is fixed to the first reduction shaft 23, and a gear 33 that meshes with the gear 31 is integrally molded.
The power of the cylinder shaft 17 is transmitted through the low speed clutch section 27 and the gear 2.
The signal is transmitted to the first deceleration shaft 23 via gears 9 and 32, and is then decelerated and transmitted to the traveling power transmission shaft 20 via gears 33 and 31. On the other hand, the high-speed clutch portion 26 directly connects the cylindrical shaft 17 and the running power transmission shaft 20 via the passive body 30, and directly transmits high-speed rotation from the engine.

A gear group 34 consisting of a large number of gears is provided between the traveling power transmission shaft 20 and the second reduction shaft 24, and is capable of reducing the speed in, for example, four steps.

A gap as small as possible is formed between the inner circumferential surface 37 of the rear end of the cylinder shaft 17 and the outer circumferential surface 38 of the center shaft 16, and a bearing that supports both shafts relatively rotatably is provided in this gap. 39, and a seal member 40 for preventing oil in the transmission case 3 from leaking into the clutch housing 2 through between the shafts 16 and 17.

The bearing 39 is formed of a needle bearing with a retainer, and is prevented from coming off by a retaining ring 41 attached to the cylindrical shaft 17.

The seal member 40 is disposed further back from the shaft end 17a of the cylindrical shaft 17 than the bearing 39, and is formed of a spring-loaded outer peripheral metal oil seal. The lip portion 42 of the sealing member 40 protrudes outward from the metal ring 43, and a spring 44 fitted around its outer periphery is formed of a rubber O-ring or the like.

A collar member 45 is interposed between the bearing 39 and the seal member 40.
5 overlaps with the lip portion 42 of the seal member 40, and restricts deformation of the lip portion 42 in the radial outward direction. That is, the collar member 45 serves as a spacer between the bearing 39 and the seal member 40, and
This is to prevent and protect the lip portion 42 from excessive deformation, and the lip portion 42 is allowed to deform in the radial direction, although only slightly by the amount that the spring 44 deforms. However, if a slight gap is formed between the spring 44 and the collar member 45, or if the spring 44 is not provided,
The outer peripheral surface of the lip portion 42 may face the inner peripheral surface of the collar member 45 with a gap therebetween.

The center shaft 16 is assembled by inserting the bearing 39, the seal member 40 and the collar member 45 into the rear end of the cylindrical shaft 17. In the above structure, the center shaft 16 is first inserted by the bearing 39. Center axis 1
Since the ends of the shafts 6 are guided while centering, there is no chance of the lip part 42 being caught in the opposite direction, and a seal between the two shafts 16 and 17 can be ensured. By doing this, oil leakage to the clutch housing 2 can be prevented, and when the spring 44 is provided, oil leakage can be prevented even more completely.Furthermore, since the bearing 39 is located closer to the shaft end than the sealing member 40, the oil leakage to the clutch housing 2 can be prevented. Lubrication with oil in the case 3 can be performed normally.

FIG. 3 shows an example of a support structure for the cylinder shaft when a double clutch is used. 17 has its tip connected to a second clutch 48, and its midway portion supported by the support base 7 and the support wall 8 via bearings 19, 49.

Conventionally, the cylindrical shaft 17 was only connected to the second clutch 48 at its tip and was not supported by a bearing 49, and the cylindrical portion 7a of the support base 7 only supported the release hub 9. . Therefore, when the second clutch 48 is engaged or disconnected, the tip of the cylinder shaft 17 may swing and come into contact with the center shaft 16, and since these shafts 16 and 17 are not lubricated with oil, vibration noise may be generated. or burn-in.

Therefore, as mentioned above, the tip of the cylindrical portion 7a and the cylindrical shaft 1
Bearing 4 such as a ball bearing between the outer peripheral surface of 7
9 prevents the cylinder shaft 17 from swinging. A gap of, for example, approximately 0.05 mm is provided between the inner ring of the bearing 49 and the outer peripheral surface of the cylinder shaft 17 to prevent the cylinder shaft 17 from being supported at three points. In this case, the bearing 49 does not support the cylindrical shaft 17, but supports it only when an excessive radial force is applied to the cylindrical shaft 17 and vibration occurs.
This eliminates contact between the cylindrical shaft 17 and the center shaft 16, improving the durability of the bearing 49 and extremely reducing the need for oil lubrication.

According to the present invention described in detail above, in a housing in which a dry chamber in which the clutch 5 is disposed and a wet chamber in which the gear 29 is disposed are formed by partitioning the inside of the housing into the front and back by the wall 7, The center shaft 16 inserted into the cylindrical shaft 17 can be supported by a needle bearing 39 in the end of the cylindrical shaft 17 on the gear 29 mounting side. Since the needle bearing 39 is used and the lip portion 42 of the seal member 40 is protruded outward from the metal ring 43, the gap between the cylindrical shaft 17 and the center shaft 16 can be prevented. can be made smaller, which makes the cylinder shaft 1
7 can be formed to have a small diameter, and the center shaft 16 can be formed to have a large diameter. Even if the lip portion 42 of the sealing member 40 protrudes, the collar member 45 overlaps at the adjacent position, so that the radial direction of the lip portion 42 can be formed. Excessive deformation can be prevented, and since the collar member 45 is backed up in contact with the inner peripheral surface of the cylindrical shaft 17, deformation of the lip portion 42 can be more reliably prevented. The position of the seal member 40 can also be set.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show an embodiment of the present invention, Fig. 1 is a sectional view, Fig. 2 is an enlarged sectional view of the main part, and Fig. 3 is an example of the support structure of the cylinder shaft. FIG. 2...Clutch housing, 3...Mission case, 15...Double shaft, 16...Center shaft, 17...
... Cylindrical shaft, 39 ... Bearing, 40 ... Seal member, 4
2...Rip part, 45...Collar member.

Claims (1)

[Scope of utility model registration request] A cylindrical shaft 17, to which power is also transmitted from the engine via the dry clutch 5, is fitted with a gap to the center shaft 16 to which power is transmitted from the engine, and this cylindrical shaft 17 is divided into front and rear sections within the housing 2. It is supported on the wall 7 via a bearing 19 and the power transmission gear 2
9 is installed, and a needle bearing with a retainer 39, a collar member 45, and a seal member 40 are arranged between the inner peripheral surface of the end of the cylinder shaft 17 on the side where the gear 29 is attached and the center shaft 16 from the cylinder shaft end surface 17a toward the rear in order. The lip portion 42 of the sealing member 40 protrudes from the metal ring 43 toward the collar member 45 in the axial direction, and both ends of the collar member 45 abut against the metal ring 43 and the retainer of the needle bearing 39, and the outer peripheral surface thereof A dual shaft structure for a tractor drive system, characterized in that the shaft abuts against the inner circumferential surface of the cylindrical shaft 17, and its inner circumferential surface overlaps the lip portion 42 at a position close to it.