JPS6112183Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cutter drive device for various types of mowers such as mid-mount type mowers. The purpose of this invention is to prevent oil intrusion without increasing the number of parts and improve the durability of oil seals, etc. in the lower end of a bearing case.

In mid-mount mowers, etc., a bearing case is provided in the mower deck with a downward opening, and a cutter shaft having a cutter at the lower end is rotatably inserted into the bearing case. An oil seal is interposed between the outer circumferential surface of the middle part in the height direction. By the way, in the past, there was a large gap between the lower end surfaces of both the bearing case and the oil seal and the top surface of the cutter, and grass, foreign matter, etc. were wrapped around the part of the cutter shaft corresponding to the gap. Since there is a risk of damaging the oil seal, conventionally, a winding prevention member has been provided that includes the above-mentioned portion of the cutter shaft. However, this is not preferable because it increases the number of parts, and there has been a conventional desire to solve the above problem without increasing the number of parts.

The present invention was devised in view of the above-mentioned circumstances, and its characteristics are that a bearing case is provided in the mower deck with a downward opening, and a cutter shaft with a cutter at the lower end is attached to the bearing case. In a mower that is rotatably inserted and supported around the vertical axis through a mower and an oil seal is interposed between the inner peripheral surface of the lower end of the bearing case and the outer peripheral surface of the cutter shaft, the lower end surface of the bearing case is inserted into the upper surface of the cutter through a small On the other hand, the lower end of the cutter shaft has a larger diameter than its upper side, and is positioned below the oil seal as a large diameter part, and the large diameter part is fitted into the lower end of the bearing case through a small hole. This is the point.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In FIG. 1, 1 is a tractor body, 2 is a front wheel, and 3 is a rear wheel. Reference numeral 4 denotes a mid-mount mower, which includes a mower deck 5, a plurality of cutters 7 attached to the mower deck 5 via cutter shafts 6, and cutting height regulating mowers arranged before and after the mower deck 5. It is equipped with a gauge wheel 8 and the like, and is mounted on the lower abdomen of the tractor body 1 via a parallel link type mounting device 9 so as to be able to rise and fall freely. The gauge wheel 8 can be adjusted up and down by an adjustment lever 10. 11 is a front power take-off device;
Each cutter shaft 6 is driven from the drive shaft 12 through the drive shaft 12.

As shown in FIGS. 2 and 3, the cutter shaft 6 has a pair of upper and lower bearings 13, 1 in a bearing case 12.
The bearing case 12 has a cylindrical shape with a flange at the upper end and is attached to the mower deck 5. A mounting boss 16 for a drive pulley 15 is spline-coupled to the upper end of the cutter shaft 6, and the boss 16 is prevented from coming off by a bolt 17.
An oil seal 18 is interposed between the outer peripheral surface of the boss 16 and the inner peripheral surface of the upper end of the bearing case 12. In addition, upper and lower bearings 1 are located midway in the height direction of the cutter shaft 6.
A collar 19 for positioning the parts 3 and 14 is fitted onto the collar 19, and the lower end thereof has first and second large diameter parts 20 and 21 whose diameters are gradually increased from the upper side.
It is formed in a two-step stepped shape consisting of. 1st
The large diameter portion 20 supports the lower bearing 14 on its upper surface side, and also supports the outer peripheral surface of the first large diameter portion 20 and the bearing case 1.
An oil seal 22 is interposed between the inner peripheral surfaces of the two lower ends. The second large diameter portion 21 supports the oil seal 22 on its upper surface side, and is also fitted into the lower end portion of the bearing case 12 via a small hole. The lower end opening of 12 is closed by a second large diameter portion 21 . Second
The cutter 7 is attached to a friction plate 23 on the lower end surface of the large diameter portion 21.
The bolt 25 is held between the disk spring 24 and the bolt 25.
However, the friction plate 23 has an upwardly protruding projecting piece 26 that is attached to the insertion recess 2 of the second large diameter part 21.
The cutter 7 is fitted into the cutter shaft 6 to prevent it from rotating, and the cutter 7 is pressed against the friction plate 23 by a disc spring 24 to rotate integrally with the cutter shaft 6. Further, the lower end surfaces of both the outer peripheral side of the second large diameter portion 21 and the bearing case 12 are opposed to the upper surface of the cutter 7 across the entire circumference. An annular wall 28 projecting upward is formed on the upper surface of the central portion of the cutter 7, and this annular wall 28 is externally fitted onto the lower end of the bearing case 12 via a small hole. In addition, 29 is a belt, 30 is its belt cover, 31, 3
2 is a rotation stopper made of a wear-resistant material.

According to the above configuration, the lower end surface of the bearing case 12 faces the upper surface of the cutter 7 across the entire circumference, and the second large diameter portion 2 of the cutter shaft 6
1 is fitted into the lower end of the bearing case 12 through a small hole, and a labyrinth structure is formed between the lower ends of the bearing case 12 and the cutter shaft 6, and the cutter 7. Grass and other foreign objects may enter the bearing case 12 through the space between the lower end surface of the bearing case 12 and the upper surface of the cutter 7, causing damage to the oil seal 22.
There is no risk of damaging the. It is preferable to form an annular wall 28 on the upper surface of the cutter 7 as shown in the figure, since the above-mentioned intrusion can be further completely prevented.

As shown in FIGS. 4 and 5, a guide cover 3 is provided on the mower deck 5 on the grass cuttings discharge side.
2 is permanently installed. An air volume detection plate 33 is attached to the lower surface of the guide cover 32 via a hinge 34 so as to be vertically swingable. This detection plate 33 is provided to detect clogging of grass clippings in the mower deck 5 during mowing work (this tends to occur when the grass is damp) by the amount of air flowing toward the guide cover 32 side. Then, due to the clogged grass, the air volume towards the guide cover 32 side decreases and the detection plate 3
3 is lowered by a predetermined amount or more as shown by the imaginary line in FIG. 5 from the position shown by the solid line in FIG.
is turned on via the actuator 36. The limit switch 35 is an alarm device 3 such as a buzzer or a lamp.
7. Together with the battery 38 and the switch 39, the grass clogging alarm circuit 40 is configured. The switch 39 is turned on only when the cutter 7 is rotated, that is, during mowing work, and the alarm is not activated when the cutter 7 is rotated, that is, during mowing work. 37 will never operate. Therefore, when the mower deck 5 becomes clogged with grass clippings during mowing work, the alarm 37 is activated immediately, and there is a risk that the operator will not notice the decrease in rotation of the cutter 7 due to the clogged grass, resulting in uneven cutting. There isn't. In addition, reference numeral 41 denotes a lower limit position setting metal fitting for the detection plate 33, which projects upward from the detection plate 33 and connects the elongated hole 42 of the guide cover 32.
It is inserted through the inside and has a stopper part 43 at the upper end. Reference numeral 44 denotes an upper limit position setting bolt for the detection plate 33, which is screwed into the guide cover 32.

As described in detail above, the present invention has the lower end face of the bearing case facing the upper face of the cutter via a small diameter part, and the large diameter part located below the oil seal at the lower end of the cutter shaft is inserted into the bearing case. The lower ends of the bearing case and the cutter shaft are fitted together through the cutter, forming a labyrinth structure between the lower end of the bearing case and the cutter shaft. There is no risk of grass or foreign matter entering the inside of the bearing case and damaging the oil seal, etc., improving the durability of the oil seal, etc., and since no special parts are required separately. There is no increase in the number of parts, and the structure is simple and can be implemented at low cost.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a partially cutaway side view, Fig. 2 is an enlarged sectional view of the main part, Fig. 3 is a sectional view taken along line A-A in Fig. 2, and Fig. 4 is a partial perspective view, and FIG. 5 is a sectional view thereof. 1... Tractor body, 4... Mid-mount mower, 5... Mower deck, 6... Cutter shaft,
7...Cutter, 12...Bearing case, 13,1
4... Bearing, 15... Drive pulley, 18, 22
...Oil seal, 20, 21...First and second large diameter portions.

Claims (1)

[Scope of utility model registration request] A bearing case is provided in the mower deck with a downward opening, and a cutter shaft having a cutter at the lower end is inserted into the bearing case so as to be rotatable around the vertical axis via the bearing, and the cutter shaft is rotatably supported on the lower end of the bearing case. In a mower in which an oil seal is interposed between the outer circumferential surface of the cutter shaft, the lower end surface of the bearing case is opposed to the upper surface of the cutter with a small gap in between, and the lower end of the cutter shaft has a larger diameter than its upper side. A cutter drive device for a mower, characterized in that the large diameter portion is located below an oil seal, and the large diameter portion is fitted into the lower end of a bearing case through a small diameter.