JPH051754A - Power unit of working vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] We would like to configure the entire drive unit equipped with a friction type continuously variable transmission in the transmission section to be compact so that it can be mounted on a small mid-mower lawn mower. [Structure] A vertical axis of a PTO shaft 10 connected to an output shaft 6 via a PTO clutch 9 is provided with a freely rotatable taper cone 14 that is revolved integrally with a flywheel 7 attached to an engine output shaft 6. A friction type continuously variable transmission device 12 is provided, which is provided around the main shaft 11 fitted to the PTO shaft 10 and equipped with a rotating body 15 that comes into contact with the taper cone 14 to take out continuously variable transmission power for traveling. A pulley 23 for driving the midmower 4 is provided on the PTO shaft 10 protruding downward from 11, and the hydraulic pump 20 is driven by a gear 7a on the outer circumference of the flywheel 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit integrated with an engine and a transmission suitable for working vehicles such as lawnmowers and tractors.

[0002]

2. Description of the Related Art A midmore lawn mower is disclosed in Japanese Patent Laid-Open No. 2-19.
As shown in Japanese Patent No. 0662, a drive device including a friction type continuously variable transmission capable of continuously changing the traveling speed at low cost is increasingly used.

[0003]

However, in the above-mentioned prior art, the engine, the mission, and the friction type continuously variable transmission are separately configured, and the installation space for the drive unit including their interlocking mechanism is considerable. Necessary,
It is expected that it will be difficult to mount on smaller work vehicles. SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to configure a whole drive device having a friction type continuously variable transmission in a transmission portion into a compact one that can be mounted on a small work vehicle.

[0004]

To achieve the above object, the present invention provides a flywheel mounted on a vertical engine output shaft, and outputs a self-rotating taper cone that is revolvingly driven integrally with the flywheel. A friction-type continuously variable transmission is provided by disposing a plurality of cylinders around a shaft that is fitted onto the shaft, and equipping the main shaft with a rotating body that comes into contact with the taper cone to take out continuously variable transmission power for traveling from the main shaft. At the same time, a power take-out portion for the attached work device is provided at a portion of the output shaft projecting downward from the lower end of the main shaft, and the flywheel is provided with a drive portion of the hydraulic pump to constitute a power unit.

[0005]

According to the above characteristic structure, the friction type continuously variable transmission,
Both the power take-out parts for traveling and working equipment will be configured and deployed on the output shaft center of the engine. Moreover, since the flywheel also serves as the support body of the taper cone, the engine, the transmission, and the two powers are used. A power unit is integrated with the take-out section. Further, since a lawn mower, a tractor and the like are equipped with a hydraulic device such as a hydraulic lift device, it is convenient to provide a drive unit for the hydraulic pump on the flywheel because it can further promote compactness. Therefore, it is possible to construct a power unit in which the engine and the friction type continuously variable transmission, which have been separately provided in the past, are integrated in such a state that their constituent parts are partially shared. Even if a mission equipped with a differential mechanism is separately provided, the bulk of the drive unit can be reduced as compared with the conventional case.

[0006]

As a result, the space occupied by the drive unit can be made smaller than before, and it can be mounted on a smaller work vehicle, and it is easy to install peripheral machinery and equipment. I was able to provide a power unit.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a mid-mower lawnmower that is an example of a work vehicle. 1 is a power unit, 2 is a rear wheel, 3 is a mission having a differential mechanism 5, and 4 is a mower. As shown in FIG. 1, the power unit 1 is roughly divided into a vertical axis type engine E, a transmission section H and an output take-out section D, and a flywheel 7 is attached to an output shaft 6 directly below the engine E. .. The speed change unit H includes a flywheel 7 in a speed change case 8 connected to the lower surface of the engine E, a PTO shaft 10 connected to the flywheel 7 via a multi-plate PTO clutch 9, and an axis center of the PTO shaft 10. Frictionless continuously variable transmission constructed on P (continuous va
riable transmission (hereinafter CVT
Will be abbreviated)]. CVT12
Is a taper cone 14 which is rotatably supported by a support member 13 attached to the outer diameter side surface of the flywheel 7.
A plurality of shafts are provided around the shaft 10, and a traveling pulley 16 is attached to the transmission cylinder shaft 11 in order to take out continuously variable transmission power for traveling from the transmission cylinder shaft 11 fitted to the PTO shaft 10 so as to be relatively rotatable. The driven rotating body 1 in contact with the taper cone 14
5, the operation ring 17 circumscribing the taper cone 14 is slid in the axial direction to move the traveling pulley 1.
6 rotation is continuously variable. PTO shaft 10 traveling pulley 1
A PTO pulley (corresponding to a power take-out portion) 23 for driving the mower 4 is attached to the tip projecting downward from 6.
In addition, 18 is a support rotary body, 19 is a pressing mechanism that presses the driven rotary body 15 against the tapered cone 14, and a thrust collar 22 for receiving a reaction force by the pressing mechanism 19 between the tapered cone 14 and the support member 13. Is fitted. In this CVT 12, by operating the operating ring 17, a forward drive range covering low speed to high speed, a neutral position in a transmission state of zero speed, and a reverse drive range only in the low speed range can be revealed. 1 is also configured to have a forward / reverse switching function. Further, a gear 7 a is formed on the outer periphery of the flywheel 7, and the mower 4
The hydraulic pump 20 for driving the lifting cylinder (not shown) of FIG. Reference numeral 21 is a hydraulic port for taking the hydraulic pressure out of the transmission case 8. The hydraulic pump 20 and the flywheel 7 may be interlocked with the belt. For that reason, the pulley portion formed on the outer periphery of the flywheel 7 and the gear 7a are generically defined as a drive portion A. Further, the PTO shaft 10 may be the one in which the PTO clutch 9 is omitted and the output shaft 6 is extended, and the PTO shaft 10 and the extended output shaft 6 are collectively referred to as the output shaft 6.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a power unit.

[Fig. 2] Side view of a mid-mower

[Explanation of symbols]

 6 Output shaft 7 Flywheel 11 Main shaft 12 Friction type continuously variable transmission (CVT) 14 Tapered cone 15 Rotating body 20 Hydraulic pump 23 Power extraction part A Drive part P Shaft center

Claims (1)

Claims: 1. A flywheel (7) is attached to an engine output shaft (6) having a vertical shaft shape, and the flywheel (7) is attached.
A plurality of taper cones (14) capable of revolving in the state of being integrated with the rotation shaft are provided around the shaft center (P) of the output shaft (6) and are fitted onto the output shaft (6) so as to be relatively rotatable. In order to extract the continuously variable transmission power for traveling from the main shaft (11), the main shaft (11) is equipped with a rotating body (15) in contact with the tapered cone (14), and a friction type continuously variable transmission (1) is provided.
2), a power take-out portion (23) for an attached work device is provided at a portion of the output shaft (6) projecting downward from the lower end of the main shaft (11), and the flywheel (7). ) Is a power unit for a work vehicle, the drive unit (A) of the hydraulic pump (20) being provided in the power unit.