JPS6224770Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention has a separate PTO shaft structure that uses a PTO output shaft that is separate and independent from the crankshaft and camshaft when a small engine drives a generator or other working equipment. It is possible to freely select the rotation speed of the PTO output shaft by changing the gear ratio, and it is possible to select the rotation speed of the PTO output shaft with a same-direction rotating engine without preparing a counter-rotating engine. The purpose is to facilitate disassembly for changing gear ratios, to ensure reliable meshing of the PTO output gear, etc.

In conventional gasoline engines, there are 1/1 rotation PTO (power extraction at the same rotation speed as the crankshaft rotation speed) and 1/2 rotation PTO (power extraction at the same rotation speed as the crankshaft rotation speed), the former takes power from the crankshaft, and the latter rotates in the opposite direction. It is extracted from the camshaft by the engine. Also, horizontal water-cooled diesel engines only use a 1/1 turn PTO from the crankshaft. However, 1/2 rotation
When using PTO, a reverse rotation engine is required, and it is impossible to easily extract 1/2 rotation at the work site. Also, select the rotation speed: 1/1 rotation PTO, 1/2
Since there are only two types of rotary PTO, the engine speed must be increased or decreased from the maximum efficiency speed in order to match the required speed of the work equipment, resulting in problems such as insufficient horsepower and increased fuel consumption. Problems are inevitable. During 1/2-turn PTO, the camshaft is extended to serve as the PTO output shaft, so the camshaft must be made thicker, which increases manufacturing costs and weight.

The present invention is an attempt to solve the above-mentioned conventional problem. One end of the crankshaft 1 is supported on the side wall of the cylinder body 5 via a bearing 3, and the crankshaft 1 is connected to the crankshaft 1 from the bearing 3 via a stepped portion 1b. The concentric and integral small diameter portion 1a protrudes to form the drive side PTO output gear 9.
are fitted via a locking mechanism, and then attach the PTO output side cover 14 to the side wall of the cylinder body 5 with bolts 1.
5 to form a gear chamber 16, and a bush 17 on the side wall of the cylinder body and a bearing 1 on the cover 14.
3 supports a PTO output shaft 2 separate from the camshaft at two points, and a driven side PTO output gear 10 fitted onto the PTO output shaft 2 via a rotation prevention mechanism in the gear chamber 16 and the drive side. When the PTO output gears 9 are engaged and the PTO output gears 9 and 10 on the drive side and the driven side are operated, the bearings 13 on the stepped portion 1b side and the cover side, respectively.
The gear is characterized by a helical gear that receives thrust toward the inner ring of the gear, and one embodiment is shown in FIG.

In Figure 1, 1 is the crankshaft, 2 is the PTO output shaft parallel to the crankshaft 1, and the crankshaft 1 is parallel to the PTO output shaft.
A journal portion on the PTO output shaft side is supported by the cylinder body 5 via a bearing 3 and a metal shell 4, and a journal portion on the opposite side is supported by the cylinder body 5 via a bearing 6. The drive side is connected to the PTO output shaft small diameter portion 1a of the crankshaft 1 through the key
A PTO output gear 9 is removably fitted, and a PTO output gear 10 on the driven side meshes with this gear 9.
is similarly removably fitted onto the PTO output shaft 2 via a key 11. A spline or serration fitting method may be used instead of the keys 8 and 11. Both gears 9 and 10 shown in the figure are composed of helical gears, and during normal rotation to transmit power to the PTO output shaft 2, the drive side gear 9 receives thrust in the direction of arrow A, and the driven side gear 10 receives thrust in the direction of arrow B. When the twisting direction of the teeth is determined so as to receive the thrust of It is pressed against the inner ring and held in the position shown. The bearing 13 is supported by a PTO output side cover 14, and the cover 14 is fastened to the cylinder body 5 with a plurality of bolts 15 to form a gear chamber 16 between the cover 14 and the cylinder body 5. PTO output shaft 2
The end of the engine side is supported by the cylinder body 5 by a bush 17. 18 is an oil seal, 1
9 is a packing, 20 is a crank gear, 21 is a cam gear, 22 is a camshaft, 23 is a connecting rod, 24 is a piston, and 25 is a liner.

When the crankshaft 1 rotates in a predetermined direction while the engine is running, part of the rotational force is transferred to the key 8, output gear 9,
10, the signal is transmitted to the PTO output shaft 2 via the key 11, and the PTO output shaft 2 rotates in the opposite direction to the crankshaft 1 at a constant ratio determined by the gear ratio of the gears 9 and 10. If you want to change the rotation speed of the PTO output shaft 2 while maintaining the rotation speed of the crankshaft 1 at the rotation speed at which the maximum efficiency of the engine is achieved, remove the cover 14 and replace the output gears 9 and 10 with another one. The gear ratio output gear (not shown) may be attached to the crankshaft 1 and the PTO output shaft 2 using the keys 8 and 11, and the cover 14 may be attached so that both gears are meshed in the gear chamber 16.

In FIG. 2 showing a conventional example, a PTO output shaft 28 is integrally provided at the tip of a camshaft 27.

As explained above, in the present invention, the PTO is separate and independent from the crankshaft 1 and the camshafts 22 and 27.
An output shaft 2 is provided, and the PTO output shaft 2 is connected to gears 9 and 10.
(1) The rotation speed of the PTO output shaft 2 can be freely selected in engines running in the same direction, and the rotation speed of the PTO output shaft 2 can be freely selected in engines rotating in the same direction. This eliminates the need for engine reversal, increasing the versatility of the engine, and eliminating the need to prepare and replace special parts for engine reversal.

(2) By selecting the gear ratio, a variety of PTO rotation speeds can be selected, so the desired rotation speed of the work equipment can be obtained while maintaining the engine at the predetermined rotation speed for maximum efficiency.

(3) Since the PTO shaft has an independent structure, the camshaft and crankshaft need only be of minimal size.
The structure is lightweight and simple.

(4) For example, each gear and output shaft can be shared between 3-10Ps series. Due to parts management costs,
Manufacturing costs etc. are reduced.

(5) Disassembly for changing the gear ratio of the PTO output gears 9 and 10 on the driving side and the driven side becomes extremely easy.
To disassemble, remove the multiple bolts 15 and pull the cover 14 to the right in Figure 1, the tip of the PTO output shaft 2 will come out of the bush 17, and the drive gear 9 will be in the position shown in Figure 1. Remaining driven side gear 10
separates from the drive side gear 9 to the right. In this state, pull out gear 9 from the small diameter part 1a to the right, and
0 to the left, another pair of gears with different gear ratios can be inserted into the small diameter portion 1a and the PTO output shaft 2 in place of these gears 9 and 10 by reversing the above operation. gears 9 and 10 are key 8,
11. A rotation prevention mechanism such as a spline or a serration prevents relative rotation, thereby making it possible to reliably transmit rotational force. Disassembled cover 14
To install the PTO output shaft 2, insert the tip of the PTO output shaft 2 into the bush 17 while meshing both gears 9 and 10, and tighten the plurality of bolts 15.

(6) During operation, the drive side gear 9 moves to the stepped portion 1 due to thrust.
b, and does not interfere with the inner surface of the cover 14. Moreover, the driven gear 10 is always pressed against the inner ring of the cover side bearing 13 via the collar 12, and does not wobble in the axial direction. Therefore, both gears 9,
10 is fixed on the shaft via a simple locking mechanism such as keys 8 and 11 to facilitate gear replacement, reliable meshing of both gears 9 and 10 can be guaranteed. .

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional partial view passing through the center of the crankshaft of a small engine to which the present invention is applied, and FIG. 2 is a vertical cross-sectional partial view showing an example of a conventional structure. 1...Crankshaft, 2...PTO output shaft, 9,
10...Gear, 22...Camshaft.

Claims (1)

[Scope of utility model registration request] One end of the crankshaft 1 is supported on the side wall of the cylinder body 5 via a bearing 3, and a small diameter portion 1a that is concentric and integral with the crankshaft 1 protrudes from the bearing 3 via a stepped portion 1b. The output gear 9 is fitted via a rotation prevention mechanism, and the PTO output side cover 14 is attached to the side wall of the cylinder body 5 with bolts 15.
The bushing 17 on the side wall of the cylinder body and the bearing 13 on the cover 14 are tightened to form a gear chamber 16.
A PTO output shaft 2 separate from the camshaft is supported at two points, and the driven side PTO output gear 10 and the driving side PTO are fitted on the PTO output shaft 2 via a rotation prevention mechanism in the gear chamber 16. When the output gear 9 is engaged and the PTO output gears 9 and 10 on the drive side and the driven side are operated, the bearings 13 on the stepped portion 1b side and the cover side are respectively
A separate structure for the PTO shaft of a small engine, characterized by a helical gear that receives thrust toward the inner ring of the engine.