JPS6343899A - Power transmitting gear for small ship - Google Patents

Abstract

PURPOSE:To easily perform replacement, maintenance and inspection of a coupling member, by connecting an intermediate shaft, being a separate member, with a crankshaft of an engine by a spline and the coupling member in a side of the crankshaft with the intermediate shaft by a thread. CONSTITUTION:A water injection type small leisure ship obtains propulsive force in such a manner that the action of an engine 14, including a crankshaft 36, rotates a propeller shaft (not shown), connected with the engine 14 through a coupling 22, causing an impeller to rotate. Here the crankshaft 36 forms its output side end part in a hollow shape while an internal side spline 46 in this hollow part. And this spline 46 connects with an intermediate shaft 48, being a separate member from the crankshaft 36, by a spline. The intermediate shaft 48, which forms a large contour part 52 to the center side and an external threaded part 54 to the right of said large contour part 52, screws a coupling member 60 in an engine side of the coupling 22 to be threaded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a power transmission device for a small boat, and particularly to a coupling structure that connects the crankshaft of an engine and a propulsion unit.

[Prior Art] Conventionally, in a power transmission device for a small boat that connects a crankshaft to a propulsion unit via a cup link, the cup link member on the engine side is directly threadedly connected to the crankshaft. Therefore, if the positional relationship between the crankshaft and the propulsion unit has to be changed, the position of the cup printer must also be changed, or in this case, it is extremely difficult to remove the cup link member on the engine side from the crankshaft. Have difficulty. In other words, when removing a threadedly connected cup link member from the crankshaft, the crankshaft must be fixed at the end opposite to the end to which the cup link member is connected so as not to rotate, and a large amount of force must be applied. The cup link member must be rotated in a direction to loosen the screw, which is very difficult considering that the engine is installed in a relatively narrow engine room or hull. Furthermore, even if the cup link member can be removed from the crankshaft, it is equally difficult to attach a new coupling member to the crankshaft. I have to. Furthermore, the need to replace the coupling member is quite frequent as the damper pawls provided within the coupling often break.

[Problems to be Solved by the Invention] The present invention has been made in view of these conventional problems, and its purpose is to make it extremely easy to replace the coupling member on the engine side, that is, on the crankshaft side. The purpose of the present invention is to provide a power transmission system for a small boat that can be used for various purposes.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a small ship, in which the crankshaft of the ship's engine is connected via a cup link to a propulsion unit located at the rear of the ship. In the power transmission device, an intermediate shaft, which is a separate member, is spline-coupled to the crankshaft, and a coupling member on the crankshaft side is screw-coupled to the intermediate shaft.

[Operation] As a result, the intermediate shaft can be removed from the crankshaft by simply shifting the engine including the crankshaft by the length of the spline of the intermediate shaft, and then the coupling member can be removed from the intermediate shaft by loosening the screw. , another coupling member can be screwed to the intermediate shaft.

[Example] Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

1 to 3 show an embodiment in which the present invention is applied to a power transmission device for a small water jet type leisure boat.

FIG. 3 is a cross-sectional view of the main parts of the small water jet leisure boat. Here, a water injection unit 12 as a propulsion unit is installed at the rear lower part of the hull 10, and an engine 14 is mounted toward the front from the center of the hull 10. The water injection unit 12 mainly includes an impeller 16. propeller shaft 1
8 and a steering nozzle 20, and the input side end of the propeller shaft 18 is connected to the engine 14 with a coupling 22, which will be described later.
This allows the power of the engine 14 to be transmitted to the propeller shaft 18 while reducing torsional vibration. The impeller 16 is driven via a propeller shaft 18 and injects water to the rear of the hull 10 via a steering nozzle 20. The steering nozzle 20 is connected to a handle device 24, and the jet is ejected by operating the steering nozzle 20. is deflected, allowing the hull 10 to sail in any direction.

The engine 14 mainly includes a cylinder block 26, a cylinder head 28 disposed above the cylinder block 26,
An engine body consisting of a crankcase 30 located below the cylinder block 26, an exhaust expansion chamber 32 located above the cylinder head 28, and the cylinder block 26.
The exhaust passage 34 connects the exhaust expansion chamber 32 to the exhaust expansion chamber 32.

In FIG. 3, reference numeral 36 is a crankshaft connected to the coupling 22, 38 is a fuel tank, 39 is an engine hanger, 40 is a spark plug, 41 is a hatch disposed above the engine, and 42 is the bottom of the ship.

FIG. 2 shows a view taken along the line ■--■ in FIG. 3. 1 is a sectional view of the exhaust expansion chamber 32 taken along the line Ia-Ia in FIG. 2, a sectional view of a main part of the exhaust passage 34 along the line Ib-Ib in FIG. FIG. 2 is a cross-sectional view of the main parts of the engine around the coupling 22 taken along the line -Ic, and a partial side view of the engine 14 taken along the direction of the arrow Id in FIG. 2.

In FIGS. 1 and 2, the output end of the crankshaft 36 is rotatably supported around its outer periphery by a bearing 44, and is formed hollow. A female spline 46 is formed on the inner periphery of the end of the crankshaft 36. An intermediate shaft 48, which is a separate member from the crankshaft 36, is spline-coupled to the end of the crankshaft 36, particularly to the female spline 46. More specifically, a male spline 50 corresponding to the female spline 46 is formed at one end of the intermediate shaft 48, and a large diameter portion 52 is formed closer to the center than the male spline 50. A male threaded portion 54 is formed on the opposite side of the male spline 50 from the portion 52, and the intermediate shaft 48 in the male spline 50 is connected to the female spline 4 of the crankshaft 36.
6 is splined. The intermediate shaft 48 is rotatably supported at the large diameter portion 52 by an exhaust bracket 56 that forms the exhaust passage 34 via a bearing 58 . As shown in FIGS. 1 and 2, this intermediate shaft 48 is provided at the bottom of the crankshaft 36 or the engine 14, so it is necessarily close to the bottom 42 of the ship.
0 and therefore its bottom 42
Constructed from stainless steel to prevent rust from accumulating water.

The male threaded portion 54 of the intermediate shaft 48 projects outward from the exhaust bracket 56, that is, to the rear of the ship, and the engine-side coupling member 60 of the coupling 22, that is, the output side flange, is screwed to this male threaded portion 54. .

This coupling member 60 has a plurality of claws 62 on its end surface, and is engaged with a coupling member (not shown) on the propeller shaft 18 side through a damper 64 made of rubber or the like, as shown in FIG. ing.

In FIG. 1, reference numeral 66 is an exhaust casing that forms the exhaust expansion chamber 32. A rubber tube 68 is detachably connected to the end of the exhaust casing 66, and the exhaust is discharged from an exhaust outlet (not shown) to the outside of the boat. It is designed to be discharged. The exhaust casing 66 is fixed to the exhaust bracket 56 and the engine 14 with bolts 70 (see FIG. 2). Further, reference numeral 72 is an exhaust cover attached to the outside of the exhaust bracket 56, and forms one side wall of the exhaust passage 34. Also, reference numeral 74 indicates the cylinder block 26.
The exhaust outlet 76 formed in the flywheel makneto casing.

Further, in FIG. 2, reference numeral 78 is an intake manifold disposed in the crankcase 30, 80 is a carburetor, and 82 is an anti-vibration damper.

In the embodiments described above, if it is necessary to change the position of the cup link 22 or if the pawl 62 of the coupling member 60 is damaged, open the hatch 41 and open the engine 14.

With the engine suspended by the engine hanger 39, the intermediate shaft 48 may be shifted by the length of the male spline 50 to the left side in FIG. To remove the intermediate shaft 48, since it is spline-coupled to the crankshaft 36, it is sufficient to simply pull out the intermediate shaft 48. After that, it is easy to remove the coupling member 60 of the coupling 22 from the intermediate shaft 48 by loosening the screw, and to install a new coupling member 60, the intermediate shaft 48 is spline-coupled to the crankshaft 36 again. Bye.

In the above embodiment, the intermediate shaft 48 is made of stainless steel, so even if the intermediate shaft 48 is not connected to the bottom 42 of the ship,
Even if it is located nearby and is exposed to water that accumulates near the bottom 42 of the ship,
This intermediate shaft 48 is prevented from easily collapsing.

[Effects] As described above, according to the present invention, the coupling member that connects the crankshaft and the propulsion unit can be removed with an extremely simple operation, and therefore it is possible to remove the coupling member that connects the crankshaft and the propulsion unit. This has the excellent effect of making it easier to replace and maintain the coupling member.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part showing an embodiment of a power transmission device for a small boat according to the present invention, and in particular, a partial cross-sectional view along the Ia-Ia line in FIG. 2 and a portion along the Ib-Ib line. It is a combination of a cross-sectional view, a partial cross-sectional view along the line Ic-Ic, and a view in the direction of the Id arrow, and FIG. 2 is a side view showing the engine part of the embodiment, and in particular, The drawing is taken along the line 1--2, and FIG. 3 is a cross-sectional side view showing the main parts of a small water jet leisure boat to which the present invention is applied. lO...hull 12...water injection unit 22...coupling 36...crankshaft 42...bottom 46...female spline 48...intermediate shaft 50...male spline 60 ...Coupling member

Claims (2)

[Claims] (1) In a power transmission system for a small boat that connects the crankshaft of a marine engine to a propulsion unit located at the rear of the hull via a coupling, an intermediate shaft of a separate member is spline-coupled to the crankshaft, and the crankshaft side A power transmission device for a small boat, wherein a coupling member is screwed to the intermediate shaft. (2) The power transmission device for a small boat according to claim 1, wherein the crankshaft is located near the bottom of the ship, and the intermediate shaft is made of stainless steel.