JPH0224903Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a direct-engine-coupled generator, and in particular, it directly connects the crankshaft of the engine and the rotor shaft of the generator. This invention relates to an engine-directly coupled generator to which a cooling fan is attached.

[Background technology and its problems]

Engine-coupled generators are widely used as a means of generating electrical output in places where commercial power is not easily available. By attaching a cooling fan to the joint between the engine and generator of such a generator, it becomes possible for this cooling fan to serve as a cooling means for both the engine and the generator. The structure can be simplified.

In such a generator, as shown in FIG. 5, conventionally, for example, a tapered shaft portion 4 is formed on the tip side of a crankshaft 3 rotatably supported by a crankcase 1 via a bearing 2. A taper hole 6 of a cooling fan 5 was fitted into the tapered shaft portion 4, and the fan 5 was fixed with a half-moon key 7. Further, the distal end side of the crankshaft 3 is formed into a straight shaft portion 8, and this shaft portion 8 is fitted into a hole 10 formed at the distal end of the rotor shaft 9. It was supposed to be fixed to the crankshaft 3 by the screw. Further, the through bolt 12 prevents the rotor shaft 9 from falling off, and at the same time, the end face of the rotor shaft 9 pushes the end face of the fan 5 to prevent the fan 5 from moving.

According to the coupling structure of the crankshaft 3 and the rotorshaft 9, which also serves as the mounting structure of the cooling fan 5 in the conventional engine-directly coupled generator, both the crankshaft 3 and the rotorshaft 9 become parts that require a large number of machining steps. It ends up.
In particular, there is a parallel key 1 on the inner circumference side of the rotor shaft 9.
It is necessary to form a keyway for engaging 1, and for this purpose, processing is generally performed using a slotter machine, but this processing is not only very troublesome, but also requires a large number of man-hours. Furthermore, for machining with this slotter machine, an escape groove 13 had to be formed in the inner part of the hole 10, resulting in an even more complicated structure.

[Purpose of invention]

The present invention has been developed in view of these problems, and has been developed by simplifying the structure of the joint between the crankshaft and the rotor shaft and the structure of attaching the cooling fan to this joint. The object of the present invention is to provide an engine-directly coupled generator that is advantageous in terms of cost.

[Summary of the idea]

The present invention provides an engine-directly coupled generator in which the engine crankshaft and the generator rotor shaft are directly connected, and a cooling fan is attached to the joint between these two shafts.
The connecting portion of the crankshaft is a tapered shaft, tapered holes are provided at the center of the fan and the connecting portion of the rotor shaft, and the taper hole of the fan is fitted into the root portion of the tapered shaft of the crankshaft. At the same time, the tip of the tapered shaft of the crankshaft is fitted into the taper hole of the rotorshaft, and the rotorshaft is fixed to the crankshaft by a fixing means, and the end face of the rotorshaft and the fan are fixed. The engine-directly coupled generator is characterized in that the fan is pressed toward the engine in the axial direction by an elastic body interposed between the fan and the fan, which is formed at the tip of the crankshaft. The tapered shaft holds the cooling fan and connects it to the rotor shaft, resulting in a simple structure.

〔Example〕

The present invention will be explained below with reference to an illustrated embodiment.
FIG. 1 shows an engine-directly coupled generator according to an embodiment of the present invention. The engine for driving the generator is equipped with a cylinder 16, and a piston 17 is installed inside the cylinder 16. arranged,
Further, the upper part thereof is closed by a cylinder head 19 having a spark plug 18. A crankcase 20 is integrally formed on the lower end side of the cylinder 16, and a crankshaft 22 is rotatably supported by the crankcase 20 via a bearing 21. A crank pin portion of the crankshaft 22 is connected to the piston 17 via a connecting rod 23.

Next, the structure of the generator 24 driven by this engine will be explained. The casing of the generator 24 is composed of a rear bracket 25 and a front bracket 26, and these brackets 25 and 26 sandwich a stator 28. They are connected by a connecting bolt 46 so as to fit together. The front bracket 26 is fixed to the crankcase 20 of the engine with fixing bolts 27.

An armature coil 29 constituting a power generation coil is wound around the stator 28 . A rotor 30 is disposed inside the stator 28 and is rotatably supported by a rotor shaft 31. That is, the rotor shaft 31
The right end is rotatably supported by a bearing 32, and the left end is directly connected to the tip of the crankshaft 22. For example, a field coil 33 is wound around the rotor 30.

Next, the cooling fan 34 disposed between the engine and the generator 24 will be explained.
A cooling fan 34 is disposed on the outer surface of the crankcase 20 on the side of the generator 24, and is supported by the tip of the crankshaft 22. A fan cover 35 is attached from the side to the top of the engine so as to cover the fan 34.

A tapered shaft portion 36 is formed at the tip of the crankshaft 22, and as shown in FIGS. 2 and 3, this tapered shaft portion 36 is connected to a cooling fan 3.
A groove 39 formed in the boss of the fan 34 is fitted into a taper hole 37 formed in the center of the fan 34, and a knock pin 38 implanted in the tapered shaft part 36 is fitted into a groove 39 formed in the boss of the fan 34.
is engaged with. Furthermore, crankshaft 22
The tapered shaft portion 36 is fitted into the tapered hole 40 of the rotor shaft 31 at the tip side of the rotor shaft 31 .
Moreover, as shown in FIG. 4, a dowel pin 41 implanted in the tapered shaft portion 36 is engaged with a groove 42 in the end surface of the rotor shaft 31. A through bolt 44 inserted into a through hole 43 passing through the rotor shaft 31 in the axial direction is inserted into the rotor shaft 31.
is fixed in the thrust direction. A disc spring 45 is disposed on the tip side of the rotor shaft 31, and this disc spring 45 is connected to the cooling fan 34.
It is designed to press elastically.

Next, the operation of this engine-directly coupled generator configured as described above will be explained. cylinder 1
By supplying a mixture containing fuel into the internal space of the cylinder 6 and igniting it at a predetermined timing with the spark plug 18, a combustion explosion occurs within the cylinder 16, and the piston 17 makes a sliding movement. Let's do it. This sliding motion of the piston 17 is converted into rotational motion by the crankshaft 22, and is taken out as an output from the crankshaft 22. This output drives the rotor 30 of the generator 24, and since this rotor 30 is equipped with a field coil 33, the magnetic flux generated by the field coil 33 is transferred to the armature on the stator 28 side. The armature coil 29 interlinks with the coil 29, and this armature coil 29 generates a power generation output. Therefore, this power generation output makes it possible to energize the load, and it can be easily used as a power source even in places where there is no commercial power source.

In this manner, when the generator 24 is driven by the engine, the cooling fan 34 is rotated together with the crankshaft 22.
This fan 34 is attached to the rear bracket 2 of the generator 24.
5 through the opening 47 formed in the generator 24
Introduce cooling air into the interior. The interior of the generator 24 is cooled by this cooling air. This cooling air is forcibly blown in the direction shown by the arrow in FIG. 1 by the cooling fan 34, and is discharged while cooling the cylinder 16 and cylinder head 19. Note that an opening 48 formed in the outer peripheral surface of the front bracket 26 is designed to directly suck air from the outside.

The presence of such a cooling fan 34 makes it possible to cool both the generator 24 and the engine that drives the generator 24, simplifying the cooling structure and reducing the number of parts. It can be reduced.

Further, the cooling fan 34 is supported by a tapered shaft portion 36 formed at the tip of the crankshaft 22. This shaft part 3
6 also supports the end of the rotor shaft 31 of the generator 24, and a single tapered shaft 3
6 makes it possible to both support the cooling fan 34 and connect it to the rotor shaft 31. Tapered hole 40 of rotor shaft 31
are pressed to the tapered shaft portion 36 by through bolts 44, and the tapered hole 37 of the cooling fan 34 is pressed to the tapered shaft portion 36 by a disc spring 45 pressed by the end surface of the rotor shaft 31.
In addition, the cooling fan 34 and the rotor shaft 31
Its positioning with respect to the crankshaft 22 is achieved by tapered pins 38 and 41, respectively. Therefore, with this structure, it is sufficient to form a single and common taper shaft portion 36 at the tip of the crankshaft 22, and there is no need to machine a keyway inside the rotor shaft 31. This makes it possible to reduce costs by reducing the number of man-hours required to process parts.

Although the present invention has been described above with reference to one embodiment of the drawings, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the technical idea of the present invention. For example, in the above embodiment, the disc spring 45 is used as the elastic body interposed between the rotor shaft 31 and the cooling fan 34, but instead of the disc spring 45, another elastic body,
For example, it is also possible to use a wave washer, a compression coil spring, or the like.

Further, in the above embodiment, the cooling fan 34 is attached to a common tapered shaft portion 36 formed at the tip of the crankshaft 22, and the rotor shaft 31 is coupled thereto. However, instead of such a configuration, the tapered shaft portion to which the fan 34 is attached and the tapered shaft portion coupled to the rotor shaft 31 may be formed separately on the crankshaft 22. In this case, a disc spring 4 is attached to the straight part between the two tapered shaft parts.
5 should be installed.

[Effect of idea]

As described above, the present invention uses a tapered shaft as the coupling part of the crankshaft, provides tapered holes in the center of the fan and in the coupling part of the rotor shaft, and has a tapered hole in the fan in the root part of the tapered shaft of the crankshaft. At the same time, the tapered hole of the rotor shaft is fitted to the tip of the tapered shaft of the crankshaft, and the rotor shaft is fixed to the crankshaft by the fixing means, and the gap between the end face of the rotor shaft and the fan is The fan is pushed toward the engine in the axial direction by an elastic body interposed in the fan. Therefore, according to the present invention, it is possible to simplify the structure of the joint, reduce the number of man-hours for machining parts, and provide an engine-directly coupled generator that is advantageous in terms of cost.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the whole of a direct-engine-coupled generator according to an embodiment of the present invention, and FIG. 2 shows the connecting portion between the crankshaft, cooling fan, and rotor shaft of this direct-engine-coupled generator. The main part enlarged vertical sectional view shown in FIG. 3 is ~ in FIG. 2.
4 is a cross-sectional view taken along the line ˜ in FIG. 2, and FIG. 5 is a vertical cross-sectional view showing the main parts of a conventional engine-direct-coupled generator, showing the joints between the crankshaft, the cooling fan, and the rotor shaft. be. In addition, in the symbols used in the drawings, 22...crankshaft, 24...generator, 31...rotor shaft, 34...cooling fan, 36...tapered shaft, 37, 40...tapered hole, 44... Through bolt, 45... disc spring.

Claims (1)

[Scope of utility model registration request] In an engine-directly coupled generator in which the engine crankshaft and the rotor shaft of the generator are directly connected, and a cooling fan is attached to the joint of these two shafts, the joint of the crankshaft is a tapered shaft. With,
A tapered hole is provided in the center of the fan and a connecting portion of the rotor shaft, and the taper hole of the fan is fitted into the root of the tapered shaft of the crankshaft, and the tip of the tapered shaft of the crankshaft is fitted with a tapered hole. The tapered hole of the rotor shaft is fitted into the rotor shaft, and the rotor shaft is fixed to the crankshaft by a fixing means, and the elastic body interposed between the end surface of the rotor shaft and the fan An engine-directly coupled generator characterized by a fan that is pushed toward the engine in the axial direction.