JPH11275809A - Engine generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and small number of parts and to reduce a troublesome press-fitting work and a tightening work, while firmly and easily locking a rotor and a crankshaft in a rotational direction. Provide an engine generator that can. SOLUTION: A bowl-shaped stator housing case 2 provided with a single bearing portion 8 rotatably supporting a crankshaft 4 of an engine E, a stator 6 fixed to an inner surface of the stator housing case 2, A rotor 5 fitted into the crankshaft 4 and having an outer surface held from the inner surface of the stator 6 via a small gap g, and a rotor fan 7 fixed to the outer end of the crankshaft 4 by a single rotor bolt 13; , A cover 13 for covering the rotor fan 7, key grooves 4 c 1, 5 a 2 are formed on respective mating surfaces of the crank shaft 4 and the rotor 5, and the key 9 is inserted into each key groove, thereby forming the crankshaft 4. The rotation relative to the rotor 5 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine generator in which a rotor is rotated with a crankshaft which is rotated by driving an engine, and the rotation of the rotor generates electric power in a stator.

[0002]

2. Description of the Related Art An engine generator generally used at present is, for example, as shown in FIG.
The engine generator 20 shown here includes inner and outer housings 21 and 22 fixed to side ends of a crankcase C, and a stator 2 held between the housings 21 and 22.
3 and a generator cover 24 that covers the outer end of the outer housing 21, the outer shell of which is formed. A bearing 25 provided at the center of the bottom of one of the housings 21 has a bearing 25 inside of the outer shell. A crankshaft 34 is rotatably supported, and the other housing 2
One end of a pipe-shaped rotor shaft 27 is rotatably supported by a bearing 26 fixed to the center of the rotor 2.

The other end of the rotor shaft 27 has a tapered fitting surface 2 whose diameter increases toward the tip.
The crankshaft 34 is fitted on the fitting surface 27a. And the two shafts 2
7, 34 are connected by screwing a long bolt 28 inserted from the outer end of the rotor shaft 27 into a screw hole 34a formed at one end of the crankshaft 34, and rotate together with the crankshaft 34. It has become something. A rotor 29 is fixed to the rotor shaft 27, and an outer surface of the rotor 29 faces an inner surface of the stator 23 via a predetermined gap.

Further, the two housings 21 and 22 are
A plurality of (three in this case) long stator bolts 30 are connected to each other, and the stator 23 is fastened to the two housings 21 by fastening the respective stator bolts 30.
22 so as to be firmly held. An annular rotor fan bracket 32 is press-fitted and fixed to the outer periphery of one end of the rotor shaft 27, and a plurality of screws 3 are attached to the rotor fan bracket 32.
3, the rotor fan 31 is fixed.

In the generator having the above configuration, the engine e
Is driven, the reciprocating motion of the piston p is converted into the rotation of the crankshaft 34 via the connecting rod r, and the rotor shaft 27 connected to the crankshaft 34 rotates to rotate the rotor 29, The electric power is generated in the stator 23 to be driven. At this time, the rotation of the rotor shaft 27 causes the rotor fan 3 to rotate.
1 rotates, the external air introduced from the cover 24 is supplied to the stator 23 and the like, and is discharged from the housing 21, whereby heat generated during power generation is supplied from the rotor fan 31. Cooled by air.

[0006]

However, the conventional engine generator 20 has a problem that the structure is complicated, the number of parts is large, and the assembling work is difficult, so that the manufacturing cost is increased. Was. That is, since the rotation of the crankshaft 34 is transmitted to the rotor 29 via the rotor shaft 27, a high precision is required for the connecting portion between the two shafts 27 and 34, and Tightening and fixing the 34 require long bolts 28 and 30 that are out of specification, and the production of such special parts requires a lot of cost, and there is a problem that the cost of the whole apparatus is greatly increased. Was.

Further, since it is necessary to maintain a small gap between the rotor 29 and the stator 23, high precision is required for holding the rotor 29. However, in the prior art, the rotor fan 31 is interposed between the rotor 29 and the bearing 25, and the distance from the bearing 25 to the rotor 29 is increased. 27 and the crankshaft 34 are likely to generate vibration. For this reason, in order to suppress the vibration, the shafts 27 and 34 must be held at two places, and two expensive bearings are required, which causes a cost increase. Furthermore, since the bracket 32 and the plurality of bolts 33 are used for fixing the rotor fan 31, the number of parts is large, which also causes an increase in cost.

In the assembling process, first, in addition to the press-fitting operation of the rotor 29 into the rotor shaft 27,
Each housing 21, 22 of two bearings 25, 26
, Press-fitting of the crankshaft 34 and the rotor shaft 27 to the bearings 25 and 26, and press-fitting of the rotor fan bracket 32 to the rotor shaft 27 need to be performed many times. Since the number of bolts to be worked is large, there has been a problem that the assembly process is complicated. In addition, since the rotor 29 is fixed by being pressed into the rotor shaft 27, it is difficult to firmly lock the rotor shaft 27 and the rotor 29 in the rotation direction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and can be firmly constructed with a small number of parts at a low cost and can reduce troublesome press-fitting work and tightening work. It aims to provide an engine generator with excellent productivity.

[0010]

The present invention has the following arrangement to solve the above-mentioned problems. That is, the present invention provides a bowl-shaped stator storage case including a bearing portion that rotatably supports a crankshaft that is rotated by driving of an engine, an annular stator fixed to an inner surface of the stator storage case, A rotor having a through-hole for loosely inserting a crankshaft extending inward of the stator, an outer surface of which is screwed to an outer end of the crankshaft; A rotor fan having a central portion fastened by a single rotor bolt, a cover fastened to an opening edge of the stator housing case so as to cover the rotor fan, and a rotation direction of the rotor and the crankshaft. Anti-rotation means for preventing relative rotation, wherein the anti-rotation means comprises a deformed outer peripheral surface formed on a crankshaft; By the through hole formed in a central portion of said rotor so as to form an outer peripheral surface and substantially the same shape of Kushafuto is obtained by configuration. Also,
As the rotation preventing means, for example, a flat portion formed at at least one location on the circumferential surface of the crankshaft, and a central portion of the rotor formed to have substantially the same shape as the circumferential surface and the flat portion of the crankshaft. It is conceivable to configure with the through hole.

In the present invention having the above-described structure, the rotor and the rotor fan are sequentially provided outwardly on the crankshaft which is cantilevered by the single bearing provided in the stator housing case. The distance between the rotor fan and the bearing can be minimized, and even if the rotor fan is cantilevered, the gap between the rotor and stator can be properly adjusted without being affected by engine vibration. Since it can be maintained, interference between the rotor and the stator can be prevented, and stable operation can be obtained. Further, since the crankshaft is supported in a cantilever manner, the number of bearings 8 can be reduced as compared with the related art, and the press-fitting operation process required for the bearings 8 can be reduced.

Further, an outer shell structure for housing the stator and the rotor fan is formed by a rotor housing case extending in the front-rear direction corresponding to the length of the rotor, and a cover fixed to an edge of the opening. As a result, the outer shell structure can be simplified as compared with the conventional case where the outer shell is formed by the two brackets, the generator cover and the stator. In addition, since the bolts for fastening the rotor and the like need only be short, standard products can be used, and the configuration can be made at low cost. If the above-described rotation preventing means is used, the rotor and the crankshaft can be firmly locked in the rotation direction.

In addition, the rotation preventing means includes a key groove formed along a longitudinal direction on a circumferential outer peripheral surface of the crankshaft, a key fitted in the key groove, and an outer peripheral surface of the crankshaft. It is also conceivable that the keyhole is formed in a through hole having substantially the same shape so as to be fitted with the key. According to this, the crankshaft and the rotor can be firmly locked, It is only necessary to use a very common crankshaft having a circular cross section and a through-hole, and it is possible to manufacture easily at low cost.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram of a generator 1 according to an embodiment of the present invention. As shown in the figure, a generator according to the present embodiment includes a bowl-shaped stator storage case 2 integrally projecting from a side of a crankcase C of an engine E, and an opening of the stator storage case 2. And a generator cover 3 provided therein, an outer shell having a hollow body structure is formed. Inside the outer shell structure, a crankshaft 4, a rotor 5, a stator 6, a rotor fan 7, and the like are as follows. It is provided in.

That is, a bearing insertion opening 2b is formed in the center of the bottom of the stator housing case 2, and a bearing 8 is press-fitted and fixed therein. The bearing (bearing portion) 8 includes a piston P when the engine is driven.
The crankshaft 4 rotated by the vertical movement is press-fitted and protrudes inward. The crankshaft 4 is formed concentrically with a peripheral surface portion having three diameters, a large diameter portion 4a, a medium diameter portion 4b, and a small diameter portion 4c. The middle diameter portion 4b is press-fitted into the bearing 8, and the end surface of the large diameter portion 4a abuts on the end surface of the bearing 8, so that the position in the longitudinal direction is determined.

The outer end of the crankshaft 4 (the front end of the small diameter portion 4c) extends to the edge of the opening 2a of the stator housing case 2. 1 and 5 on the peripheral surface of the small diameter portion 4c of the crankshaft 4.
As shown in FIG. 6, a keyway 4c having a predetermined length and depth along the longitudinal direction (central axis direction) from the front end.
1 is formed, and a straight key 9 is inserted into the key groove 4c1. Further, a screw hole 4c2 for screwing the rotor bolt 13 is formed at the outer end of the crankshaft 4.

As shown in FIGS. 1 and 3, the stator 6 is formed by winding a conductive wire around an annular iron core 6a to form an annular coil 6b.
Is a locking step 2 formed on the inner surface of the stator storage case 2.
c, and two stator fixing plates 11, 1 fixed to the edge of the opening 2a of the stator housing case 2 by bolts 10.
1 sandwiches the front and rear ends thereof, and is fixed. As shown in FIG. 2, the fixing plates 11, 11 each have an arc shape, and have two arc-shaped projections 2 d protruding outward from an edge of the opening 2 a of the stator housing case 2. , Bolts 10.

As shown in FIGS. 1 and 4, the rotor 5 has an iron core 5 having a pair of arc-shaped outer peripheral surfaces.
and a coil 5b formed by winding a conductive wire around the iron core 5a. A small-diameter portion 4 of the crankshaft 4 is provided in a through hole 5a1 formed at the center of the iron core 5a.
c is inserted, and the edge of the opening of the through hole 5a1 abuts on the end surface 4b1 of the middle diameter portion 4b of the crankshaft 4 to prevent the crankshaft 4 from moving toward the middle diameter portion 4b. Also,
On the inner peripheral surface of the iron core 5a, a key groove 5a2 is formed along the central axis direction, and this key groove 5a2 is
The straight key 9 is inserted into the key groove 4c1 of the small diameter portion 4c of the crankshaft 4. For this reason, the rotor 5 and the crankshaft 4 are hung in the rotation direction via the straight key 9, and both rotate integrally. The outer peripheral surface of the iron core 5a of the rotor 5 is opposed to the inner peripheral surface of the iron core 6a of the stator 6 via a small gap g. The keyways 4c1 and 5a2 and the straight key 9 constitute a rotation preventing means.

The rotor fan 7 is formed as shown in FIGS. 1 and 7, and has a horn-shaped plate body having a central portion having a diameter gradually increasing outward from a cylindrical mounting portion 7a. A fin 7c is protruded from the outer surface of the crankshaft 4 at the center of the mounting portion 7a. By being screwed into the screw hole 4c2 formed in the above, it is fastened and fixed. Reference numeral 7d denotes a ring-shaped rotor locking plate that fits into a concave portion formed at the center end surface of the rotor fan 7, and comes into contact with the outer end surface of the small diameter portion 4c of the crankshaft 4 when the rotor fan 7 is mounted. It has become.
For this reason, it is sandwiched between the rotor locking plate 7d of the rotor fan 7 and the end face of the middle diameter portion 4b of the crankshaft 4, and the position in the axial direction is determined. As shown in FIG. 8, the generator cover 3 has an exhaust port 3a on the side.
It is constituted by a container-like member formed by
It is fastened and fixed to the opening edge of the stator 6 by a screw (not shown).

In the engine generator having the above structure, when the crankshaft 4 rotates via the connecting rod R due to the reciprocation of the piston P, the crankshaft 4
, The rotor 5 engaged by the key 9 rotates together,
Electric power is generated in the stator 6. Rotor 5 and bearing 8
The rotor 5 is disposed as close to the bearing 8 as possible without any intervening member between them. Therefore, even if vibrations such as vibrations generated in the engine E occur in the surroundings, the rotors 5 are affected. The small gap g formed between the rotor 5 and the stator 6 is always kept constant, and there is no possibility that the rotor 5 will interfere with the stator 6.

The rotor fan 7 also rotates with the rotation of the rotor 5, and the air heated by the stator 6 and the like in the generator is discharged from the exhaust port 3 a of the generator cover 3, while the air enters the stator housing case 2. In this case, low-temperature external air is introduced, and the air is blown to the stator 6 and the rotor 5, so that the stator 6 and the rotor 5 are surely cooled. Moreover, in this embodiment, the rotor 5
Since the rotor fan 7 is provided further outward (forward), the outer diameter of the rotor fan 7 can be adjusted according to the required air flow without being affected by the dimensions and shape of the stator storage case 2 and the like.
And the height of the fins 7c can be set, and desired cooling performance can be obtained.

Further, as described above, in the engine generator 1 of this embodiment, since the crankshaft 4 projecting inward is supported in a cantilever state, it is extremely inexpensive and requires a small number of parts as compared with the prior art. And assembling can be easily performed. That is, upon assembling, the bearing 8 is fitted into the bearing insertion hole 2 b of the stator housing case 2, the crankshaft 4 is pressed into the bearing 8, and the stator housing case 2 is held by the crankshaft 4. Next, the stator 6 is placed in the stator storage case 2.
And the stator 6 is fixed by fixing the stator fixing plate 11 with the screw 10. After this, the keyway 5a
Insert the straight key 9 into the 2
The rotor 5 is inserted into the small diameter portion 4c of the crankshaft 4 while engaging with the key groove 5a2. Here, the rotor fan 7 and the rotor 5 are connected to the crankshaft 4 by the rotor bolt 1.
Fasten with 3 and fix. Finally, fasten the fan cover.

As described above, in this embodiment, it can be performed by two press-fitting operations relating to the bearing 8 and a joint tightening operation of the rotor fan 7 and the rotor 5 by the rotor bolts 13. On the other hand, in the case of the conventional engine generator, four press-fitting operations involving two bearings 8 are required, and the fastening operation also includes fixing of the rotor 29 and fixing of the rotor fan 31. In contrast, according to this embodiment, the operation is greatly simplified, and the labor and time required for the operation are greatly reduced.

Further, in this embodiment, since the outer shell of the generator is constituted by the two parts of the stator housing case 2 and the generator cover 3, the outer shell is formed by the inner and outer housings 21, 22 and the generator cover 24 as in the prior art. First, the number of parts is reduced in the outer shell structure compared to the shell structure, and further, as the inner structure,
The number of bearings 8 has been reduced from two to one,
The number of screws to be used is reduced as described above, and the rotor shaft, which has been conventionally required, is not required. In addition, the screws used in this embodiment are all short and can be used within the range of the standard, so that the cost of the screws themselves is reduced.

Furthermore, in this embodiment, since the engagement between the rotor 5 and the crankshaft 4 is performed through the straight key 9, the two can be firmly engaged in the rotation direction, and the rotor 5 and the crankshaft 4 can be completely engaged. And can be rotated integrally. Further, since the outer peripheral surface of the crankshaft 4 and the inner peripheral surface of the through hole 5a1 of the rotor 5 may be formed in a very general shape having a circular cross section, they can be manufactured extremely easily.

In the above embodiment, the rotation preventing means for preventing the rotation of the crankshaft and the rotor is provided.
The rotation grooves are formed by the key grooves 5a2, 4c2 and the straight key 9. The rotation locking means includes a deformed outer peripheral surface formed on the crankshaft and a central portion of the rotor so as to form substantially the same outer peripheral surface as the crankshaft. It is also possible to configure with a through hole formed in the hole. For example,
A configuration like the second embodiment of the present invention shown in FIGS. 9 to 11 is also possible. In each figure, the first
The same reference numerals are given to the same or corresponding parts as in the embodiment.

In the second embodiment, the outer peripheral surface 41 of the small diameter portion 4c of the crankshaft 4 is formed by a pair of circular arc surfaces 42 and a flat portion 43, while the through hole 5a1 of the rotor 5 is formed by the crankshaft 4 Of the crankshaft 4 and the small diameter portion 4c of the crankshaft 4 can be fitted into the through-hole 5a1 of the rotor 5 without any gap. The flat portion 43 of the outer peripheral surface 41 and the flat portion 53 of the through-hole 5a1 are in contact with each other, so that the crankshaft 4 and the rotor 5 are locked to each other in the rotation direction. Is configured. In the second embodiment, the crankshaft 4
In this case, since it is only necessary to form the flat portions 43 at two places on the outer peripheral surface 41, it can be easily processed and the manufacturing cost can be reduced.

The irregular shape of the outer peripheral surface of the crankshaft and the through hole of the rotor for constituting the rotation preventing means may be any shape other than the shape shown in the above embodiment, for example, polygon, ellipse, etc. The present invention is not particularly limited to the above embodiment.

[0029]

As described above, according to the first and second aspects of the present invention, the crankshaft rotating by the driving force of the engine is extended together with the stator housing case and is held cantilevered by a single bearing. A rotor and a rotor fan are sequentially held on a crankshaft, and these are covered by the stator housing case and a cover provided on an edge of an opening of the stator housing case. Means for preventing rotation of the rotor with respect to the crankshaft are formed on the crankshaft. Since the outer peripheral surface of the irregular shape and the through-hole formed in the central portion of the rotor so as to have substantially the same shape as the outer peripheral surface of the crankshaft, the rotor and the crankshaft can be easily and securely locked. . Further, since the number of parts can be significantly reduced and a large number of standard products can be used for each part, the configuration can be made extremely inexpensively and easily. Further, since the press-fitting work and the fastening work in the assembling work can be greatly reduced, excellent productivity can be obtained. Also,
As in the third aspect of the present invention, a key groove is formed in each fitting surface of the crankshaft and the rotor, and a key is inserted into the key groove to prevent relative rotation between the crankshaft and the rotor. By doing so, it is possible to use general ones each having a circular cross section on the outer peripheral surface of the crankshaft and the inner peripheral surface of the rotor, and it is possible to manufacture the device more cheaply and easily.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the present invention.

FIG. 2 is a front view showing a stator storage case and a locking plate shown in FIG. 1;

FIG. 3 is a front view showing the stator in FIG. 1;

FIG. 4 is a front view showing the rotor in FIG. 1;

FIG. 5 is a sectional view taken along line AA of FIG. 4, showing a fitted state of the rotor fan, the crankshaft, and the straight key.

FIG. 6 is an explanatory perspective view showing a small diameter portion and a key of the crankshaft shown in FIG. 1;

FIG. 7 is a front view showing the rotor fan in FIG. 1;

FIG. 8 is a front view showing the inner surface of the generator cover in FIG.

FIG. 9 is a perspective view showing a shape of a small diameter portion of a crankshaft according to a second embodiment of the present invention.

FIG. 10 is a vertical sectional side view of a main part according to a second embodiment of the present invention.

FIG. 11 is a vertical sectional side view taken along line BB of the present invention.

FIG. 12 is a vertical sectional side view showing a conventional engine generator.

[Explanation of symbols]

 E Engine C Crankshaft 1 Engine generator 2 Stator storage case 3 Cover 4 Crankshaft 4c1 Keyway 5 Rotor 5a2 Keyway 6 Stator 7 Rotor fan 8 Bearing 9 Key 13 Rotor bolt

Claims (3)

[Claims] 1. A bowl-shaped stator storage case having a bearing for rotatably supporting a crankshaft rotated by driving of an engine; an annular stator fixed to an inner surface of the stator storage case; And a rotor having an outer surface held through a predetermined minute gap from an inner surface of the stator and an outer end portion of the crankshaft. A rotor fan having a central portion fastened by a single rotor bolt; a cover fastened to an edge of an opening of the stator housing case so as to cover the rotor fan; Anti-rotation means for preventing relative rotation, wherein the anti-rotation means comprises a deformed outer peripheral surface formed on a crankshaft; An engine generator comprising: a through hole formed in a central portion of the rotor so as to have substantially the same shape as an outer peripheral surface of a shaft. The rotation preventing means includes a flat portion formed at least at one position on a circumferential surface of the crankshaft, and a through hole of a rotor having substantially the same shape as the circumferential surface and the flat portion of the crankshaft. The engine generator according to claim 1, wherein the engine generator is configured. 3. A bowl-shaped stator storage case having a bearing for rotatably supporting a crankshaft rotated by driving of an engine, an annular stator fixed to an inner surface of the stator storage case, and the stator. And a rotor having an outer surface held through a predetermined minute gap from an inner surface of the stator and an outer end portion of the crankshaft. A rotor fan having a central portion fastened by a single rotor bolt, a cover fastened to an edge of an opening of the crankcase so as to cover the rotor fan, and a relative rotation direction of the rotor and the crankshaft. Anti-rotation means for preventing the target rotation, the anti-rotation means is formed along the longitudinal direction on the circumferential outer peripheral surface of the crankshaft. An engine generator comprising: a key groove, a key that fits in the key groove, and a key groove formed so that the key can fit in a through hole of the rotor.