JP2547589B2 - 4-cylinder rotary piston engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a four-cylinder rotary piston engine, and more particularly to a structure of an eccentric shaft of a four-cylinder rotary piston engine.

(Prior art and its problems) In a rotary piston engine, as is well known, in order to eccentrically rotate a rotor in an operation chamber defined by a pair of side housings and a rotor housing, an eccentric rotor bearing portion is eccentrically rotated. The eccentric shaft formed in the state is arranged. In a multi-cylinder rotary piston engine, it is necessary to form the eccentric portion of this eccentric shaft by the number of cylinders. However, forming a plurality of eccentric portions on one eccentric shaft means that the eccentric portion and the eccentric portion are formed. When installing a bearing part between
It is difficult to assemble. Therefore, conventionally, as disclosed in, for example, Japanese Utility Model Publication No. 45-8482, there has been proposed a structure in which the eccentric shaft is divided into a number corresponding to the number of cylinders. The eccentric shaft described in this publication is for a four-cylinder rotary piston engine. The eccentric shafts of the cylinders are connected to each other by a toothed joint, and these eccentric shafts are integrally connected by a single through bolt. Has been done.

However, in the eccentric shaft having such a structure, the bolt may be thermally deformed or stress-deformed to reduce its fastening force, resulting in a decrease in rigidity and an increase in vibration. Also, 4
It may be difficult to accurately connect the eccentric shafts coaxially with each other due to manufacturing errors and the like.

On the other hand, as a structure of such an eccentric shaft that does not use a through bolt, there is one described in JP-A-60-69208. The eccentric shaft described in this publication is for a three-rotary piston engine, cannot be used as it is as an eccentric shaft of a four-cylinder rotary piston engine, and it is necessary to install another eccentric portion of the rotor. In that case, it is conceivable to add another eccentric part of the rotor to the sub-eccentric shaft that is fitted and fixed to the main eccentric shaft. It is considered that the shake becomes large and the centering becomes troublesome.

Therefore, an object of the present invention is to realize an eccentric shaft structure suitable for use in a four-cylinder rotary piston engine.

(Means for Solving Problems) In order to achieve the above object, in the present invention, 4
The eccentric shaft of the cylinder rotary piston engine has the following structure. That is, the eccentric shaft of the present invention comprises three main eccentric shafts that define the center of rotation of each rotor, and cylindrical first and second eccentric shafts that are fitted to the outer circumferences of both sides of the main eccentric shaft from the end side. It is composed of members. The outer shape of the main eccentric shaft is such that the central portion has a large diameter and both end portions have a small diameter, and the central portion and both end portions are continuous through the tapered portions. Eccentric parts that axially support the rotors of the second and third cylinders are formed on the outer circumferences of the large-diameter portions, while the first and second eccentric shafts are formed on the outer circumferences of the first and second eccentric shafts, respectively. An eccentric portion that axially supports the rotor of four cylinders is formed. The connection between the main eccentric shaft and the first and second eccentric shafts is formed by the following structure. On the inner circumferences of the first and second eccentric shafts, there are formed tapered portions that are fitted to the outer peripheral surfaces of the tapered eccentric shafts by pressing the tapered portions of the main eccentric shafts from the end side of the main eccentric shafts. Therefore, by tightening the first and second eccentric shafts fitted from both ends of the main eccentric shaft in the axial direction from the respective end sides with fastening fittings such as bolts, the first and second eccentric shafts are fitted to the outer periphery of the main eccentric shaft. The eccentric shaft is coupled. In this way, 4 with eccentric parts at 4 locations
An eccentric shaft for a cylinder rotary piston engine is constructed. Furthermore, in the present invention, the bearing portion of the eccentric shaft having the above-described configuration is arranged in each of the pair of housings forming the side wall of the first cylinder and in each of the pair of housings forming the side wall of the fourth cylinder. Has been done.

(Example) Below, the Example of this invention is described with reference to drawings.

FIG. 1 is a vertical sectional view showing a four-cylinder rotary piston engine according to an embodiment of the present invention. As shown in the figure, the engine body 1 includes a first to a fourth cylinder 2 from the left side in the figure.
~ 5 are configured. That is, between the annular rotor housings 6-9, the intermediate housing 10-
12 are arranged, and side housings 13 and 14 are attached to both ends of the rotor housings.These housings define the working chambers 15 to 18 of each cylinder, and the rotors 19 to 22 are arranged therein. is there. The above housing is
Each is positioned by a hollow pin 23 for positioning, and is tightly connected to each other by a tension bolt 24.

An eccentric shaft assembly 31 that defines the center of rotation of the rotor of each cylinder is attached to the engine body 1 of this configuration in a state of penetrating each cylinder. As shown in FIG. 2, the eccentric shaft assembly 31 is composed of a main eccentric shaft 32 and second and second eccentric shafts 33 and 34 mounted on both sides of the main eccentric shaft 32. The main eccentric shaft 32 has a large-diameter portion 321 at a central portion penetrating at least the second and third cylinders, and has thin-diameter portions 322, 323 at both end portions penetrating the other first and fourth cylinders. It is formed so that. And these smaller diameters 322, 3
Tapered portions 324 and 325 are provided on the outer circumference between the 23 and the large diameter portion 321.
Has been formed. On the outer circumference of the large diameter portion 321, the second
And the rotor 20 on the portion of the third cylinder facing the working chamber,
21 eccentric bearing portions 326 and 327 are integrally formed.

On the other hand, the cylindrical first and second eccentric shafts 33 and 34 shown in FIGS. 3 and 4 are fitted on the outer circumferences of the small-diameter portions 322 and 323 on both sides of the main eccentric shaft 32 from both ends. Is. An eccentric bearing portion 331 that supports the rotor 19 of the first cylinder is integrally formed on the outer periphery of the first eccentric shaft 33. On the inner peripheral surface of the eccentric shaft, a taper portion 332 that fits into the taper portion of the main eccentric shaft is formed on the second cylinder side, and the remaining inner peripheral portion following this is a small-diameter portion of the main eccentric shaft. It has a shape that fits on the outer periphery of the. Therefore, by fitting the eccentric shaft from the end of the main eccentric shaft and pushing the main eccentric shaft toward the center side, the eccentric shaft is fitted to the outer periphery of the small-diameter portion of the main eccentric shaft and the tapered parts The two are joined to each other, the positioning is performed in the axial direction, and the rotor eccentric bearing portion 331 is positioned in the working chamber of the first cylinder. The second eccentric shaft 34 has the same structure as that of the first eccentric shaft, and the rotor bearing portion 341 of the fourth cylinder is formed on the outer circumference of the second eccentric shaft 34, and the other taper of the main eccentric shaft is formed on the inner circumference thereof. A tapered portion 342 is formed to fit the portion.

Next, the structure of the bearing portion of the eccentric shaft assembly 31 having the above structure will be described. As can be seen from FIG. 5, the eccentric shaft assembly 31 is pivotally supported at four positions of both side housings 13 and 14 and intermediate housings 10 and 12. In the first bearing portion 41 formed in the side housing 13 forming the first cylinder, 411 is a cylindrical gear hub, and this gear hub is opened in the side housing and the flange portion 412 located outside the side housing. It has a fitting portion 413 fitted in the eccentric shaft through hole 42. The collar portion 412 is bolted to the outer surface of the side housing 12, and a bearing 416 for supporting the outer peripheral portion of the first eccentric shaft 33 is formed on the inner periphery of the fitting portion. Also,
A fixed external gear 414 is formed on the outer periphery of the tip of the fitting portion, that is, a portion facing the working chamber of the first cylinder. The gear 414 is a rotor internal gear fixed to the side housing 13 side of the rotor 19. It meshes with 415. Second to this
The bearing portion 43 has a fitting portion 432 fitted into the eccentric shaft through hole 44 of the intermediate housing 9 of the gear hub 431, and this portion is bolted to the housing. A bearing portion 433 that supports the large-diameter portion 32 of the eccentric shaft 31 is formed on the inner circumference of the fitting portion. In addition, a rotor is provided on the outer periphery of the tip portion protruding into the working chamber of the second cylinder.
An external gear 435 that meshes with 20 internal gears 434 is formed. The third bearing portion 45 has a structure similar to that of the second bearing portion, and the fitting portion 452 of the gear hub 451 fitted into the eccentric shaft through hole 46 has the fitting portion 452.
The fixed external gear 453, which is bolted to 11, and formed at the tip portion protruding into the working chamber of the third cylinder, is in mesh with the rotor internal gear 454. Furthermore, the fourth bearing portion 46
Is similar to the structure of the first bearing portion described above, the collar portion 462 of the gear hub 461 is bolted to the outer surface of the side housing 13, and the rotor inner teeth are provided on the outer periphery of the tip portion protruding into the working chamber of the fourth cylinder. A fixed external gear 464 that meshes with the gear 463 is formed.

On the other hand, a balance weight 51, an output gear 53 for transmitting a driving force to the oil pump 52, and the like are spline-coupled to the tip of the eccentric shaft assembly 31 protruding from the side housing 12. These members are fastened in the axial direction of the eccentric shaft assembly by bolts 54 screwed to the tip of the eccentric shaft assembly. Here, the first
The tip end of the eccentric shaft is pushed by the balance weight 51 via the slide bearing 55, and the pushing force keeps the first eccentric shaft 32 tightly connected to the main eccentric shaft 31. On the other hand, the other end of the eccentric shaft assembly also projects from the other side housing 13, and the balance weight 56 and the flywheel 57 are also provided in this part.
Is fixed.

As described above, the eccentric shaft assembly 31 of this example is
32 on the main eccentric shaft having the eccentric parts of the second and third cylinders,
First and second eccentric parts of first and fourth cylinders
The eccentric shaft is attached. Therefore, compared to the conventional structure in which each eccentric part is divided in the material axis direction and these are tightened with fastening bolts,
The overall rigidity can be increased. Further, the other two eccentric shafts 33 with respect to the common main eccentric shaft 32 penetrating each cylinder,
Since 34 can be assembled, its structure is simple, centering can be performed easily, and assembly workability is improved.

Further, in this example, the bearing portions of the eccentric shaft assembly 31 are arranged on both end sides thereof. Since the cross section of the main eccentric shaft is small at both end portions, the rigidity thereof is also low, and it is preferable to support such a low rigidity portion because deformation of the main eccentric shaft can be effectively prevented. Further, by arranging the bearing portions on the side housings 12 and 14 at both ends in this way, this portion occupies more space for arranging the bearing portions as compared with other intermediate housing portions positioned inside the engine body. It is possible to take
Therefore, a thick bearing member can be arranged. Therefore, also from this point, the deformation of the eccentric shaft assembly can be effectively prevented.

Further, in this example, the fixed external gear that meshes with the internal gear of the rotor is supported by the outer housing when viewed in the axial direction of the eccentric shaft assembly. For example, the fixed external gear 414 meshing with the rotor internal gear of the first cylinder is provided by the side housing 12 located outside of the side housing 12 and the intermediate housing 9 that form the first cylinder. It is supported in a cantilever form. In this way, it is preferable to support the fixed external gear at the position of the tip side of the eccentric shaft assembly where deformation easily occurs, because the fixed external gear is firmly supported by the housing.

(Effects of the Invention) As described above, in the present invention, the eccentric bearing portions of the rotors of the second and third cylinders are formed on the main eccentric shaft that penetrates each cylinder, and both sides of this main eccentric shaft are An eccentric shaft assembly for a four-cylinder rotary piston engine is constructed by fitting first and second eccentric shafts with eccentric bearing parts of the first and fourth cylinder rollers, and the bearing part of this assembly. The position of is set appropriately. Therefore, according to the present invention, an eccentric shaft for a four-cylinder rotary piston engine having a simple structure and easy to assemble can be obtained. Further, an eccentric shaft structure having high rigidity can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of a four-cylinder rotary piston engine of the present invention, FIG. 2 is a vertical sectional view showing a main eccentric shaft incorporated in FIG. 1, FIG. 3 and FIG. 1 is a vertical cross-sectional view showing the first and second eccentric shafts incorporated in FIG. 1, respectively, and FIG. 5 is a vertical cross-sectional view showing a side housing and an intermediate housing partitioning and forming each cylinder of FIG. Is. 1 ... Engine body 2-5 ... Cylinder 6-9 ... Rotor housing 10-12 ... Intermediate housing 13, 14 ... Side housing 15-18 ... Working chamber 19-22 ... Rotor 31 ... Eccentric shaft assembly 32 …… Main eccentric shaft 33,34 …… Eccentric shaft 41,43,45,46 ……

Front page continuation (72) Inventor Yoshitaka Matsumuro 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) Reference JP-A-63-100227 (JP, A)

Claims (1)

(57) [Claims] 1. A main eccentric shaft that defines a center of rotation of each rotor, and cylindrical first and second eccentric shafts that are fitted to both outer circumferences of the main eccentric shaft from end sides thereof. The central portion of the shaft has a large diameter and both end portions have a small diameter, and the central portion and both end portions are continuous via a tapered portion, and the second and third cylinders are provided on the outer periphery of the large diameter portion. Eccentric portions that rotatably support the rotors of the first and second eccentric shafts are formed on the outer circumferences of the first and second eccentric shafts, respectively. And a taper portion that is fitted to the taper portion of the main eccentric shaft from the end side of the main eccentric shaft, the first and second eccentric shafts being formed on the main eccentric shaft. The bearing portion of the eccentric shaft assembly configured by fitting the shaft constitutes the side wall of the first cylinder. 4-cylinder rotary piston engine, characterized in that arranged on each of the pair of housings constituting respectively, and a side wall of the fourth cylinder of the pair of housings that.