JPS641502Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a circumscribed gear pump or motor that can be used in the field of hydraulic equipment, etc.

(b) Prior art As this type of gear pump or motor, the first
As shown in the figure, gears a and b are housed in a hole d formed in a body c and has a spectacle-shaped cross section, and covers e and f are attached to the entrance end of the body c. There is one in which a bearing j for supporting the spindles h and i of the gears a and b is mounted in the shaft hole g of the gear.

Incidentally, in such a gear pump or motor, it is necessary to bring the tooth tips k and m of the gears a and b close to the inner peripheral surface n of the hole d of the body c through a precise gap. Therefore, in a system in which the spindles h and i of the gears a and b are supported by bearings j provided in the covers e and f, mutual positioning of the covers e and f and the body c is important. . Therefore, in the conventional type, a positioning pin p is generally interposed between the body c and the covers e and f. However, when positioning is performed using the pin p, the hole d of the body c
and a pin hole q between the shaft hole g of the covers e and f,
Since a large number of mutually independent machined parts such as the pin p and the pin hole r are involved, it is difficult to accurately align the axis of the hole d with the axis of the shaft hole. Therefore, gaps between the tooth tips k and m of the gears a and b and the inner circumferential surface n of the body c are likely to become misaligned. Furthermore, in such a structure, when the pressure of the working fluid increases, the force (shearing force) acting on the pin p increases, so in the case of a high pressure specification, it is necessary to make the pin p thicker. In order to eliminate this inconvenience, a technique of joining the covers e, f and the body c by soldering (Utility Model Application Publication No. 1987-87 "Gear pump or motor that prevents deformation of cylindrical body")
has also been proposed, but in this case, the cylindrical insert method is circular and does not have a positioning function, and if this cylindrical insert method is applied to a body with a spectacle-shaped hole, it will lead to a decrease in the strength of the body c or an increase in the size of the body c. There is this inconvenience.

(c) Purpose The present invention was developed in view of the above circumstances, and utilizes the spectacle-shaped hole in the body to position the inner circumferential surface of the gear and the gear without requiring high processing accuracy. A gear pump or motor that stabilizes pump performance by adjusting the gap between the teeth and the tips of the teeth to an appropriate value, and that can be made compact and high-pressure without reducing the strength or increasing the size of the body. The purpose is to provide

(D) Structure In order to achieve the above object, the present invention provides a dowel part protruding from the cover instead of the pin method, and this dowel part is fitted into the inner periphery of the opening end of the body, so that the cover can be closed. is positioned and joined to the body. In particular, the dowel provided in the cover has the same shape as the spectacle-shaped hole in the body, and forms a dowel joint by cooperating with the spectacle-shaped hole in the body.

(E) Embodiment Hereinafter, an embodiment in which the present invention is applied to a gear pump will be described with reference to FIGS. 4 to 6.

FIG. 4 is a front sectional view of the gear pump according to the present invention. This gear pump has gears 1 and 2 for oil feeding.
A front cover 4 and a rear cover 5 are respectively attached to the open end 3a of the body 3 housing the
Side plates 6 and 7 are interposed between and the tooth side surfaces 1a and 2a of the gears 1 and 2, respectively. gears 1, 2
are spur gears that mesh with each other, and the spindles 8, 9 of these gears 1, 2 are supported by bearings 11 provided on both the covers 4, 5. Body 3 is
It is cylindrical with a hole 12 having a spectacle-shaped cross section, and its width W1 is set larger than the face width W2 of the gears 1 and 2. And this glasses-shaped hole 12
The tooth tips 1b, 2b of the gears 1, 2 are provided on the inner circumferential surface 13 of the gears 1, 2.
are placed close to each other through a small gap. Further, the bearing portion 11 has a bushing 15 fitted into a shaft hole 14 bored in the covers 4 and 5.
5 and the support shafts 8 and 9 are rotatably fitted therein.

Now, in this invention, in the above-described configuration, the cover 4, 5 is provided with a dowel portion 16 protrudingly provided, and this dowel portion 1 is provided.
Each of the covers 4 and 5 is joined to the body 3 by fitting the cover 6 into the inner periphery of the hole 12 of the body 3. The dowel portion 16 is integrally provided on the covers 4 and 5, and is connected to the gears 1 and 2.
It is formed in the same shape as a pair of spectacles corresponding to the tooth tips 1a and 2a, and is adapted to fit into the inner circumferential surface 13 of the holding hole 12. That is,
This is a method in which the spectacle-shaped hole 12 of the body 3 itself is used as a hole for dowel-braze bonding, without providing a special hole or step for dowel-braze bonding. Also,
The body 3 and the covers 4, 5 are connected using a plurality of bolts 17. Note that the tip end surface 1 of the dowel portion 16 of the covers 4 and 5
6a is provided with a groove 19 for accommodating a gasket 18 that partitions a high pressure region and a low pressure region. As shown in FIG. 5, this groove 19 has a general general shape, and the gasket 18 accommodated in this groove 19 is elastically fitted to the side plates 6, 7.

With such a configuration, the dowel portions 16 protruding from the covers 4 and 5 that support the support shafts 8 and 9 of the gears 1 and 2 have a certain height and are shaped like spectacles on the body 3. Since the gears 1 and 2 are fitted and connected to the inner circumferential surface 13 of the hole 12, even if a radial force is applied to the gears 1 and 2 due to the pressure difference between the high pressure region and the low pressure region,
The covers 4 and 5 will not be misaligned with respect to the body 3. Moreover, the cover 4,
Since the shaft hole 14 of the bearing part 11 and the dowel part 16 are integrally protruded from the same side of the covers 4 and 5, they can be machined with high precision with simple operation. is possible. Moreover, this dowel portion 16 is formed by the eyeglass-shaped hole 1 in the body 3.
It is directly fitted onto the inner circumferential surface 13 of No. 2. Since this spectacle-shaped hole 12 is machined with high precision, it is possible to align the axes of the gears 1 and 2 supported by the bearing portion 11 without worrying about the positional accuracy of the pin hole or the machining accuracy of the pin. The axis of the holding hole 12 can be aligned accurately. Therefore, the positioning is made appropriate, and the tooth tips 1a, 2 of the gears 1, 2 are
The minute gap formed between a and the inner circumferential surface 13 of the body 3 can be defined to an appropriate value.
Furthermore, since the dowel portion 16 has a much larger diameter than a conventional positioning pin, it can withstand a large load, that is, a shearing force generated by the pressure difference mentioned above. Therefore, it is possible to increase the pressure of the pump without reducing the strength or increasing the size of the body. In other words, it is possible to downsize the body.

In the above-mentioned embodiments, a case in which a cover is attached to both ends of the body has been described, but the present invention is not limited to this type of structure. It can be similarly applied to a type of body in which a cover is attached to an opening at one end of the body. In the case of the illustrated example, a groove 19 is provided in the tip end surface 16a of the soldering mark part 16, and the gasket 1 which is elastically installed in the side plates 6 and 7 is inserted into this groove 19.
8, the end of the groove 19 is connected to the body 3.
The end of the gasket 18 can be elastically installed on the inner periphery of the body 3. Therefore, gasket 18
It is possible to easily and reliably seal the end portion of the pressure region, and therefore it is possible to reliably seal between the high pressure region and the low pressure region with a simple configuration.

Furthermore, this invention can also be implemented as a gear motor that outputs torque by introducing pressure oil or the like.

(F) Effect Since the present invention has the above-mentioned configuration, positioning can be effectively achieved by utilizing the spectacle-shaped hole in the body without requiring high processing accuracy. A gear pump that can stabilize pump performance by regulating the gap between the surface and the tooth tip of the gear to an appropriate value, and can also achieve high pressure without reducing the strength or increasing the size of the body. or can provide a motor.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line in Fig. 1, and Fig. 4 is a sectional view showing an embodiment of the present invention. 5 is a sectional view taken along the - line in FIG. 4, and FIG. 6 is a sectional view taken along the - line in FIG. 4. 1, 2...Gear, 1a, 2a...Tooth side, 1
b, 2b...Tooth tip, 3...Body, 3a...Open end, 4, 5...Cover, 6, 7...Side plate, 8,
9... Support shaft, 11... Bearing portion, 12... Glass-shaped hole, 13... Inner peripheral surface of body, 14... Shaft hole,
15...Butsuyu, 16...Sealing section, 16a...
...Tip surface, 18...Gasket, 19...Groove, W
1...Body width, W2...Tooth width.

Claims (1)

[Scope of utility model registration request] A gear in which a cover is attached to the open end of a cylindrical body having a hole having a spectacle-shaped cross section and which accommodates two mutually meshing gears, and a bearing part for supporting a support shaft of the gears is provided on the cover. In the pump or motor, the cover is provided with a convex dowel part having the same shape as the spectacles, and the convex dowel part is fitted into the inner periphery of the open end of the spectacles-shaped hole in the body, so that the cover is attached to the body. A gear pump or motor, characterized in that it is joined to a gear pump or motor.