JPH06137279A - Gear pump - Google Patents

Abstract

PURPOSE:To prevent displacement in a device position of a body, a mounting flange, and a cover by pressing cylindrical dowel pins in respective holes in which respective tie bolts are inserted. CONSTITUTION:Both sides of a body B in which a gear is incorporated are covered with a closing member, such as a cover. Three members of the body B, a mounting flange M, and a cover are fastened against each other by means of tie bolts 11-14. Further, cylindrical dowel pins 21 are pressed in the respective bolt holes 20 of the tie bolts 11-14. Thus, the same number of dowel pins 21 as that of the tie bolts 11-14 are provided. Besides, since the tie bolts 11-14 can be inserted in the respective dowel pins 21, the bolt holes 20 for the tie bolts 11-14 and holes in which the dowel pins 21 are inserted can be used in common.

Description

Detailed Description of the Invention

The present invention relates to a gear pump in which both sides of a body are covered with a closing member such as a cover.

[0002]

2. Description of the Related Art In the conventional gear pump shown in FIGS. 3 and 4, one side of a body B incorporating a pair of gears 1 and 2 is covered with a mounting flange M, and the other side is covered with a cover C. The shafts 3 and 4 of the gears 1 and 2 are supported by the winding bushes 5 and 6 press-fitted into the mounting flange M, and the other shafts 7 and 8 are supported by the winding bushes 9 and 10 press-fitted into the cover C. ing. The body B, mounting flange M and cover C thus configured
Each of them is firmly fastened with four tie bolts 11-14. When the relative positions of the body B, the mounting flange M, and the cover C are deviated, the engagement of the gears 1 and 2 and the sealing performance are affected. Therefore, conventionally, in order to prevent such displacement, two dowel pins 16 and 17 are inserted into the body B and the mounting flange M side, and two dowel pins 18 are also provided in the body B and cover C sides. 1
9 is inserted.

[0003]

In the conventional gear pump as described above, the holes into which the dowel pins 16 to 19 are inserted are made slightly larger than the pins so that the assemblability is improved. There is. However, on the other hand, the rattling may cause the relative positions of the body B, the mounting flange M, and the cover C to shift,
The intended purpose of preventing the deviation could not be achieved. In addition, this type of gear pump has tie bolts 11 to 1
The deformation around 4 is the least. However, in the above-mentioned conventional gear pump, the dowel pin cannot be provided around the tie bolt because of a problem in strength. Therefore, the dowel pin must be provided at a position apart from the tie bolt. The more the dowel pin is separated from the tie bolt, the more likely it is to be affected by the deformation, and in the end, relative displacement of the body B, the mounting flange M and the cover C could not be prevented.

Furthermore, since the dowel pins must be set apart from the tie bolts, a special space for inserting the dowel pins must be secured,
That was also an obstacle to miniaturization of the gear pump.
Furthermore, only two dowel pins can be provided on one side of the body due to structural restrictions. But,
If the number of dowel pins is small, those processing errors will occur.
Immediately, it affected the displacement of the body, mounting flange and cover. An object of the present invention is to provide a gear pump which can surely prevent the body, the mounting flange, and the cover from being displaced and can be downsized.

[0005]

According to the present invention, the tie bolts are inserted into a gear pump in which both sides of a body incorporating a gear are closed by closing members such as covers, and the body and the closing members are fastened with four tie bolts. The feature is that a tubular dowel pin is press-fitted into the bolt hole.

Since the present invention is configured as described above, since the tubular dowel pin is press-fitted into the bolt hole into which the tie bolt is inserted, the same number of dowel pins as the tie bolt can be provided. Moreover, since the tie bolt can be inserted into this dowel pin, the bolt hole of the tie bolt and the hole for inserting the dowel pin can be made common.

[0006]

According to the gear pump of the present invention, since the same number of dowel pins as the tie bolts are provided, even if each dowel pin has a processing error, the error is averaged by the four dowel pins, It does not appear as a big error. Further, since the bolt hole of the tie bolt and the insertion hole of the dowel pin are made common, the dowel pin can be positioned around the tie bolt with the least deformation. Therefore, there is no problem that their positions are displaced due to the influence of deformation of the body or the like. Moreover, since it is not necessary to secure a space for inserting the dowel pin, it is useful for downsizing the gear pump. Furthermore, since the dowel pin is press-fitted into the bolt hole, there is no inconvenience due to rattling of the dowel pin as in the conventional case.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in FIGS. 1 and 2 has eight bolt holes 2 on the side of the body B into which the tie bolts 11 to 14 are inserted.
A tubular dowel pin 21 is press-fitted into the shaft 0 and one end of the dowel pin 21 is projected from the side surface of the body B. Then, one end of the dowel pin 21 is inserted into the bolt holes formed in the mounting flange M and the cover C. After joining the body B, the mounting flange M and the cover C in this manner, the tie bolts 11 to 14 are passed through the bolt holes 20 and the dowel pins 21 to firmly fasten these three elements.

As shown in FIG. 2, the bolt hole 20 into which the cylindrical dowel pin 21 is inserted has a slightly larger opening, and when the dowel pin 21 is press-fitted, the inner periphery of the dowel pin 21 and the bolt hole 20 are separated from each other. I try to be the same. According to the gear pump of this embodiment as described above, since the same number of four dowel pins 21 as the tie bolts 11 to 14 are provided, even if each dowel pin has a processing error, the error is Averaged at four dowel pins, and does not appear as a large error.

Further, the bolt holes 2 of the tie bolts 11 to 14
Since 0 and the hole for inserting the dowel pin 21 are made common, the dowel pin can be positioned around the tie bolt with the least deformation. Therefore, body B
The positions of them do not shift due to deformation such as.
Moreover, since it is not necessary to secure a space for inserting the dowel pin 21, it is useful for downsizing the gear pump. Furthermore, since the dowel pin is press-fitted into the bolt hole, there is no inconvenience due to rattling of the dowel pin as in the conventional case.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention with a cover removed.

FIG. 2 is likewise an enlarged cross-sectional view of a main part.

FIG. 3 is a sectional view of a conventional gear pump.

4 is a sectional view taken along line IV-IV in FIG.

[Code]

 B Body M Mounting Flange C Cover 11 Tie Bolt 12 〃 13 〃 14 〃 20 Bolt Hole 21 Dowel Pin

Claims (1)

[Claims] 1. A gear pump in which both sides of a body incorporating a gear are closed by closing members such as covers, and the body and closing members are fastened with four tie bolts.
A gear pump characterized in that a tubular dowel pin is press-fitted into a bolt hole into which the tie bolt is inserted.