JPS62206281A - Gear pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in gear pumps, particularly triple gear pumps.

[Conventional technology]

The gear pump is small! ! It is used in various places because of its simple texture and structure. For example, Utility Model No. 59-34086
The so-called triple gear pump disclosed in the above publication has three gears arranged in series, and when the three gears mesh and rotate, there are two suction parts and two discharge parts. By connecting these to each other, we can create two
It has a series of gear pumps installed in parallel, and although it is small, it is a large ω pump, so it is often used in applications that require such characteristics.

[Problems to be Solved by the Invention] In the conventional triple gear pump, the axes of the three gears are arranged in a straight line. This is due to the ease of manufacturing, that is, the ease of centering and processing, or because it is convenient for maintaining the balance of loads on each gear.

However, because of this, there were problems that caused problems as a pump. In other words, pulsations were caused in the respective actions at the suction section and the discharge section at two locations in the front, which are located on each side of the two meshing sections of the three gears.

For the two suction portions, the gear 7 is disengaged at the same time, and for the two discharge portions, the gear 115 is disengaged at the same time, resulting in the pulsation. This pulsation causes the pump load to fluctuate greatly, causing vibration and noise.

Further, due to fluctuations in the driving force, a bubbling phenomenon may occur on the meshing tooth surface of each gear, including the input gear portion for rotation of the gear bomb drive, which has an adverse effect on the life of the gears.

The present invention was devised in view of the above-mentioned conventional problems.
The object of the present invention is to provide a triple gear pump in which the pulsation is significantly reduced by a simple construction.

[Means for solving problems]

In order to achieve the above object, the present invention provides a straight line connecting the axis of the central gear of three gears meshing with each other and the axis of one of the two left and right gears. A straight line connecting the gear in the center and the axis of the gear A of one of the two left and right gears is connected to the gear in the center of the city record and the two left and right gears.
From the extension of the straight line connecting the axial center of the other gear of the gears, each gear 7
It was constructed by rotating and displacing the meshing timing of the two.

[Effect]

Since the Gi\7 pump of the present invention is configured as described above, 3
There are two suction parts on each side of the gear arrangement and zero
In both Tabe and Tabe, the meshing phase, that is, the meshing timing, of each gear, in which the suction at these parts becomes the acting force for discharge, occurs at each of the two parts. Therefore, the pulsation that occurs in the conventional triple gear pump cancels out each other on both sides, and the overall pulsation is significantly reduced.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the gear pump of the present invention will be described below with reference to FIGS. 1 and 2.

Two gears 3a and 3b that mesh with and rotate with a gear 171 in the center are arranged on the left and right sides. These three gears 1, 3a, and 3b are rotatably supported by the case 5. One end of the shaft 7 of the gear 1 in the center extends and protrudes outside the case 5, and a driving gear 9 is fitted therein.

One of the left and right gears 3a and 3b with respect to the gear 1 in the center, in this embodiment, the gear 3b on the right side of the drawing
The straight line 1i115 connecting the axis 11 of gear 1 and the axis 13 of gear 3b is slightly bent with respect to the other side.

Meanwhile, the other gear 3 of the two gears 3a and 3b
With respect to the extension of the straight line 19 connecting the axis 17 of a and the axis 11 of the gear 1 in the center, approximately the axis of the gear 1 in the center It is arranged with a rotational displacement of an angle equivalent to 1/4 pitch. Therefore, the meshing timing of the gears 1.3a and 3b is shifted.

As a result, each axis 1 of the three gears 1.3a, 3b
1.17.13 are not arranged in a straight line like before,
The axis 11 of the gear 1 in the center is bent at a small angle into a dogleg shape. The refraction angle θ at this time is θ=180°/2
Z (Z=number of teeth of gear 71 in the center), that is, it is an angle equivalent to 1/4 pitch of gear 1 in the center.

Since the gear pump according to the embodiment of the present invention is configured in this way, pulsation caused by meshing rotation of the three gears is significantly reduced compared to the conventional pump. That is, there are suction portions 21a on both sides of each meshing portion of the three gears 1, 3a, and 3b, that is, two suction portions 21a in total.
21b, discharge portions 23a, and 23b function with a phase difference of 1/4 pitch of gear 1 in the center in each combination.

As a result, the suction portions 21a and 21b1 at each of the 2fIi locations are
In the suction ports and discharge ports (not shown) that connect the discharge portions 23a and 23b, the individual suction portions 21a and 21b
Since the pulsations generated in each of the discharge portions 23a and 23b are shifted by 1/4 pitch, when they are connected and collected, they cancel each other out, thereby significantly reducing the pulsations and further reducing vibrations and noise.

Furthermore, in this case, it is preferable to minimize the backlash of the gear to an extreme extent. Furthermore, due to the bending arrangement of the left and right gears 3a, 3b and the gear 1 at the center, the points of engagement of these gears are also bent at the same angle. For this reason, gear 1 in the center is meshed with drive reaction force A from left and right gears 3a and 3b as shown in Figure 2.
The line of action of
As shown in , a slight amount of pressure is generated toward the sides, resulting in so-called unbalanced pressure.

This resultant force C is equal to 1/4 of gear 1 at the center.
Since it is a resultant force resulting from a slight refraction at an angle equivalent to a bit, its value is small and normally there is no risk of causing major damage.

However, since this is not a desirable situation, this imbalance can be almost canceled out by taking the following measures against the resultant force C.

That is, by determining the installation position of the transmission gear 25 that transmits input to the driving gear 9 fitted to one end of the shaft 7 of the gear 1 in the center in a specific direction, @ By generating lateral pressure (indicated by the symbol in the figure) against 7 and directing this lateral pressure in the opposite direction to the resultant force C, the resultant force C is almost canceled out.
It is possible to eliminate 18 expenses.

The gear bomb of the present invention is not limited to the above-mentioned embodiment, but can be modified in various ways. For example, the refraction angle θ is θ-180”/
It can also be an odd multiple of 2Z.

In addition, if there is backlash and the gear in the center has an even number of teeth, the diffraction angle θ is set to an odd number 8 of θ=180°/Z.
Furthermore, if there is backlash and the number of teeth in the central gear is an odd number, θ=3.
Optimal effects can also be obtained by using an integer multiple of 60/Z.

〔Effect of the invention〕

As is clear from the above description, according to the gear pump of the present invention, the pulsation that occurs in a triple gear pump can be reduced by slightly bending the gear arrangement due to two simple points in its construction. It can be significantly reduced by shooting,
Noise etc. are greatly reduced and smooth operation is possible.

Further, since the configuration is as described above, there is almost no change in the structure of the gear pump itself, and no increase in size or weight occurs.

[Brief explanation of drawings]

FIG. 1 is a plan view of the inside of a case of a gear pump according to the present invention, and FIG. 2 is a diagram showing the relationship between the forces exerted by three gears and an external input drive gear. Explanation of main drawing symbols 1...Central gears 3a, 3b...Left and right gears

Claims (1)

[Claims] In a gear pump consisting of three gears that mesh with each other, whichever of the two gears on the left and right is connected to the axis of the central gear, the straight line connecting the axis of the gear in the center and the two gears on the left and right is From the extension of the straight line connecting the axis of the other gear, centering on the axis of the central gear,
A gear pump characterized in that each gear is rotationally displaced so as to shift the meshing timing of each gear.