JPH0441272Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a gear pump, particularly a triple gear pump.

[Prior Art] Gear pumps are often used in various places because they have a simple structure, are small and lightweight. Among these gear pumps, the so-called triple type, in which three gears are arranged in series inside the case, and the central gear drives and rotates the left and right gears, is relatively small and can have a large discharge capacity.
Used in applications that require large amounts of liquid to be delivered in a short period of time.

[Problems to be solved by the invention] Since the above-mentioned triple gear pump has two suction holes and two discharge holes at the meshing parts of the center gear and left and right gears, these suction holes and discharge holes are Each of them must be made into one suction port and one discharge port and connected to the outside, but the structure for this is complicated.

For example, as disclosed in Japanese Utility Model Application Publication No. 59-34086, passages connecting two suction holes and two discharge holes are provided in the cover portion of the side surface of the case, and these passages communicate with each other. It has been proposed that a suction port and a discharge port are further provided on the outer periphery of the case. A case with such a configuration requires a complicated casting process, and furthermore, the suction port and the discharge port that communicate with each passage are either located at one end of the gear axis in the center when viewed from the pump as a whole. It is set off to one side.

For this reason, since the passage lengths of the two suction holes or discharge holes are different between the two places, a difference naturally occurs in the flow resistance. This causes an imbalance in the pumping action between the left and right gears, contributing to vibrations and causing adverse effects such as noise and uneven bearing load.

The present invention was devised in view of the above-mentioned conventional problems, and aims to provide a triple gear pump that can be easily manufactured and can operate in a well-balanced manner.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides left and right gears that mesh with the central gear, a case that surrounds and supports the outer periphery of these gears, and a meshing portion of the gears. two suction parts on the suction side and two discharge parts on the discharge side which are arranged alternately on both sides of the case and communicate with the meshing part, and the two suction parts or two which are provided on at least one side in the axial direction of the case. The central part of the collecting part is located at the axial center of the gear in the central part, and the peripheral part communicates with the two suction parts or the two discharge parts. did.

[Function] Since the gear pump of the present invention is constructed as described above, at least one of the two suction holes and the two discharge holes in the triple gear pump is connected to the gear shaft in the center by the gathering part. They will be gathered nearby.

[Embodiment] An embodiment of the gear pump of the present invention will be described below with reference to FIGS. 1 to 5.

In the gear pump of the present invention, a central gear 1 and left and right gears (two gears) 3a, 3b are arranged in a substantially straight line in mesh with each other, and the outer periphery of these three gears is surrounded and rotatably supported. Case 5
is provided.

Two suction portions 7a, 7b and two discharge portions 9a, 9b of liquid that accompany the meshing rotation of the three gears 1, 3a, 3b are located on both sides of each meshing portion of each gear 1, 3a, 3b. The three gears are arranged in an alternating arrangement, that is, they are arranged obliquely and intersecting each other with respect to a straight line connecting the axes of the three gears arranged substantially in a straight line.

At least one of these two suction parts 7a, 7b and two discharge parts 9a, 9b, in this embodiment, the suction parts 7a, 7b are the two suction parts 7a, 7b. Provide a connecting route. For this purpose, a large-diameter circular hole 13 is provided on the inner surface of the cover 15 on one side of the case 5 as a gathering part centered on the axis of the shaft 11 of the gear 1 in the center. The suction portions 7a and 7b are connected to each other by short suction holes 14a and 14b.

That is, the two suction parts 7a and 7b are connected to the circular hole 1.
3 are connected by suction holes 14a and 14b and gathered at circular hole 13. The circular hole 13 extends directly from the inner surface to the outer surface of the cover 15 and reaches a flange surface 17 provided on the outer surface of the cover 13. The hole in the flange surface 17 serves as a mouth portion connected to the outside, that is, a suction port 19 in this case.

On the other hand, the two discharge portions 9a and 9b are connected to the discharge path 2.
1 and 23, it is connected to a discharge port 27 with a flange surface 25 provided on the side surface of the case. Furthermore, a safety valve and a pressure regulating valve (not shown) are provided in the middle of the discharge paths 21 and 23.

Since the gear pump of the present invention is configured as described above, in this case, the distance from the suction port 19 and the path shape are the same for the suction portions 7a and 7b. Therefore, the flow resistance of the liquid reaching the two suction parts 7a and 7b from the suction port 19 is also the same, and the liquid is sucked into the two suction parts almost equally. Now gear 1 in the center and gear 3 on the left and right
The use of the pump by meshing rotation with a and 3b is also under almost the same conditions on the left and right sides, and the pumping action is performed in an extremely well-balanced manner.

In order to be operated under the favorable conditions mentioned above, the gear pump of the present invention can perform an extremely well-balanced pumping action between the left and right gears 3a and 3b, with less vibration and noise, which is favorable for the life of bearings, gears, etc. Get results.

FIG. 6 shows another embodiment of the present invention in which both the suction side and the discharge side are assembled, and the two discharge parts 9a and 9b of the gear pump are also connected to the central gear 1 as described above. Since the short discharge holes 20a and 20b are gathered around the circular hole 31 centered on the shaft 11 and then extended to the side discharge ports 32, it is possible to contribute to a more balanced pumping action.

Further, a large-diameter circular hole 13 or 21 is provided near the shaft 11 of the gear 1 at the center of the gear pump of the present invention, and two suction portions 7a, 7b,
Alternatively, the form in which a very short path connecting the discharge parts 9a and 9b is provided is a form that is much easier to manufacture by casting compared to the long suction passage and discharge passage provided diagonally in the conventional case cover, etc. But it's extremely streamlined.

[Effects] As is clear from the above explanation, according to the gear pump of the present invention, the flow resistance to each of the two suction or discharge parts of the triple gear pump can be equalized, and the passage can be shortened, resulting in an extremely well-balanced gear pump. It can operate well. Therefore, favorable results can be obtained for the life of each gear, bearing, etc., and vibration and noise are also reduced. It also has the effect of reducing flow resistance and maximizing pump performance. Furthermore, since it is a gathering part, it is extremely easy to manufacture it as a casting.

[Brief explanation of drawings]

Figure 1 is a plan view of the inside of the gear pump of the present invention with the cover removed, Figure 2 is a side view showing the overall appearance, Figure 3 is a plan view with the suction port facing upward, and Figure 4. is a longitudinal sectional view, FIG. 5 is a plan view seen from the discharge side, and FIG. 6 is a longitudinal sectional view corresponding to FIG. 4 showing another embodiment of the present invention. Explanation of main drawing symbols, 1...Central gear, 3
a, 3b... Left and right gears, 5... Case, 7a,
7b...Suction part, 9a, 9b...Discharge part, 11...
...Axle of center gear 1, 13...Circular hole (gathering part).

Claims (1)

[Scope of utility model registration request] Left and right gears that mesh with the central gear, a case that surrounds and supports the outer periphery of these gears, and two suction side suctions that are alternately arranged on both sides of the meshing part of the gears and communicate with the meshing part. and a collection part provided on at least one side in the axial direction of the case to collect the two suction parts or the two discharge parts, and the central part of the collection part is the central part of the collection part. A gear pump characterized in that it is located at the axial center of a central gear and communicates with the two suction sections or the two discharge sections at the periphery.