JPS6148636B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gear pump or motor that can be operated in both directions of rotation.

[Prior art]

Conventionally, a gear pump or motor has a side plate that is movable toward the side of the gear and is arranged on the side of the gear.
A pressure chamber on which low pressure and high pressure fluid pressure acts is provided on the side of the side plate opposite to the side that contacts the gear side surface, and a pressing force that acts from this pressure chamber side,
By balancing the pressing force acting from the side of the gear under certain conditions (increasing the pressing force from the pressure chamber side), the sealing force on the side of the gear is compensated for according to fluctuations in fluid pressure on the discharge side. Accordingly, a pressure compensator is provided to compensate for the discharge pressure.

[Problems that gears try to solve]

When a gear pump or motor is used under high fluid pressure, the pressing force due to the fluid pressure acting on the gears of the gear pump or motor becomes large;
Accordingly, it was necessary to increase the diameter of the shaft that supported the gear.

For this reason, the area of the pressure chamber must be reduced.

As mentioned above, in gear pumps or motors whose rotational direction is set in a constant direction even if the diameter of the shaft is increased, a high-pressure pressure chamber is moved to a low pressure By extending it to the side, the pressure receiving area of the high pressure chamber can be secured.

However, in a gear pump or motor in which the direction of rotation changes, it is necessary that the area relationship between the high-pressure pressure chamber and the low-pressure pressure chamber be the same regardless of the rotation direction. In other words, it is necessary to form them bilaterally symmetrically. Therefore, the effective pressure receiving areas of the pressure chambers connected to each of the high pressure and low pressure must be made small. As a result, the condition of the pressing force acting on the side plate cannot be fully satisfied, and the sealing force on the side surface of the gear cannot be ensured. Therefore, there have been problems such as a decrease in volumetric efficiency and the inability to withstand use under high fluid pressure.

[Means for solving problems]

Means for solving the above-mentioned problems of the present invention is provided with a gear that is opened in the main body and is fitted into an inner hole to which ports communicating with the high-pressure side and the low-pressure side are connected, and that meshes and rotates. A side plate is provided which seals the side surface of the gear by contacting the side surface of the gear, and a first pressure chamber always connected to the low pressure side and a first pressure chamber connected to the high pressure side are provided on the opposite side of the side plate to the side that abuts the side surface of the gear. In a gear pump or motor having two pressure chambers and two intermediate pressure chambers between the first pressure chamber and the second pressure chamber, the intermediate pressure chamber and the first pressure chamber
between the pressure chamber and between the intermediate chamber and the second pressure chamber,
This is because a sealing member is disposed to allow fluid flow only from the first pressure chamber and the second pressure chamber toward the intermediate chamber.

[Effect]

According to the means of the present invention, a high-pressure and low-pressure pressure chamber connected to the suction and exhaust ports are provided on the opposite side of the gear pump or motor that can be operated in both rotational directions from the side that abuts the side surface of the gear, and these two pressure chambers are provided. In a configuration in which two intermediate chambers are provided between the chambers, the two intermediate chambers and the two
A sealing member is placed between the two pressure chambers to allow fluid to flow only in the direction of the intermediate chamber, so when the gear pump or motor is driven in one direction, it is not driven in the other direction. Then, the above 2
The other of the two pressure chambers and the intermediate chamber become high pressure chambers.
For this reason, even if the diameter of the shaft increases, a sufficient pressure receiving area of the pressure chamber for pressing the side plate can be ensured.

〔Example〕

An example in which this invention is applied to a gear pump will be described below.

The main body 1 includes gears 2 and 3 that mesh at the center, and bearings 7 and 7a that support the shafts 4 and 5 of the gears 2 and 3.
8 and 8a are inserted, and the suction port 9 and the discharge port 10 (second
) has an open inner hole 12. This inner hole 12
is formed by connecting two circular inner holes 11 and 13 at the center, and the suction port 9 and discharge port 10 are opened at the connecting portion. The end portion 14 is
After positioning with pins 15, 15a provided at the right end of the main body 1, it is fixed with a plurality of bolts (not shown). This end cover 14 stops the gears 2, 3, side plates 16, 16a, and bearings 7, 8, which will be described later, from moving in the right direction. After positioning the end cover 17 with pins 18 and 18a provided at the left end of the main body 1, it is fixed to the left end of the main body 1 with a plurality of bolts (not shown), and a hole 19 through which the shaft 4 of the gear 2 passes is fixed. has. This end cover 17 includes gears 2, 3, side plates 16a, 1, which will be described later.
6, and the leftward movement of the bearings 7a and 8a is stopped. Further, the protruding portion 4a of the shaft 4 that protrudes to the outside through the hole 19 of the end cover 17 is connected to the output side of a drive source of a motor or an engine. The sealing member 20 is inserted between the hole 19 and the shaft 4 to prevent fluid from flowing out of the end cap 17. When the shaft 4 receives a driving force in the direction of the arrow in FIG. 1, the gears 2 and 3 rotate in opposite directions and convey the fluid in the suction port 9 to the discharge port 10. Note that when driven in the direction opposite to the arrow in FIG. 2, the suction port 9 and the discharge port 10 are in opposite positions.

The side plates 16, 16a have bearings 7, 8 and gears 2, 3.
and between the bearings 7a, 8a and the gears 2, 3, respectively. These side plates 16, 16a are
It comes into contact with the sides of gears 2 and 3,
As shown in FIG. 2, there are a low pressure chamber 21, a first pressure chamber 22, and a second pressure chamber between the bearings 7 and 8 and the bearings 7a and 8a.
Seal grooves 25, 26a, 26b, 26c forming the pressure chamber 23 and two intermediate chambers 24a, 24b,
It has 26d.

Figure 2 will be described below.

The seal groove 25 is formed in a figure eight shape along the circumference of the shafts 4 and 5, and an endless seal member 27 is inserted therein. The low pressure chamber 21 is formed around the shafts 4 and 5 surrounded by the endless seal member 27, and is constantly connected to the tank, although not shown. Seal groove 26
a, 26b, 26c, and 26d are formed radially from the centers of the drive shafts 4 and 5 at four appropriate locations in the seal groove 25, and are connected to the seal groove 25 and the inner hole 12. These seal grooves 26a, 26b, 2
6c, 26d have a U-shaped cross section as shown in FIG. 3, and have two lip portions 29a, 2
Ended seal members 28a, 28b, 2 having 9b
8c and 28d are inserted. First pressure chamber 22
is formed by a part 27b of the endless seal member 27 and endless seal members 28b and 28c, and is connected to the discharge port 10. The second pressure chamber 23 includes a portion 27a of the endless seal member 27 and an end seal member 28.
a and 28d, and is connected to the suction port 9. The two intermediate chambers 24a and 24b are located between the first pressure chamber 22 and the second pressure chamber 23, and the end sealing member 2
7 part 27c and the end seal members 28a, 28
b, a portion 27d of the end seal member 27, and the end seal members 28c, 28d, respectively, and the gear 2,
Connect to the side of the tip of tooth No.3. Since the endless seal member 27 is arranged along the axes 4 and 5, the area on which the fluid pressure from the first pressure chamber 22 acts is minimized. Also, the end seal members 28a, 2
8b, 28c, 28d respectively connect their lip portions 29a, 29b to two intermediate chambers 24a, 24b.
It is mounted facing the direction. Therefore, fluid flow from the first pressure chamber 22 toward the two intermediate chambers 24a, 24b is allowed, but the flow in the opposite direction is interrupted. It functions as a so-called check valve.

The operation of this embodiment will be described below.

When the drive source drives the shaft 4 in the direction of the arrow, the gears 2 and 3 rotate in opposite directions, conveying the fluid in the inlet 9 to the outlet 10. The fluid pressure at the outlet 10 increases to a value depending on the load connected to the outlet 10. The fluid pressure of this discharge port 10 is
The first pressure chamber 22
Also acts to press the side plate 16 to the left. The pressure fluid flowing into the first pressure chamber 22 is transmitted through the lip portions 2 of the end seal members 28b and 28c.
9a is pressed in the side direction of the gears 2 and 3, and flows into the two intermediate chambers 24a and 24b. The pressure fluid that has flowed into the two intermediate chambers 24a and 24b is
Lip portion 29 of end sealing members 28a, 28d
a, 29d, and flows into the lip portions 29a, 29d.
Push open 29b. Therefore, the lip portion 29a
is pressed against the side surfaces of the bearings 7 and 8 and the lip portion 29b
are pressed against the bottoms of the seal grooves 26a and 26d. For this reason, the two intermediate chambers 24a, 24
The flow of fluid from b to the second pressure chamber 23 can be completely cut off. In other words, the pressure receiving area of the first pressure chamber 22 is substantially larger than the sum of the pressure receiving area of the first pressure chamber 22 and the two intermediate chambers 24a and 24b. Also, the fluid pressure at the tips of gears 2 and 3 is
The distribution decreases from the discharge port 10 toward the suction port 9. Therefore, the pressing force that presses the side plate 16 in the side direction of the gears 2 and 3 can be made stronger than the pressing force that acts from the side side of the gears, and as a result, the side plate 16 is connected to the discharge port 10. It comes into contact with the sides of the gears 2 and 3 with a pressing force depending on the load, and maintains the sealing properties of the sides of the gears.

Next, when the shaft 4 is driven in the opposite direction, the suction port 9 and the discharge port 10 are reversed. The high pressure fluid acting on the suction port 9 flows through the second pressure chamber 23 and the two intermediate chambers 2.
4a, 24b, the side plate 16 comes into contact with the side surfaces of the gears 2, 3 and maintains the sealing properties of the side surfaces of the gears, as in the case described above.

Although only the side plate 16 has been described in the above explanation of the structure and operation, the explanation is omitted for the side plate 16a as it is completely the same.

Thus, according to the present invention, another pressure chamber is formed between the pressure chamber connected to the high pressure side and the pressure chamber connected to the low pressure side, and the gap between this other pressure chamber and both pressure chambers is A sealing member having a check valve function is disposed in the gear, and the separate pressure chamber is connected to the pressure chamber connected to the high pressure side regardless of the direction of rotation of the gear, so that a large pressure receiving area can be obtained. For this reason,
This has the effect of obtaining a gear pump or motor with good volumetric efficiency without causing fluid leakage at the side surface of the gear due to insufficient pressing force of the side plate.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an inventive pump according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A in FIG.
FIG. 3 is a sectional view taken along line BB in FIG. 2. 1...Main body, 2, 3...Gear, 4, 5...Shaft,
7, 7a, 8, 8a... bearing, 21... low pressure chamber,
22...First pressure chamber, 23...Second pressure chamber, 24
a, 24b...Intermediate chamber, 27...Endless seal member, 28a, 28b, 28c, 28d...Ended seal member, 29a, 29b...Rip portion.

Claims (1)

[Claims] 1. A gear that opens in the main body and fits into the inner hole connected to the ports communicating with the high pressure side and the low pressure side, meshes and rotates, and seals the side of the gear by coming into contact with the side of the gear. A side plate is provided, and a first pressure chamber connected to the low pressure side and a second pressure chamber connected to the high pressure side are provided on the side of the side plate opposite to the side that contacts the side surface of the gear, and the first pressure chamber is connected to the high pressure side. In a gear pump or motor having two intermediate chambers between a chamber and a second pressure chamber, a first chamber is provided between the intermediate chamber and the first pressure chamber and between the intermediate chamber and the second pressure chamber. A gear pump or motor characterized in that a sealing member is disposed that allows fluid flow only from the pressure chamber and the second pressure chamber toward the intermediate chamber.