JPS6329114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an improvement in the seal on the side of a gear of a reversibly operable gear pump or motor.

[Conventional technology]

Conventionally, a gear pump or motor has a side plate or a bearing box that is movable in the axial direction of the gear on the side of the gear, and low pressure and high pressure are applied to the side of the side plate or bearing box that is opposite to the side that contacts the side of the gear. A pressure chamber is provided where the fluid pressure of This is done by balancing the conditions such that the pressing force is strong.

As this type of technology, there are Japanese Patent Application Laid-open Nos. 50-108605 and 52-26606. These two technologies are
A high pressure chamber connected to a hole on the high pressure side, a low pressure chamber connected to a hole on the low pressure side, and an intermediate pressure chamber on which a pressure intermediate between the high pressure side and the low pressure side acts are provided in the side plate or the bearing box. . However, with this technology, when the discharge oil pressure of the gear pump and motor or the supply oil pressure becomes high, the pressing force from the oil pressure from the gear side becomes stronger, so the sealing force between the side of the gear and the side plate or the side of the bearing box increases. decreases. When the sealing force is reduced in this way, a portion of the fluid on the high pressure side flows out from the high pressure side to the low pressure side, which has the disadvantage of reducing volumetric efficiency.

As a technology that solved this problem,
There is number 34763. Similar to the two technologies mentioned above, this technology consists of a high pressure chamber connected to the supply hole on the high pressure side, a low pressure chamber connected to the supply hole on the low pressure side, and a separate chamber between the high pressure chamber and the low pressure chamber. It has a structure with a chamber. This technology takes advantage of the fact that when a gear pump or motor is operated, the side plate is moved to the low pressure side by the hydraulic pressure, and is connected to the high pressure side, thereby creating a force that presses the side plate. This is to ensure that Note that a part of the fluid supplied from the high pressure side acts on the sealing members forming each pressure chamber to ensure sealing force.

[Problem that the invention seeks to solve]

In the conventional technology described above, when a gear pump or motor is operated, a gap is created between the side plate and the main body by the pressing force of the fluid pressure on the high pressure side, and this gap is used to connect the high pressure side and one It connects the room. Therefore, if pressure fluctuations occur during operation of the gear pump or motor, pressure transmission is likely to be delayed. Therefore, whenever a pressure fluctuation occurs during operation of the gear pump or motor, the sealing force on the side of the gear decreases. Therefore, the volumetric efficiency tends to decrease.

[Means for solving problems]

Means of the present invention for solving the above-mentioned problems is provided with a gear that is opened in the main body and rotates by fitting into and meshing with an inner hole to which ports communicating with the high pressure side and the low pressure side are respectively connected. a side plate that seals the side surface of the gear by contacting the side surface of the gear, and a first side plate formed around the shaft of the gear and held at a constant low pressure on the side of the side plate opposite to the side that abuts the side surface of the gear. a pressure chamber, a second pressure chamber connected to the high pressure side, a third pressure chamber connected to the low pressure side, and a fourth pressure chamber provided between the second pressure chamber and the third pressure chamber; In a gear pump or motor in which an endless seal member is arranged between a first pressure chamber, a second pressure chamber, a third pressure chamber, and a fourth pressure chamber, fluid flow is allowed only in one direction, and one end is connected to the endless seal member. An end sealing member that abuts the member and whose other end abuts the inner hole of the main body is provided between the second pressure chamber and the fourth pressure chamber, between the third pressure chamber and the fourth pressure chamber, or both. Second
A gear pump or motor, characterized in that it is installed in a direction that allows flow from a pressure chamber and a third pressure chamber toward a fourth pressure chamber.

[Effect]

In the present invention having the above means, the second pressure chamber, the third pressure chamber, and The fourth pressure chamber is connected to one of the high pressure sides. In addition, the passage area at the time of connection is
Since the entire width of the end sealing member is ensured, the sealing force on the side surface of the gear can reliably follow pressure fluctuations during operation.

〔Example〕

Hereinafter, the diagrams showing the gear pump according to the present invention will be described.

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
The rotation direction shown in the figure changes depending on the rotation direction of the gears 2 and 3. ) has an inner hole 12 that is open. This inner hole 1
Reference numeral 2 has a shape in which two circular inner holes 11 and 11a are connected at the center, and the suction port 9 and the discharge port 10 are opened at this connection portion. End cover 13
is fixed to the main body 1 with a plurality of bolts (not shown) after being positioned with pins 15 and 15a provided at the right end of the main body 1, and the gears 2 and 3, a side plate 20 to be described later, and the gears 2, The rightward movement of the bearings 7 and 8 of the shafts 4 and 5 of No. 3 is stopped. The end cover 14 is positioned with pins 18, 18a provided at the left end of the main body 1, and then fixed with a plurality of bolts (not shown), and has a hole 16 through which the shaft 4 of the gear 2 passes. , gears 2 and 3, a side plate 20a to be described later, and a bearing 7a,
8a stops moving to the left. A portion 4a of the shaft 4 that penetrates the hole 16 and projects to the outside is connected to a drive source such as an engine or a motor. When the drive source drives the shaft 4 clockwise as indicated by the arrow in FIG. 2, the gears 2 and 3 rotate in opposite directions. Due to this rotation, the gears 2 and 3
The fluid is conveyed to the discharge port 10. Note that 17 is a sealing member provided between the hole 16 and the shaft 4.

20, 20a are side surfaces 2a, 2 of the gears 2, 3
This is a side plate inserted between the side surfaces 21a, 21b, 22a, 22b of the bearings 7, 7a, 8, 8a. (Since the side plates 20 and 20a have the same configuration, only the side plate 20 will be described below.) One surface of this side plate 20 comes into contact with the side surfaces 2a and 3a of the gears 2 and 3, and Acts as a seal. The contact surfaces between the side plate 20 and the bearings 7, 8 are provided with seal grooves 23, 24, into which seal members for forming the first, second, third, and fourth pressure chambers shown in FIG. 2 are inserted. It has 25, 26, and 27.

Figure 2 will be described below.

The seal groove 23 is formed in a figure 8 shape surrounding the shafts 4 and 5, and an endless seal member 28 is inserted therein. The first pressure chamber 29 includes the endless seal member 28
It is surrounded by and formed around the shafts 4 and 5, and is always connected to the low pressure side. Seal groove 24, 25, 26, 2
7 is formed radially and linearly from the seal groove 23, and has a U-shaped cross section as shown in FIG.
0d has been inserted. The second pressure chamber 31 has an inner hole 1
2, a part 28b of the endless seal member 28, and the end seal members 30a, 30b, and are always connected to the discharge port 10. The third pressure chamber has an inner hole 12
, a part 28d of the endless seal member 28, and the end seal members 30c and 30d, and are always connected to the suction port 9. The fourth pressure chambers 33a, 33b include the inner hole 12 and the portions 28a, 28 of the endless seal member.
c and end seal members 30a, 30b, 30c,
30d, and communicates with the side surfaces of the tips of the gears 2 and 3 via cutouts 39a and 39b provided in a portion of the side plate 20. Note that the notch 3 of the side plate 20
Ends 39a', 39a'', 39b', 3 of 9a, 39b
9b'', approximately the center of the seal grooves 24, 25, 26, 27, and the center of the shafts 4, 5. Slightly larger.Ended seal member 30
a, 30b, 30c, 30d are the lip portions 3
4a and 34b are directed toward the fourth pressure chamber, and both ends thereof are pressed against the endless seal member 28 and the inner hole 12, and are inserted into the seal grooves 24, 25, 26, and 27. Therefore, the fluid pressure generated at the discharge port 10 when the shaft 4 is driven in the direction of the arrow in FIG.
By pressing the lip portion 34a of the gears 2 and 3 in the direction of the end surfaces of the gears 2 and 3, the pressure fluid in the second pressure chamber flows into the fourth pressure chamber 3.
3a and 33b. When the fluid pressure in the fourth pressure chamber acts on the lip portions 34a, 34b of the end seal members 30c, 30d, the lip portions 34a, 34b open, and the fourth pressure chambers 33a, 33
It has a function of ensuring a sealing force between the third pressure chamber 32 and the third pressure chamber 32.

The operation of this embodiment will be described below.

When the drive source drives the shaft 4 in the direction of the arrow in FIG. 2, the gears 2 and 3 rotate in opposite directions (in the direction of the arrow in FIG. 2) and convey the fluid in the suction port 9 to the discharge port 10. The pressure of the fluid at the discharge port 10 is
It will rise depending on the load connected to it. Moreover, the fluid pressure of the discharge port 10 acts on the second pressure chamber 31 and the fourth pressure chambers 33a and 33b. Therefore, the axial pressing force acting on the side plate 20 is
A pressing force acts to the right from the sides a and 3a, and a pressing force acts from the second pressure chamber 31 and fourth pressure chambers 33a and 33b toward the side surface of the gear. The pressing force acting from the second pressure chamber toward the side surface of the gear is canceled out by the same pressing force acting from the side surface of the gear. The pressing force from the fourth pressure chambers 33a, 33b side to the side surface of the gear is determined by changing the angle θ as described above to the gear 2,
Since the circular pitch of the tooth No. 3 is slightly larger than the angle formed with the center, the force that presses the side plate against the side of the gear increases accordingly. Therefore, the side plate 20 comes into contact with the side surfaces 2a and 3a of the gears 2 and 3, and maintains an appropriate sealing force according to the load connected to the discharge port 10.

From the second pressure chamber 31 to the fourth pressure chamber 33a, 33b
The pressure fluid flowing into the first and third pressure chambers 29,
The endless seal member 28 and the end seal members 30c and 30d almost completely cut off leakage to the 32 side. That is, since the endless seal member 28 provided between the first pressure chamber 29 and the second and fourth pressure chambers 31, 33a, and 33b is integrally formed in a figure 8 shape,
Since it can be arranged as close as possible to the shafts 4 and 5, the area on which fluid pressure acts can be minimized. In addition, the fourth pressure chamber 33
The end sealing members 30c, 30d disposed between the third pressure chambers a, 33b have their lip portions 34a, 3
4b receives a pressing force in the opening direction due to fluid pressure, and also receives a pressing force to be crushed in the longitudinal direction. Therefore, the lip portions 34a, 3
4b is the fourth pressure chamber 33a, 33b and the third pressure chamber 3
The inner hole 12 and the endless seal member 28, and the end seal member 30c,
It acts to strengthen the contact force of 30d, and acts to prevent leakage of fluid from this contact portion. Note that the above-mentioned operation is the same for the side plate 20a, so a description of the operation of the side plate 20a will be omitted.

Since the above embodiment is a gear pump that can be operated reversibly, the end seal members are arranged at four locations, but in the case of a gear pump that does not operate reversibly, two of the end seal members may be omitted. . Furthermore, the same applies to gear motors.

〔Effect of the invention〕

As described above, the present invention provides an end seal member that allows fluid flow in only one direction.
Disposed between each of the pressure chamber and the third pressure chamber and the fourth pressure chamber, and allows fluid to flow only from each of the second pressure chamber and the third pressure chamber toward the fourth pressure chamber. It is something. Therefore, pressure fluctuations that occur during operation of the gear pump or motor are transmitted from the second pressure chamber or the third pressure chamber to the fourth pressure chamber through the passage spanning the entire width of the end sealing member, so that the pressure fluctuations that occur during operation are transmitted from the second pressure chamber or the third pressure chamber to the fourth pressure chamber. The sealing force on the side of the gear can be quickly changed in response to pressure fluctuations. Therefore, its volumetric efficiency can be improved. In addition, since the end seal member is arranged, the structure can be simplified.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a gear pump according to the present invention. FIG. 2 is a sectional view taken along line AA in FIG. FIG. 3 is a sectional view taken along line BB in FIG. 1...Body, 2,3...Gear, 4,5...Shaft, 7,7
a, 8, 8a...Bearing, 9...Suction port, 10...Discharge port, 12...Inner hole, 23-27...Seal groove, 28...
Endless seal member, 29...first pressure chamber, 30a-3
0d...Ended seal member, 31...Second pressure chamber, 32
...Third pressure chamber.

Claims (1)

[Claims] 1 A side plate that opens in the main body and is equipped with a gear that fits into an inner hole connected to an opening that communicates with the high-pressure side and the low-pressure side, and that meshes and rotates, and that comes into contact with the side surface of this gear to seal the side surface of the gear. a first pressure chamber that is always maintained at a low pressure and is formed around the shaft of the gear, and a second pressure chamber that is connected to the high pressure side, on the opposite side of the side plate that contacts the side surface of the gear. and a third pressure chamber connected to the low pressure side, and a fourth pressure chamber is provided between the second pressure chamber and the third pressure chamber, and a fourth pressure chamber is provided between the first pressure chamber, the second pressure chamber, and the third pressure chamber. In a gear pump or motor in which an endless seal member is arranged between a chamber and a fourth pressure chamber, fluid flow is allowed in only one direction, with one end abutting the endless seal member and the other end abutting the inner hole of the main body. An end sealing member is placed between the second pressure chamber and the fourth pressure chamber, between the third pressure chamber and the fourth pressure chamber, or between the second pressure chamber and the fourth pressure chamber.
A gear pump or motor, characterized in that it is installed in a direction that allows flow from a pressure chamber and a third pressure chamber toward a fourth pressure chamber.