JP4593531B2 - Pump unit with seal ring lubrication structure - Google Patents

Description

  The present invention relates to a pump unit having a lubrication structure for a seal ring.

For example, at a gas station such as a gas station, fuel oil is supplied from an underground tank to a vehicle or the like using a pump unit built in the meter (see Patent Document 1).
As is well known, the fuel oil may be in a state where gas such as gas or air vaporized in the transport process is mixed as bubbles. Therefore, at the time of the refueling, the fuel oil is separated into a gas liquid and a liquid containing a gas by using a separation device.
Japanese Patent Publication No. 5-50593 (first and second pages)

  Incidentally, in the pump unit, it is important to lubricate the rotary shaft of the pump. In particular, lubrication of the seal ring that seals between the rotary shaft of the pump and the casing on the side where the driving force is input to the rotary shaft is important.

  As a method of lubricating the seal ring, for example, there is a method of filling a lubricant such as grease. However, with such a method, it is unavoidable that grease is lost or lost over time, and it is difficult to perform sufficient lubrication.

  On the other hand, Patent Document 1 discloses a structure in which fuel oil is sprinkled on a rotating shaft of a pump from above. However, it is not disclosed to lubricate the rotating shaft using fuel oil.

  Therefore, a main object of the present invention is to provide a pump unit having a seal ring lubrication structure that can reliably perform lubrication of the seal ring with a simple structure using fuel oil.

  As a lubricating structure of the rotating shaft by the fuel oil, it is conceivable to lubricate the seal ring by injecting the gas liquid from the separation device from above in a state of communication with the atmosphere.

  However, in this case, when the pump is stopped, the gas liquid from the separation device falls into the separation chamber, so that the liquid level in the liquid phase part of the separation chamber rises, and therefore the space volume in the gas phase part of the separation chamber decreases. When a large amount of gas / liquid is introduced into the separation chamber when the pump is restarted, fuel oil may be blown out from the atmosphere opening (air vent).

  In addition, when the rotating shaft is lubricated with fuel oil, the fuel oil such as gasoline has a very low viscosity, so when the pump stops, the fuel oil falls from around the rotating shaft, and the pump is restarted. Sometimes sufficient lubrication is not possible.

  Accordingly, another object of the present invention is to provide a pump unit having a sealing ring lubrication structure that lubricates the rotating shaft with fuel oil at the moment when the pump is restarted and that does not cause the fuel oil to blow off from the air vent. Is to provide.

  In order to achieve the main object, a pump unit having a seal ring lubrication structure of the present invention comprises a gas liquid and a liquid, which are liquids containing gas by swirling fuel oil discharged from a rotary pump. A separation device for separating the gas, a separation chamber for receiving and storing the gas liquid separated by the separation device from above, and separating the gas therefrom; and the pump is provided in a casing; A pump unit having a seal ring lubrication structure that seals a gap between the casing and the casing on a side where a driving force is input to the rotary shaft, wherein fuel oil from the pump is discharged by the pump, and the seal ring And a discharge passage for discharging the fuel oil in the storage space to the separation chamber.

  According to the present invention, since the fuel oil is pumped by the pump exhaust pressure and lubricated, the seal ring can be reliably lubricated with the fuel oil supplied by the pump itself. In addition, since it is not necessary to use a lubricant such as grease separately, frequent maintenance and the like are unnecessary, which is economical.

In order to achieve the other object, in the present invention, it is preferable that the discharge passage opens in the accommodating space and opens in a liquid phase portion that does not communicate with the atmosphere of the separation chamber.
According to such an aspect, since the discharge passage is opened in the liquid phase portion that does not communicate with the atmosphere of the separation chamber, the space in which the pump and the rotation shaft are accommodated does not communicate with the gas phase portion of the separation chamber. It is a sealed space that does not communicate with the atmosphere. Therefore, even if the pump is stopped, the fuel oil above the liquid level in the separation chamber does not flow into the separation chamber. That is, since the fuel oil in the seal portion of the rotating shaft does not fall, when the pump is stopped and restarted, better lubricity can be exhibited than at the beginning of the restart.
Further, since the discharge passage is not communicated with the atmosphere, as described above, the fuel oil does not flow into the separation chamber when the pump is stopped, so that there is no possibility that the liquid level in the liquid phase portion of the separation chamber is significantly increased. . Therefore, the space volume of the gas phase part of the separation chamber does not decrease, and there is no possibility that a large amount of gas liquid is suddenly introduced into the separation chamber when the pump is restarted. There is no risk of spilling fuel oil.

In the present invention, the casing includes a bearing that rotatably supports the rotating shaft, and a cylindrical portion that accommodates the pump, the bearing, and a seal ring, and the introduction passage is surrounded by the cylindrical portion. It is preferably formed in a space.
According to this aspect, lubrication is further ensured.

In the present invention, it is preferable that the introduction passage is formed by a groove formed along an axial direction on a surface of the bearing in contact with the rotation shaft.
According to this aspect, the lubrication of the bearing portion is ensured together with the seal ring. Further, the structure of the introduction passage is simplified, and the cost can be reduced.

In the present invention, the gas-liquid passage for guiding the gas-liquid discharged from the separation device to the liquid phase part of the separation chamber while maintaining a state in which the gas-liquid is not communicated with the atmosphere is further provided, and the gas-liquid passage, the storage space, It is preferable that the communication passage and the gas-liquid passage that are open to form a discharge passage.
According to this aspect, since the gas-liquid passage is used as a part of the discharge passage, the structure of the discharge passage is simple and the cost can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Lubrication system:
First, an example of an oil supply system in which the present pump unit is used will be described.

As shown in FIG. 1, the oil supply system includes an underground tank 1, a pipe 2, a pump unit 3, a solenoid valve 4, a flow meter 5, a hose 6, and a nozzle 7.
When the nozzle 7 is inserted into the fueling port of the vehicle and fueling is started, the fuel oil F is pumped up from the underground tank 1 embedded in the fueling station via the pipe 2 by the pump unit 3 and discharged from the nozzle 7.

  As described above, since gas such as vaporized gas or air may be mixed in the fuel oil F, the gas mixed in the fuel oil F is removed by the pump unit 3, and the gas is removed. Only the liquid L passes through the solenoid valve 4, the flow meter 5, the hose 6, and the nozzle 7 and is supplied to the vehicle.

Pump unit 3:
Next, a schematic configuration of the pump unit 3 will be described.
Flow of fuel oil F and liquid L;
The pump unit 3 includes a rotary pump 20. When the pump 20 is activated, the fuel oil F supplied from the underground tank 1 through the pipe 2 to the pump unit 3 is sent from the inlet 10 of the pump unit 3 to the primary filter 11 (see FIG. 2A).

  The fuel oil F passes through the first check valve 12 from the primary filter 11, is sucked into the pump 20 from the suction side 20a of the pump 20, and is discharged from the discharge side 20b of the pump 20 to the separation device 31 (see FIG. 2B). ).

  The separation device 31 swirls the fuel oil F discharged from the discharge side 20b of the pump 20 and separates it into gas liquid FA and liquid L, which are liquids containing gas A (see FIG. 3A).

The separator 31 shown in FIG. 3A swirls the fuel oil F fed from the pump 20 in the separator 31 and collects the liquid L outward in the radius and the gas liquid FA in the radius due to the difference in centrifugal force. Gather toward you. Thereby, the liquid L and the gas liquid FA are separated (see, for example, Japanese Patent Publication No. 4-15399).
The liquid L separated by the swirling is sent to the secondary filter 32 in FIG. On the other hand, the gas liquid FA is led out to the gas liquid passage 35.

  The liquid L separated from the fuel oil F passes through the secondary filter 32, passes through the second check valve 33, and is supplied from the outlet 34 to the hose 6 through the electromagnetic valve 4 and the flow meter 5 (FIG. 3B). And FIG. 4).

Flow of gas-liquid FA;
The gas-liquid FA led out to the gas-liquid passage 35 is sent to the separation chamber 40. The separation chamber 40 stores the gas liquid FA. As a result, the liquid L accumulates in the lower liquid phase portion 40a and is separated into the liquid L in the liquid phase portion 40a and the gas A in the gas phase portion 40b (see FIG. 5B).
The liquid L separated by the separation chamber 40 is returned to the suction side 20a of the pump 20 through the first return passage 41 and the second return passage 42 (see FIGS. 4 and 2B).
On the other hand, the gas phase part 40b in the upper part of the separation chamber 40 communicates with the atmosphere via the air vent 45, and the gas A accumulated in the gas phase part 40b is discharged from the air vent 45 to the atmosphere (FIG. 2A). reference).

  Here, the gas-liquid passage 35 has an opening 35 a in the liquid phase portion 40 a of the liquid L accumulated in the separation chamber 40. Therefore, the gas-liquid FA discharged from the separation device 31 passes through the gas-liquid passage 35 and is guided to the liquid phase portion 40a of the separation chamber 40 while maintaining a state not communicating with the atmosphere.

First float valve V1;
A first float valve V <b> 1 is provided between the separation chamber 40 and the first return passage 41. The first float valve V1 includes a first float F1, and opens when the liquid L in the separation chamber 40 reaches a first predetermined amount. When the pump 20 is in operation, the liquid L passes through the first return passage 41. Then, the air passes through the second return passage 42 and is sucked into the suction side 20a of the pump 20. The first float F1 functions to keep the liquid level of the liquid phase portion 40a so as to be always higher than the position of the opening 35a of the gas-liquid passage 35. That is, the first float valve V1 keeps the liquid level of the liquid phase portion 40a at or above a predetermined lower limit level.

Second float valve V2;
On the other hand, the air vent 45 is provided with a second float valve V2. The second float valve V2 includes a second float F2. When the liquid L in the separation chamber 40 exceeds a second predetermined amount, the second float F2 rises and closes the air vent 45. This prevents the liquid L in the separation chamber 40 from being blown out from the air vent 45. Therefore, the second float valve V2 has a function of preventing the liquid L from blowing down when the liquid level of the liquid phase part 40a exceeds a predetermined upper limit level.

Pump 20:
As shown in FIG. 2B, the pump 20, the separation device 31, and the separation chamber 40 are provided in the casing 50 of the pump unit 3.

  In FIG. 2B and FIG. 3A, the pump 20 includes an internal gear pump configured by an internal gear 25, a partition plate 26 and an external gear 27 accommodated in a pump chamber 56, for example. The rotation centers of the internal gear 25 and the external gear 27 are eccentric, and the internal gear 25 is rotated by the rotation of the external gear 27, so that the fuel oil F between the external gear 27 and the internal gear 25 is sucked into the suction side 20a. From the outlet toward the discharge side 20b. A pulley 24 for inputting a driving force is fixed to the end of the rotating shaft 23 (FIG. 6) of the external gear 27.

Next, characteristic parts of the pump unit will be described.
As shown in FIG. 6, a gap 20 s is formed between the external gear 27 and the inner periphery of the pump chamber 56. A plurality of slits 28 are formed in the external gear 27 along the longitudinal direction X of the rotary shaft 23.

Cylindrical portion 55;
The casing 50 is a cylinder that accommodates a rotating shaft 23 that rotates the external gear 27, first and second bearings 51 and 52 made of a plain bearing such as a carbon bearing or a metal bearing, and a seal ring 53. A portion 55 is provided.
The cylindrical portion 55 holds first and second bearings 51 and 52 that rotatably support the rotating shaft 23. A first groove 21 is formed in the first bearing 51. The first groove 21 includes a groove 21 a formed in the radial direction on the surface in contact with the back surface 27 a of the external gear 27 and a groove 21 b formed along the axial direction X on the surface in contact with the rotation shaft 23. The first groove 21 of the first bearing 51 communicates with the gap 20 s of the pump 20. Note that a liner (not shown) is inserted in the gap 20s, and actually the gap 20s is much narrower than the state shown in the drawing.
The second bearing 52 is provided with a second groove 22 formed along the axial direction X on the surface in contact with the rotary shaft 23.

  A communication space 55 s surrounded by the cylindrical portion 55 is formed between the first bearing 51 and the second bearing 52. In the cylindrical portion 55, an accommodation space 54 for accommodating the seal ring 53 is formed on the side where the driving force of the rotating shaft 23 is input (pulley 24 side), that is, on the pulley 24 side of the second bearing 52. Yes. Therefore, the accommodation space 54 communicates with the pump chamber 56 through the second groove 22, the communication space 55s, the first groove 21, and the gap 20s.

Introduction passage:
When the external gear 27 (FIG. 2B) is rotated by the rotary shaft 23, the internal gear 25 is rotated by the rotation of the external gear 27, and a part of the fuel oil F passes through the slit 28 into the gap 20 s in the pump chamber 56. Also leaked. The fuel oil F in the gap 20s passes through the first groove 21 of the first bearing 51 and is sent to the communication space 55s. The fuel oil F is supplied from the communication space 55 s to the accommodation space 54 through the second groove 22 of the second bearing 52.
Therefore, the first groove 21 of the first bearing 51, the communication space 55s, and the second groove 22 of the second bearing 52 accommodate the fuel oil F from the pump 20 by accommodating the seal ring 53 by the exhaust pressure of the pump 20. An introduction passage leading to the space 54 is configured. When the fuel oil F is pumped through the introduction passage, the bearings 51 and 52 and the seal ring 53 are lubricated.

Discharge passage:
The casing 50 is formed with a narrow communication passage 36 that opens to the gas-liquid passage 35 and the accommodation space 54. The fuel oil F supplied to the storage space 54 passes through the communication passage 36 and the gas-liquid passage 35 and is discharged to the liquid phase portion 40a of FIG. 1 (see FIG. 5B).
Therefore, the merging portion of the communication passage 36 and the communication passage 36 in the gas-liquid passage 35 and the lower portion thereof constitute a discharge passage for discharging the fuel oil F in the accommodation space 54 to the separation chamber 40.

As described above, the gas-liquid passage 35 opens in the liquid phase portion 40a of the liquid L accumulated in the separation chamber 40, and therefore the inside of the gas-liquid passage 35 is blocked from the atmosphere. Therefore, it is possible to prevent oil from dropping in the separation device 31 above the liquid level of the separation chamber 40 when the pump 20 is stopped, and the pump chamber 56 communicating with the communication passage 36 via the gas-liquid passage 35. Oil spillage can be prevented.
Therefore, the gas liquid FA and the fuel oil F do not flow into the separation chamber 40 even when the pump is stopped, and the liquid level of the liquid phase portion 40a is unlikely to rise, thereby preventing the volume reduction of the gas phase portion 40b of the separation chamber 40. be able to.
Further, since part or all of the rotating shaft 23 is always immersed in the fuel oil F, even when the pump 20 is restarted later, the lubrication of the seal ring 53 can be maintained from the beginning of the restart.
The cylindrical portion 55 is continuously provided so as to connect between a pair of opposing wall portions (wall surfaces orthogonal to the rotation shaft 23) 100, 101 of the casing 50 of FIG. Since the cylindrical portion 55 serves as a reinforcing material, when the end surfaces of both the wall portions 100 and 101 are milled, the wall portions 100 and 101 are not likely to be bent by the cutting pressure of the end mill. Is significantly improved.

Operation of pump unit 3:
During operation of the pump 20;
When the pump 20 is operated, the pressure on the discharge side 20 b of the pump chamber 56 increases, and the fuel oil F is separated into the gas liquid FA and the liquid L by the separation device 31. The separated liquid L passes through the secondary filter 32 and is supplied from the second check valve 33 to the hose 6 through the outlet 34.
On the other hand, the gas-liquid FA separated by the separation device 31 is conveyed to the liquid phase portion 40a of the separation chamber 40 through the gas-liquid passage 35 and separated into the gas A and the liquid L.

  On the other hand, a part of the fuel oil F in the pump chamber 56 flows from the slit 28 of the external gear 27 into the gap 20 s and passes through the first and second grooves 21 and 22 of the first and second bearings 51 and 52. To the seal ring 53 in the accommodating space 54. The fuel oil F in the storage space 54 flows into the liquid phase portion 40 a of the separation chamber 40 from the communication passage 36 through the gas-liquid passage 35 while maintaining the lubricity of the seal ring 53.

When the pump 20 is stopped;
When the operation of the pump 20 is stopped, the supply of the liquid L from the outlet 34 to the hose 6 is stopped.
Here, even if the pump 20 is stopped, only the gas phase part 40b communicating with the upper part of the separation chamber 40 via the air vent 45 communicates with the atmosphere, and the liquid phase part 40a and the liquid phase part. The gas-liquid passage 35 and the communication passage 36 communicating with 40a are blocked from the atmosphere. Therefore, the fuel oil F in the pump chamber 56 does not flow down from the communication passage 36 and the gas-liquid passage 35 toward the liquid phase portion 40a.
Accordingly, since the fuel oil F in the cylindrical portion 55 of FIG. 6 does not flow down, the lubricity of the seal ring 53 can be maintained. Therefore, when the pump is restarted, better lubricity than the initial restart is achieved. can get.
Further, when the pump 20 is stopped, the gas / liquid FA and the fuel oil F do not flow down from the gas / liquid passage 35 and the communication passage 36 into the separation chamber 40 and the liquid level in the liquid phase portion 40a does not rise significantly. At the time of starting, the liquid L from the air vent 45 is not blown out.

As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily consider various changes and modifications within the obvious range by referring to the present specification.
For example, in the above description, the separation device is set horizontally, but may be provided in the vertical direction.
Moreover, as a pump, you may use what is called a trochoid pump using the trochoid tooth profile other than the internal gear pump which provided the above-mentioned partition plate.
Accordingly, such changes and modifications are to be construed as within the scope of the present invention as defined by the claims.

  The present invention can be applied to a pump unit having a seal ring lubrication structure in a gas station or the like.

It is a schematic block diagram which shows the oil supply system using the pump unit concerning one Example of this invention. It is a schematic sectional drawing which shows a pump unit. It is a schematic sectional drawing which shows a pump unit. 4A is a schematic front view of the pump unit, and FIG. 4B is a schematic cross-sectional view thereof. It is a schematic sectional drawing which shows a pump unit. It is a general | schematic fragmentary sectional view which shows the lubrication structure of a seal ring.

Explanation of symbols

3: Pump unit 20: Pump 21: First groove (a part of the introduction passage)
22: Second groove (part of the introduction passage)
23: Rotating shaft 31: Separating device 35: Gas-liquid passage (part of the discharge passage)
36: Communication passage (part of discharge passage)
40: Separation chamber 40a: Liquid phase part 40b: Gas phase part 50: Casing 51: First bearing 52: Second bearing 53: Seal ring 54: Storage space 55: Cylindrical part 55s: Communication space (part of introduction passage)
A: Gas F: Fuel oil FA: Gas liquid L: Liquid

Claims (6)

Separation device for separating fuel gas discharged from a rotary pump into gas-liquid and liquid, which is a liquid containing gas, and a separation chamber for separating gas from the gas-liquid separated by the separation device And the pump is provided in the casing,
A pump unit having a lubricating structure of a seal ring that seals between the rotary shaft of the pump and the casing on a side where a driving force is input to the rotary shaft;
Lubricating a seal ring having an introduction passage for introducing fuel oil from the pump to a storage space for housing the seal ring with a discharge pressure of the pump, and a discharge passage for discharging the fuel oil in the storage space to the separation chamber Pump unit with structure.   2. The pump unit having a seal ring lubrication structure according to claim 1, wherein the discharge passage opens into the accommodating space and opens in a liquid phase portion that does not communicate with the atmosphere of the separation chamber. 2. The casing according to claim 1, wherein the casing includes a bearing that rotatably supports the rotating shaft, and a cylindrical portion that houses the pump, the bearing, and a seal ring, and the introduction passage is surrounded by the cylindrical portion. A pump unit having a lubrication structure of a seal ring formed in the space. 4. The pump unit according to claim 3, further comprising a seal ring lubrication structure in which the introduction passage is formed by a groove formed along an axial direction on a surface of the bearing in contact with the rotation shaft. The gas-liquid passage according to claim 1, further comprising a gas-liquid passage that guides the gas-liquid discharged from the separation device to a liquid phase part of the separation chamber while maintaining a state not communicating with the atmosphere.
A pump unit comprising: a communication passage that opens to the gas-liquid passage and the housing space; and a seal ring lubrication structure in which the gas-liquid passage forms the discharge passage.   4. The pump unit according to claim 3, wherein the cylindrical portion includes a seal ring lubrication structure that is continuously provided so as to connect between a pair of opposing wall portions of the casing.

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