JP2017025858A - Submerged motor-driven pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a submerged motor-driven pump facilitating maintenance management.SOLUTION: A submerged motor-driven pump 100 includes: a motor 1; a pump chamber 4 in which an impeller 3 driven by the motor 1 is disposed; an oil chamber 5 which is provided with a mechanism seal 6 having a sliding portion 6a, and disposed between the motor 1 and the pump chamber 4; an oil collecting portion 8 which is disposed between the motor 1 and the oil chamber 5; a fluid return path 9 which communicates the oil collecting portion 8 and the oil chamber 5; and a control valve 91 which is provided in the fluid return path 9, and can be electrically opened/closed. According to an operation state of the motor 1, open/close control of the control valve 91 is performed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a submersible electric pump.

  Conventionally, a small submersible electric pump including an oil chamber in which a mechanical seal is provided between the pump chamber and the motor is known so that the pressure water in the pump chamber does not enter the motor. However, this submersible electric pump has a disadvantage that pressure water, oil, or the like entering the oil chamber from the sliding portion may flow into the motor due to wear or surface roughness of the sliding portion of the mechanical seal.

  Therefore, in order to prevent pressure water, oil, etc. from flowing into the motor, a submersible pump that shuts off the power supply to the motor by installing a submersion detection sensor in the oil chamber and detecting the submersion in the oil chamber. (Submersible electric pump) has been proposed (see, for example, Patent Document 1). In addition, an additional immersion chamber is provided between the oil chamber and the motor to prevent the pressure water in the pump chamber and the oil in the oil chamber from entering the motor, so that the inundation detector can detect inundation in the immersion chamber. Based on this, a submersible pump (submersible electric pump) having a configuration that ensures a long time until the motor is de-energized has also been proposed (see, for example, Patent Document 2).

JP 2002-310091 A JP 2007-332825 A

  However, in the submersible pump (submersible electric pump) of the above-mentioned Patent Document 1, when the water detection sensor detects that the pressure water in the pump chamber has submerged in the oil chamber, the pressure water, oil, or the like flows into the motor. In order to minimize this, it is necessary to forcibly stop the submersible pump, pull it out of the water, remove the pump casing, the oil casing, etc., perform the maintenance work, and restore the pump. In this case, in order to continue the operation, it is necessary to have a spare submersible pump and take emergency measures with the spare submersible pump. For this reason, there is a problem that a lot of labor is required for maintenance.

  Moreover, in the submersible pump (submersible electric pump) of the above-mentioned patent document 2, since a submerged pool chamber is provided between the oil chamber and the motor, it is possible to ensure a long time until the motor is deenergized. However, the structure becomes complicated accordingly, and at the same time, the overall height of the pump increases and the size increases. In addition, when the inundation detector detects inundation into the inundation pool chamber, the submersible pump is forcibly stopped and pulled up from the water in the same manner as the submersible pump described in Patent Document 1 to perform maintenance work. Need to be restored. In this case, in order to continue the operation, an emergency response must be made with a spare submersible pump. For this reason, there is a problem that a lot of labor is required for maintenance.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a submersible electric pump that can be easily maintained.

  The submersible electric pump according to one aspect of the present invention is provided with a motor, a pump chamber in which an impeller driven by the motor is disposed, and a mechanical seal having a sliding portion, and is disposed between the motor and the pump chamber. The oil reservoir, the oil reservoir disposed between the motor and the oil chamber, the fluid return path that communicates between the oil reservoir and the oil chamber, and the fluid return path can be electrically opened and closed. The control valve is configured to perform opening / closing control of the control valve according to the operating state of the motor.

  In the submersible electric pump according to one aspect of the present invention, as described above, the fluid return path that communicates the oil reservoir and the oil chamber, and the control valve that is provided in the fluid return path and can be electrically opened and closed. The control valve is opened and closed according to the operating state of the motor. Thereby, since the control valve in the fluid return path can be opened according to the operating state of the motor, the oil that has flowed into the oil reservoir can be returned to the oil chamber via the fluid return path. As a result, it is possible to suppress the oil flowing into the oil reservoir from the oil chamber from being stored as it is, so that it is not necessary to perform maintenance work by removing the pump casing, the oil casing, and the like. Further, by providing the oil reservoir, it is possible to prevent oil from flowing into the motor bearing and flowing grease of the motor bearing even when oil rises. Moreover, it is not necessary to have a spare submersible pump in order to continue operation. As a result, maintenance and management of the submersible electric pump can be easily performed without requiring much labor and cost for maintenance.

  In the submersible electric pump according to the above aspect, the control valve is preferably configured to be closed when the motor is stopped. With this configuration, even when the submersible electric pump is moved or placed sideways when the submersible electric pump is stopped, the oil flows back from the oil chamber to the oil reservoir through the fluid return path. Can be prevented.

  In this case, preferably, the control valve is configured to be controlled to open when the motor is operated. If comprised in this way, the oil which flowed into the oil storage part can be returned to an oil chamber via a fluid return path at the time of operation of a submersible electric pump.

  In the configuration in which the control valve is controlled to be closed when the motor is stopped, the control valve is preferably configured to be opened for a predetermined time after the motor is stopped. If comprised in this way, the oil which flowed into the oil storage part can be returned to an oil chamber via a fluid return path, after the operation of a submersible electric pump stops.

  In this case, preferably, the control valve is configured to be controlled to be closed after a predetermined time has elapsed after the motor is stopped. If comprised in this way, after returning the oil which flowed into the oil storage part to an oil chamber via a fluid return path, since a control valve is closed, while being able to return oil to an oil chamber, an underwater electric pump It is possible to prevent the oil from flowing back to the oil reservoir after the oil is returned at the stop.

  In the submersible electric pump according to the above aspect, the mechanical seal is preferably provided on the pump chamber side of the oil chamber. If comprised in this way, the water immersion from a pump chamber to an oil chamber can be suppressed effectively. In addition, when a mechanical seal is provided on the pump chamber side of the oil chamber and no mechanical seal is provided on the oil reservoir side of the oil chamber, the structure of the mechanical seal can be simplified and the mechanical seal is provided on the oil reservoir side. Since the seal is not provided, the height dimension of the submersible electric pump can be reduced.

  The submersible electric pump according to the above aspect preferably further includes a pump mechanism that is provided in the oil reservoir and sends fluid to the oil chamber side. If comprised in this way, since a pressure can be applied downward with respect to the fluid which flows in into an oil storage part from an oil chamber, the oil rising from an oil chamber can be suppressed. Further, since pressure can be applied to the fluid flowing into the oil reservoir so as to guide it to the fluid return path, the oil that has flowed into the oil reservoir can be returned to the oil chamber more effectively.

  In the configuration in which the mechanical seal is provided on the pump chamber side of the oil chamber, it is preferable to further include a first seal that is provided at the oil chamber side end of the oil reservoir and seals the oil chamber. If comprised in this way, it can suppress effectively that oil penetrate | invades into an oil storage part from an oil chamber.

  The submersible electric pump according to the above aspect preferably further includes a second seal that is provided at the motor side end of the oil reservoir and seals the oil reservoir. If comprised in this way, it can suppress effectively that the oil which flowed into the oil storage part flows into a motor.

  ADVANTAGE OF THE INVENTION According to this invention, as mentioned above, the submersible electric pump which can perform maintenance management easily can be provided.

It is the schematic which showed the submersible electric pump by 1st Embodiment of this invention. It is a flowchart for demonstrating the oil return control process of the submersible electric pump by 1st Embodiment of this invention. It is a flowchart for demonstrating the oil return control process of the submersible electric pump by the modification of 1st Embodiment of this invention. It is the schematic which showed the submersible electric pump by 2nd Embodiment of this invention. It is the schematic which showed the submersible electric pump by 3rd Embodiment of this invention. It is the figure which showed the pump mechanism part of the submersible electric pump by 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
(Configuration of submersible electric pump)
A first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the submersible electric pump 100 according to the first embodiment is a mechanical seal having a motor 1, a rotating shaft 2, an impeller 3, a pump chamber 4, an oil chamber 5, and a sliding portion 6a. 6, an annular body 7, an oil reservoir 8, and a fluid return path 9. A control unit 10 is connected to the submersible electric pump 100. The submersible electric pump 100 is a vertical submersible electric pump in which the rotary shaft 2 extends in the vertical direction.

  The motor 1 includes a stator 11 and a rotor 12. The motor 1 is sealed so that water from the outside does not enter. Further, the motor 1 is configured to rotationally drive the impeller 3 (rotating shaft 2).

  The stator 11 has a coil. The stator 11 is disposed on the outer periphery of the motor 1. Further, the power is supplied from the cable 13 to the coil of the stator 11 so that a magnetic field is generated. The rotor 12 is disposed inside the motor 1 so as to face the stator 11. The rotor 12 is attached to the rotating shaft 2. The rotor 12 is configured to rotate by a magnetic field from the stator 11.

  The rotating shaft 2 is configured to rotate by driving the motor 1. The rotary shaft 2 is configured to transmit the drive of the motor 1 to the impeller 3. The rotating shaft 2 is rotatably supported by bearings 21 and 22. The bearing 21 is provided on the opposite side of the motor 1 (the side opposite to the pump chamber 4). The bearing 22 is provided on the load side (pump chamber 4 side) of the motor 1. The rotating shaft 2 is arranged so as to extend from the motor 1 through the oil chamber 5 to the pump chamber 4. An impeller 3 is attached to the end of the rotary shaft 2 on the pump chamber 4 side.

  The impeller 3 is disposed in the pump chamber 4. Moreover, the impeller 3 gives speed energy to water by rotationally driving. And it is comprised so that pressure may be acted on and sent to water, when the velocity energy of water is converted into pressure energy within the pump chamber 4. That is, by the rotational drive of the impeller 3, water is sucked up from the water suction port 41 of the pump chamber 4, and the water sucked up from the discharge port 42 is discharged.

  The oil chamber 5 is disposed between the motor 1 and the pump chamber 4, and the oil chamber 5 is filled with oil. A wall 51 is disposed on the motor 1 side of the oil chamber 5. Further, a mechanical seal 6 having a sliding portion 6a is provided in the oil chamber 5. The sliding portion 6a is lubricated by the oil filled in the oil chamber 5, and the sliding portion 6a is seized. It is configured not to be cooled. Specifically, the mechanical seal 6 is provided on the oil chamber 5 on the pump chamber 4 side. That is, the sliding part 6a of the mechanical seal 6 is provided on the load side (pump chamber 4 side). The sliding portion 6 a on the load side (pump chamber 4 side) of the mechanical seal 6 is provided so that the pressure water in the pump chamber 4 does not enter the oil chamber 5.

  The mechanical seal 6 includes a fixed member 61, a rotating member 62, a spring 63, and a support member 64. The fixing member 61 has a sliding surface 611. The rotating member 62 has a sliding surface 621. The fixing member 61 is fixed to the housing of the oil chamber 5. The fixing member 61 is formed in an annular shape so as to surround the rotating shaft 2. The rotating member 62 is attached to the rotating shaft 2. That is, the rotating member 62 is configured to rotate together with the rotating shaft 2. The rotating member 62 is formed in an annular shape so as to surround the rotating shaft 2. The rotating member 62 is urged toward the fixed member 61 by a spring 63. The spring 63 is in contact with the rotating member 62 on the pump chamber 4 side, and is in contact with the support member 64 on the oil chamber 5 side.

  The support member 64 is configured to support the upper side of the spring 63. The support member 64 is attached to the rotary shaft 2. The support member 64 is formed in an annular shape.

  The fixed member 61 and the rotating member 62 are disposed so as to face each other in the axial direction of the rotating shaft 2. In the sliding part 6a, the sliding surface 611 of the fixing member 61 and the sliding surface 621 of the rotating member 62 are configured to slide relative to each other. Further, the oil in the oil chamber 5 slightly enters between the sliding surfaces 611 and 621. As a result, the sliding surfaces 611 and 621 are lubricated, cooled by oil so that the sliding surfaces 611 and 621 are not seized, and the sliding portion 6a (oil chamber 5) is sealed. Yes.

  The annular body 7 is provided so as to protrude from the wall 51 on the side opposite to the load side of the oil chamber 5 (the side opposite to the pump chamber 4) to the motor 1 side. The annular body 7 is provided in an annular shape so as to surround the rotation shaft 2 with a predetermined distance from the rotation shaft 2. A seal 71 is provided at the end of the annular body 7 on the oil chamber 5 side. As the seal 71, for example, an oil seal, a seal lip, or a seal having a mechanism for generating a thrust force on the load side such as an inclined rib or a groove at a lip portion that slides with the rotary shaft 2 is used. The seal 71 is disposed between the annular body 7 and the rotary shaft 2. The seal 71 is an example of the “first seal” in the claims.

  The oil reservoir 8 is surrounded by the annular body 7. The oil reservoir 8 is formed to extend toward the motor 1 so as to surround the rotating shaft 2. The oil reservoir 8 is disposed between the motor 1 and the oil chamber 5. The oil reservoir 8 is configured such that a fluid containing oil leaking from the seal 71 flows in. Further, the oil chamber 5 side end of the oil reservoir 8 is sealed with a seal 71. That is, the oil reservoir 5 side of the oil chamber 5 is sealed with the seal 71.

  Here, in the first embodiment, the fluid return path 9 is provided so as to communicate the oil reservoir 8 and the oil chamber 5. Specifically, the fluid return path 9 includes a hole 51 a provided in the wall 51 on the side opposite to the load of the oil chamber 5 (the side opposite to the pump chamber 4), and a hole 7 a provided in the annular body 7. Is formed to communicate with each other. That is, the fluid return path 9 is configured to return the fluid containing the oil in the oil reservoir 8 to the oil chamber 5. In addition, the fluid return path 9 is preferably configured by a pipe member such as a pipe or a tube, but may be configured such that an opening formed in an integral shape or a groove shape is sealed with a lid. That is, the fluid return path 9 only needs to be configured so that the oil reservoir 8 and the oil chamber 5 communicate with each other.

  In the first embodiment, a control valve 91 is provided in the fluid return path 9. The control valve 91 is configured to be opened and closed electrically. The control valve 91 is composed of, for example, an electromagnetic valve that opens and closes a valve by driving an electromagnet by energization. In addition, the control valve 91 is configured so that opening / closing control is performed by the control unit 10.

  The control unit 10 is connected to the submersible electric pump 100 via the cable 13. The control unit 10 is provided on a control panel for driving the submersible electric pump 100. The control unit 10 is configured to control the driving of the motor 1. The control unit 10 is configured to control the opening / closing operation of the control valve 91.

  Here, in the first embodiment, the control unit 10 is configured to perform opening / closing control of the control valve 91 in accordance with the operating state of the motor 1. Specifically, the control unit 10 is configured to control the control valve 91 to close when the motor 1 is stopped. Further, the control unit 10 is configured to control the control valve 91 so that it opens when the motor 1 is operated.

(Description of oil return control process)
Next, the oil return control process of the submersible electric pump 100 of the first embodiment will be described with reference to FIG. The oil return control process is performed by the control unit 10.

  When the submersible electric pump 100 (motor 1) is driven, the control valve 91 is opened in step S1. Thereafter, in step S2, it is determined whether or not driving of the submersible electric pump 100 (motor 1) is stopped. If the driving of the submersible electric pump 100 (motor 1) is not stopped, the determination in step S2 is repeated until the driving is stopped. If driving of the submersible electric pump 100 (motor 1) is stopped, the control valve 91 is closed in step S3. Thereafter, the oil return control process is terminated. As a result, when the submersible electric pump 100 (motor 1) is driven, the fluid containing the oil in the oil reservoir 8 can be returned to the oil chamber 5 (oil return).

(Effect of 1st Embodiment)
In the first embodiment, the following effects can be obtained.

  In the first embodiment, as described above, the fluid return path 9 that connects the oil reservoir 8 and the oil chamber 5 and the control valve 91 that is provided in the fluid return path 9 and can be electrically opened and closed are provided. The control valve 91 is configured to be opened and closed in accordance with the operating state of the motor 1. Thereby, since the control valve 91 in the fluid return path 9 can be opened according to the operating state of the motor 1, the oil that has flowed into the oil reservoir 8 can be returned to the oil chamber 5 via the fluid return path 9. it can. As a result, it is possible to suppress the oil flowing into the oil reservoir 8 from the oil chamber 5 from being stored as it is, so that it is not necessary to perform maintenance work by removing the pump casing, the oil casing, and the like. Further, by providing the oil reservoir 8, it is possible to prevent oil from flowing into the bearing 22 of the motor 1 and flowing grease of the bearing 22 of the motor 1 even when oil rises. Moreover, it is not necessary to have a spare submersible pump in order to continue operation. As a result, maintenance and management of the submersible electric pump 100 can be easily performed without requiring much labor and cost for maintenance.

  In the first embodiment, as described above, the control valve 91 is controlled to be closed when the motor 1 is stopped. Thus, when the submersible electric pump 100 is stopped, even when the submersible electric pump 100 is moved or placed sideways, the oil flows back from the oil chamber 5 to the oil reservoir 8 via the fluid return path 9. Can be prevented.

  Further, in the first embodiment, as described above, the control valve 91 is configured to be controlled to open when the motor 1 is in operation. As a result, during operation of the submersible electric pump 100, oil that has flowed into the oil reservoir 8 can be returned to the oil chamber 5 via the fluid return path 9.

  In the first embodiment, the mechanical seal 6 is provided on the oil chamber 5 on the pump chamber 4 side as described above. As a result, it is possible to effectively suppress water from the pump chamber 4 to the oil chamber 5. In addition, since the mechanical seal 6 is provided on the pump chamber 4 side of the oil chamber 5 and the mechanical seal 6 is not provided on the oil storage portion 8 side of the oil chamber 5, the configuration of the mechanical seal 6 can be simplified. Since the mechanical seal 6 is not provided on the oil reservoir 8 side, the height of the submersible electric pump 100 can be reduced and the amount of oil filled in the oil chamber 5 can be reduced.

  In the first embodiment, as described above, the seal 71 that is disposed at the oil chamber 5 side end of the oil reservoir 8 and seals the oil chamber 5 is provided. Thereby, it can suppress effectively that oil penetrate | invades into the oil storage part 8 from the oil chamber 5. FIG.

(Modification of the first embodiment)
Next, a modification of the first embodiment of the present invention will be described with reference to FIG.

  In the modification of the first embodiment, the control unit 10 is configured to control the control valve 91 to open for a predetermined time (for example, 30 seconds) after the motor 1 is stopped. The control unit 10 is configured to control the control valve 91 to close after a predetermined time (for example, 30 seconds) after the motor 1 is stopped.

(Description of oil return control process)
With reference to FIG. 3, the oil return control process of the submersible electric pump 100 of the modification of 1st Embodiment is demonstrated. The oil return control process is performed by the control unit 10.

  While driving the submersible electric pump 100, it is determined in step S11 whether or not the driving of the submersible electric pump 100 (motor 1) has been stopped. If the driving of the submersible electric pump 100 (motor 1) is not stopped, the determination in step S11 is repeated until the driving is stopped. If driving of the submersible electric pump 100 (motor 1) is stopped, the control valve 91 is opened in step S12.

  In step S13, it is determined whether or not a predetermined time (for example, 30 seconds) has elapsed since the control valve 91 was opened. That is, it is determined whether or not the control valve 91 is opened and the oil in the oil reservoir 8 is returned to the oil chamber 5 (oil return) for a predetermined time. The determination in step S13 is repeated until a predetermined time has elapsed.

  When the predetermined time has elapsed, the control valve 91 is closed in step S14. Thereafter, the oil return control process is terminated.

  The remaining configuration of the modification of the first embodiment is the same as that of the first embodiment.

(Effects of Modification of First Embodiment)
In the modification of the first embodiment, the following effects can be obtained.

  In the modification of the first embodiment, as described above, the control valve 91 is configured to be controlled to open for a predetermined time after the motor 1 is stopped. Thereby, after the operation of the submersible electric pump 100 is stopped, the oil that has flowed into the oil reservoir 8 can be returned to the oil chamber 5 via the fluid return path 9.

  Further, in the modified example of the first embodiment, as described above, the control valve 91 is configured to be controlled to close after a predetermined time has elapsed after the motor 1 is stopped. Thus, after the oil flowing into the oil reservoir 8 is returned to the oil chamber 5 via the fluid return path 9, the control valve 91 is closed, so that the oil can be returned to the oil chamber 5 and the underwater It is possible to prevent the oil from flowing back to the oil reservoir 8 after the oil is returned when the pump 100 is stopped.

  The remaining effects of the modification of the first embodiment are similar to those of the aforementioned first embodiment.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, unlike the first embodiment in which a seal 71 is provided on the oil reservoir 5 side of the oil reservoir 8, a configuration in which a seal 72 is provided on the motor 1 side of the oil reservoir 8 will be described.

  As shown in FIG. 4, the submersible electric pump 200 according to the second embodiment includes a motor 1, a rotary shaft 2, an impeller 3, a pump chamber 4, an oil chamber 5, and a mechanical seal having a sliding portion 6a. 6, an annular body 7, an oil reservoir 8, and a fluid return path 9. Further, the controller 10 is connected to the submersible electric pump 200. The submersible electric pump 200 is a vertical submersible electric pump in which the rotary shaft 2 extends in the up-down direction.

  Here, in 2nd Embodiment, as shown in FIG. 4, the seal | sticker 72 which seals the oil storage part 8 is provided in the motor 1 side end of the oil storage part 8. As shown in FIG. Specifically, a seal 72 is provided at the end of the annular body 7 on the motor 1 side. As the seal 72, for example, an oil seal, a seal lip, or a seal having a mechanism for generating a thrust force on the load side such as an inclined rib or a groove at a lip portion that slides with the rotary shaft 2 is used. The seal 72 is disposed between the annular body 7 and the rotating shaft 2. The seal 72 is an example of the “second seal” in the claims.

  A contact seal 511 is provided on the wall 51 between the oil chamber 5 and the oil reservoir 8. The contact seal 511 has a labyrinth structure. Thereby, the inflow of oil from the oil chamber 5 to the oil reservoir 8 is suppressed.

  Moreover, in 2nd Embodiment, it is comprised so that the opening / closing control of the control valve 91 may be performed according to the driving | running state of the motor 1. FIG.

  In addition, the other structure of 2nd Embodiment is the same as that of the said 1st Embodiment.

(Effect of 2nd Embodiment)
In the second embodiment, the following effects can be obtained.

  In the second embodiment, as in the first embodiment, a fluid return path 9 that communicates between the oil reservoir 8 and the oil chamber 5, and a control valve that is provided in the fluid return path 9 and can be electrically opened and closed. 91, and is configured such that the opening / closing control of the control valve 91 is performed according to the operating state of the motor 1. Thereby, maintenance and management of the submersible electric pump 200 can be easily performed without requiring much labor and expense for maintenance.

  Moreover, in 2nd Embodiment, as mentioned above, the seal | sticker 72 which is arrange | positioned at the motor 1 side end of the oil storage part 8 and seals the oil storage part 8 is provided. Thereby, it can suppress effectively that the oil which flowed into the oil storage part 8 flows into the motor 1. FIG.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, unlike the first and second embodiments, an example of a configuration in which a pump mechanism 81 is provided in the oil reservoir 8 will be described.

  As shown in FIG. 5, the submersible electric pump 300 according to the third embodiment includes a motor 1, a rotating shaft 2, an impeller 3, a pump chamber 4, an oil chamber 5, and sliding portions 6a and 6b. A mechanical seal 6, an annular body 7, an oil reservoir 8, and a fluid return path 9 are provided. Further, the controller 10 is connected to the submersible electric pump 300. The submersible electric pump 300 is a vertical submersible electric pump in which the rotary shaft 2 extends in the vertical direction.

  The oil chamber 5 is disposed between the motor 1 and the pump chamber 4, and the oil chamber 5 is filled with oil. A wall 51 is disposed on the motor 1 side of the oil chamber 5. An oil lifter 52 is provided around the rotation shaft 2 of the oil chamber 5. Also, a mechanical seal 6 having sliding portions 6a and 6b is provided in the oil chamber 5, and the sliding portions 6a and 6b are lubricated by the oil filled in the oil chamber 5, and the sliding portion It is comprised so that 6a and 6b may be cooled so that it may not burn. Specifically, the sliding portion 6 a on the load side (pump chamber 4 side) of the mechanical seal 6 is provided on the pump chamber 4 side of the oil chamber 5. That is, the sliding portion 6 a on the load side (pump chamber 4 side) of the mechanical seal 6 is provided so that the pressure water in the pump chamber 4 does not enter the oil chamber 5. A sliding portion 6 b on the side opposite to the load side of the mechanical seal 6 (the side opposite to the pump chamber 4) is provided on the motor 1 side of the oil chamber 5. That is, the sliding portion 6b on the side opposite to the load side of the mechanical seal 6 (the side opposite to the pump chamber 4) is provided so that the fluid containing the oil in the oil chamber 5 does not enter the motor 1 side.

  The oil lifter 52 is provided in a cylindrical shape around the rotation shaft 2. The oil lifter 52 is configured to lift up the oil that moves as the rotary shaft 2 rotates. That is, the oil lifter 52 is configured to supply oil to the sliding portion 6b. A through hole 521 is provided in the lower part of the oil lifter 52. The oil is guided from the through hole 521 to the inner peripheral side of the oil lifter 52.

  A seal 73 for sealing the oil reservoir 8 is provided at the end of the oil reservoir 8 on the motor 1 side. Specifically, a seal 73 is provided at the end of the annular body 7 on the motor 1 side. As the seal 73, for example, an oil seal, a seal lip, or a seal having a mechanism for generating a thrust force on the load side such as an inclined rib or a groove at a lip portion that slides with the rotary shaft 2 is used. The seal 73 is disposed between the annular body 7 and the rotary shaft 2. The seal 73 is an example of the “second seal” in the claims.

  Here, in the fourth embodiment, the oil reservoir 8 is provided with a pump mechanism 81 that sends fluid to the sliding portion 6b side of the mechanical seal 6 on the side opposite to the load (the side opposite to the pump chamber 4). ing. As shown in FIG. 6, the pump mechanism portion 81 is disposed on the outer peripheral portion of the rotating shaft 2. The pump mechanism 81 has a spiral groove 811. Thereby, when the pump mechanism 81 rotates with the rotary shaft 2, the fluid in the oil reservoir 8 is sent along the spiral groove 811 to the oil chamber 5 side. Further, the pump mechanism portion 81 is configured to send the fluid accumulated in the oil storage portion 8 to the oil chamber 5 through the fluid return path 9 by rotating.

  Moreover, in 3rd Embodiment, it is comprised so that the opening / closing control of the control valve 91 may be performed according to the driving | running state of the motor 1. FIG.

  The remaining configuration of the third embodiment is similar to that of the aforementioned first embodiment.

(Effect of the third embodiment)
In the third embodiment, the following effects can be obtained.

  In the third embodiment, as in the first embodiment, a fluid return path 9 that connects the oil reservoir 8 and the oil chamber 5 and a control valve that is provided in the fluid return path 9 and can be electrically opened and closed. 91, and is configured such that the opening / closing control of the control valve 91 is performed according to the operating state of the motor 1. Accordingly, maintenance and management of the submersible electric pump 300 can be easily performed without requiring much labor and cost for maintenance.

  Moreover, in 3rd Embodiment, as mentioned above, the pump mechanism part 81 which is arrange | positioned at the oil storage part 8 and sends a fluid to the oil chamber 5 side is provided. As a result, pressure can be applied downward to the fluid that is about to flow into the oil reservoir 8 from the oil chamber 5, so that oil rising from the oil chamber 5 can be suppressed. In addition, since pressure can be applied to the fluid that has flowed into the oil reservoir 8 so as to guide it to the fluid return path 9, the oil that has flowed into the oil reservoir 8 can be more effectively returned to the oil chamber 5. it can.

  The remaining effects of the third embodiment are similar to those of the aforementioned first embodiment.

(Modification)
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first to third embodiments, the example in which the present invention is applied to the vertical submersible electric pump arranged so that the rotation axis extends in the vertical direction is shown, but the present invention is not limited to this. You may apply this invention to the horizontal submersible electric pump arrange | positioned so that a rotating shaft may extend in a horizontal direction.

  Moreover, in the said 1st-3rd embodiment, although the example of the structure which uses an electromagnetic valve driven by an electromagnet as a control valve was shown, this invention is not restricted to this. In the present invention, an electrically openable / closable control valve other than the electromagnetic valve may be used as the control valve.

  In the first embodiment, the seal is provided on the oil chamber side of the oil reservoir, and in the second and third embodiments, the seal is provided on the motor side of the oil reservoir. The present invention is not limited to this. In the present invention, a seal may be provided on both the oil chamber side and the motor side of the oil reservoir, or a seal may not be provided on both the oil chamber side and the motor side of the oil reservoir.

  Moreover, in the said 1st-3rd embodiment, although the fluid return path showed the example comprised by pipe members, such as a pipe and a tube, this invention is not limited to this. In the present invention, the fluid return path may be provided by forming a groove in a housing or the like and capping the groove. Further, a fluid return path may be formed by digging a channel in the housing.

  Moreover, in the said 3rd Embodiment, although the example of the structure by which the pump mechanism part is arrange | positioned at the outer peripheral part of the rotating shaft was shown, this invention is not limited to this. In this invention, you may arrange | position a pump mechanism part in the position facing the outer peripheral part of a rotating shaft.

  Moreover, in the said 3rd Embodiment, although the example of the structure by which the spiral groove was provided in the pump mechanism part was shown, this invention is not limited to this. In the present invention, a wing-shaped blade or a centrifugal blade may be provided in the pump mechanism unit to send (pressurize) the fluid in the oil storage unit.

  Moreover, although the example of the structure which provides the oil lifter for raising oil in an oil chamber was shown in the said 3rd Embodiment, this invention is not limited to this. In the present invention, the oil lift may not be provided in the oil chamber.

  In the first embodiment, for convenience of explanation, the processing operation of the control unit has been described using a flow-driven flowchart that performs processing in order along the processing flow. However, the present invention is not limited to this. In the present invention, the processing operation of the control unit may be performed by event-driven (event-driven) processing that executes processing in units of events. In this case, it may be performed by a complete event drive type or a combination of event drive and flow drive.

DESCRIPTION OF SYMBOLS 1 Motor 3 Impeller 4 Pump chamber 5 Oil chamber 6 Mechanical seal 6a Sliding part 8 Oil storage part 9 Fluid return path 71 Seal (1st seal)
72, 73 seal (second seal)
81 Pump mechanism 91 Control valve 100, 200, 300 Submersible electric pump

Claims (9)

A motor,
A pump chamber in which an impeller driven by the motor is disposed;
An oil chamber provided with a mechanical seal having a sliding portion, and disposed between the motor and the pump chamber;
An oil reservoir disposed between the motor and the oil chamber;
A fluid return path communicating the oil reservoir and the oil chamber;
A control valve provided in the fluid return path and electrically openable and closable,
A submersible electric pump configured to perform opening / closing control of the control valve according to an operating state of the motor.   The submersible electric pump according to claim 1, wherein the control valve is configured to be controlled to be closed when the motor is stopped.   The submersible electric pump according to claim 2, wherein the control valve is configured to be controlled to open during operation of the motor.   The submersible electric pump according to claim 2, wherein the control valve is configured to be controlled to open for a predetermined time after the motor is stopped.   The submersible electric pump according to claim 4, wherein the control valve is configured to be closed after a predetermined time has elapsed after the motor is stopped.   The submersible electric pump according to any one of claims 1 to 5, wherein the mechanical seal is provided on the pump chamber side of the oil chamber.   The submersible electric pump according to any one of claims 1 to 6, further comprising a pump mechanism section that is provided in the oil storage section and sends a fluid to the oil chamber side.   The submersible electric pump according to claim 6, further comprising a first seal that is provided at an end of the oil storage portion on the oil chamber side and seals the oil chamber.   The submersible electric pump according to any one of claims 1 to 8, further comprising a second seal that is provided at the motor side end of the oil reservoir and seals the oil reservoir.

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