Motor pump

Abstract

To provide a motor pump that prevents contact between the pump's rotating part and the discharge-side component of the pump's rotating part, thereby preventing damage to both the pump's rotating part and the discharge-side component. [Solution] The motor pump comprises a main shaft, a pump rotating part fixed to the main shaft, a casing housing the pump rotating part and the main shaft, and a discharge bearing positioned on the discharge side of the pump rotating part and rotatably supporting the main shaft. The discharge bearing consists of a rotating-side discharge bearing provided on the main shaft and a stationary-side discharge bearing provided on the casing. An intervening part is provided between the pump rotating part and the stationary-side discharge bearing in the axial direction. A gap is formed between the intervening part and the stationary-side discharge bearing in the axial direction.

Description

Technical Field

[0001] The present invention relates to a motor pump. Background Art

[0002] Conventionally, there has been known a motor pump including an impeller (pump rotating part), a motor that rotates the impeller, a return vane, and a casing that accommodates the impeller and the return vane. Patent Document 1 discloses a motor pump having an impeller and a return vane. The return vane guides fluid discharged from the impeller toward a discharge port. Prior Art Documents Patent Documents

[0003] Patent Document 1 International Publication No. 2022 / 201731 Summary of the Invention Problem to be Solved by the Invention

[0004] Conventional motor pumps are not provided with a member for preventing contact between the impeller and a member on the downstream side (discharge side) of the impeller such as a return vane or a bearing. Therefore, when an abnormality such as air entrainment in the motor pump occurs during operation of the motor pump and the impeller moves toward the downstream side (discharge side) in the axial direction, the impeller may come into contact with the return vane or the bearing, resulting in damage.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a motor pump capable of preventing contact between a pump rotating part and a member on the discharge side of the pump rotating part, thereby preventing damage to the pump rotating part and the member on the discharge side of the pump rotating part. Means for Solving the Problem

[0006] (1) A motor pump according to one aspect of the present invention comprises a main shaft, a pump rotating part fixed to the main shaft, a casing housing the pump rotating part and the main shaft, and a discharge bearing disposed on the discharge side of the pump rotating part and rotatably supporting the main shaft, wherein the discharge bearing consists of a rotating-side discharge bearing provided on the main shaft and a stationary-side discharge bearing provided on the casing, an intervening part is provided between the axial direction of the pump rotating part and the stationary-side discharge bearing, and a gap is formed between the intervening part and the stationary-side discharge bearing in the axial direction.

[0007] (2): The motor pump according to (1) further has a suction bearing disposed on the suction side of the pump rotating part, the suction bearing consisting of a rotating side suction bearing provided on the pump rotating part and a stationary side suction bearing provided on the casing.

[0008] (3): In the motor pump according to (2), the casing comprises a suction casing and a discharge casing fixed to the suction casing, the main shaft and the pump rotating part are configured to be movable in the axial direction when the discharge casing is detached from the suction casing, and the fixed-side suction bearing and the rotating-side suction bearing are configured to be in contact with each other when the pump rotating part is in a predetermined position in the axial direction.

[0009] (4): In a motor pump relating to any one of (1) to (3), the intervening portion is a ring portion fixed to the outer circumference of the main shaft, and the outer diameter of the intervening portion is larger than the inner diameter of the fixed-side discharge bearing.

[0010] (5): In a motor pump relating to any one of (1) to (3), the intervening portion is a projection formed on the back surface of the discharge side of the rotating part of the pump and extending toward the stationary discharge bearing.

[0011] (6): In a motor pump relating to any one of (1) to (5), the intervening part and the fixed-side discharge bearing are separated in the axial direction during normal operation, and during abnormal operation in which the pump rotating part moves toward the discharge side, the intervening part and the fixed-side discharge bearing come into contact, thereby restricting the movement of the pump rotating part toward the discharge side.

[0012] (7): In a motor pump relating to any one of (1) to (6), the wear resistance of the intervening portion is less than the wear resistance of the fixed-side discharge bearing.

[0013] (8) In a motor pump relating to any one of (1) to (4) and (6) to (7), the intervening portion is provided integrally with the rotating discharge bearing.

[0014] (9): In a motor pump relating to any one of (1) to (8), the casing has a fixed bearing casing that abuts against the discharge side surface of the fixed discharge bearing.

[0015] (10): A motor pump relating to any one of (1) to (9) further comprises a return vane positioned on the discharge side of the pump rotating section and guiding the fluid discharged from the pump rotating section to the discharge side, and a partition plate separating the pump rotating section and the return vane, wherein the axial distance between the intervening section and the stationary discharge bearing is shorter than the axial distance between the pump rotating section and the partition plate. [Effects of the Invention]

[0016] According to one aspect of the present invention described above, it is possible to provide a motor pump that can prevent contact between the pump rotating part and the discharge-side member of the pump rotating part, thereby preventing damage to the pump rotating part and the discharge-side member of the pump rotating part. [Brief explanation of the drawing]

[0017] [Figure 1] This is a diagram showing a motor pump according to the first embodiment. [Figure 2] It is a diagram showing a motor pump according to a second embodiment. [Figure 3] It is a diagram showing a motor pump according to a third embodiment. [Figure 4] It is a diagram showing a motor pump according to a fourth embodiment. MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0019] <First Embodiment> Figure 1 is a diagram showing a motor pump 1 according to a first embodiment. The motor pump 1 includes a pump rotating part 2, a main shaft 30, a motor 40, a casing 50, a first bearing (suction bearing) 60, and a second bearing (discharge bearing) 70. The pump rotating part 2 has a first pump rotating part 10 and a second pump rotating part 20. Inside the casing 50, a flow path FP through which a fluid (handled liquid) flows is formed. The casing 50 is formed with a suction port 50a for sucking in the fluid and a discharge port 50b for discharging the fluid.

[0020] <Direction Definition> In this specification, the direction along the center line CL of the motor pump 1 is referred to as the axial direction. When viewed from the axial direction, the direction intersecting the center line CL of the motor pump 1 is referred to as the radial direction, and the direction rotating around the center line CL of the motor pump 1 is referred to as the circumferential direction. Furthermore, in the flow path FP of the casing 50, the fluid flows from the suction port 50a toward the discharge port 50b. The upstream side in the flow direction of the fluid is also simply referred to as the upstream side or the suction side. The downstream side in the flow direction of the fluid is also simply referred to as the downstream side or the discharge side.

[0021] The first pump rotating part 10 is arranged in the flow path FP of the casing 50. The first pump rotating part 10 is fixed to the main shaft 30. Rotation of the first pump rotating part 10 pressurizes the fluid sucked into the first pump rotating part 10, and discharges the fluid to the outside of the first pump rotating part 10. In the illustrated example, the first pump rotating part 10 is a centrifugal pump rotating part (centrifugal impeller), and the fluid pressurized by the first pump rotating part 10 is discharged in a direction perpendicular to the center line CL (radial direction). The first pump rotating part 10 may be a mixed flow pump rotating part (mixed flow impeller).

[0022] The first pump rotating part 10 includes a first main plate 11, a first side plate 12, a plurality of first blades 13, and a first boss part 14. In the present embodiment, the first side plate 12 and a rotor 41 of a motor 40 described later are integrated. Further, the first main plate 11, the first side plate 12, the plurality of first blades 13, and the first boss part 14 may be integrally molded. The first main plate 11, the first side plate 12, the plurality of first blades 13, and the first boss part 14 may be separately molded and joined after molding.

[0023] The first main plate 11 has a disk shape. The first side plate 12 is arranged to face the first main plate 11. The first blades 13 are arranged between the first main plate 11 and the first side plate 12. The plurality of first blades 13 are arranged side by side in the circumferential direction. The first boss part 14 has a cylindrical shape and is provided at a center portion of the first main plate 11. The first boss part 14 is a part connected to the main shaft 30.

[0024] The second pump rotating section 20 is located in the flow path FP of the casing 50. The second pump rotating section 20 is located on the discharge side of the first pump rotating section 10. The second pump rotating section 20 is fixed to the main shaft 30. The rotational force of the first pump rotating section 10 is transmitted to the second pump rotating section 20 via the main shaft 30. As the second pump rotating section 20 rotates, the fluid drawn into the second pump rotating section 20 is pressurized and discharged to the outside of the second pump rotating section 20. In the illustrated example, the second pump rotating section 20 is a centrifugal pump rotating section (centrifugal impeller), and the fluid pressurized by the second pump rotating section 20 is discharged in a direction perpendicular to the center line CL (radial direction). The second pump rotating section 20 may also be a mixed-flow pump rotating section (mixed-flow impeller).

[0025] The second pump rotating section 20 includes a second main plate 21, a second side plate 22, a plurality of second blades 23, and a second boss section 24. The second main plate 21, the second side plate 22, the plurality of second blades 23, and the second boss section 24 may be integrally molded. Alternatively, the second main plate 21, the second side plate 22, the plurality of second blades 23, and the second boss section 24 may be molded separately and then joined together after molding.

[0026] The second main plate 21 is disc-shaped. The second side plate 22 is positioned opposite the second main plate 21. The second wing 23 is positioned between the second main plate 21 and the second side plate 22. Multiple second wings 23 are arranged in a circumferential direction. The second boss portion 24 is cylindrical and is located in the center of the second main plate 21. The second boss portion 24 is the part that connects to the main shaft 30.

[0027] The main shaft 30 is positioned on the centerline CL of the motor pump 1. The main shaft 30 extends in the axial direction. The first pump rotating part 10 and the second pump rotating part 20 are fixed to the main shaft 30.

[0028] The main shaft 30 has a first mounting portion 31 and a second mounting portion 32 located on the discharge side of the first mounting portion 31. The downstream end 30a of the main shaft 30 is located in the flow path FP of the casing 50.

[0029] The first mounting portion 31 has a substantially cylindrical shape. The first pump rotating portion 10 is attached to the first mounting portion 31. The first boss portion 14 of the first pump rotating portion 10 has an insertion hole formed therein that corresponds to the shape of the first mounting portion 31. The first boss portion 14 is inserted into the first mounting portion 31 so as not to rotate relative to it. As a result, the rotational force of the first pump rotating portion 10 is transmitted to the main shaft 30. Furthermore, "approximately cylindrical" includes not only columnar shapes with a circular cross-section and columnar shapes with an approximately circular cross-section such as an ellipse, but also columnar shapes with a polygonal cross-section, and also columnar shapes in which part of the columnar shape is chamfered.

[0030] The second mounting portion 32 has a substantially cylindrical shape. The second pump rotating portion 20 is attached to the second mounting portion 32. The second boss portion 24 of the second pump rotating portion 20 has an insertion hole formed therein that corresponds to the shape of the second mounting portion 32. The second boss portion 24 is inserted into the second mounting portion 32 so as not to rotate relative to it. As a result, the rotational force of the main shaft 30 is transmitted to the second pump rotating portion 20.

[0031] A sleeve 33 is provided between the first boss portion 14 and the second boss portion 24. The sleeve 33 is cylindrical and is inserted into the second mounting portion 32. The sleeve 33 contacts the first boss portion 14 of the first pump rotating portion 10 from the discharge side and contacts the second boss portion 24 of the second pump rotating portion 20 from the suction side. The sleeve 33 forms a predetermined distance between the first pump rotating portion 10 and the second pump rotating portion 20. By providing the sleeve 33, the distance between the first pump rotating portion 10 and the second pump rotating portion 20 can be easily controlled.

[0032] Furthermore, a ring portion (intervening portion) 34 is provided on the discharge side of the second boss portion 24. The ring portion 34 is cylindrical, inserted through the second mounting portion 32, and fixed to the outer circumference of the main shaft 30. The ring portion 34 contacts the second boss portion 24 of the second pump rotating portion 20 from the discharge side and contacts the second rotating side bearing 71, which will be described later, from the suction side. The ring portion 34 is located on the suction side of the second stationary side bearing (stationary side discharge bearing) 72, which will be described later. The outer diameter of the ring portion 34 is larger than the inner diameter of the second stationary side bearing 72. The ring portion 34 can have any shape that allows it to be inserted into the second mounting portion 32, and does not have to be cylindrical. Alternatively, a sleeve (second sleeve) may be provided between the second boss portion 24 and the ring portion 34. In this case, the second boss portion 24 and the ring portion 34 will be in contact with each other via the second sleeve.

[0033] During non-operation and normal operation, the ring portion 34 and the second fixed-side bearing 72 are spaced apart in the axial direction, and a gap is formed between the ring portion 34 and the second fixed-side bearing 72. The axial distance between the ring portion 34 and the second fixed-side bearing 72 (length of the gap in the axial direction) is shorter than the distance between the second pump rotating portion 20 (second main plate 21) and the second partition plate 84 described later, and shorter than the distance between the first pump rotating portion 10 (first main plate 11) and the first partition plate 82 described later. The wear resistance of the ring portion 34 is less than that of the second fixed bearing 72, which will be described later. However, the wear resistance of the ring portion 34 may be the same as that of the second fixed bearing 72. If the wear resistance of the ring portion 34 is the same as that of the second fixed bearing 72, the ring portion 34 and the second fixed bearing 72 may be made from the same material.

[0034] The first pump rotating section 10 and the second pump rotating section 20 are fixed to the main shaft 30 by fastening fasteners (not shown) to both ends of the main shaft 30, for example, with the first boss section 14 inserted through the second mounting section 32. The suction-side end of the first mounting section 31 and the discharge-side end of the second mounting section 32 may each be provided with threaded sections to which the fasteners are fastened. However, even in this case, the downstream end 30a of the main shaft 30 is located in the flow path FP of the casing 50.

[0035] A sleeve 33 is positioned between the first pump rotating section 10 and the second pump rotating section 20, and a ring section 34 and a second rotating side bearing 71 are positioned downstream of the second pump rotating section 20. The first pump rotating section 10 is sandwiched between a fastener and the sleeve 33, and the second pump rotating section 20 is sandwiched between the sleeve 33, the ring section 34, the second rotating side bearing 71, and the fastener. As a result, the first pump rotating section 10 and the second pump rotating section 20 are firmly fixed to the main shaft 30. Furthermore, if a second sleeve is provided between the second boss portion 24 and the ring portion 34, the second pump rotating portion 20 is sandwiched between the sleeve 33, the second sleeve, the ring portion 34, the second rotating side bearing 71, and the fastener, thereby firmly fixing the second pump rotating portion 20 to the main shaft 30.

[0036] The motor 40 rotates the first pump rotating section 10. The motor 40 comprises an annular rotor 41 fixed to the first pump rotating section 10 and a stator 42 positioned radially outward from the rotor 41. The stator 42 is fixed to the casing 50. The motor 40 is, for example, a permanent magnet motor. In this case, the rotor 41 has a rotor core and permanent magnets attached to the rotor core. The motor 40 may also be an induction motor, a reluctance motor, or the like.

[0037] The rotor 41 rotates relative to the stator 42. Since the rotor 41 is fixed to the first pump rotating part 10, the rotational force of the rotor 41 acts on the first pump rotating part 10. The rotational force acting on the first pump rotating part 10 is transmitted to the second pump rotating part 20 via the main shaft 30. Therefore, when the rotor 41 rotates relative to the stator 42, the first pump rotating part 10, the main shaft 30, and the second pump rotating part 20 rotate together as a unit around the centerline CL of the motor pump 1.

[0038] The rotor 41 is housed in the rotor holder 43. The rotor holder 43 is integrally formed with the first pump rotating section 10 (first side plate 12). The rotor holder 43 rotates together with the rotor 41 around the centerline CL of the motor pump 1.

[0039] The casing 50 houses the first pump rotating section 10, the second pump rotating section 20, the main shaft 30, and the motor 40. The casing 50 includes a suction casing 51, a discharge casing 52, an intermediate casing 53, and a stator casing 54.

[0040] The suction casing 51 is located upstream (suction side) of the first pump rotating section 10. The suction casing 51 has a suction port 50a. The discharge casing 52 is located downstream (discharge side) of the second pump rotating section 20. The discharge casing 52 is fixed to the suction casing 51. The discharge casing 52 has a discharge port 50b. The suction port 50a and the discharge port 50b are located on the centerline CL of the motor pump 1. However, the suction port 50a and the discharge port 50b do not necessarily have to be located on the centerline CL of the motor pump 1.

[0041] The discharge casing 52 is fixed to the suction casing 51, thereby restricting the axial movement of the pump rotating section 2 and the main shaft 30 toward the discharge side. When the discharge casing 52 is detached from the suction casing 51 (when the discharge casing 52 is released from its fixation to the suction casing 51), the pump rotating section 2 and the main shaft 30 are able to move in the axial direction.

[0042] The intermediate casing 53 is an annular partition wall that separates the downstream side (discharge side) of the first pump rotating section 10 from the upstream side (suction side) of the second pump rotating section 20. The intermediate casing 53 houses the second pump rotating section 20. In this embodiment, the intermediate casing 53 is held by an intermediate casing holder 55. The intermediate casing 53 is fixed to the discharge casing 52 via the intermediate casing holder 55.

[0043] The stator casing 54 houses the stator 42. The stator casing 54 is located radially outward from the first pump rotating section 10. The stator casing 54 is positioned between the suction casing 51 and the discharge casing 52. The stator casing 54 is fixed to the suction casing 51 and the discharge casing 52.

[0044] The first bearing (suction bearing) 60 rotatably supports the first pump rotating section 10. The first bearing 60 includes a first rotating-side bearing 61 (rotating-side suction bearing) fixed to the rotor holder 43, and a first stationary-side bearing 62 (stationary-side suction bearing) fixed to the suction casing 51. Since the rotor holder 43 to which the first rotating-side bearing 61 is fixed is integrally formed with the first pump rotating section 10 (first side plate 12), the first rotating-side bearing 61 is provided on the first pump rotating section 10 (first side plate 12). The first stationary-side bearing 62 is positioned radially inward from the first rotating-side bearing 61. The first rotating-side bearing 61 is a rotating member that rotates together with the rotation of the first pump rotating section 10 (rotor 41), while the first stationary-side bearing 62 is a stationary member that does not rotate even when the first pump rotating section 10 rotates.

[0045] When assembling the motor pump 1, with the discharge casing 52 detached from the suction casing 51, the main shaft 30 and the pump rotating part 2 are inserted into the suction casing 51 from the discharge side toward the suction side. After the main shaft 30 and the pump rotating part 2 are inserted into the suction casing 51, the discharge casing 52 is fixed to the suction casing 51. The motor pump 1 is configured such that the first rotating bearing 61 and the first stationary bearing 62 can come into contact when the pump rotating part 2 (first pump rotating part 10) inserted into the suction casing 51 is in a predetermined position in the axial direction. This makes it easier to assemble the motor pump 1.

[0046] The second bearing (discharge bearing) 70 rotatably supports the main shaft 30. The second bearing 70 includes a second rotating-side bearing 71 (rotating-side discharge bearing) fixed to the second mounting portion 32 of the main shaft 30, and a second stationary-side bearing 72 (stationary-side discharge bearing) fixed to the intermediate casing 53 via a second partition plate 84, which will be described later. The second stationary-side bearing 72 is positioned radially outward from the second rotating-side bearing 71. The second rotating-side bearing 71 is a rotating member that rotates together with the rotation of the first pump rotating section 10 (main shaft 30), while the second stationary-side bearing 72 is a stationary member that does not rotate even when the first pump rotating section 10 rotates.

[0047] The motor pump 1 includes a plurality of first return vanes 81 and a first partition plate 82 that guide the fluid discharged from the first pump rotating section 10 toward the second pump rotating section 20. The first return vanes 81 are positioned on the rear side of the first pump rotating section 10. The first return vanes 81 face the first main plate 11 of the first pump rotating section 10. The first return vanes 81 are fixed to the intermediate casing 53. The plurality of first return vanes 81 are arranged, for example, to extend in a spiral shape. The first partition plate 82 separates the first pump rotating section 10 (first main plate 11) from the first return vanes 81. The first partition plate 82 is fixed to the first return vanes 81. The first return vanes 81 and the first partition plate 82 may be integrally molded.

[0048] The motor pump 1 includes a plurality of second return vanes 83 and a second partition plate 84 that guide the fluid discharged from the second pump rotating section 20 toward the discharge port 50b. The second return vanes 83 are positioned on the rear side of the second pump rotating section 20. The second return vanes 83 face the second main plate 21 of the second pump rotating section 20. The second return vanes 83 are fixed to the intermediate casing 53. The plurality of second return vanes 83 are arranged, for example, to extend in a spiral shape. The second partition plate 84 separates the second pump rotating section 20 (second main plate 21) from the second return vanes 83. The second partition plate 84 is fixed to the second return vanes 83. The second return vanes 83 and the second partition plate 84 may be integrally molded.

[0049] Referring to Figure 1, the fluid (handled liquid) flow in the flow path FP of the casing 50 will be explained. In Figure 1, the fluid flow is indicated by arrows. When the motor pump 1 is operated, the fluid is drawn in from the suction port 50a. The fluid is pressurized by the rotation of the first pump rotating section 10 and discharged to the outside of the first pump rotating section 10. The fluid discharged to the outside of the first pump rotating section 10 collides with the stator cannon 44 of the stator 42, and its flow direction is changed. After that, the fluid flows through the first return vane 81 and flows towards the second pump rotating section 20. The fluid is pressurized by the rotation of the second pump rotating section 20 and discharged to the outside of the second pump rotating section 20. The fluid discharged to the outside of the second pump rotating section 20 collides with the inner circumferential surface of the intermediate casing 53, and its flow direction is changed. After that, the fluid flows through the second return vane 83 and is discharged from the discharge port 50b.

[0050] In normal operation of the motor pump 1, the ring portion 34 and the second fixed bearing 72 are spaced apart in the axial direction, and a gap is formed between the ring portion 34 and the second fixed bearing 72. In the motor pump 1 during normal operation, a load (axial thrust) acts on the pump rotating portion 2 and the ring portion 34 from the discharge side to the suction side due to the pressure difference between the suction side and the discharge side of the pump rotating portion 2. As a result, the axially spaced ring portion 34 and the second fixed bearing 72 do not come into contact and do not wear.

[0051] On the other hand, when the motor pump 1 is operated under abnormal conditions (non-normal operation), the second pump rotating part 20 may move downstream. In this case, the ring part 34 is pressed by the second boss part 24 of the second pump rotating part 20 and moves to the discharge side. The ring part 34 that has moved to the discharge side comes into contact with the second fixed bearing 72 from the suction side. Abnormal conditions refer to conditions in which an abnormality occurs, such as air being mixed into the motor pump 1. In the motor pump 1 of this embodiment, the axial distance between the ring portion 34 and the second fixed-side bearing 72 is shorter than the axial distance between the second pump rotating portion 20 (second main plate 21) and the second partition plate 84, and shorter than the axial distance between the first pump rotating portion 10 (first main plate 11) and the first partition plate 82. Therefore, when the motor pump 1 is operated under such abnormal conditions, even if the second pump rotating portion 20 moves, the ring portion 34 moves to the discharge side and contacts the second fixed-side bearing 72 from the suction side, preventing the second pump rotating portion 20 (second main plate 21) from contacting the second partition plate 84 and the second fixed-side bearing 72, while allowing the first pump rotating portion 10 (first main plate 11) to contact the first partition plate 82. Furthermore, because a gap is formed between the ring portion 34 and the second fixed-side bearing 72, even during abnormal operation, if the distance the ring portion 34 moves toward the discharge side is shorter than the length of the gap in the axial direction, the ring portion 34 and the second fixed-side bearing 72 do not come into contact and therefore do not wear. In addition, if the motor pump 1 is operated under abnormal conditions, the ring portion 34 may move to the discharge side and come into contact with the second fixed bearing 72, causing damage to the ring portion 34. In such cases, the damaged ring portion 34 can be replaced with a new ring portion 34.

[0052] The ring portion 34 and the second bearing 70 are configured such that a gap is formed between the ring portion 34 and the second fixed bearing 72 during non-operation and normal operation. This configuration of the ring portion 34 and the second bearing 70 allows them to be applied to pumps of different sizes without changing their dimensions. Furthermore, the ring portion 34 and the second bearing 70, which are configured to form such a gap, can absorb dimensional errors in the ring portion 34 and the second bearing 70 within the gap, thus allowing for lower dimensional accuracy.

[0053] As described above, the motor pump 1 according to this embodiment includes a main shaft 30, a pump rotating part 2 fixed to the main shaft 30, a casing 50 housing the pump rotating part 2 and the main shaft 30, and a second bearing (discharge bearing) 70 arranged on the discharge side of the pump rotating part 2. The second bearing 70 is composed of a second rotating side bearing (rotating side discharge bearing) 71 provided on the main shaft 30 and a second stationary side bearing (stationary side discharge bearing) 72 provided on the casing 50. A ring portion (intervening portion) 34 is provided between the pump rotating part 2 and the second stationary side bearing 72 in the axial direction to prevent contact between the pump rotating part 2 and the second stationary side bearing 72, and a gap is formed between the ring portion 34 and the second stationary side bearing 72 in the axial direction.

[0054] With this type of motor pump 1, a ring portion 34 is provided between the pump rotating portion 2 and the second fixed bearing 72 in the axial direction, thereby preventing contact between the pump rotating portion 2 and the second fixed bearing 72. This prevents damage from occurring due to contact between the pump rotating portion 2 and the second fixed bearing 72, which is the discharge-side component of the pump rotating portion 2. Furthermore, if a first return vane 81 (return vane) and a first partition plate 82 (partition plate) are provided on the discharge side of the first pump rotating section 10 (pump rotating section 2), or if a second return vane 83 (return vane) and a second partition plate 84 (partition plate) are provided on the discharge side of the second pump rotating section 20 (pump rotating section 2), the ring section 34 comes into contact with the second fixed-side bearing 72, thereby preventing damage from occurring due to contact between the pump rotating section 2 and the partition plate, which is a component on the discharge side of the pump rotating section 2.

[0055] Furthermore, the motor pump 1 has a first bearing (suction bearing) 60 located on the suction side of the pump rotating section 2, and the first bearing 60 consists of a first rotating-side bearing (rotating-side suction bearing) 61 provided on the pump rotating section 2 and a first stationary-side bearing (stationary-side suction bearing) 62 provided on the casing 50. With this configuration, the pump rotating part 2 can be held in the casing 50 via a bearing (first bearing 60) not only on the discharge side but also on the suction side.

[0056] The casing 50 includes a suction casing 51 and a discharge casing 52 fixed to the suction casing 51. The main shaft 30 and the pump rotating section 2 are configured to be movable in the axial direction when the discharge casing 52 is detached from the suction casing 51, and the first fixed bearing 62 and the first rotating bearing 61 are configured to be in contact when the pump rotating section 2 is in a predetermined position in the axial direction. This configuration allows for easy assembly of the motor pump 1.

[0057] Furthermore, the ring portion 34 is fixed to the outer circumference of the main shaft 30, and the outer diameter of the ring portion 34 is larger than the inner diameter of the second fixed bearing 72. With this configuration, the ring portion 34 overlaps the second fixed bearing 72 in the radial direction, so that when the pump rotating portion 2 moves towards the discharge side, the ring portion 34 can be reliably brought into contact with the second fixed bearing 72.

[0058] Furthermore, during normal operation, the ring portion 34 and the second fixed-side bearing 72 are spaced apart in the axial direction, and during abnormal operation when the pump rotating portion 2 moves toward the discharge side, the ring portion 34 and the second fixed-side bearing 72 come into contact, thereby restricting the movement of the pump rotating portion 2 toward the discharge side. With this configuration, the movement of the pump rotating part 2 toward the discharge side is reliably restricted during emergency operation, thus preventing the pump rotating part 2 from coming into contact with the discharge side components and causing damage.

[0059] Furthermore, the wear resistance of the ring portion 34 is lower than that of the second fixed bearing 72. With this configuration, the ring portion 34 is worn preferentially over the second fixed bearing 72, thereby suppressing wear on the second fixed bearing 72, and allowing the use of inexpensive materials with low wear resistance for the ring portion 34.

[0060] Furthermore, the motor pump 1 is positioned on the discharge side of the pump rotating section 2 (first pump rotating section 10 or second pump rotating section 20) and further includes a return vane (first return vane 81 or second return vane 83) that guides the fluid discharged from the pump rotating section 2 to the discharge side, and a partition plate (first partition plate 82 or second partition plate 84) that separates the pump rotating section 2 and the return vane. The axial distance between the ring section 34 and the second fixed-side bearing 72 is shorter than the axial distance between the pump rotating section 2 and the partition plate (the axial distance between the first pump rotating section 10 and the first partition plate 82, or the axial distance between the second pump rotating section 20 and the second partition plate 84). With this configuration, even when the first return vane 81 (return vane) and the first partition plate 82 (partition plate) are provided on the discharge side of the first pump rotating section 10 (pump rotating section 2), or when the second return vane 83 (return vane) and the second partition plate 84 (partition plate) are provided on the discharge side of the second pump rotating section 20 (pump rotating section 2), the ring portion 34 contacts the second fixed-side bearing 72, thereby more reliably preventing damage from occurring due to contact between the pump rotating section 2 and the partition plate, which is a component on the discharge side of the pump rotating section 2.

[0061] <Second Embodiment> Next, the motor pump 1A according to the second embodiment will be described. Since the basic configuration of the motor pump 1A according to this embodiment is the same as that of the first embodiment, the differences will be described in detail.

[0062] Figure 2 shows a motor pump 1A according to this embodiment. As shown in Figure 2, in this embodiment, a projection 34A is provided as an intervening part, projecting toward the discharge side from the second boss portion 24 of the second pump rotating portion 20. The projection 34A is spaced apart in the axial direction from the second stationary bearing 72, and a gap is formed between the projection 34A and the second stationary bearing 72. The axial distance between the projection 34A and the second stationary bearing 72 is shorter than the axial distance between the second pump rotating portion 20 (second main plate 21) and the second partition plate 84, and shorter than the axial distance between the first pump rotating portion 10 (first main plate 11) and the first partition plate 82.

[0063] In Figure 2, the projection 34A is formed integrally with the second pump rotating part 20. For example, the projection 34A and the second pump rotating part 20 are formed by integral casting from the same material. Furthermore, the projection 34A and the second pump rotating part 20 do not necessarily have to be formed integrally. In this case, the projection 34A may be formed from a different material than the second pump rotating part 20. For example, the projection 34A may be formed as a separate component from the second pump rotating part 20 and then joined to the second pump rotating part 20 by means of welding or other means.

[0064] Here, during normal operation of the motor pump 1A (normal operation), the projection 34A is spaced axially apart from the second fixed bearing 72. On the other hand, during abnormal operation of the motor pump 1A (abnormal operation), when the second pump rotating part 20 moves to the discharge side, the projection 34A moves to the discharge side together with the second boss part 24 of the second pump rotating part 20. The projection 34A that has moved to the discharge side comes into contact with the second fixed bearing 72 from the suction side. In the motor pump 1A of this embodiment, the axial distance between the projection 34A and the second fixed-side bearing 72 is shorter than the axial distance between the second pump rotating section 20 (second main plate 21) and the second partition plate 84, and shorter than the axial distance between the first pump rotating section 10 (first main plate 11) and the first partition plate 82. Therefore, even when the second pump rotating section 20 moves during operation of the motor pump 1A under such abnormal conditions, the projection 34A moves to the discharge side and contacts the second fixed-side bearing 72 from the suction side, thereby preventing the second pump rotating section 20 (second main plate 21) from contacting the second partition plate 84, and preventing the first pump rotating section 10 (first main plate 11) from contacting the first partition plate 82.

[0065] As described above, in the motor pump 1A according to this embodiment, the projection (intervening portion) 34A is formed on the back surface of the discharge side of the pump rotating portion 2 and is a projection that extends toward the second fixed-side bearing (fixed-side discharge bearing) 72. With this configuration, the pump rotating part 2 and the projection 34A can be attached to the main shaft 30 as a single unit, eliminating the need to attach the pump rotating part 2 and the projection 34A separately to the main shaft 30, thus simplifying the attachment of the projection 34A.

[0066] <Third Embodiment> Next, the motor pump 1B according to the third embodiment will be described. Since the basic configuration of the motor pump 1B according to this embodiment is the same as that of the first embodiment, the differences will be described in detail.

[0067] Figure 3 shows a motor pump 1B according to this embodiment. As shown in Figure 3, in this embodiment, a ring portion 34B is provided as an intervening part on the second rotating side bearing 71, projecting radially outward. The ring portion 34B is spaced apart from the second stationary side bearing 72 in the axial direction, and a gap is formed between the ring portion 34B and the second stationary side bearing 72. The axial distance between the ring portion 34B and the second stationary side bearing 72 is shorter than the axial distance between the second pump rotating part 20 (second main plate 21) and the second partition plate 84, and shorter than the axial distance between the first pump rotating part 10 (first main plate 11) and the first partition plate 82. The outer diameter of the ring portion 34B is larger than the inner diameter of the second stationary side bearing 72.

[0068] In Figure 3, the ring portion 34B is integrally formed with the second rotating side bearing 71. For example, the ring portion 34B and the second rotating side bearing 71 are integrally cast from the same material. Furthermore, the ring portion 34B and the second rotating side bearing 71 do not necessarily have to be formed integrally. In this case, the ring portion 34B may be formed from a different material than the second rotating side bearing 71. For example, the ring portion 34B may be formed as a separate component from the second rotating side bearing 71 and then joined to the second rotating side bearing 71 by means of welding or other means.

[0069] Here, under normal operating conditions, the ring portion 34B is spaced axially apart from the second fixed bearing 72. On the other hand, under abnormal operating conditions, when the motor pump 1B is operated and the pump rotating portion 2 moves to the discharge side, the ring portion 34B is pressed by the second boss portion 24 of the second pump rotating portion 20 and moves to the discharge side. The ring portion 34B that has moved to the discharge side comes into contact with the second fixed bearing 72 from the suction side. In the motor pump 1B of this embodiment, the axial distance between the ring portion 34B and the second fixed-side bearing 72 is shorter than the axial distance between the second pump rotating portion 20 (second main plate 21) and the second partition plate 84, and shorter than the axial distance between the first pump rotating portion 10 (first main plate 11) and the first partition plate 82. Therefore, when the motor pump 1B is operated under such abnormal conditions, even if the pump rotating portion 2 moves, the ring portion 34B moves to the discharge side and contacts the second fixed-side bearing 72 from the suction side, thereby preventing the second pump rotating portion 20 (second main plate 21) from contacting the second partition plate 84, and preventing the first pump rotating portion 10 (first main plate 11) from contacting the first partition plate 82.

[0070] As described above, in the motor pump 1B according to this embodiment, the ring portion (intervening portion) 34B is integrally provided with the second rotating side bearing (rotating side discharge bearing) 71. With this configuration, the second rotating side bearing 71 and the ring portion (intervening portion) 34B can be attached integrally to the main shaft 30, eliminating the need to attach the second rotating side bearing 71 and the ring portion 34B separately to the main shaft 30, thus simplifying the installation of the ring portion 34B.

[0071] <Fourth Embodiment> Next, the motor pump 1C according to the fourth embodiment will be described. Since the basic configuration of the motor pump 1C according to this embodiment is the same as that of the first embodiment, the differences will be described in detail.

[0072] Figure 4 shows a motor pump 1C according to this embodiment. As shown in Figure 4, in this embodiment, the casing 50 (discharge casing 52) has a stationary bearing casing 85. The stationary bearing casing 85 is provided so as to protrude radially inward from the discharge end of the second partition plate 84. The stationary bearing casing 85 is located on the discharge side of the second stationary bearing 72. The suction side (upstream side) surface of the stationary bearing casing 85 abuts against the discharge side (discharge side) surface of the second stationary bearing 72, supporting the second stationary bearing 72 from the discharge side.

[0073] As described above, in the motor pump 1C according to this embodiment, the casing 50 has a fixed-side bearing casing 85 that abuts against the discharge-side surface of the second fixed-side bearing (fixed-side discharge bearing) 72. With this configuration, since the second fixed-side bearing 72 is supported from the discharge side by the fixed-side bearing casing 85, it is possible to prevent the second fixed-side bearing 72 from moving toward the discharge side and coming off the casing 50.

[0074] The technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.

[0075] For example, the motor pumps 1A and 1B according to the second and third embodiments may include the fixed-side bearing casing 85 that is present in the motor pump 1C according to the fourth embodiment.

[0076] Furthermore, the pump rotating section 2 of the motor pumps 1, 1A, 1B, and 1C according to the first to fourth embodiments has a first pump rotating section 10 and a second pump rotating section 20, but it may also have only the first pump rotating section 10. In this case, the sleeve 33, the second return vane 83 and the second partition plate 84 are not provided, the second rotating-side bearing 71 abuts against the ring section 34 or the first boss section 14 from the discharge side, the first boss section 14 abuts against the ring section 34 or the second rotating-side bearing 71 from the suction side, and the second stationary-side bearing 72 is fixed to the intermediate casing 53 via the first partition plate 82. In this case, the sleeve 33 may be provided between the first pump rotating section 10 and the ring section 34. Also in this case, the axial distance (length of the gap in the axial direction) between the ring section 34 and the second stationary-side bearing 72 should be shorter than the distance between the first pump rotating section 10 and the first partition plate 82. Furthermore, although the motor pumps 1, 1A, 1B, and 1C according to the first to fourth embodiments have two pump rotating parts, a first pump rotating part 10 and a second pump rotating part 20, they may have three or more pump rotating parts.

[0077] Furthermore, without departing from the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments and modifications may be combined as appropriate. [Explanation of Symbols]

[0078] 1, 1A, 1B, 1C Motor Pumps 2. Pump Rotating Section 10. First pump rotating section 20. Second pump rotating section 30 spindle 34. Ring portion (intervening portion) 34A Protrusion (interposed part) 34B Ring portion (intervening portion) 40 motors 50 Casing 60. First bearing (suction bearing) 61. First rotating side bearing (rotating side suction bearing) 62. First fixed-side bearing (fixed-side suction bearing) 70. Second bearing (discharge bearing) 71. Second rotating side bearing (rotating side discharge bearing) 72. Second fixed-side bearing (fixed-side discharge bearing) 81 First return feather 82. First partition plate 83 Second return feather 84. Second partition plate 85 Fixed-side bearing casing

Claims

1. The main shaft, The pump rotating part is fixed to the main shaft, The casing housing the pump rotating section and the main shaft, A discharge bearing is positioned on the discharge side of the pump's rotating section and rotatably supports the main shaft, Equipped with, The discharge bearing is composed of a rotating discharge bearing provided on the main shaft and a stationary discharge bearing provided on the casing. An intervening portion is provided between the rotating part of the pump and the stationary discharge bearing in the axial direction. A gap is formed between the intervening portion and the fixed-side discharge bearing in the axial direction. Motor pump.

2. The pump further includes a suction bearing positioned on the suction side of the rotating part of the pump, The suction bearing consists of a rotating-side suction bearing provided in the pump's rotating section and a stationary-side suction bearing provided in the casing. The motor pump according to claim 1.

3. The casing comprises a suction casing and a discharge casing fixed to the suction casing. The main shaft and the pump rotating part are movable in the axial direction with the discharge casing detached from the suction casing. When the pump rotating part is located at a predetermined position in the axial direction, the stationary suction bearing and the rotating suction bearing are configured to be in contact with each other. The motor pump according to claim 2.

4. The intervening portion is a ring portion fixed to the outer circumference of the main shaft, The outer diameter of the intervening portion is larger than the inner diameter of the fixed-side discharge bearing. The motor pump according to claim 1 or 2.

5. The intervening portion is a projection formed on the back surface of the discharge side of the pump's rotating section and extending toward the stationary discharge bearing. The motor pump according to claim 1 or 2.

6. The intervening portion and the fixed-side discharge bearing are spaced apart in the axial direction during normal operation. During abnormal operation when the pump rotating part moves toward the discharge side, the intervening part and the fixed discharge bearing come into contact, thereby restricting the movement of the pump rotating part toward the discharge side. The motor pump according to claim 1 or 2.

7. The wear resistance of the intervening portion is less than that of the fixed-side discharge bearing. The motor pump according to claim 1 or 2.

8. The intervening portion is integrally provided with the rotating discharge bearing. The motor pump according to claim 1 or 2.

9. The casing has a fixed-side bearing casing that abuts against the discharge-side surface of the fixed-side discharge bearing. The motor pump according to claim 1 or 2.

10. A return vane is positioned on the discharge side of the pump's rotating section and guides the fluid discharged from the pump's rotating section toward the discharge side. The pump further comprises a partition plate separating the rotating part of the pump from the return blade, The axial distance between the intervening portion and the fixed-side discharge bearing is shorter than the axial distance between the pump rotating portion and the partition plate. The motor pump according to claim 1 or 2.

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