JP7638841B2 - Bearing lubrication system - Google Patents

Description

The present invention relates to a bearing lubrication device.

Patent Document 1 discloses a lubrication device for a bearing that supports a portion of a rotating shaft that protrudes from a pump casing to the outside. This lubrication device includes an oil receiver that surrounds the bearing, an oil chamber that surrounds the oil receiver, a discharge pipe that has one end located within the oil chamber and the other end located above the oil receiver, and an oil lifter that sends the lubricating oil in the oil chamber to the discharge pipe, and circulates and supplies the lubricating oil in the oil chamber to the bearing. The lubrication device also includes an overflow pipe that returns excess lubricating oil supplied to the oil receiver through the discharge pipe to the oil chamber.

JP 2021-46918 A

The lubrication device in Patent Document 1 requires piping and an oil lifter to circulate the lubricating oil to the bearings, making the structure complex and large. Therefore, there is room for improvement in simplifying the structure and making the device more compact in Patent Document 1.

The objective of the present invention is to provide a bearing lubrication device that can circulate and supply lubricating oil without using piping, and that can simplify and miniaturize the structure.

The bearing lubrication device of the present invention is a bearing lubrication device that is mounted within a cylindrical insertion portion formed in a pump casing so as to surround a vertically extending rotating shaft and rotatably support the rotating shaft, the device having an oil tank that is positioned below the insertion portion and has a bottom portion attached to the rotating shaft, and an outer periphery portion that protrudes from the outer periphery of the bottom portion to above the bearing and surrounds the insertion portion, and rotates integrally with the rotating shaft, and a through hole that is provided in the insertion portion so as to be located above the bearing and below the upper end of the outer periphery portion, that penetrates the insertion portion in the radial direction of the rotating shaft and allows the flow of lubricating oil supplied from within the oil tank, and a straightening vane is provided at the lower end of the insertion portion to flow the lubricating oil from the outside to the inside of the oil tank in the radial direction of the rotating shaft .
The first aspect of the present invention further provides a bearing lubrication device comprising: impellers provided on an outer surface of at least the bottom of the oil tank for blowing air from the inside to the outside in the radial direction of the rotating shaft; and a first cover attached to the pump casing and surrounding the impellers and at least a portion of the outer periphery of the oil tank .
In addition, a second aspect of the present invention provides a bearing lubrication device, wherein the outer periphery of the oil tank further has a cylindrical window portion for checking the flow of the lubricating oil, a lower cylindrical portion below the window portion, an upper cylindrical portion above the window portion, and a connecting vane connecting the lower cylindrical portion and the upper cylindrical portion.

In this embodiment, when the oil tank rotates together with the rotating shaft due to the operation of the pump, the lubricating oil also rotates together with the oil tank. At this time, the flow speed (angular velocity) of the lubricating oil in the inner and outer parts of the oil tank in the radial direction of the rotating shaft is constant, so the circumferential speed in the oil tank is faster on the outer side than on the inner side in the radial direction. At this time, the straightening vane provided at the lower end of the insertion part causes the lubricating oil on the radially outer side, which has a faster circumferential speed, to flow to the radially inner side, which has a slower circumferential speed. This pushes up the lubricating oil in the inner part and supplies it to the bearing through the insertion part and the rotating shaft. The lubricating oil that has passed through the bearing then flows from the inside to the outside of the insertion part through a through hole provided on the upper side of the bearing, and then returns to the bottom side of the oil tank through the gap between the outer periphery of the oil tank and the insertion part.

In this manner, in this embodiment, an oil tank is provided that rotates integrally with the rotating shaft, and a through hole is provided in the insertion portion of the rotating shaft to return the lubricating oil that has passed through the bearing. In addition, a flow straightening vane is provided to cause the lubricating oil to flow from the outside to the inside of the oil tank in the radial direction of the rotating shaft. This allows the lubricating oil to be circulated and supplied to the bearing without using piping or oil lifters, simplifying the structure of the lubrication device and making it smaller.

The present invention allows lubricating oil to be circulated without using piping, simplifying and miniaturizing the structure.

1 is a cross-sectional view of a pump equipped with a bearing lubrication device according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of part II in FIG. 1 . FIG. Cross-sectional view taken along line III-III in Figure 2. Cross-sectional view taken along line IV-IV in Figure 2. Cross-sectional view of line VV in Figure 2. FIG. 5 is a cross-sectional view similar to FIG. 2 , showing a bearing lubrication device according to a second embodiment.

The following describes an embodiment of the present invention with reference to the drawings.

First Embodiment
1 shows a centrifugal pump 10 using a lubrication device 50 for a bearing 40 according to a first embodiment of the present invention. This centrifugal pump 10 is installed on an installation floor (not shown) of a pump facility, and sucks up water in a suction tank (not shown) and discharges it downstream.

First, we will explain the configuration of the volute pump 10.

Referring to FIG. 1, the volute pump 10 comprises a pump casing 20, a rotating shaft 30 attached to the pump casing 20, and an impeller 35 attached to the rotating shaft 30. The volute pump 10 also comprises a ball bearing (bearing) 40 and a thrust bearing 45 on the upper side (outside) of the pump casing 20, which rotatably support the rotating shaft 30. The lubrication device 50 of this embodiment is attached so as to surround the ball bearing 40, and circulates and supplies lubricating oil to the ball bearing 40.

The pump casing 20 includes a suction bend 21 and a volute casing 22 attached to the upper side of the suction bend 21. The pump casing 20 also includes a base 24 attached to the upper side of the volute casing 22.

The suction bend 21 is a curved pipe that allows the pumped water to flow from the inlet 21a at the lower end to the outlet 21b at the upper end, from a horizontal direction upwards in a vertical direction.

The volute casing 22 has a volute passage 23 that is shaped like a volute and extends around the rotating shaft 30. An outlet section 22b including an outlet port is formed on the downstream side of the volute passage 23 in the outer wall 22a that defines the volute passage 23. The outer wall 22a is provided with a connection port 22c and an attachment port 22d. The connection port 22c spatially connects the connected suction bend 21 to the volute passage 23. The attachment port 22d is provided so as to be located directly above the connection port 22c and within the base 24, and allows the installation of the impeller 35 in the volute passage 23.

The base 24 includes a fixed seat 25, an outer wall 27, a cover wall 28, and an insertion portion 29, with a ball bearing 40 attached in the insertion portion 29 and a thrust bearing 45 attached on the cover wall 28.

The fixed seat 25 is attached liquid-tight to the mounting port 22d of the volute casing 22. The fixed seat 25 is integrally provided with a protector 25a that supports the impeller 35. Referring to FIG. 2, the fixed seat 25 is formed with an insertion hole 25b through which the rotating shaft 30 is inserted. A mechanical seal 26 is attached between the insertion hole 25b and the rotating shaft 30 to prevent leakage of pumped water.

Continuing to refer to FIG. 2, the outer peripheral wall 27 has a cylindrical lower portion 27a that protrudes upward from the outer periphery of the fixed seat 25, and a conical upper portion 27b that is attached to the upper end of the lower portion 27a. The upper portion 27b has a plurality of radially penetrating openings 27c that are spaced apart in the circumferential direction.

The cover wall 28 is disk-shaped and is attached to the upper end of the upper portion 27b. The cover wall 28 has an insertion hole 28a through which the rotating shaft 30 passes. The diameter of the insertion hole 28a is larger than the diameter of the rotating shaft 30, and the gap between them is covered by a thrust bearing 45.

2 and 3, the insertion portion 29 is cylindrical and extends vertically from the outer periphery of the insertion hole 28a toward the spiral casing 22, surrounding a portion of the rotating shaft 30. The insertion portion 29 has a flange portion 29a at its upper end for attachment to the cover wall 28. In this embodiment, the insertion portion 29 is cylindrical, but may be polygonal as long as it does not interfere with the flow of the lubricating oil, which will be described later.

Referring to FIG. 1, the rotating shaft 30 is disposed so as to pass through the insertion portion 29 and extend vertically relative to the pump casing 20. The rotating shaft 30 has an inner portion 31 that passes through the fixed seat 25 and is disposed in the volute passage 23 (inside the pump casing 20), and an outer portion 32 that is disposed outside the pump casing 20. The upper end of the outer portion 32 passes through the base 24 and protrudes upward from the cover wall 28. A coupling 33 is attached to the upper end of the outer portion 32, which mechanically connects the output shaft of an electric motor (drive unit) (not shown).

Continuing to refer to FIG. 1, the impeller 35 is attached to the lower end of the inner portion 31 (rotating shaft 30) and is disposed in the volute passage 23 through the mounting port 22d. When the rotating shaft 30 is rotated by the electric motor during operation of the volute pump 10, the impeller 35 rotates integrally. As a result, water in the suction tank is sucked in through the suction bend 21 and discharged from the discharge portion 22b through the volute passage 23.

The ball bearing 40 is a radial bearing (rolling bearing) and is mounted in the insertion portion 29 of the base 24 (pump casing 20). However, a roller bearing may be used instead of the ball bearing 40, and the bearing in which the lubrication device 50 is disposed can be changed as necessary as long as it is configured to rotatably support the rotating shaft 30.

2 and 4, the ball bearing 40 comprises an inner ring 41 and an outer ring 42, both of which are circular, and a number of spherical ball members 43. The inner ring 41 is attached to the rotating shaft 30 and rotates integrally with the rotating shaft 30 when the rotating shaft 30 rotates. The outer ring 42 is attached to the insertion portion 29 so as to face the inner ring 41, and does not rotate even when the rotating shaft 30 rotates. The ball members 43 are disposed between the inner ring 41 and the outer ring 42 so as to be able to roll freely. There is a gap between the outer peripheral surface of the inner ring 41 and the inner peripheral surface of the outer ring 42, which is sufficient to allow the flow of lubricating oil and prevent the ball members 43 from falling off.

Referring to FIG. 1, the thrust bearing 45 is attached to the cover wall 28 of the base 24, rotatably supports the upper end of the rotating shaft 30, and receives the force acting in the axial direction of the rotating shaft 30.

Next, the configuration of the lubrication device 50 will be described in detail.

Referring to FIG. 1, the lubrication device 50 is attached so as to surround the ball bearings 40, and circulates and supplies lubricating oil to the ball bearings 40 when the centrifugal pump 10 is in operation. Referring to FIG. 2, the lubrication device 50 includes the aforementioned insertion portion 29 provided in the pump casing 20, an oil tank 60 that surrounds the lower side of the insertion portion 29 from near the upper end thereof, and an air-cooling mechanism 70 for air-cooling the lubricating oil in the oil tank 60. Of these, the insertion portion 29 is a stationary member that does not rotate or move, and the oil tank 60 is a rotating member that rotates integrally with the rotating shaft 30.

Continuing to refer to FIG. 2, the insertion portion 29 is provided on the base 24 as described above, and the ball bearing 40 is attached below the center of the overall height. The insertion portion 29 is provided with a through hole 55 that allows the passage of lubricating oil and air, a flow straightening vane 56 that promotes the circulation of the lubricating oil, and a rib 58 that suppresses leakage of the lubricating oil.

2 and 3, the through hole 55 is provided in the insertion portion 29 above the ball bearing 40 and below the upper end of the oil tank 60, and penetrates the insertion portion 29 in the radial direction. The through hole 55 is preferably provided in the middle region when the total height of the insertion portion 29 including the straightening vane 56 is divided into three equal parts, and is provided approximately in the center in this embodiment. Referring to FIG. 5, a plurality of through holes 55 (four in this embodiment) are provided at intervals in the circumferential direction of the insertion portion 29. The diameter of the through hole 55 is large enough to ensure an air ventilation area without clogging with viscous lubricating oil.

2 and 3, the flow straightening vane 56 is provided at the lower end of the insertion portion 29 via an annular end plate 57 extending in the radial direction of the rotating shaft 30. More specifically, the flow straightening vane 56 is provided integrally with the end plate 57, which is attached to the lower end of the insertion portion 29. Referring to FIG. 2, the inner diameter of the end plate 57 is larger than the outer diameter of the rotating shaft 30 and smaller than the inner diameter of the insertion portion 29. The outer diameter of the end plate 57 is larger than the outer diameter of the insertion portion 29 including the rib 58.

Referring to FIG. 6, the flow straightening vane 56 has an arc-shaped (semi-cylindrical) cross section that protrudes in the direction R (counterclockwise) in which the rotating shaft 30 rotates, and protrudes downward from the end plate 57 along the rotating shaft 30. In the radial direction of the rotating shaft 30, the flow straightening vane 56 causes the lubricating oil to flow from the outside to the inside of the oil tank 60.

2 and 3, the rib 58 is a convex ridge that protrudes radially outward from the outer surface of the insertion portion 29 and extends along the rotation shaft 30 from the end plate 57 to the same height as the upper end of the oil tank 60. Referring to FIG. 5, a plurality of ribs 58 (12 in this embodiment) are provided at intervals around the circumference of the insertion portion 29 so as not to coincide with the angular position at which the through hole 55 is formed.

Referring to FIG. 2, the oil tank 60 is attached to the rotating shaft 30 and rotates integrally with the rotating shaft 30. The oil tank 60 has a bottom 62 attached to the rotating shaft 30 and an outer periphery 69 protruding upward from the outer periphery of the bottom 62. The upper end of the outer periphery 69 is an opening that is open to the atmosphere. More specifically, as shown in FIG. 2 and FIG. 3, the oil tank 60 is composed of a lower tank body 61 including the bottom 62, and an upper tubular member 64.

The tank body 61 is made of a metal with good thermal conductivity (e.g., copper or aluminum alloy), has a bottom 62 and a peripheral wall 63, and surrounds the end plate 57 and the flow straightening vanes 56.

The bottom 62 is annular and is spaced below the lower end of the flow straightening vane 56 (insertion portion 29), covering the underside of the insertion portion 29. The inner periphery of the bottom 62 is provided with a cylindrical mounting portion 62a for liquid-tight mounting to the rotating shaft 30. The outer diameter of the bottom 62 is larger than the outer diameter of the end plate 57.

The peripheral wall portion 63 is cylindrical, continues to the outer periphery of the bottom portion 62, and constitutes part of the outer periphery 69. The peripheral wall portion 63 extends to the upper side of the end plate 57, and surrounds the end plate 57 including the lower end of the insertion portion 29 and the flow straightening vane 56. The inner diameter of the peripheral wall portion 63 is larger than the outer diameter of the end plate 57, and a gap is formed between the peripheral wall portion 63 and the end plate 57 that is large enough to allow the flow of lubricating oil and prevent interference between them.

Referring to FIG. 2, the inner surface of the tank body 61 facing the flow straightening vane 56 stores lubricating oil for lubricating the ball bearings 40. In addition, the outer surface of the tank body 61 opposite the flow straightening vane 56 is integrally provided with a vane 71, which will be described in detail later.

The tubular member 64 is attached to the upper end of the tank body 61 and constitutes most of the outer periphery 69. The tubular member 64 extends from near the lower end of the insertion portion 29 above the through hole 55 (ball bearing 40) and surrounds the insertion portion 29. The inner diameter of the tubular member 64 is larger than the dimension from the axis of the rotating shaft 30 to the tip of the rib 58, and a gap is provided between the tubular member 64 and the insertion portion 29 to allow the flow of lubricating oil, and a gap is provided between the tubular member 64 and the rib 58 to prevent interference between them.

Continuing to refer to FIG. 2, the tubular member 64 of this embodiment includes a window portion 65 for checking the flow of the lubricating oil, a lower tubular portion 66 below the window portion 65, and an upper tubular portion 67 above the window portion 65. The tubular member 64 also includes a connecting vane 68 for forming an integral structure between the lower tubular portion 66 and the upper tubular portion 67. Of these, the portions other than the window portion 65 are made of a metal with good thermal conductivity (e.g., copper or an aluminum alloy).

The window portion 65 is provided so as to be located radially outward of the rotating shaft 30 with respect to the through hole 55. With reference to Figures 3 and 5, the window portion 65 is made of a transparent resin (e.g., acrylic resin) that allows the inside to be seen from the outside, and is formed into a cylindrical shape between the lower tube portion 66 and the upper tube portion 67 by outsert processing.

2 and 3, the lower tube portion 66 extends from the window portion 65 to the upper end of the tank body 61. In other words, the lower tube portion 66 is cylindrical, has a flange portion 66a at its lower end for connecting to the upper end of the peripheral wall portion 63, and extends to the lower end of the through hole 55.

Continuing to refer to Figures 2 and 3, the upper tube portion 67 extends upward from the window portion 65. More specifically, the upper tube portion 67 is cylindrical, and the upper end of the upper tube portion 67 is located below the flange portion 29a of the insertion portion 29 with a gap therebetween.

Of the tank body 61 and the tubular member 64 configured as described above, the peripheral wall portion 63, the lower tubular portion 66, the window portion 65, and the upper tubular portion 67 form a single outer periphery 69.

2 and 3, a labyrinth structure 67a is provided near the upper end of the outer circumferential portion 69 (upper cylinder portion 67), i.e., above the through hole 55 of the oil tank 60. The labyrinth structure 67a is composed of a pair of annular grooves recessed radially outward from the inner circumferential surface of the upper cylinder portion 67 in a semicircular cross section. This labyrinth structure 67a uses the surface tension of the attached hydraulic oil to suppress the upward flow (passage) of the hydraulic oil and suppress leakage of lubricating oil from the upper end of the upper cylinder portion 67. On the other hand, the labyrinth structure 67a allows air that has flowed into the outer circumferential portion 69 from the upper end of the upper cylinder portion 67 to pass through to the through hole 55 side.

Continuing to refer to Figures 2 and 3, the connecting vane 68 is provided by extending a specific guide vane 68a from among the multiple guide vanes 68a provided in the lower cylinder portion 66.

The guide vanes 68a protrude radially outward from the outer surface of the lower cylinder portion 66 and extend along the rotation shaft 30 from the lower end of the lower cylinder portion 66 to near the upper end. With reference to Figures 3 and 4, multiple guide vanes 68a (24 in this embodiment) are provided at intervals around the circumference of the lower cylinder portion 66.

3 and 5, the connecting vane 68 extends from the lower cylinder portion 66 across the window portion 65 to the upper cylinder portion 67, and protrudes radially outward from the outer surfaces of these portions. The amount of protrusion of the connecting vane 68 in the radial direction is smaller than the amount of protrusion of the guide vane 68a. In this embodiment, of the 24 equally spaced guide vanes 68a, the connecting vane 68 protrudes integrally from the upper ends of four guide vanes 68a located at 90 degree intervals. The connecting vane 68 including the guide vane 68a extends from the lower cylinder portion 66 to near the upper end of the upper cylinder portion 67.

In addition, guide vanes 68a other than the specific guide vanes 68a that are equipped with the connecting vanes 68 may not be provided. Also, the connecting vanes 68 and the guide vanes 68a may be provided separately. Also, if multiple window portions 65 are provided intermittently at intervals in the circumferential direction and the lower cylindrical portion 66 and the upper cylindrical portion 67 are made into an integral structure, the connecting vane 68 may not be provided.

Referring to FIG. 2, the air-cooling mechanism 70 includes a blade 71 that rotates integrally with the rotation of the rotating shaft 30, and a blade cover 75 that surrounds the blade 71 and the lower part of the outer periphery 69, and forcibly air-cools the lubricating oil in the oil tank 60. The blade cover 75 is attached to the base 24 (pump casing 20) and is a stationary member that does not rotate or move.

Referring to Figures 2 and 3, multiple impellers 71 are provided radially on the outer surface of the tank body 61 (oil tank 60). When the centrifugal pump 10 is operated, the impellers 71 rotate together with the oil tank 60, blowing air from the inside to the outside in the radial direction of the rotating shaft 30.

Specifically, the blade 71 comprises a first portion 72 provided on the bottom 62 of the oil tank 60, and a second portion 73 provided on the peripheral wall portion 63 (outer periphery 69). The first portion 72 protrudes downward from the bottom portion 62 and extends radially outward from the mounting portion 62a to the peripheral wall portion 63. The second portion 73 is connected to the radial outer end of the first portion 72 and extends along the rotation axis 30 to near the upper end of the peripheral wall portion 63.

2 and 6, the blade cover 75 includes a first cover 76 that covers the outside of the blade 71, and a second cover 77 that further covers the outside of the first cover 76. In this embodiment, the first cover 76 and the second cover 77 are integrally provided via a plurality of connecting plates 78, and are attached to the base 24 via a bracket 79 protruding from the second cover 77. However, the first cover 76 and the second cover 77 may be provided separately and attached individually to the base 24.

The first cover 76 has a first bottom portion 76a that is spaced apart from the bottom of the first portion 72 of the blade 71, and a first outer periphery portion 76b that protrudes upward from the outer periphery of the first bottom portion 76a.

The first bottom 76a is an annular plate that surrounds the rotating shaft 30. The inner diameter of the first bottom 76a is larger than the outer diameter of the rotating shaft 30, and a gap is provided between them to allow air to pass through. The outer diameter of the first bottom 76a is larger than the dimension from the axis of the rotating shaft 30 to the radial outer end of the second portion 73 of the blade 71.

The first outer periphery 76b is cylindrical and connected to the outer periphery of the first bottom 76a. The inner diameter of the first outer periphery 76b is larger than the dimension from the axis of the rotating shaft 30 to the radial outer end of the second portion 73, and a gap is provided between the first outer periphery 76b and the peripheral wall 63 to allow air to pass through. The upper end of the first outer periphery 76b is positioned at the same position as the upper end of the lower cylinder 66 of the oil tank 60 so that the window 65 can be seen through the opening 27c from outside the base 24.

The second cover 77 has a second bottom portion 77a arranged below the first bottom portion 76a at a distance, and a second outer periphery portion 77b protruding upward from the outer periphery of the second bottom portion 77a, and guides air outside the first cover 76 toward the inner end side of the blades 71.

The second bottom 77a is an annular plate that surrounds the rotating shaft 30. The inner diameter of the second bottom 77a is larger than the outer diameter of the rotating shaft 30 and smaller than the inner diameter of the first bottom 76a. The outer diameter of the second bottom 77a is larger than the outer diameter of the first bottom 76a and smaller than the inner diameter of the lower portion 27a. A cylindrical insertion portion 77c that surrounds the rotating shaft 30 is provided on the inner periphery of the second bottom 77a.

The second outer periphery 77b is cylindrical and connected to the outer periphery of the second bottom 77a. The inner diameter of the second outer periphery 77b is larger than the outer diameter of the first outer periphery 76b, and a gap is provided between them to allow air to pass through. The upper end of the second outer periphery 77b is lower than the upper end of the first outer periphery 76b, and is located at a height approximately half the total height of the first outer periphery 76b.

The connecting plate 78 has an upper end connected to the first bottom 76a and a lower end connected to the second bottom 77a, and connects the first bottom 76a and the second bottom 77a. The connecting plates 78 extend in the radial direction of the rotating shaft 30 and are provided radially at intervals in the circumferential direction. When the volute pump 10 is in operation, the connecting plate 78 functions as a straightening plate that straightens the air passing between the covers 76 and 77 toward the inner ends of the blades 71.

The brackets 79 protrude radially outward from the second outer periphery 77b, and multiple brackets (six in this embodiment) are provided at intervals in the circumferential direction. The outer ends of the brackets 79 are mechanically connected to the lower portion 27a of the base 24. In this way, the entire blade cover 75 is attached to the base 24.

Referring to FIG. 2, a circular top plate 80 is provided on the upper end side of the insertion portion 29, against which the air blown out from the first cover 76 collides and is guided into the oil tank 60. The top plate 80 is attached to the underside of the flange portion 29a so as to be connected to the insertion portion 29, and covers the opening at the upper end of the outer periphery 69 with a gap that allows air to flow. The outer diameter of the top plate 80 is equal to the inner diameter of the first cover 76.

2 and 3, the flange portion 29a of the insertion portion 29 located above the through hole 55 has a plurality of (four in this embodiment) radially penetrating through holes 29b spaced apart in the circumferential direction. The diameter of the through holes 29b is large enough to allow air to pass through, and when the centrifugal pump 10 is in operation, the through holes 29b function as vent holes through which air that has passed between the oil tank 60 and the insertion portion 29 and through the through holes 55 flows out to the outside of the insertion portion 29. The diameter of the through holes 29b is large enough to insert an oil supply pipe 82 for refilling oil, and when the centrifugal pump 10 is stopped, the through holes 29b function as an inlet for hydraulic oil.

Next, referring to Figure 2, the flow of lubricating oil and air during operation of the centrifugal pump 10 will be described. In Figure 2, the solid arrows indicate the flow of lubricating oil, and the dashed arrows indicate the flow of air.

First, when the centrifugal pump 10 is stopped, the oil tank 60 is filled with lubricating oil up to the end plate 57. The inside of the base 24 in which the lubricating device 50 is located is at atmospheric pressure because it is connected to the outside through the opening 27c.

When the operation of the volute pump 10 is started and the oil tank 60 rotates integrally with the rotating shaft 30, the lubricating oil rotates in the same direction together with the oil tank 60. At this time, since the flow speed (angular velocity) of the lubricating oil in the inner and outer parts of the oil tank 60 in the radial direction of the rotating shaft 30 is constant, the circumferential speed in the oil tank 60 is faster on the outer side than on the inner side in the radial direction.

In this state, the straightening vanes 56 in the oil tank 60 cause the lubricating oil on the radially outer side, where the circumferential speed is high, to flow (guide) to the radially inner side, where the circumferential speed is low. As a result, the lubricating oil in the inner part of the oil tank 60 is pushed up and supplied to the ball bearing 40 through the space between the insertion part 29 and the rotating shaft 30. The lubricating oil that has passed through the ball bearing 40 then flows from the inside to the outside of the insertion part 29 through the through hole 55 provided on the upper side of the ball bearing 40.

Then, the lubricating oil that reaches the gap between the outer periphery 69 of the oil tank 60 and the insertion portion 29 returns to the bottom 62 side of the oil tank 60 through the gap between them. At this time, the flow of the lubricating oil from the through hole 55 toward the upper side is prevented by air circulation, which will be described in detail later, and by the rib 58 provided on the insertion portion 29, which suppresses the circumferential flow. Therefore, the lubricating oil flows toward the bottom 62 side of the oil tank 60.

In this way, the lubrication device 50 of this embodiment can circulate and supply lubricating oil to the ball bearings 40 with a simple configuration, without using special mechanisms such as piping or oil lifters.

On the other hand, when the oil tank 60 rotates due to the rotation of the rotating shaft 30, the blades 71 also rotate in the same direction. As a result, the air located on the rotating shaft 30 side is sent outward in the radial direction. The sent cooling air flows upward through the gap between the outer periphery 69 of the oil tank 60 and the first outer periphery 76b of the first cover 76. In addition, because the inner end side of the blades 71 becomes negative pressure, the air inside the base 24 (outside the first cover 76) flows toward the rotating shaft 30 side through the gap between the first cover 76 and the second cover 77.

The cooling air is sent out from the first cover 76 through the spaces between the adjacent guide vanes 68a and the connecting vanes 68, and collides with the top plate 80. Some of the air then flows into the oil tank 60 from the upper end of the outer periphery 69, and the remainder flows away from the oil tank 60.

The cooling air that flows into the oil tank 60 flows downward between the outer periphery 69 and the insertion portion 29, and when it reaches the through hole 55, the circulating lubricating oil prevents it from flowing any further downward. As a result, it flows from the outside to the inside of the insertion portion 29 through the through hole 55, and since the lubricating oil also prevents it from flowing downward here, it flows upward between the insertion portion 29 and the rotating shaft 30. Then, when it reaches the top end of the insertion portion 29, it flows out of the insertion portion 29 through the through hole 29b.

In this way, in the lubrication device 50 of this embodiment, the cooling air flows along the oil tank 60 due to the vanes 71 that rotate integrally with the rotating shaft 30, so that the lubricating oil in the oil tank 60 can be forcibly air-cooled through the oil tank 60.

The lubrication device 50 configured in this manner has the following features:

An oil tank 60 is provided that rotates integrally with the rotating shaft 30, and the insertion portion 29 of the rotating shaft 30 is provided with a through hole 55 that returns the lubricating oil that has passed through the ball bearings 40. Furthermore, at the lower end of the insertion portion 29, a flow straightening vane 56 is provided that causes the lubricating oil to flow from the outside to the inside in the radial direction of the rotating shaft 30 within the oil tank 60. This allows the lubricating oil to be circulated and supplied to the ball bearings 40 without using piping or an oil lifter, simplifying the structure of the lubrication device 50 and making it more compact.

A number of ribs 58 are provided on the outer periphery of the insertion portion 29. These ribs 58 can suppress the circumferential flow of the lubricating oil that has flowed through the through hole 55 to the outside of the insertion portion 29. As a result, the flow of the lubricating oil toward the upper end of the oil tank 60 can be suppressed, and therefore leakage of the lubricating oil from the upper end of the oil tank 60 can be suppressed.

Air blowing vanes 71 are provided on the bottom 62 of the oil tank 60, and a first cover 76 that surrounds the vanes 71 is attached to the pump casing 20. Therefore, the lubricating oil can be forcibly cooled through the oil tank 60 by the air flowing outside the oil tank 60. As a result, the lubricating oil can be maintained at a temperature lower than the allowable temperature, which essentially eliminates restrictions on the operating time of the pump 10.

The blades 71 have a first portion 72 provided on the bottom 62 and a second portion 73 provided on the outer periphery 69. This ensures a sufficient amount of air flow, ensuring forced cooling of the lubricating oil.

The pump casing 20 is fitted with a second cover 77 that guides the air outside the first cover 76 to the impeller 71. This allows the air to circulate and ensures forced cooling of the lubricating oil through the oil tank 60.

The first cover 76 has a first bottom 76a and a first outer periphery 76b, and the second cover 77 has a second bottom 77a and a second outer periphery 77b, with the first bottom 76a and the second bottom 77a being connected via a connecting plate 78. The air flowing toward the impeller 71 is rectified by the connecting plate 78, which promotes air circulation. In addition, the first cover 76 and the second cover 77 can be handled as a single unit, which improves workability during assembly or maintenance of the pump 10.

A top plate 80 is provided to guide the air blown out from the first cover 76 between the oil tank 60 and the insertion portion 29, and the insertion portion 29 is provided with a through hole (air vent) 29b through which the air that has passed through the through hole 55 flows out to the outside of the insertion portion 29. Therefore, the air circulating around the insertion portion 29 can suppress the upward flow of the lubricating oil that has passed through the through hole 55, so leakage of the lubricating oil from the oil tank 60 can be effectively suppressed.

A labyrinth structure 67a is provided above the through-hole 55 of the oil tank 60, which prevents the passage of lubricating oil while allowing air to pass through. Therefore, even if the lubricating oil that passes through the through-hole 55 flows toward the upper end of the oil tank 60, leakage of the lubricating oil out of the oil tank 60 can be prevented.

A window 65 is provided on the outer periphery 69 of the oil tank 60. This allows the circulation state of the lubricating oil in the oil tank 60 to be confirmed through the opening 27c and the window 65. If it is determined that there is a shortage of lubricating oil, the oil tank 60 can be replenished with lubricating oil by inserting an oil supply pipe 82 into a specified through hole 29b. As a result, it is possible to prevent the pump 10 from operating when there is a shortage of lubricating oil.

The window portion 65 of the oil tank 60 is cylindrical, and the lower cylinder portion 66 below the window portion 65 and the upper cylinder portion 67 above it are connected by a connecting vane 68. Therefore, the circulation state of the lubricating oil in the rotating oil tank 60 while the pump 10 is in operation can be easily confirmed through the cylindrical window portion 65. Furthermore, the surface area of the oil tank 60 is increased by the connecting vane 68, improving the cooling efficiency of the lubricating oil.

A number of guide vanes 68a extending along the rotating shaft 30 are provided on the outer periphery 69 of the oil tank 60. These guide vanes 68a increase the surface area of the oil tank 60, improving the cooling efficiency of the lubricating oil.

Other embodiments and various modified examples of the present invention will be described below, but in these descriptions, points that are not specifically mentioned are the same as those in the first embodiment. In the drawings referred to below, elements that are the same as those in the first embodiment are given the same reference numerals.

Second Embodiment
7 shows a lubrication device 50 according to a second embodiment. This lubrication device 50 differs from the lubrication device 50 according to the first embodiment in that a guide portion 80a that guides the cooling air blown by the vanes 71 into the oil tank 60 is provided on the top plate 80.

The guide portion 80a is provided on the radially outer side of the top plate 80. The guide portion 80a is inclined downward as it moves from the radially inner side to the radially outer side. The outer periphery of the guide portion 80a is located radially outer than the first outer periphery 76b of the first cover 76.

The lubrication device 50 of the second embodiment configured in this manner can achieve the same effects and advantages as the first embodiment. Moreover, most of the cooling air sent out from the first cover 76 can be guided into the oil tank 60 by the guide portion 80a. As a result, the amount of air that flows in and circulates between the outer periphery 69 of the oil tank 60 and the insertion portion 29 can be secured, so leakage of lubricating oil from the oil tank 60 can be reliably prevented.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

For example, the straightening vane 56 may be directly connected to the lower end of the insertion portion 29 without providing an end plate 57.

The ribs 58 may not be provided on the outer periphery of the insertion portion 29. Alternatively, the air blown out by the blades 71 may not flow into the oil tank 60.

The blade 71 may be configured with only the first portion 72 protruding from the bottom portion 62, without providing a second portion 73 protruding from the peripheral wall portion 63.

The blade cover 75 may be composed of only the first cover 76 without providing the second cover 77.

The oil tank 60 may be configured without the window portion 65. It may also be configured without the labyrinth structure portion 67a.

The pump to which the lubrication device 50 for the bearing 40 is applied may be a vertical shaft pump with a straight lift pipe, and the lubrication device 50 of the present invention can be applied to any pump with a rotating shaft that extends vertically and is supported by a bearing, and the same action and effect can be obtained.

REFERENCE SIGNS LIST 10 Volute pump 20 Pump casing 21 Suction bend 21a Inlet 21b Outlet 22 Volute casing 22a Outer wall 22b Discharge portion 22c Connection port 22d Mounting port 23 Volute passage 24 Base 25 Fixing seat 25a Protector 25b Insertion hole 26 Mechanical seal 27 Outer wall 27a Lower portion 27b Upper portion 27c Opening 28 Cover wall 28a Insertion hole 29 Insertion portion 29a Flange portion 29b Through hole (vent hole)
30 Rotating shaft 31 Inner part 32 Outer part 33 Coupling 35 Impeller 40 Ball bearing (bearing)
Description of the Reference Signs 41 Inner ring 42 Outer ring 43 Ball member 45 Thrust bearing 50 Lubrication device 55 Through hole 56 Flow straightening vane 57 End plate 58 Rib 60 Oil tank 61 Tank body 62 Bottom 62a Mounting portion 63 Peripheral wall portion 64 Cylindrical member 65 Window portion 66 Lower cylindrical portion 66a Flange portion 67 Upper cylindrical portion 67a Labyrinth structure portion 68 Connecting vane 68a Guide vane 69 Outer periphery 70 Air cooling mechanism 71 Blade 72 First portion 73 Second portion 75 Blade cover 76 First cover 76a First bottom portion 76b First outer periphery portion 77 Second cover 77a Second bottom portion 77b Second outer periphery portion 77c Insertion portion 78 Connecting plate 79 Bracket 80 Top plate 80a Guide portion 82 Oil supply pipe

Claims (11)

A bearing lubrication device that is attached to a cylindrical insertion portion formed in a pump casing so as to surround a rotating shaft extending in a vertical direction and rotatably supports the rotating shaft, comprising:
an oil tank that is disposed below the insertion portion and has a bottom portion attached to the rotating shaft, and an outer periphery that protrudes from an outer periphery of the bottom portion to a position above the bearing and surrounds the insertion portion, and that rotates integrally with the rotating shaft;
a through hole provided in the insertion portion so as to be located above the bearing and below an upper end of the outer circumferential portion of the oil tank, the through hole penetrating the insertion portion in the radial direction of the rotating shaft and allowing the flow of lubricating oil supplied from inside the oil tank;
A straightening vane is provided at a lower end of the insertion portion to cause the lubricating oil to flow from the outside to the inside of the oil tank in the radial direction of the rotating shaft , and further
a blade provided on at least an outer surface of the bottom of the oil tank and configured to blow air from the inside to the outside in a radial direction of the rotating shaft;
a first cover attached to the pump casing and surrounding the impeller and at least a portion of the outer periphery of the oil tank;
A bearing lubrication device comprising : The bearing lubrication device according to claim 1, wherein the outer periphery of the insertion portion is provided with a plurality of ribs extending along the rotation shaft. 3. The bearing lubrication device according to claim 1, wherein the vane has a first portion provided at the bottom of the oil tank and extending in the radial direction of the rotating shaft, and a second portion provided at the outer periphery of the oil tank and extending along the rotating shaft. 4. The bearing lubrication device according to claim 1, further comprising a second cover attached to the pump casing for guiding air outside the first cover to the vanes. the first cover has a first bottom portion disposed below the blade and a cylindrical first outer circumferential portion protruding upward from an outer periphery of the first bottom portion,
the second cover has a second bottom portion disposed below the first bottom portion and a cylindrical second outer periphery portion protruding upward from an outer periphery of the second bottom portion,
The first bottom portion and the second bottom portion are connected via a plurality of connecting plates extending in a radial direction of the rotating shaft.
5. A bearing lubricating device according to claim 4 . a top plate that is connected to the insertion portion, covers an upper end of the oil vat, and guides the air blown out from the first cover to a space between the oil vat and the insertion portion;
a vent hole provided in the insertion portion so as to be positioned above the through hole, through which the air that has passed through the through hole flows out to the outside of the insertion portion. 7. The bearing lubrication device according to claim 6 , wherein a labyrinth structure portion that restricts passage of the lubricating oil while allowing passage of the air is provided in the oil tank above the through hole. 8. The bearing lubrication device according to claim 1 , wherein the outer periphery of the oil tank is provided with a window for checking the flow of the lubricating oil. 9. The bearing lubrication device according to claim 8, wherein the outer circumferential portion of the oil tank has a cylindrical window portion, a lower cylindrical portion below the window portion, an upper cylindrical portion above the window portion, and a connecting vane connecting the lower cylindrical portion and the upper cylindrical portion . A bearing lubrication device that is attached to a cylindrical insertion portion formed in a pump casing so as to surround a rotating shaft extending in a vertical direction and rotatably supports the rotating shaft, comprising:
an oil tank that is disposed below the insertion portion and has a bottom portion attached to the rotating shaft, and an outer periphery that protrudes from an outer periphery of the bottom portion to a position above the bearing and surrounds the insertion portion, and that rotates integrally with the rotating shaft;
a through hole that is provided in the insertion portion so as to be located above the bearing and below an upper end of the outer circumferential portion of the oil tank, the through hole penetrating the insertion portion in the radial direction of the rotating shaft and allowing the flow of lubricating oil supplied from inside the oil tank;
Equipped with
A straightening vane is provided at a lower end of the insertion portion to cause the lubricating oil to flow from the outside to the inside of the oil tank in the radial direction of the rotating shaft, and further
A bearing lubrication device, wherein the outer periphery of the oil tank has a cylindrical window portion for checking the flow of the lubricating oil, a lower cylindrical portion below the window portion, an upper cylindrical portion above the window portion, and a connecting vane connecting the lower cylindrical portion and the upper cylindrical portion. The bearing lubrication device according to any one of claims 1 to 10, wherein a plurality of plate-shaped guide vanes extending along the rotating shaft are provided on the outer periphery of the oil tank.

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