CN114294256B

CN114294256B - Bearing lubricating structure and barrel pump with same

Info

Publication number: CN114294256B
Application number: CN202210108304.4A
Authority: CN
Inventors: 余敏; 余梦琪; 缪杰; 周维坚; 张丹艺
Original assignee: Zhejiang Pump Factory Co Ltd
Current assignee: Zhejiang Pump Factory Co Ltd
Priority date: 2022-01-28
Filing date: 2022-01-28
Publication date: 2023-04-11
Anticipated expiration: 2042-01-28
Also published as: CN114294256A; WO2023142188A1

Abstract

The invention relates to a bearing lubricating structure and a cylindrical belt pump with the same. The bearing lubricating structure is used for a barrel pump and comprises an oil tank, a main shaft and a duplex bearing, wherein the main shaft penetrates through the oil tank; the duplex bearing comprises two groups of bearings and an outer space ring, the outer space ring is positioned between the two groups of bearings and is fixedly connected with the outer rings of the two groups of bearings, and the outer space ring is provided with a plurality of first through holes along the radial direction; the duplex bearing divides the interior of the oil tank into an upper space and a lower space; the oil tank is also provided with a plurality of passages with the upper ends communicated with the upper space, the lower end of at least one passage is communicated with the first communication hole, and the lower ends of other passages are communicated with the lower space; the oil in the upper space can be introduced between the two groups of bearings through the passage communicated with the first communication hole at the lower end, and the oil in the part can change the flow direction in a self-adaptive manner according to the amount of the oil in the upper space, so that the dynamic balance of the amount of the oil in the circulation is realized, and the abnormal operation caused by too much or too little oil in the circulation is avoided.

Description

Bearing lubricating structure and barrel pump with same

Technical Field

The invention relates to the technical field of water pumps, in particular to a bearing lubricating structure and a barrel bag pump with the bearing lubricating structure.

Background

In order to avoid additional axial force and limit a shaft within an axial clearance range in two directions, the conventional barrel bag pump and other water pump shafts mostly adopt angular contact ball bearings which are arranged in a pair-to-pair manner; in consideration of the lubricating requirement of the bearing, the duplex bearing is mostly arranged in an oil tank filled with lubricating oil;

the lubricating oil in the oil tank is usually kept in a circulating state, and the bearing balls rotating at high speed pull the oil to be conveyed upwards to the upper part of the oil tank and flow back to the lower part of the oil tank through a passage so as to finish the lubrication of the bearing in the circulating process; however, the amount of oil circulated is easily affected by the factors such as the rotation speed of the main shaft, the amount of oil in the oil tank, whether the passage is smooth and the like, if the amount of oil in the circulation process is too small or too large, the former may cause insufficient lubrication of the bearing, and the latter may cause oil to be retained at the upper part of the oil tank, so that leakage is easily generated at the gland;

at present, after the condition that the oil volume of the oil tank inner loop is too little or too much appears, mostly can only observe the abnormal back of operation of oil tank at the user, through maintaining the oil tank in order to get rid of the factor that influences the circulating oil volume, efficiency is lower.

Disclosure of Invention

Therefore, the bearing lubricating structure capable of dynamically balancing the amount of circulating oil and the barrel pump with the bearing lubricating structure are needed to solve the problem that the amount of oil circulating in the oil tank is easily influenced by external factors to cause abnormal operation.

The invention firstly provides a bearing lubricating structure for a barrel pump, which comprises an oil tank, a main shaft and a duplex bearing, wherein the main shaft penetrates through the oil tank; the duplex bearing comprises two groups of bearings and an outer space ring, the outer space ring is positioned between the two groups of bearings and is fixedly connected with outer rings of the two groups of bearings, and the outer space ring is provided with a plurality of first through holes along the radial direction; the inner ring of the bearing is relatively fixed with the main shaft, and the outer ring of the bearing is relatively fixed with the oil tank so as to divide the interior of the oil tank into an upper space and a lower space through the duplex bearing; the oil tank is further provided with a plurality of passages with the upper ends communicated with the upper space, the lower end of at least one passage is communicated with the first communication hole, and the lower ends of the other passages are communicated with the lower space.

Above-mentioned bearing lubrication structure, the passageway through lower extreme and first through-hole intercommunication can introduce between two sets of bearings with the fluid in the headroom space, and this part fluid can be according to the change flow direction of the fluid volume self-adaptation in the headroom space to the dynamic balance of fluid volume in the realization is to the circulation, avoids leading to the condition emergence of operation anomaly because of the too much or too little fluid volume in the circulation.

In one embodiment, one passage is formed in each of the passages, the lower ends of which are communicated with the first communication hole and the lower end of which is communicated with the lower space, and the two passages are symmetrically arranged by taking the central axis of the main shaft as a center.

In one embodiment, the duplex bearing further comprises an inner spacer ring, the inner spacer ring is positioned between the two groups of bearings and fixedly connected with inner rings of the two groups of bearings, and the inner spacer ring is provided with a plurality of second communication holes in a penetrating manner along the radial direction; the bearing lubricating structure further comprises a shaft sleeve, the shaft sleeve is fixedly arranged on the main shaft, the inner ring of the bearing is fixedly arranged on the outer edge surface of the shaft sleeve, and a plurality of oil through grooves which are communicated with the lower space and the upper end of the shaft sleeve are formed in the outer edge surface of the shaft sleeve.

It can be understood that the oil liquid which is dragged and conveyed to the position between the two groups of bearings along the oil through groove by rotating the shaft sleeve can also change the flow direction in a self-adaptive manner according to the oil liquid amount in the upper space, so that the dynamic balance of the oil liquid amount in circulation is realized, and the self-adaptive adjusting capability of the oil liquid amount in circulation is further improved.

In one embodiment, the shaft sleeve is circumferentially provided with a plurality of oil return holes which are inclined from bottom to top in the direction away from the main shaft, and the oil return holes are communicated with the oil through groove.

It can be understood that the lubricating oil between the shaft sleeve and the main shaft can return to the oil through groove along the oil return hole under the action of centrifugal force, so that the amount of the oil which can be used for dynamic balance is increased.

In one embodiment, the bottom end of the oil tank is further provided with a sealing baffle sleeve, and the outer side of the sealing baffle sleeve is fixedly connected with the oil tank.

It can be understood that the sealing spacer sleeve can prevent the lubricating oil in the oil tank from leaking from the part penetrating through the oil tank along the main shaft, and further reduce the possibility of oil leakage.

In one embodiment, a part of the sealing spacer is located between the spindle and the shaft sleeve, and the top end of the sealing spacer corresponds to an inner side opening of the oil return hole.

It can be understood that, the fluid between sealed spacer and the main shaft, most can be under the rotation effect of main shaft, upwards carry and get rid of back to logical oil groove through the oil gallery to reach the effect that increases the sealed effect of sealed spacer, further reduce the possibility that fluid leaked.

In one embodiment, the bottom end of the shaft sleeve is located at the lower side of the duplex bearing, and the bottom end of the shaft sleeve is provided with a chamfer inclined from bottom to top in a direction away from the main shaft.

It can be understood that lubricating oil can throw away the ball down to duplex bearing along the chamfer under the centrifugal force effect to when satisfying lubricated demand, the oil liquid volume of upwards transporting under the operating condition has been reduced, thereby has reached the effect of avoiding lubricating oil to leak.

In one embodiment, the chamfer is inclined in a direction towards the balls of the bearing on the lower side.

It can be understood that the great proportion of fluid that throws away via the axle sleeve can directly be thrown away to lower row ball to through lower row ball upward transportation, with the transport efficiency who increases lubricating oil fluid.

In one embodiment, the outer edge surface of the shaft sleeve is symmetrically provided with two oil through grooves by taking the central axis of the main shaft as a center.

The second aspect of the present invention provides a cartridge pump comprising the above-described bearing lubrication structure.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a front view, in cross-section, schematic structural view of a pouch pump bracket portion in accordance with one embodiment of the present invention;

FIG. 2 is an enlarged schematic view of the structure at A in FIG. 1;

FIG. 3 is a front view, sectional structural view of a bearing lubrication structure according to another embodiment of the present invention;

FIG. 4 is an enlarged schematic view of the bushing of FIG. 3;

reference numerals: 10. an oil tank; 110. a box body; 120. a bearing housing; 130. a gland; 11. an upper space; 12. a lower space; 13. a passage; 14. sealing the blocking sleeve; 20. a main shaft; 30. a duplex bearing; 31. a bearing; 32. an outer space ring; 321. a first communication hole; 33. inner spacing rings; 331. a second communication hole; 40. a shaft sleeve; 41. an oil groove is communicated; 42. and an oil return hole.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "secured to" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used in the description of the present application are for illustrative purposes only and do not represent the only embodiments.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may mean that the first feature is in direct contact with the second feature or that the first feature is in indirect contact with the second feature via an intermediate medium. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the description of the present application, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 2, the present application provides a bearing lubrication structure for a cartridge pump, including an oil tank 10, a main shaft 20, and a duplex bearing 30, where the main shaft 20 penetrates through the oil tank 10; the duplex bearing 30 comprises two groups of bearings 31 and an outer space ring 32, the outer space ring 32 is positioned between the two groups of bearings 31 and is fixedly connected with the outer rings of the two groups of bearings 31, and the outer space ring 32 is provided with a plurality of first through holes 321 along the radial direction; the inner ring of the bearing 31 is fixed relative to the main shaft 20, and the outer ring is fixed relative to the oil tank 10, so that the interior of the oil tank 10 is divided into an upper space 11 and a lower space 12 by the duplex bearing 30; the fuel tank 10 is further provided with a plurality of passages 13 having upper ends communicating with the upper space 11, a lower end of at least one passage 13 communicating with the first communication hole 321, and a lower end of the other passage 13 communicating with the lower space 12.

The oil level in the oil tank 10 is usually at the level of the ball center of the lower bearing 31, so that after the main shaft 20 starts to rotate, the lubricating fluid is delivered upward to the upper space 11 by the traction force generated by the high-speed rotation of the balls of the bearing 31, and the oil in the upper space 11 can flow back to the lower space 12 through the passage 13 whose lower end is communicated with the lower space 12, so as to form an oil circuit circulation;

in this oil circulation, part of the oil in the upper space 11 will flow back to between the two sets of bearings 31 along the passage 13 whose lower end is communicated with the first communication hole 321:

if the oil amount in the upper space 11 is small, the oil amount conveyed upwards in the oil circuit circulation is small, and the pressure of the oil in the upper space 11 on the upper row of balls is small, so that the influence on the rotation of the upper row of balls to pull the oil upwards is small or even no influence is caused, and therefore the oil between the two groups of bearings 31 is pulled upwards by the upper row of balls to be transported, so that the oil amount transported upwards is increased, and the oil amount in the circulation is increased;

and the fluid volume in the upper space 11 this moment is more, it is more to represent the fluid volume of upwards carrying in the oil circuit circulation this moment promptly, and the fluid in the upper space 11 this moment is great to the pressure of last row of ball, and it is great to the influence that goes up the ball upwards traction fluid, therefore the difficult further upwards transportation of fluid between two sets of bearings 31, and can be under self action of gravity along the ball backward flow down of arranging down, and then hinder the ball upwards transportation fluid of arranging down, with the fluid volume that reduces the transportation that makes progress, and then reduce the fluid volume in the circulation.

Therefore, the oil in the upper space 11 can be introduced between the two sets of bearings 31 through the passage 13 with the lower end communicated with the first communication hole 321, and the flow direction of the part of the oil can be adaptively changed according to the oil amount in the upper space 11, so that the dynamic balance of the oil amount in the circulation is realized, and the abnormal operation caused by too much or too little oil amount in the circulation is avoided.

In the embodiment shown in fig. 2, the oil tank 10 includes a tank body 110, a bearing box 120 and a gland 130, wherein the bearing box 120 is located between the tank body 110 and the gland 130, and a flange portion of the bearing box 120 is fixedly connected with the tank body 110 and the gland 130, respectively, an outer ring of the bearing 31 is fixed with the bearing box 120, so that the outer ring of the bearing 31 is relatively fixed with the oil tank 10, and an inner space formed by the tank body 110 and the gland 130 is divided into two parts, namely an upper space 11 and a lower space 12, by the cooperation of the duplex bearing 30 and the bearing box 120;

a through hole is formed at the bottom end of the bearing housing 120, so that lubricating oil can enter the bearing housing 120 through the through hole and lubricate the duplex bearing 30; the top end of the duplex bearing 30 is located below the contact surface of the gland 130 and the bearing housing 120 to ensure that the highest point of the circulating oil is lower than the contact surface of the gland 130 and the bearing housing 120, thereby further reducing the possibility of lubricating oil leakage.

In the embodiment shown in fig. 2, one passage 13 is opened at each of the passages 13 having lower ends communicating with the first communication hole 321 and lower ends communicating with the lower space 12, and the two passages 13 are symmetrically arranged with respect to the central axis of the main shaft 20;

for the convenience of the following description, the passage 13, the lower end of which communicates with the first communication hole, is defined as an oil suction passage, which can perform an oil return function when self-balancing, and which mainly functions to draw oil upward in a normal operating state; a passage 13 whose lower end communicates with the lower space 12 is defined as an oil return passage, which mainly functions to return oil to the lower space 12, preventing the oil from being accumulated in the upper space 11;

the number of oil suction holes is reduced, the number of oil return holes is increased, and the increase of leakage risks caused by excessive accumulation of oil in the upper space 11 can be prevented; in addition, after the oil return effect is increased, the required circulating oil quantity can be correspondingly reduced.

Preferably, the number of the oil suction holes is one, the number of the oil return holes is seven, eight passages 13 are uniformly distributed in the circumferential direction by taking the main shaft 20 as the center, and through multiple test tests, the passages 13 arranged in the proportion and position relation can achieve a good oil lubrication circulation effect.

In the embodiment shown in fig. 3, the duplex bearing 30 further includes an inner spacer 33, the inner spacer 33 is located between the two sets of bearings 31 and is fixedly connected with the inner rings of the two sets of bearings 31, and the inner spacer 33 radially penetrates through the plurality of second communication holes 331; the bearing lubrication structure further includes a shaft sleeve 40, the shaft sleeve 40 is fixedly disposed on the main shaft 20, an inner ring of the bearing 31 is fixedly disposed on an outer edge surface of the shaft sleeve 40, and a plurality of oil through grooves 41 are formed in the outer edge surface of the shaft sleeve 40, wherein a lower end of each oil through groove is communicated with the lower space 12, and an upper end of each oil through groove is communicated with the second communication hole 331.

The oil through groove 41 can convey oil upwards along the oil through groove 41 by means of upward traction force generated by rotation of the shaft sleeve 40 after the shaft sleeve 40 is driven by the main shaft 20 to start rotating; since the inner spacer 33 has the second communication hole 331 formed therethrough and the upper end of the oil groove 41 communicates with the second communication hole 331, the oil is fed between the two sets of bearings 31 along the second communication hole 331.

If the oil amount in the upper space 11 is small, the oil amount conveyed upwards in the oil circuit circulation is small at the moment, the pressure of the oil in the upper space 11 on the upper row of balls is small at the moment, and the influence on the rotation of the upper row of balls to pull the oil upwards is small or even no influence is caused; therefore, compared with the prior art that the oil in the lower space 12 is drawn between the two sets of bearings 31 only by the rotation of the lower row of balls, in the present application, the oil in the lower space 12 can be drawn and conveyed between the two sets of bearings 31 along the oil through groove 41 by the rotation of the shaft sleeve 40, so that more oil can be conveyed to the upper space 11 through the upper row of balls to increase the oil amount in the circulation;

at this time, the oil amount in the upper space 11 is large, which means that the oil amount conveyed upwards in the oil circuit circulation is large at this time, the pressure of the oil in the upper space 11 on the upper row of balls is large at this time, and the influence on the upward traction of the oil on the upper row of balls is large, so that the oil between the two groups of bearings 31 is difficult to further transport upwards; therefore, the oil liquid which is drawn and conveyed between the two groups of bearings 31 along the oil through groove 41 flows back downwards along the lower row of balls under the action of the gravity of the oil liquid, so that the lower row of balls is prevented from conveying the oil liquid upwards, and the amount of the oil liquid which is conveyed upwards is reduced;

therefore, the flow direction of the oil liquid which is drawn and conveyed to the space between the two groups of bearings 31 along the oil through groove 41 can be adaptively changed according to the oil liquid amount in the upper space 11, so that the dynamic balance of the oil liquid amount in the circulation is realized, and the adaptive adjustment capability of the oil liquid amount in the circulation is further improved.

In the embodiment shown in fig. 3 and 4, the shaft sleeve 40 is circumferentially provided with a plurality of oil return holes 42 inclined from bottom to top in the direction away from the main shaft 20, and the oil return holes 42 are communicated with the oil through groove 41; so that the lubricating oil between the sleeve 40 and the main shaft 20 can be returned to the oil-passing groove 41 along the oil-returning holes 42 by centrifugal force to increase the amount of the oil that can be used for dynamic balance.

In the embodiment shown in fig. 3, a sealing spacer sleeve 14 is further arranged at the bottom end of the oil tank 10, and the outer side of the sealing spacer sleeve 14 is fixedly connected with the oil tank 10; the sealing sleeve 14 is able to avoid the leakage of the lubricant oil in the oil tank 10 from the place where the oil tank 10 is penetrated along the main shaft 20 by the principle of labyrinth seal, thereby reducing the possibility of oil leakage.

In the embodiment shown in fig. 3, a part of the seal retainer 14 is located between the main shaft 20 and the shaft sleeve 40, and the top end of the seal retainer 14 corresponds to the inner opening of the oil return hole 42; so that the most part of the oil between the sealing baffle sleeve 14 and the main shaft 20 can be upwards conveyed and thrown back to the oil through groove 41 through the oil return hole 42 under the rotating action of the main shaft 20, and the small part of the residual oil can be prevented from leaking from the lower side by depending on the sealing action of the sealing baffle sleeve 14, so that the sealing effect of the sealing baffle sleeve 14 is increased, and the possibility of oil leakage is further reduced.

In the embodiment shown in fig. 3, the bottom end of the shaft sleeve 40 is located at the lower side of the duplex bearing 30, and the bottom end of the shaft sleeve 40 has a chamfer inclined from bottom to top in a direction away from the main shaft 20.

In the above embodiment, in the static state, the initial oil level in the oil tank 10 only needs to be located below the duplex bearing 30 and submerge the bottom end of the shaft sleeve 40, and after the shaft sleeve 40 is driven by the main shaft 20 to start rotating, the lubricating oil can be thrown out to the balls of the bearing 31 located at the lower side along the bottom end chamfer of the shaft sleeve 40 under the action of centrifugal force, and is conveyed to the upper space 11 through the traction force generated by the rotation of the balls of the bearing 31, so as to complete the lubrication of the duplex bearing 30;

through the process of throwing away lubricating oil fluid with the chamfer as the intermediary to make also can realize the transport of making progress of fluid under the circumstances that initial oil level reduces, when satisfying lubricated demand, reduced the fluid volume of upwards transporting under the operating condition, avoid leading to easily taking place to leak because of the lubricating oil level is too high.

Of course, the bottom end of the shaft sleeve 40 may be provided with other commonly used guiding structures, such as a through hole with an inclined guiding hole, as long as the bottom end can convey the lubricating oil to a specified direction during rotation.

Also in the above embodiment, the inclination direction of the chamfer is toward the balls of the bearing 31 located on the lower side; so that the oil thrown out through the shaft sleeve 40 can be directly thrown to the balls of the lower bearing 31 in a large proportion and is conveyed upwards through the balls of the two bearings 31, and the conveying efficiency of the lubricating oil is increased.

In the embodiment shown in fig. 3, the outer edge surface of the shaft sleeve 40 is symmetrically provided with two oil through grooves 41 centered on the central axis of the main shaft 20; under this condition, the oil volume of upwards transporting through oil groove 41 can satisfy the lubricated demand of duplex bearing 30 just, and fluid can form unobstructed circulation, can not be detained in gland 130 and bearing box 120's contact surface department to reach the effect of avoiding lubricating oil to leak.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is specific and detailed, but not construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A bearing lubricating structure for a barrel pump is characterized by comprising an oil tank (10), a main shaft (20) and a duplex bearing (30), wherein the main shaft (20) penetrates through the oil tank (10);

the duplex bearing (30) comprises two groups of bearings (31) and an outer space ring (32), the outer space ring (32) is positioned between the two groups of bearings (31) and fixedly connected with the outer rings of the two groups of bearings (31), and the outer space ring (32) is provided with a plurality of first through holes (321) in a penetrating manner along the radial direction;

the inner ring of the bearing (31) is fixed relative to the main shaft (20), and the outer ring of the bearing is fixed relative to the oil tank (10) so as to divide the interior of the oil tank (10) into an upper space (11) and a lower space (12) through the duplex bearing (30);

the oil tank (10) is also provided with a plurality of passages (13) with the upper ends communicated with the upper space (11), the lower end of at least one passage (13) is communicated with the first communication hole (321), and the lower ends of other passages (13) are communicated with the lower space (12);

the duplex bearing (30) further comprises an inner spacer ring (33), the inner spacer ring (33) is positioned between the two groups of bearings (31) and fixedly connected with inner rings of the two groups of bearings (31), and the inner spacer ring (33) is provided with a plurality of second communicating holes (331) in a penetrating manner along the radial direction;

bearing lubrication structure still includes axle sleeve (40), axle sleeve (40) set firmly in main shaft (20), the inner circle of bearing (31) set firmly in the outer fringe face of axle sleeve (40), the outer fringe face of axle sleeve (40) seted up the multichannel lower extreme with lower part space (12) intercommunication and upper end with logical oil groove (41) of second intercommunicating pore (331) intercommunication.

2. The bearing lubrication structure according to claim 1, wherein one of the passages (13) having lower ends communicating with the first communication hole (321) and lower ends communicating with the lower space (12) is opened, and the two passages (13) are arranged symmetrically with respect to a central axis of the main shaft (20).

3. The bearing lubrication structure according to claim 1, wherein a plurality of oil return holes (42) inclined from bottom to top in a direction away from the main shaft (20) are circumferentially formed through the shaft sleeve (40), and the oil return holes (42) are communicated with the oil through grooves (41).

4. The bearing lubrication structure according to claim 3, wherein a sealing spacer sleeve (14) is further arranged at the bottom end of the oil tank (10), and the outer side of the sealing spacer sleeve (14) is fixedly connected with the oil tank (10).

5. The bearing lubrication structure according to claim 4, wherein a portion of the seal spacer (14) is located between the main shaft (20) and the bushing (40), and a top end of the seal spacer (14) corresponds to an inner opening of the oil return hole (42).

6. The bearing lubrication structure according to claim 1, wherein the bottom end of the shaft sleeve (40) is located at the lower side of the duplex bearing (30), and the bottom end of the shaft sleeve (40) has a chamfer inclined from bottom to top in a direction away from the main shaft (20).

7. Bearing lubrication structure according to claim 6, characterised in that the chamfer has an inclination directed towards the balls of the bearing (31) on the lower side.

8. The bearing lubrication structure according to claim 1, wherein the outer peripheral surface of the sleeve (40) is symmetrically provided with two oil grooves (41) centered on the central axis of the main shaft (20).

9. A cartridge pump characterized by comprising the bearing lubrication structure according to any one of claims 1 to 8.