A sliding bearing structure with sand-proof seal

Abstract

The application provides a sliding bearing structure with sandproof seal and belongs to the technical field of pumps. It solves the technical problems of the lack of effective isolation seal structure between the bearing chamber and the water inlet channel of the existing deep well pump, the invasion of the sand-containing water flow into the bearing chamber, the abrasive wear, the decline of the running accuracy and the stuck shaft and the like. The sliding bearing structure comprises a base, a pump shell fixedly connected to the upper end of the base, a guide vane and an impeller arranged in the pump shell, a motor fixedly connected to the upper end of the pump shell, a rotating shaft of the motor, the rotating shaft extending into the pump shell and the base, the impeller being fixedly connected to the rotating shaft, the base being formed with a water inlet and a shaft fixing portion, the water inlet being uniformly arranged around the shaft fixing portion in the circumferential direction, the rotating shaft extending into the shaft fixing portion, a sliding inner sleeve and a sliding outer sleeve being arranged between the rotating shaft and the shaft fixing portion, a bearing cover being sealingly and fixedly connected to the outer end of the shaft fixing portion, and a first sealing member being fixedly arranged at the inner end of the shaft fixing portion. The application has the advantages of reliable sandproof seal, long service life of the bearing and suitability for sand-containing high water pressure working conditions.

Description

Technical Field

[0001] This invention relates to the field of pump technology, specifically to a sliding bearing structure with a sand-proof seal. Background Technology

[0002] Deep well pumps, as water-lifting devices that operate submerged in water, are widely used in deep well water extraction, mine rescue, agricultural irrigation and drainage, and industrial water circulation. However, the working environment of deep well pumps is quite harsh, as the well water generally contains silt particles of varying sizes. These silt particles move at high speed with the water flow, posing a serious threat to the internal components of the pump, especially the rotating support components.

[0003] For example, the novel deep well pump disclosed in patent application number CN202311687702.7 has its impeller shaft rear end mounted in the bearing chamber of the inlet flange via an impeller shaft rear support and an impeller shaft rear bearing. This inlet flange is located at the water inlet end of the pump body, with multiple flow channels in the middle for water to enter. Because the impeller shaft rear bearing is directly mounted in the bearing chamber of the inlet flange, and there is no effective isolation and sealing structure between the bearing chamber and the inlet channel, sand-laden water easily intrudes into the bearing chamber and into the clearance between the impeller shaft rear bearing and the journal as it flows through the inlet flange into the impeller assembly's suction port. With prolonged operation, the intruded sand will cause continuous abrasive wear on the bearing, leading to increased bearing clearance, decreased operating accuracy, and in severe cases, even bearing jamming or seizure. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a sliding bearing structure with a sand-proof seal.

[0005] The objective of this invention can be achieved through the following technical solution: A sliding bearing structure with a sand-proof seal includes a base, a pump housing fixedly connected to the upper end of the base, a guide vane and an impeller disposed inside the pump housing, a motor fixedly connected to the upper end of the pump housing, the motor including a rotating shaft extending into the pump housing and the base, the impeller and the rotating shaft being fixedly connected, the base being formed with a water inlet and a shaft fixing part, the water inlet being evenly arranged around the shaft fixing part circumferentially, the rotating shaft extending into the shaft fixing part, a sliding inner sleeve and a sliding outer sleeve being disposed between the rotating shaft and the shaft fixing part, a bearing cover being sealed and fixedly connected to the outer end of the shaft fixing part, and a first sealing element being fixedly disposed at the inner end of the shaft fixing part.

[0006] Furthermore, the shaft fixing part includes a first cylindrical part and a second cylindrical part. The outer circumferential diameter of the second cylindrical part is larger than that of the first cylindrical part. An annular part protrudes outward from the inner circumference of the first cylindrical part. The outer circumferential surface of the sliding sleeve abuts and is fixed against the inner circumference of the first cylindrical part. The upper end of the sliding sleeve abuts and is fixed against the lower end of the annular part. The sliding inner sleeve is fixedly connected to the rotating shaft. The outer circumferential surface of the sliding inner sleeve slides and engages with the inner circumferential surface of the sliding sleeve. The upper end of the sliding inner sleeve extends out of the annular part. A first sealing groove is formed by the upper end surface of the annular part, the inner circumferential surface of the first cylindrical part, and the outer circumferential surface of the sliding inner sleeve. The first sealing element is located in the first sealing groove.

[0007] Furthermore, the first seal is a skeleton oil seal.

[0008] Furthermore, grease is applied between the inner sliding sleeve and the outer sliding sleeve.

[0009] Furthermore, a first fastener and a second fastener are fixedly connected to the rotating shaft. The first fastener and the second fastener are located at the axial ends of the sliding inner sleeve. An elastic washer and a bushing are provided on the upper end of the second fastener. The elastic washer is located between the bushing and the second fastener, and the upper end of the bushing abuts against the impeller. The elastic washer is an elastic component.

[0010] Furthermore, the pump casing is formed by a plurality of stacked and sealed components. The pump casing includes a first cylindrical wall, a second cylindrical wall, a third cylindrical wall, and a fourth cylindrical wall. The inner circumferential diameter of the first cylindrical wall is larger than that of the second cylindrical wall, and the outer circumferential diameter of the third cylindrical wall is smaller than that of the second and fourth cylindrical walls. The upper end face of the first cylindrical wall abuts against the lower end face of the second cylindrical wall, and the outer circumferential surface of the fourth cylindrical wall abuts against the inner circumferential surface of the first cylindrical wall. A gap exists between the lower end face of the fourth cylindrical wall and the upper end face of the second cylindrical wall. The first, second, third, and fourth cylindrical walls together form a second sealing groove, and a second sealing element is disposed within the second sealing groove. The impeller also includes a multi-stage impeller, with elastic gaskets and bushings disposed between each stage of the impeller.

[0011] Compared with existing technologies, the technical advantages of this invention are as follows: First, by setting a bearing cap at the outer end of the shaft fixing part and a first sealing element at the inner end, combined with grease filling between the sliding inner sleeve and the sliding outer sleeve, a double-protected sand-proof sealing system is constructed. The bearing cap, as the first barrier, effectively prevents large external particles of impurities from directly entering the bearing chamber; while the first sealing element (preferably a skeleton oil seal), as the second precision seal, can maintain contact sealing even when the rotating shaft is in rotation, thereby completely blocking the path of sand-laden water flowing into the bearing interior along the journal gap. At the same time, the sealing cavity reserved between the sliding inner sleeve and the sliding outer sleeve is filled with grease, which on the one hand forms a flexible sealing layer to further block small sand particles, and on the other hand provides initial lubrication for the sliding pair, avoiding dry friction wear caused by the lack of water film formation at the moment of pump start-up. This structural design fundamentally solves the problem of mud and sand intrusion caused by the direct exposure of the bearing to the water inlet channel in existing deep well pumps, and significantly extends the service life of the bearing under sand-laden conditions. II. The sliding inner sleeve is axially bidirectionally limited by the first and second fasteners. The axial movement and vibration impact generated by the impeller operation are absorbed by the compression deformation of the elastic gasket, preventing rigid collision and damage between the sliding inner sleeve and the end face of the shaft fixing part. III. The pump casing adopts a multi-segment superimposed structure. At the connection of each segment, the first, second, third, and fourth cylindrical walls form a second sealing groove. The second sealing element is built into the second sealing groove, realizing inter-stage sealing between the pump casing stages. It should be noted that there is a gap between the lower end face of the fourth cylindrical wall and the upper end face of the second cylindrical wall—this design allows the second sealing element to only undertake the radial elastic sealing function, without bearing axial compressive force and impact load. At the same time, the elastic gasket on the rotating shaft independently undertakes the axial elastic buffering function. The division of labor between the two is clear: the elastic gasket absorbs the axial movement and vibration impact generated by the impeller operation, ensuring that the sealing element is always in a stable radial compression state and is not disturbed by axial disturbance. This design, which separates axial buffering from radial sealing, allows the second seal to focus on its optimal radial sealing performance, effectively preventing high-pressure water from leaking outward from the assembly gap between adjacent pump casing sections. This significantly improves the sealing reliability and long-term pressure resistance of the entire unit under deep well high water pressure and strong vibration conditions. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the present invention.

[0013] Figure 2 This is an enlarged view of point A in the present invention.

[0014] Figure 3 This is a cross-sectional view of the pump casing of the present invention.

[0015] Drawing number markings: 1. Base; 11. Inlet; 12. Shaft fixing part; 121. First cylindrical part; 122. Second cylindrical part; 123. Circular part; 2. Pump casing; 21. First cylindrical wall; 22. Second cylindrical wall; 23. Third cylindrical wall; 24. Fourth cylindrical wall; 3. Guide vane; 4. Impeller; 5. Motor; 51. Rotating shaft; 61. Sliding inner sleeve; 62. Sliding outer sleeve; 7. Bearing cover; 8. First seal; 9. First sealing groove; 101. First fastener; 102. Second fastener; 103. Elastic gasket; 104. Shaft sleeve; 110. Second sealing groove; 111. Second seal. Detailed Implementation

[0016] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0017] It should be noted that the descriptions of directions such as "upper", "lower", "left", "right", "top", and "bottom" in this invention are defined based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] according to Figures 1 to 3 As shown, a sliding bearing structure with a sand-proof seal includes a base 1, a pump casing 2 fixedly connected to the upper end of the base 1, a guide vane 3 and an impeller 4 disposed inside the pump casing 2, and a motor 5 fixedly connected to the upper end of the pump casing 2. The motor 5 includes a rotating shaft 51, which extends downward into the interior of the pump casing 2 and the base 1, and the impeller 4 is fixedly connected to the rotating shaft 51. The motor 5 drives the impeller to rotate to achieve water pumping operation.

[0019] The base 1 has an inlet 11 and a shaft fixing part 12. Multiple inlets 11 are provided, and a filter screen is fixedly installed on the outer periphery of each inlet 11. The inlets 11 are evenly arranged around the shaft fixing part 12 to ensure uniform water flow into the pump body. The lower end of the rotating shaft 51 extends into the shaft fixing part 12, and a sliding inner sleeve 61 and a sliding outer sleeve 62 are provided between the rotating shaft 51 and the shaft fixing part 12. Specifically, the sliding outer sleeve 62 is fixedly installed relative to the shaft fixing part 12, the sliding inner sleeve 61 is fixedly connected to the rotating shaft 51 and rotates with the rotating shaft 51, and the outer peripheral surface of the sliding inner sleeve 61 and the inner peripheral surface of the sliding outer sleeve 62 form a sliding fit pair, providing radial support for the rotating shaft 51.

[0020] The outer end (lower end) of the shaft fixing part 12 is sealed and fixedly connected to a bearing cover 7. The bearing cover 7 serves as the first protective barrier, preventing large external particles from directly entering the bearing chamber. The inner end (upper end) of the shaft fixing part 12 is fixedly provided with a first seal 8. This first seal 8 is preferably a skeleton oil seal, which can maintain contact and seal when the rotating shaft 51 is rotating at high speed, blocking the path of sand-containing water to penetrate into the bearing along the journal gap.

[0021] Specifically, the shaft fixing part 12 includes a first cylindrical part 121 and a second cylindrical part 122. The outer circumferential diameter of the second cylindrical part 122 is larger than that of the first cylindrical part 121, thus forming a stepped structure inside the base 1. A ring part 123 protrudes outward from the middle of the inner circumferential wall of the first cylindrical part 121. The outer circumferential surface of the sliding sleeve 62 abuts against the inner circumferential wall of the first cylindrical part 121, and the upper end surface of the sliding sleeve 62 abuts against the lower end surface of the ring part 123, thereby achieving axial positioning of the sliding sleeve 62. The upper end of the sliding inner sleeve 61 extends beyond the upper end surface of the ring part 123. Thus, the upper end surface of the ring part 123, the inner circumferential wall of the first cylindrical part 121, and the outer circumferential surface of the sliding inner sleeve 61 together form a first sealing groove 9, and the first sealing member 8 is installed in the first sealing groove 9 to achieve reliable sealing.

[0022] In addition, grease is applied to the mating gap between the inner sliding sleeve 61 and the outer sliding sleeve 62. The grease filling reduces the coefficient of friction, facilitates installation, and significantly improves the service life of the whole machine under high mud and sand conditions.

[0023] To achieve axial positioning of the sliding inner sleeve 61 on the rotating shaft 51, a first fastener 101 and a second fastener 102 are fixedly connected to the rotating shaft 51. The first fastener 101 and the second fastener 102 are located at opposite axial ends of the sliding inner sleeve 61, providing bidirectional positioning for the sliding inner sleeve 61. The upper end of the second fastener 102 is provided with an elastic washer 103 and a bushing 104. The elastic washer 103 is located between the bushing 104 and the second fastener 102, and the upper end of the bushing 104 abuts against the impeller 4. Through the compression deformation of the elastic washer 103, the axial movement and vibration impact generated during the operation of the impeller 4 can be effectively absorbed, preventing the sliding inner sleeve 61 from being damaged by rigid collision with the end face of the shaft fixing part 12.

[0024] For a multi-stage impeller structure, the pump casing 2 is formed by several stacked and sealed components, with the aforementioned elastic gasket 103 and bushing 104 provided between each impeller stage. Specifically, taking the connection between two adjacent pump casings as an example, the pump casing 2 includes a first cylindrical wall 21, a second cylindrical wall 22, a third cylindrical wall 23, and a fourth cylindrical wall 24. The inner circumferential diameter of the first cylindrical wall 21 is larger than that of the second cylindrical wall 22, and the outer circumferential diameter of the third cylindrical wall 23 is smaller than that of the second and fourth cylindrical walls 22 and 24, respectively. During assembly, the upper end face of the first cylindrical wall 21 abuts against the lower end face of the second cylindrical wall 22, and the outer circumferential surface of the fourth cylindrical wall 24 abuts against the inner circumferential surface of the first cylindrical wall 21, with a gap H maintained between the lower end face of the fourth cylindrical wall 24 and the upper end face of the second cylindrical wall 22. Thus, the first cylindrical wall 21, the second cylindrical wall 22, the third cylindrical wall 23 and the fourth cylindrical wall 24 together enclose and form the second sealing groove 110, and a second sealing element 111 is provided in the second sealing groove 110, preferably an O-ring.

[0025] It is particularly noteworthy that, due to the gap H between the lower end face of the fourth cylindrical wall 24 and the upper end face of the second cylindrical wall 22, the second seal 111 only undertakes the radial elastic sealing function and does not bear axial compressive force and impact load. This effectively avoids the transmission of axial force caused by the accumulation of assembly tolerances or thermal expansion and contraction to the seal, which could lead to premature aging or failure. Simultaneously, the elastic gasket 103 on the rotating shaft 51 independently undertakes the axial elastic buffering function. The two functions are clearly defined and do not interfere with each other: the elastic gasket 103 absorbs the axial movement and vibration impact generated by the impeller 4, ensuring that the second seal 111 is always in a stable radial compression state without being disturbed by axial disturbances. This design, which separates the "axial buffering" and "radial sealing" functions, allows the second seal 111 to focus on its optimal radial sealing performance, effectively preventing high-pressure water from leaking outward from the assembly gap between adjacent pump casing sections. This significantly improves the sealing reliability and long-term pressure bearing capacity of the entire unit under deep well high water pressure and strong vibration conditions.

[0026] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection defined by the claims of the present invention.

Claims

1. A sliding bearing structure with a sand-proof seal, comprising a base (1), wherein a pump housing (2) is fixedly connected to the upper end of the base (1), a guide vane (3) and an impeller (4) are provided inside the pump housing (2), a motor (5) is fixedly connected to the upper end of the pump housing (2), the motor (5) includes a rotating shaft (51), the rotating shaft (51) extends into the pump housing (2) and the base (1), and the impeller (4) and the rotating shaft (51) are fixedly connected, characterized in that: The base (1) is formed with a water inlet (11) and a shaft fixing part (12). The water inlet (11) is evenly arranged around the shaft fixing part (12). The rotating shaft (51) extends into the shaft fixing part (12). A sliding inner sleeve (61) and a sliding outer sleeve (62) are provided between the rotating shaft (51) and the shaft fixing part (12). A bearing cover (7) is sealed and fixedly connected to the outer end of the shaft fixing part (12). A first sealing element (8) is fixedly provided at the inner end of the shaft fixing part (12). A first fastener (101) and a second fastener (102) are fixedly connected to the rotating shaft (51). The first fastener (101) and the second fastener (102) are located at both ends of the sliding inner sleeve (61). An elastic washer (103) and a bushing (104) are provided on the upper end of the second fastener (102). The elastic washer (103) is located between the bushing (104) and the second fastener (102). The upper end of the bushing (104) abuts against the impeller (4).

2. The sliding bearing structure with sand-proof seal according to claim 1, characterized in that: The shaft fixing part (12) includes a first cylindrical part (121) and a second cylindrical part (122). The outer circumferential diameter of the second cylindrical part (122) is larger than that of the first cylindrical part (121). An annular part (123) protrudes outward from the inner circumference of the first cylindrical part (121). The outer circumferential surface of the sliding sleeve (62) abuts against and is fixed to the inner circumference of the first cylindrical part (121). The upper end of the sliding sleeve (62) abuts against the lower end of the annular part (123). The sliding inner sleeve (61) is fixedly connected to the rotating shaft (51). The outer circumferential surface of the sliding inner sleeve (61) is slidably engaged with the inner circumferential surface of the sliding outer sleeve (62). The upper end of the sliding inner sleeve (61) extends out of the annular portion (123). The upper end surface of the annular portion (123), the inner circumferential surface of the first cylindrical portion (121), and the outer circumferential surface of the sliding inner sleeve (61) form a first sealing groove (9). The first sealing element (8) is located in the first sealing groove (9).

3. The sliding bearing structure with sand-proof seal according to claim 2, characterized in that: The first seal (8) is a skeleton oil seal.

4. The sliding bearing structure with sand-proof seal according to claim 2, characterized in that: Lubricant is applied between the sliding inner sleeve (61) and the sliding outer sleeve (62).

5. The sliding bearing structure with sand-proof seal according to claim 1, characterized in that: The pump casing (2) is formed by a plurality of stacked and sealed components. The pump casing (2) includes a first cylindrical wall (21), a second cylindrical wall (22), a third cylindrical wall (23), and a fourth cylindrical wall (24). The inner circumferential diameter of the first cylindrical wall (21) is larger than the inner circumferential surface of the second cylindrical wall (22), and the outer circumferential diameter of the third cylindrical wall (23) is smaller than the outer circumferential diameters of the second cylindrical wall (22) and the fourth cylindrical wall (24). The upper end face of the first cylindrical wall (21) is flush with the second cylindrical wall (24). The lower end face of the cylindrical wall (22) abuts against the inner circumferential surface of the fourth cylindrical wall (24), and there is a gap between the lower end face of the fourth cylindrical wall (24) and the upper end face of the second cylindrical wall (22). The first cylindrical wall (21), the second cylindrical wall (22), the third cylindrical wall (23) and the fourth cylindrical wall (24) surround to form a second sealing groove (110), and a second sealing element (111) is provided in the second sealing groove (110).

Images