Protective mechanical seal structure of submersible sewage pump

Abstract

The utility model discloses a submersible sewage pump protection mechanical seal structure which comprises a motor shaft, and a mechanical seal is arranged between a shell and the motor shaft. The second shaft sleeve is arranged on the periphery of the motor shaft; the first framework oil seal is arranged on the periphery of the second shaft sleeve; the first shaft sleeve is arranged in the shell, and the second shaft sleeve is located in the first shaft sleeve; at least one speed reduction groove is formed in the inner wall of the first shaft sleeve; an annular protruding eave is arranged at the end, facing the working medium, of the second shaft sleeve, and the outer diameter of the annular protruding eave is larger than the inner diameter of the first shaft sleeve. The acting force acting on the second framework oil seal is relieved by reducing the movement speed and the impact strength of solid particles. The motor shell and the impeller shell are arranged in a partitioned mode, the second framework oil seal serves as a second barrier, and solid particles are prevented from making contact with the mechanical seal on the motor.

Description

TECHNICAL FIELD

[0001] The utility model belongs to non variable volume pump technical field, especially relates to a submersible sewage pump protection machine seal structure. BACKGROUND

[0002] In the operation process of the submersible sewage pump, solid particles and other foreign matters inevitably exist in the medium water, and the pressure in the pump cavity will make the water flow to the mechanical seal end with the particles at high speed, and the specific influences include: wear - when the solid particles enter the friction end face, the dynamic ring and the static ring will be severely worn, resulting in the quick failure of the seal end face; jamming - the solid particles can make the dynamic ring sealing ring unable to move along the axial direction, so that the dynamic ring cannot float and loses the compensatory effect; corrosion - the solid particles can also carry corrosive substances, which further aggravate the damage of the mechanical seal. After the mechanical seal fails, it will further cause the medium to leak out from the gap between the seal surfaces, or cause the end face to overheat or crack, and uneven wear can also cause the pump set to vibrate and other problems, which seriously affects the service life of the submersible sewage pump.

[0003] The patent document with the publication number CN118855720A discloses a sewage submersible electric pump, which belongs to the technical field of water pumps. It solves the problem of lack of oil seal device in the prior art. It comprises a pump cover, a pump body and a pump base, the pump body and the pump base are fixedly connected, the bottom of the pump cover is fixedly installed with a connecting seat, the connecting seat is connected with one end of the pump body, a driving motor is fixedly installed inside the pump cover, the driving motor extends out of a motor shaft, the pump body comprises an upper pump body and a lower pump body, and the upper pump body and the lower pump body are fixedly attached to each other, a mechanical seal plate is formed in the upper pump body, a sealing ring is formed at the center of the mechanical seal plate, an impeller ring body and an impeller seat are fixedly installed inside the pump body, an impeller hub is formed at the center of the impeller ring body, the impeller hub extends into the sealing ring, and the outer wall of the impeller hub is tightly attached to the inner wall of the sealing ring, a first sealing groove is formed at the bottom of the mechanical seal plate, and a first skeleton oil seal is fixedly installed in the first sealing groove and is sleeved on the motor shaft.

[0004] Although the first skeleton oil seal at the bottom of the mechanical seal plate in the above-mentioned patent scheme can prevent the medium from contacting the mechanical seal, the solid particles and other foreign matters in the medium will directly act on the first skeleton oil seal, that is, the wear originally acting on the mechanical seal becomes the wear acting on the first skeleton oil seal. Even if the wear resistance of the first skeleton oil seal is excellent, but the continuous wear over a long period of time, combined with the rotation of the impeller in the sealing ring to exert pressure on the solid particles and other foreign matters, will greatly aggravate the wear. Therefore, the above-mentioned patent scheme does not fundamentally reduce the generation of wear, and to some extent, it cannot meet the use requirements. UTILITY MODEL CONTENTS

[0005] In order to overcome the prior art in the medium of solid particles and other impurities mixed in the submerged sewage pump will cause wear and erosion of the mechanical seal, and the skeleton oil seal between the mechanical seal and the medium can only change the position, but can not fundamentally reduce the generation and effect of wear and erosion. One purpose of the utility model is to provide a submerged sewage pump protection mechanical seal structure, by setting first shaft sleeve and second shaft sleeve between the skeleton oil seal and the working medium, the inner wall of the first shaft sleeve is provided with a plurality of annular speed reduction groove, the end of the second shaft sleeve is provided with annular eaves shielding the gap between the first shaft sleeve and the second shaft sleeve, through the multi-layer obstacle, reduce the impact degree and effect of the foreign matter directly on the skeleton oil seal, achieve the purpose of protecting the mechanical seal.

[0006] In order to achieve the above object, the utility model adopts the following technical scheme: a submerged sewage pump protection mechanical seal structure, including motor shaft, the motor shaft is rotatably connected in the casing, the casing is provided with mechanical seal with motor shaft;Second shaft sleeve, the second shaft sleeve is arranged on the outer periphery of the motor shaft;First skeleton oil seal, the first skeleton oil seal is arranged on the outer periphery of the second shaft sleeve, and the first skeleton oil seal is located on the side of the mechanical seal towards the working medium;First shaft sleeve, the first shaft sleeve is arranged in the casing, and the second shaft sleeve is located in the first shaft sleeve, and the first shaft sleeve is located on the side of the first skeleton oil seal towards the working medium;Wherein, the outer wall of the first shaft sleeve is sealed and tightly closed with the inner wall of the casing, and the inner wall of the first shaft sleeve is provided with at least one speed reduction groove;The one end of the second shaft sleeve towards the working medium is provided with annular eaves, and the outer diameter of the annular eaves is greater than the inner diameter of the first shaft sleeve.

[0007] The working medium is the liquid or liquid mixture required to be transported by the submerged sewage pump, wherein various solid particles and other impurities will inevitably appear.

[0008] Optionally, the speed reduction groove is an annular groove coaxially arranged with the first shaft sleeve;The annular groove has three evenly distributed along the axial direction.

[0009] Optionally, the speed reduction groove is a spiral groove, and the spiral groove has a plurality of evenly distributed along the circumferential direction.

[0010] Further, the casing includes a motor casing and an impeller casing arranged on the motor casing;The outer periphery of the second shaft sleeve is provided with two second skeleton oil seals;The second skeleton oil seal and the first shaft sleeve are located in the impeller casing;The second skeleton oil seal is in contact with the end of the first shaft sleeve away from the working medium.

[0011] Specifically, the end of the motor shaft is provided with an impeller in the impeller casing;The impeller casing is detachably connected with a supporting ring;The end of the impeller away from the motor shaft is coaxially provided with an annular protrusion;The annular protrusion is rotatably connected in the supporting ring.

[0012] Further, a ring groove is coaxially arranged in the middle part of the outer wall of the first shaft sleeve; and an O-ring is arranged in the ring groove.

[0013] Further, the first shaft sleeve and the second shaft sleeve are in clearance fit.

[0014] Further, a small-diameter shaft is arranged at the end of the motor shaft facing the working medium, the outer diameter of the small-diameter shaft is smaller than the outer diameter of the motor shaft; the inner diameter of the ring-shaped eaves is smaller than the inner diameter of the second shaft sleeve; and the inner wall of the ring-shaped eaves is in abutment with the outer wall of the small-diameter shaft.

[0015] In particular, the motor shell and the impeller shell have a gap therebetween; and the first skeleton oil seal is located at the end of the motor shell facing the impeller shell.

[0016] In particular, a cylindrical cavity is arranged in the impeller shell; and the outer wall of the second skeleton oil seal and the outer wall of the first shaft sleeve are in sealing abutment with the inner wall of the cylindrical cavity.

[0017] Compared with the prior art, the utility model has the beneficial effects that: the utility model sets a speed reduction groove in the first shaft sleeve, and sets a ring-shaped eaves at the end of the second shaft sleeve, so that the solid particles are directly limited from acting on the second skeleton oil seal by the blocking mode, that is, the acting force on the second skeleton oil seal is reduced by reducing the movement speed and impact degree of the solid particles. In addition, the motor shell and the impeller shell are arranged in sections, the second skeleton oil seal is used as a second barrier for blocking the solid particles, the solid particles in the working medium are completely prevented from contacting the mechanical seal on the motor, and the damage of the solid particles to the mechanical seal is effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a sectional structure schematic view in the application state of the utility model;

[0019] Figure 2 It is a sectional structure schematic view in the application state of the utility model; Figure 1 It is an enlarged schematic view of the section A of the utility model.

[0020] In the drawing: 1, motor shell; 11, mechanical seal; 2, impeller shell; 21, bearing ring; 3, first shaft sleeve; 31, speed reduction groove; 32, O-ring; 4, first skeleton oil seal; 5, second skeleton oil seal; 6, second shaft sleeve; 61, ring-shaped eaves; 7, motor shaft; 71, small-diameter shaft; 8, impeller; 81, ring-shaped protrusion. DETAILED DESCRIPTION

[0021] The utility model is further described below in combination with the drawings and specific embodiments, and it should be noted that the embodiments described below or the technical features can be combined to form new embodiments without conflict.

[0022] In the description of the utility model, it should be noted that for the terms of orientation, such as the terms of "center", "transverse", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation and positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the devices or elements indicated must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific protection scope of the utility model.

[0023] In addition, the terms "first" and "second" are only used for description purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. Therefore, the "first" and "second" features can be explicitly or implicitly included one or more features, and in the description of the utility model, the meaning of "several" is two or more than two, unless otherwise explicitly specified and limited.

[0024] In the utility model, unless otherwise explicitly specified and limited, the terms such as "setting" and "installation" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected; it can be directly connected, or it can be connected through an intermediate medium; it can be connected internally between two elements. For ordinary skilled persons in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.

[0025] Referring to Figures 1-2 A submersible sewage pump protection mechanical seal structure, including the casing, the motor shaft 7 that is rotatably connected in the casing and the impeller 8 that is arranged in the tail end of the motor shaft 7, the casing includes motor casing 1 and the impeller casing 2 that is arranged in the lower end of the motor casing 1, the impeller 8 is located in the impeller casing 2, the motor shaft 7 passes through the motor casing 1 and the impeller casing 2 in turn, the mechanical seal 11 is arranged between the motor casing 1 and the motor shaft 7.

[0026] The outer periphery of the motor shaft 7 is provided with a second shaft sleeve 6, a first skeleton oil seal 4 is arranged between the upper end of the second shaft sleeve 6 and the motor casing 1, there is a gap between the motor casing 1 and the impeller casing 2, and the first skeleton oil seal 4 is located at one end of the motor casing 1 towards the impeller casing 2 and is close to the mechanical seal 11.

[0027] The inner wall of the impeller shell 2 is provided with a cylindrical cavity near one side of the motor shell 1; two second skeleton oil seals 5 are arranged adjacent to each other between the cylindrical cavity and the second shaft sleeve 6; the first shaft sleeve 3 is arranged in the cylindrical cavity; and the second skeleton oil seal 5 is located at one end of the first shaft sleeve 3 facing the motor shell 1.

[0028] The inner wall of the first shaft sleeve 3 is provided with three speed reduction grooves 31 uniformly distributed in the axial direction, and the speed reduction grooves 31 are annular grooves coaxially arranged with the first shaft sleeve 3.

[0029] The second shaft sleeve 6 is located in the first shaft sleeve 3, and the two are in clearance fit; the second shaft sleeve 6 is provided with an annular eaves 61 at one end facing the working medium, and the outer diameter of the annular eaves 61 is greater than the inner diameter of the first shaft sleeve 3; the annular eaves 61 blocks the gap between the second shaft sleeve 6 and the first shaft sleeve 3.

[0030] The motor shaft 7 is provided with a small-diameter shaft 71 at one end facing the working medium, and the outer diameter of the small-diameter shaft 71 is smaller than the outer diameter of the motor shaft 7; the inner diameter of the annular eaves 61 is smaller than the inner diameter of the second shaft sleeve 6; and the inner wall of the annular eaves 61 abuts against the outer wall of the small-diameter shaft 71.

[0031] The working medium is a liquid or a mixture of liquids required to be transported by the submersible sewage pump, and various solid particles and other impurities will inevitably appear.

[0032] The outer wall of the first shaft sleeve 3 is in sealing abutment with the inner wall of the cylindrical cavity, and the outer wall of the first shaft sleeve 3 is coaxially provided with an annular groove in the middle part; and the annular groove is provided with an O-ring 32.

[0033] The impeller shell 2 is detachably connected with a supporting ring 21; the impeller 8 is coaxially provided with an annular protrusion 81 at one end away from the motor shaft 7; and the annular protrusion 81 is rotationally connected in the supporting ring 21.

[0034] The above only describes specific embodiments of the present application, but the technical features of the present application are not limited to this, and any person skilled in the art can make changes or modifications in the field of the present application, which are all covered in the patent scope of the present application.

Claims

1. A submersible sewage pump protection mechanical seal structure, characterized in that: Comprising The motor shaft is rotationally connected in the housing, and a mechanical seal is arranged between the housing and the motor shaft; A second shaft sleeve is arranged on the outer periphery of the motor shaft; A first skeleton oil seal is arranged on the outer periphery of the second shaft sleeve, and the first skeleton oil seal is located on the side of the mechanical seal facing the working medium; A first shaft sleeve is arranged in the housing, and the second shaft sleeve is located in the first shaft sleeve, and the first shaft sleeve is located on the side of the first skeleton oil seal facing the working medium; Wherein, the outer wall of the first shaft sleeve is sealed against the inner wall of the housing, and the inner wall of the first shaft sleeve is provided with at least one speed reduction groove; the end of the second shaft sleeve facing the working medium is provided with an annular eaves, and the outer diameter of the annular eaves is greater than the inner diameter of the first shaft sleeve.

2. The protective machine enclosure structure of claim 1, wherein: The speed reduction groove is an annular groove coaxially arranged with the first shaft sleeve; the annular groove has three uniformly distributed along the axial direction.

3. The protective machine enclosure structure of claim 1, wherein: The speed reduction groove is a spiral groove, and the spiral groove has a plurality of uniformly distributed along the circumferential direction.

4. The containment structure of any one of claims 1-3, wherein: The housing comprises a motor housing and an impeller housing arranged on the motor housing; the outer periphery of the second shaft sleeve is provided with two second skeleton oil seals; the second skeleton oil seal and the first shaft sleeve are located in the impeller housing; the second skeleton oil seal is located at the end of the first shaft sleeve away from the working medium.

5. The protective machine enclosure structure of claim 4, wherein: The end of the motor shaft located in the impeller housing is provided with an impeller; the impeller housing is detachably connected with a supporting ring; the end of the impeller away from the motor shaft is coaxially provided with an annular protrusion; the annular protrusion is rotationally connected in the supporting ring.

6. The containment structure of any of claims 1-3, wherein: The middle part of the outer wall of the first shaft sleeve is coaxially provided with an annular groove; an O-ring is arranged in the annular groove.

7. The containment structure of any of claims 1-3, wherein: The first shaft sleeve and the second shaft sleeve are gap-fitted.

8. The containment structure of any of claims 1-3, wherein: The end of the motor shaft facing the working medium is provided with a small-diameter shaft, and the outer diameter of the small-diameter shaft is smaller than the outer diameter of the motor shaft; the inner diameter of the annular eaves is smaller than the inner diameter of the second shaft sleeve; the inner wall of the annular eaves is in abutment with the outer wall of the small-diameter shaft.

9. The protective machine enclosure structure of claim 4, wherein: The motor housing and the impeller housing have a gap; the first skeleton oil seal is located at the end of the motor housing facing the impeller housing.

10. The protective machine enclosure structure of claim 4, wherein: A cylindrical cavity is arranged in the impeller housing; the outer wall of the second skeleton oil seal and the outer wall of the first shaft sleeve are in abutment with the inner wall of the cylindrical cavity.

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