Oil pump series double mechanical seal device and high-temperature heat-conducting oil pump

Abstract

The present invention discloses an oil pump series double mechanical seal device and a high-temperature heat-conducting oil pump using the series double mechanical seal device, belonging to the technical field of oil pumps. The seal device includes a bearing body fixed on the outer side of the pump cover of the oil pump. A first mechanical seal and a front static ring seat for installing the first mechanical seal are arranged on the pump shaft between the two end bearings in the bearing body. A second mechanical seal with a pump efficiency ring and a rear static ring seat for installing the second mechanical seal are arranged behind the front static ring seat. A mechanical seal connecting sleeve is arranged between the front static ring seat and the rear static ring seat. The high-temperature heat-conducting oil pump includes a pump body, an impeller, a pump cover and the above-mentioned seal device. The present invention reduces the working temperature of the mechanical seal and the bearing, improves the working conditions of the mechanical seal and the bearing, and ensures the long-term stable operation of the high-temperature heat-conducting oil pump.

Description

Technical Field

[0001] The present invention relates to the technical field of oil pumps, in particular to a sealing device for a pump and an oil pump using the sealing device. Background Art

[0002] There are various sealing types for high-temperature hot oil pumps, including packing seals, single-ended mechanical seals, packing + oil seals, packing + single-ended mechanical seals, and assembled double-ended mechanical seals, etc. Simple packing seals or mechanical seals have a short service life and poor reliability in heat transfer oil systems. Once leakage occurs, there are great safety hazards, and now few users choose them. Currently, the most widely used is the packing + oil seal, which has reliable sealing, can avoid a large amount of leakage, has high safety and a low price. Its disadvantage is that it is not applicable to occasions where the pump inlet pressure is higher than 0.3 MPa.

[0003] The sealing type of packing + mechanical seal solves the problem of high inlet pressure, and the sealing reliability is improved. For example, the publication number (CN 208123078 U), a combined-seal high-temperature heat transfer oil pump, is of the sealing type of packing + mechanical seal. The heat transfer oil pump includes a pump body, a pump cover, and a bearing body connected in sequence; an impeller is arranged in the pump body, and the pump shaft sequentially passes through the bearing body and the pump cover and then is connected to the impeller located in the pump body. A packing seal assembly is arranged at one end of the pump cover close to the pump body, an oil seal assembly is arranged at one end of the pump cover close to the bearing body, a mechanical seal and a static ring seat relatively fixed to the inner wall of the bearing body are arranged in the inner cavity of the bearing body; the static ring of the mechanical seal is connected to the static ring seat through an anti-rotation pin, the dynamic ring of the mechanical seal is pressed against the end face of the static ring by a spring, and the other end of the spring is fixed and positioned by a spring seat; a front bearing and a rear bearing are respectively arranged at both ends inside the bearing body. However, it has some disadvantages: 1. When using heat transfer oil to lubricate the front bearing, it is okay if the front bearing uses a sliding bearing. If a rolling bearing is used, the viscosity of the heat transfer oil is low and the lubricity is low, which will reduce the service life of the bearing and thus reduce the life of the pump; 2. Currently, most of the mechanical seals used in pumps with packing + mechanical seals are conical large springs, positioned by the shaft shoulder, and the compression amount of the mechanical seal is guaranteed by the axial dimension accuracy of the parts. That is to say, it is impossible to see how much the compression amount of the mechanical seal spring is; 3. The mechanical seal is installed between the two bearings, and the frictional heat of the sealing surface will cause the operating temperature of the bearing to rise, affecting the service life of the bearing.

[0004] There is also an assembled double mechanical seal on the market, but it has a high cost and cannot play a role in reducing the bearing temperature. In view of the self-defects of the above various seals, there is an urgent need for a new type of sealing device in the market. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an oil pump series double mechanical seal device and a high-temperature heat-conducting oil pump, which reduce the working temperature of the mechanical seal and the bearing, improve the working conditions of the mechanical seal and the bearing, and ensure the long-term stable operation of the high-temperature heat-conducting oil pump.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An oil pump series double mechanical seal device includes a bearing body fixed on the outer side of the pump cover of the oil pump. A first mechanical seal and a front static ring seat for installing the first mechanical seal are arranged on the pump shaft between the two end bearings in the bearing body. A second mechanical seal with a pump efficiency ring and a rear static ring seat for installing the second mechanical seal are arranged behind the front static ring seat. A mechanical seal connecting sleeve is arranged between the front static ring seat and the rear static ring seat.

[0008] A further improvement of the technical solution of the present invention is that: a sealing cavity is formed between the front static ring seat and the rear static ring seat, and a flushing liquid outlet and a flushing liquid inlet respectively connected to a cooler are arranged on the bearing body surrounding the sealing cavity.

[0009] A further improvement of the technical solution of the present invention is that: a packing seal is arranged between one end of the pump cover far from the bearing and the pump shaft, and an oil seal is arranged between one end of the pump cover close to the bearing and the pump shaft.

[0010] A further improvement of the technical solution of the present invention is that: a plurality of positioning steps are arranged on the outer circumferences of the front static ring seat and the rear static ring seat, and a plurality of positioning flanges are arranged on the inner side wall of the bearing body. The front end face of the positioning step of the front static ring seat contacts and positions with the positioning flange of the bearing body, the rear end face of the positioning step of the rear static ring seat contacts and positions with the outer ring of the bearing at the rear end inside the bearing body, and the mechanical seal connecting sleeve is arranged on the positioning step between the rear end face of the front static ring seat and the front end face of the rear static ring seat to achieve contact positioning.

[0011] A further improvement of the technical solution of the present invention is that: the bearing arranged at the front end of the pump shaft in the bearing body is a single deep groove ball bearing, the bearing arranged at the rear end of the pump shaft in the bearing body is a pair of thrust bearings installed back-to-back, the rear end face of the thrust bearing exceeds the shaft shoulder for installing the thrust bearing, and a round nut spirally installed on the pump shaft is arranged at the rear end of the thrust bearing.

[0012] A high-temperature heat-conducting oil pump includes a pump body, an impeller, a pump cover, and a pump shaft passing through the impeller and the pump cover. The characteristics are that: a bearing body is connected to the outer side of the pump cover by bolts, and bearings, a first mechanical seal, a front static ring seat, a second mechanical seal with a pump efficiency ring, a rear static ring seat, bearings, a round nut, and a bearing cover fixed to the bearing body by bolts are sequentially installed on the pump shaft in the bearing body. A mechanical seal connecting sleeve is arranged between the front static ring seat and the rear static ring seat.

[0013] The further improvement of the high-temperature thermal oil pump in the technical solution of the present invention is that: a sealed cavity is formed between the front static ring seat and the rear static ring seat, and a flushing liquid outlet and a flushing liquid inlet respectively connected to the cooler are provided on the bearing body that encloses the sealed cavity; a sealed space is formed between the pump cover and the front static ring seat, and a lubricating oil or grease inlet is provided on the bearing body that encloses the sealed space.

[0014] A further improvement of the high-temperature thermal oil pump of the technical solution of the present invention is that a packing seal is provided between the end of the pump cover away from the bearing and the pump shaft, and an oil seal is provided between the end of the pump cover close to the bearing and the pump shaft.

[0015] A further improvement of the high-temperature thermal oil pump of the technical solution of the present invention is that sealing rings or sealing gaskets are installed on the positioning end faces of the front static ring seat and the rear static ring seat.

[0016] Due to the adoption of the above technical solution, the technical advancements achieved by the present invention are:

[0017] The present invention provides a dual mechanical seal device for an oil pump in series, which improves sealing performance and can be applied in a variety of sealing situations. To achieve the dual mechanical seals in series, a stationary ring seat and a mechanical seal connecting sleeve are designed. The stationary ring seat provides a mounting base for the two mechanical seals, while the mechanical seal connecting sleeve positions the two stationary ring seats. Furthermore, the compression of the mechanical seal's elastic element can be adjusted before the pump shaft is assembled, ensuring assembly accuracy of the mechanical seals.

[0018] On the basis of the series double mechanical seal device, packing seal, oil seal and sealing ring or sealing gasket are added to achieve multi-pass sealing and further improve the sealing performance.

[0019] The bearing body is designed with flushing liquid inlet and outlet, and the external auxiliary cooling system takes away friction heat, reduces the operating temperature of the mechanical seal and bearing, improves the working conditions of the mechanical seal and bearing, and ensures the long-term stable operation of the high-temperature hot oil pump, thereby ensuring the reliability of the pump, extending its service life and reducing costs.

[0020] The series double mechanical seal device of the present invention is applied to a high-temperature thermal oil pump. The good sealing environment prevents the penetration of high-temperature oil, avoids power loss of the oil pump, and also prevents high-temperature oil from entering the sealing system and damaging the sealing system, thereby reducing the accident rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0022] Figure 1 It is a schematic structural diagram of the sealing device of the present invention;

[0023] Figure 2 This is a schematic structural diagram of the high-temperature thermal oil pump of the present invention;

[0024] Figure 3 This is a schematic structural diagram of the front stationary ring seat of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of the rear static ring seat of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of the mechanical seal connecting sleeve of the present invention;

[0027] Among them, 1. Pump cover, 2. Bearing body, 3. Pump shaft, 4. First mechanical seal, 5. Front static ring seat, 6. Second mechanical seal, 7. Rear static ring seat, 8. Mechanical seal connecting sleeve, 9. Flushing liquid inlet, 10. Flushing liquid outlet, 11. Packing seal, 12. Oil seal, 13. Round nut, 14. Pump body, 15. Impeller, 16. Bearing cover. DETAILED DESCRIPTION

[0028] The present invention is described in further detail below in conjunction with the embodiments:

[0029] Example 1

[0030] An oil pump series double mechanical seal device, such as Figure 1 As shown, it includes a bearing body 2 and two mechanical sealing devices connected in series installed in the bearing body 2. Specifically, the bearing body 2 is connected to the outside of the pump cover 1 by bolts. The pump shaft 3 extends from the oil pump and passes through the pump cover 1 and the bearing body 2 in sequence. The bearing body 2 is installed on the pump shaft 3 through bearings at the front and rear ends, and the two mechanical sealing devices are installed between the bearings at the front and rear ends.

[0031] The two mechanical seal devices include a first mechanical seal 4 and a second mechanical seal 6 with a pump effect ring. The first mechanical seal 4 is close to one end of the pump cover 1, and the second mechanical seal 6 is far from the pump cover 1. The first mechanical seal 4 is installed on the front stationary ring seat 5, and the second mechanical seal 6 is installed on the rear stationary ring seat 7. In this application, a mechanical seal connecting sleeve 8 is provided between the front stationary ring seat 5 and the rear stationary ring seat 7, realizing the positioning of the two stationary ring seats, and the compression amount of the mechanical seal elastic element can be adjusted before the pump shaft is assembled, ensuring the assembly accuracy of the mechanical seal. Moreover, a sealing cavity is formed between the front stationary ring seat 5 and the rear stationary ring seat 7, and a flushing liquid inlet 9 and a flushing liquid outlet 10 respectively connected to a cooler are provided on the bearing body 2 surrounding the sealing cavity. A sealing space is formed between the pump cover 1 and the front stationary ring seat 5, and a lubricating oil or grease inlet is provided on the bearing body 2 surrounding the sealing space. Under the action of the pump effect ring, the flushing medium is forced to flow to an external cooler from the flushing liquid outlet 10, and after cooling, it enters the mechanical seal cavity from the flushing liquid inlet 9. The circulating flushing medium continuously flushes, cools and reduces the temperature of the second mechanical seal 6 with a pump effect ring. At the same time, it can also take away a part of the heat generated by the rotation of the second mechanical seal 6 and the front and rear bearings and other components, reducing the operating temperature of the mechanical seal and the bearings, and improving the working conditions of the mechanical seal and the bearings.

[0032] To achieve the above effects, this application has made innovations and optimizations in the design and installation of components:

[0033] When specifically installing the mechanical seal, each mechanical seal has a dynamic ring, a static ring, as well as a spring and a spring seat. The spring and the spring seat are used to press the dynamic ring. The static ring is fixed and immovable. The dynamic ring is pressed against the end face of the static ring by the spring, and the other end of the spring is fixed and positioned by the spring seat. During specific operation, the dynamic ring rotates, and the contact surface between the dynamic ring and the static ring serves as the sealing surface. The dynamic ring of the mechanical seal is fixed to the pump shaft by fastening screws, and the fastening screws are arranged radially. The static ring of the mechanical seal is connected to the static ring seat by anti-rotation pins. When the high-temperature heat-conducting oil pump is operating, the dynamic ring rotates with the pump shaft, and each static ring is connected to the corresponding static ring seat and remains stationary. Based on the above assembly principle, in order to better install the mechanical seal, the present invention has specifically made a new design for the static ring seat, such as Figure 3 , 4 , as shown in Figure 5, a plurality of positioning steps are provided on the outer circumferences of the front stationary ring seat 5 and the rear stationary ring seat 7, and a plurality of positioning flanges are provided on the inner side wall of the bearing body 2. The front end face of the positioning step of the front stationary ring seat 5 contacts and positions with the positioning flange of the bearing body 2, and the rear end face of the positioning step of the rear stationary ring seat 7 contacts and positions with the outer ring of the bearing at the inner rear end of the bearing body 2. The mechanical seal connecting sleeve 8 is arranged on the positioning step between the rear end face of the front stationary ring seat 5 and the front end face of the rear stationary ring seat 7 to achieve contact positioning.

[0034] Meanwhile, in the selection of bearings, the bearing at the front end is a single deep groove ball bearing, and the bearings at the rear end are a pair of thrust bearings mounted back-to-back. The rear end face of the thrust bearing exceeds the shaft shoulder where the thrust bearing is installed. A round nut 13 is spirally installed on the pump shaft 3 at the rear end of the thrust bearing. The positioning of the bearings, the front static ring seat 5, and the rear static ring seat 7 is achieved by tightening the round nut 13.

[0035] To further enhance the sealing effect, a packing seal 11 can also be provided between one end of the pump cover 1 away from the bearing and the pump shaft 3, and an oil seal 12 is provided between one end of the pump cover 1 close to the bearing and the pump shaft 3. Thus, a sealing device of packing + series double mechanical seals is formed.

[0036] Embodiment 2

[0037] The high-temperature heat-conducting oil pump using the above-mentioned series double mechanical seal device for oil pumps, as Figure 2 shown, includes a pump body 14, a pump cover 1, and a bearing body 2 connected in sequence. An impeller 15 is arranged inside the pump body 14. One end of the pump body 14 is an oil inlet, and the opposite end is fixedly connected to the pump cover 1 by bolts. The bearing body 2 is fixedly connected to the other end of the pump cover 1 by bolts. Bearings, a first mechanical seal 4, a front static ring seat 5, a second mechanical seal 6 with a pump efficiency ring, a rear static ring seat 7, bearings, a round nut 13, and a bearing cover 16 fixedly connected to the bearing body 2 by bolts are sequentially installed on the pump shaft 3 inside the bearing body 2. A mechanical seal connecting sleeve 8 is arranged between the front static ring seat 5 and the rear static ring seat 7. The connection relationship and structure of the specific double mechanical seal are the same as those in Embodiment 1.

[0038] Among them, on the positioning end faces of the front static ring seat 5 and the rear static ring seat 7 and at some positions with a bonding relationship, the sealing effect can be improved by installing sealing rings or gaskets.

[0039] This application forms a high-temperature heat-conducting oil pump with packing + series double mechanical seals, and a total of the following 4 seals are formed:

[0040] The packing seal 11 and the pump cover 1 and the pump shaft 3 form the first seal, blocking impurities in the oil and reducing the backward transmission of pressure; the oil seal 12 and the pump cover 1 and the pump shaft 3 form the second seal, blocking the heat-conducting oil from entering the bearing body 2; the first mechanical seal 4 and the front static ring seat 5, the bearing body 2, and the sealing ring / gasket form the third seal of the pump. This cavity is filled with lubricating oil to ensure good lubrication conditions for the first mechanical seal 4 and the front-end bearing; the second mechanical seal 6 with a pump efficiency ring and the rear static ring seat 7, the bearing body 2, the sealing ring / gasket, and the cooler connected to the flushing liquid inlet 9 and the flushing liquid outlet 10 form the fourth seal of the pump. This cavity is filled with flushing medium to ensure good lubrication conditions for the second mechanical seal 6 with a pump efficiency.

[0041] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the spirit of the present invention's design, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A series-connected double mechanical seal device for an oil pump, comprising a bearing body (2) fixed outside the pump cover (1) of the oil pump, a first mechanical seal (4) and a front stationary ring seat (5) for installing the first mechanical seal (4) are arranged on a pump shaft (3) between the two end bearings in the bearing body (2), and it is characterized in that: A second mechanical seal (6) with a pump effect ring and a rear stationary seal seat (7) for installing the second mechanical seal (6) are provided behind the front stationary seal seat (5). A mechanical seal connecting sleeve (8) is provided between the front stationary seal seat (5) and the rear stationary seal seat (7); a packing seal (11) is provided between one end of the pump cover (1) far from the bearing and the pump shaft (3), and an oil seal (12) is provided between one end of the pump cover (1) close to the bearing and the pump shaft (3); a plurality of positioning steps are provided on the outer circumferences of the front stationary seal seat (5) and the rear stationary seal seat (7), and a plurality of positioning flanges are provided on the inner side wall of the bearing housing (2). The front end face of the positioning step of the front stationary seal seat (5) contacts and positions with the positioning flange of the bearing housing (2), and the rear end face of the positioning step of the rear stationary seal seat (7) contacts and positions with the outer ring of the bearing at the inner rear end of the bearing housing (2). The mechanical seal connecting sleeve (8) is arranged on the positioning step between the rear end face of the front stationary seal seat (5) and the front end face of the rear stationary seal seat (7) to achieve contact positioning; the bearing at the front end of the pump shaft (3) in the bearing housing (2) is a single deep groove ball bearing, and the bearing at the rear end of the pump shaft in the bearing housing (2) is a pair of thrust bearings mounted back-to-back. The rear end face of the thrust bearing exceeds the shoulder of the shaft on which the thrust bearing is installed, and a round nut (13) screwed onto the pump shaft (3) is provided at the rear end of the thrust bearing; The mechanical seal connecting sleeve (8) is an independent annular member, and its two ends are respectively fitted with the positioning steps of the rear end face of the front stationary seal seat (5) and the front end face of the rear stationary seal seat (7) to form an axial positioning structure; The length of the mechanical seal connecting sleeve (8) is adjustable and is used to independently adjust the spring compression amounts of the first mechanical seal (4) and the second mechanical seal (6) before the assembly of the pump shaft.

2. The series-connected double mechanical seal device for an oil pump according to claim 1, wherein: A sealing cavity is formed between the front stationary seal seat (5) and the rear stationary seal seat (7), and a flushing liquid inlet (9) and a flushing liquid outlet (10) respectively connected to a cooler are provided on the bearing housing (2) surrounding the sealing cavity.

3. A high-temperature heat-conducting oil pump using the series double mechanical seal device of the oil pump according to any one of claims 1 to 2, comprising a pump body (14), an impeller (15), a pump cover (1), and a pump shaft (3) inserted into the impeller (15) and passing through the pump cover (1), characterized in that: The pump cover (1) is connected to the bearing housing (2) by bolts. A bearing, a first mechanical seal (4), a front stationary seal seat (5), a second mechanical seal (6) with a pump effect ring, a rear stationary seal seat (7), a bearing, a round nut (13), and a bearing cover (16) fixed to the bearing housing (2) by bolts are sequentially installed on the pump shaft (3) in the bearing housing (2). A mechanical seal connecting sleeve (8) is provided between the front stationary seal seat (5) and the rear stationary seal seat (7).

4. The high-temperature heat-conducting oil pump according to claim 3, wherein: A sealing cavity is formed between the front stationary seal seat (5) and the rear stationary seal seat (7), and a flushing liquid inlet (9) and a flushing liquid outlet (10) respectively connected to a cooler are provided on the bearing housing (2) surrounding the sealing cavity; a sealing space is formed between the pump cover (1) and the front stationary seal seat (5), and a lubricating oil or grease inlet is provided on the bearing housing surrounding the sealing space.

5. The high-temperature heat-conducting oil pump according to claim 4, characterized in that: A packing seal (11) is provided between one end of the pump cover (1) far from the bearing and the pump shaft (3), and an oil seal (12) is provided between one end of the pump cover (1) close to the bearing and the pump shaft (3).

6. The high-temperature heat-conducting oil pump according to claim 3, characterized in that: Sealing rings or gaskets are installed on the positioning end faces of the front stationary seal seat (5) and the rear stationary seal seat (7).

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