Breathable sealing structure of oil-free screw machine

Abstract

The utility model provides a breathable sealing structure of an oil-free screw machine, which comprises a floating oil seal structure and a floating gas seal structure, the floating oil seal structure and the floating gas seal structure are both axially sleeved in a rotating shaft and a shaft hole of the oil-free screw machine, and the shaft hole is provided with a spacing section between the floating oil seal structure and the floating gas seal structure. A vent hole is formed in the inner circumferential wall of the interval section, a communicating hole is formed in a shell of the oil-free screw machine, the vent hole is communicated with the outside through the communicating hole, the interval section is further provided with an axial section for axially limiting the floating type oil seal structure and the floating type air seal structure, and a channel is formed between the inner circumference of the axial section and the vent hole. Gas leaked from the floating type gas seal structure is discharged through a gap between the inner circumference of the axial section and the rotating shaft, a channel, a vent hole and a communicating hole; the gas-permeable sealing structure can be ventilated, so that gas leaked from the gas-permeable sealing structure is discharged to the outside, and the gas is prevented from entering the oil tank.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of oil -free screw machine, specifically is a kind of breathable seal structure of oil -free screw machine. BACKGROUND

[0002] Oil -free screw machine, such as screw blower, is widely used in sewage treatment, cement production, chemical industry, textile and other fields.The sealing structure of screw blower is particularly important, and the sealing of general oil -free screw is divided into gas seal and oil seal, and an effective and reliable gas seal and oil seal structure can avoid the leakage of lubricating oil in oil tank to the working cavity of screw blower, and the high-efficiency gas seal structure can also reduce the leakage amount of compressed gas in the working cavity of screw blower.

[0003] Although it is theoretically desirable to be completely isolated, but in actual engineering, it cannot be done, when the gas on one side of gas seal structure leaks to the outside (i.e.to the side of oil seal structure), with the accumulation of gas, it will further enter the oil tank of gear box, thereby bringing adverse effects, therefore, how to solve the technical problem needs further research.

[0004] The applicant will propose a breathable seal structure of oil -free screw machine, which can be breathable, so as to discharge the gas leaked from the gas seal structure to the outside, to prevent the gas from entering the oil tank. UTILITY MODEL CONTENTS

[0005] The utility model solves the technical problems, overcomes the defects of prior art, and proposes a breathable seal structure of oil -free screw machine, which can be breathable, so as to discharge the gas leaked from the gas seal structure to the outside, to prevent the gas from entering the oil tank.

[0006] Compared with prior art, the utility model proposes a breathable seal structure of oil -free screw machine, which comprises floating oil seal structure and floating gas seal structure, and the floating oil seal structure and the floating gas seal structure are axially sleeved in the rotating shaft and the shaft hole of the oil -free screw machine, and an adjusting sleeve is arranged between the floating oil seal structure and the floating gas seal structure, the adjusting sleeve is sleeved in the shaft hole, the outer side end of the adjusting sleeve abuts against the rear end of the oil seal seat of the floating oil seal structure, and the inner side end of the adjusting sleeve abuts against the front end of the gas seal seat of the floating gas seal structure, and the spacing between the floating oil seal structure and the floating gas seal structure is adjusted by replacing adjusting sleeves with different axial lengths.

[0007] After adopting the above structure, compared with prior art, the utility model has the following advantages:

[0008] The present disclosure adjusts the spacing between the floating oil seal structure and the floating gas seal structure by adding an adjusting sleeve and replacing adjusting sleeves with different axial lengths, realizes the design of adjustable axial size, thereby improving compatibility, and the floating oil seal structure and the floating gas seal structure can be universal.

[0009] As an improvement, the floating oil seal structure comprises a spring limiting sleeve, a first spring, an oil seal ring, and an oil seal seat. The oil seal ring is provided with a first circumferential protrusion. The first spring is sleeved on the oil seal ring from an outer side of the oil seal ring and abuts against an outer side end of the first circumferential protrusion. The oil seal ring is inserted into the oil seal seat from an outer side of the oil seal seat and is movably sleeved with the oil seal seat. The oil seal seat is provided with a first inner circumferential portion. The spring limiting sleeve axially limits the first spring. The first spring presses the oil seal ring on the oil seal seat through cooperation of the first circumferential protrusion and the first inner circumferential portion, and the rear end of the oil seal seat abuts against the outer side end of the adjusting sleeve.

[0010] As an improvement, the cylindrical portion of the oil seal ring, on which the first spring is sleeved, extends outward. The spring limiting sleeve is sleeved on the outer circumferential portion of the cylindrical portion and also presses the first spring in the axial direction.

[0011] As an improvement, the inner circumferential portion of the oil seal ring is provided with a spiral groove.

[0012] As an improvement, a sealing ring is arranged between the first circumferential protrusion and the first inner circumferential portion.

[0013] As an improvement, the floating gas seal structure comprises a gas seal ring, a second spring, and a gas seal seat. The gas seal ring is provided with a second circumferential protrusion. The second spring is sleeved on the gas seal ring from an inner side of the gas seal ring and abuts against an inner side end of the second circumferential protrusion. The gas seal ring is inserted into the gas seal seat from an outer side of the gas seal seat and is movably sleeved with the gas seal seat. The gas seal seat is provided with a second inner circumferential portion. The second spring is axially limited between the second circumferential protrusion and the second inner circumferential portion. The inner side end of the adjusting sleeve extends radially and blocks the outer side of the gas seal ring. The axial distance between the inner side end of the adjusting sleeve and the second inner circumferential portion is greater than the axial length of the gas seal ring, so that the inner side end of the adjusting sleeve axially limits the gas seal ring movably in the axial direction between the inner side end of the adjusting sleeve and the second inner circumferential portion. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a sectional view of a rotor on the input shaft side of an oil-free screw machine without a gas permeable seal structure and the rotor on the input shaft.

[0015] Figure 2 It is a sectional view of a rotor on the input shaft side of an oil-free screw machine with a gas permeable seal structure and the rotor on the input shaft.

[0016] Figure 3 It is an enlarged view of A.

[0017] Figure 4 It is a perspective view of a gas permeable seal structure of an oil-free screw machine.

[0018] The reference signs are explained as follows: 1. floating oil seal structure, 2. floating gas seal structure, 3. rotating shaft, 4. shaft hole, 5. spacing section, 6. air hole, 7. shell, 8. communication hole, 9. axial section, 10. adjusting section part, 11. cylindrical section part, 12. axial protrusion, 13. gap, 14. space, 15. spring limiting sleeve, 16. first spring, 17. oil seal ring, 18. oil seal seat, 19. first circumferential protrusion, 20. first inner circumferential part, 21. gas seal ring, 22. second spring, 23. gas seal seat, 24. second circumferential protrusion, 25. second inner circumferential part, 26. oil retaining ring, 27. bearing, 28. working cavity, 29. sealing ring. DETAILED DESCRIPTION

[0019] The following description is provided to disclose the present application so that those skilled in the art can implement the present application. The examples in the following description are only used as examples, and other obvious modifications can be thought of by those skilled in the art. The basic principles defined in the following description can be applied to other embodiments, modifications, improvements, equivalents and other technical solutions without departing from the spirit and scope of the present application.

[0020] The present application is further described in detail as follows:

[0021] For the convenience of description and understanding, the directional description is only used as an illustration and does not constitute a limitation on the scope of protection.

[0022] As shown in Figures 1 to 4 , the present disclosure proposes a breathable seal structure of an oil-free screw machine, which comprises a floating oil seal structure 1 and a floating gas seal structure 2. The floating oil seal structure 1 and the floating gas seal structure 2 are axially sleeved on the rotating shaft 3 and the shaft hole 4 of the oil-free screw machine. The shaft hole 4 is provided with a spacing section 5 between the floating oil seal structure 1 and the floating gas seal structure 2. An air hole 6 is provided on the inner circumferential wall of the spacing section 5. A communication hole 8 is provided on the shell 7 of the oil-free screw machine. The air hole 6 is communicated with the outside through the communication hole 8. The spacing section 5 is further provided with an axial section 9 for limiting the floating oil seal structure 1 and the floating gas seal structure 2 in the axial direction. A passage is provided between the inner circumferential wall of the axial section 9 and the air hole 6. A rotor is installed in the working cavity 28 in cooperation. The working cavity 28 is air-tightly sealed by the floating gas seal structure 2. The gas leaked from the floating gas seal structure 2 is discharged through the gap 13 between the inner circumferential wall of the axial section 9 and the rotating shaft 3, the passage, the air hole 6 and the communication hole 8.

[0023] As shown in Figure 1 , 2 , the shaft hole 4 is composed of a plurality of stepped holes. The part where the spacing section 5 is located is provided with a cylindrical straight hole with equal diameter, thereby facilitating assembly.

[0024] In order to further simplify the structure, as shown inFigure 3 As shown, the air seal seat 23 of the floating air seal structure 2 is arranged at the same outer diameter as the axial section 9, specifically, when the axial section 9 is sequentially arranged from outside to inside with the adjusting section 10 and the cylindrical section 11, the air seal seat 23 of the floating air seal structure 2 is arranged at the same outer diameter as the cylindrical section 11.

[0025] In this example, as shown in Figure 3 , 4 , the axial section 9 is sequentially arranged from outside to inside with the adjusting section 10 and the cylindrical section 11, the adjusting section 10 includes a plurality of axial protrusions 12 sequentially arranged along the inner periphery of the shaft hole 4, the interval between the inner periphery of the cylindrical section 11 and the outer periphery of the rotating shaft 3 constitutes the gap 13, and the space 14 between adjacent axial protrusions 12 exposes the rotating shaft 3. During assembly, the axial section 9 is rotated so that the space 14 is located at the air passage hole 6, the outer side end of the axial protrusion 12 is arranged axially limited with the floating oil seal structure 1, and the inner side end of the cylindrical section 11 is arranged axially limited with the floating air seal structure 2. In this way, for different oil-free screw machines, since the positions of the air passage holes 6 are different, the axial section 9 can be rotated to solve the problem, thereby improving the versatility.

[0026] In particular, when the communication hole 8 is arranged as a radial straight hole, since different oil-free screw machines have different structures on the shell 7, such as the need to avoid other structures, the position of the air passage hole 6 should be based on the position of the communication hole 8, and then the axial section 9 is sequentially arranged from outside to inside with the adjusting section 10 and the cylindrical section 11, which is of great significance.

[0027] In some embodiments, as shown in Figure 3 , 4 , the adjusting section 10 and the cylindrical section 11 are integrally arranged, and the adjusting section 10 is arranged radially inward so that the outer periphery wall of the adjusting section 10 is arranged non-contacting with the inner periphery of the shaft hole 4. This is beneficial to reduce the contact area of the length of the adjusting section 10 during assembly, thereby reducing the processing difficulty, and it is also easier to assemble.

[0028] Any floating oil seal structure 1 and floating air seal structure 2 applicable to the present disclosure can be applied in the present disclosure.

[0029] As shown in Figure 3As shown, the floating oil seal structure 1 includes, for example, a spring limiting sleeve 15, a first spring 16, an oil sealing ring 17, and an oil sealing seat 18. The oil sealing ring 17 is provided with a first circumferential protrusion 19, which is, for example, an annular protrusion arranged radially outward along the outer peripheral wall of the oil sealing ring 17. The first spring 16 is fitted onto the oil sealing ring 17 from one end outside and abuts against the outer end of the first circumferential protrusion 19. The oil sealing ring 17 is inserted into the oil sealing seat 18 from the outside and abuts against the oil sealing seat 18. The sealing seat 18 is movably fitted together. The oil sealing seat 18 is provided with a first inner circumferential portion 20. For example, the first inner circumferential portion 20 is an annular protrusion arranged radially inward along the inner circumferential wall of the oil sealing seat 18. The spring limiting sleeve 15 axially limits the first spring 16. The first spring 16 presses the oil sealing ring 17 against the oil sealing seat 18 through the cooperation of the first circumferential protrusion 19 and the first inner circumferential portion 20. In order to better seal, a sealing ring 29 is also provided between the first circumferential protrusion 19 and the first inner circumferential portion 20.

[0030] The rear end of the oil seal seat 18 is integrally provided with the axial section 9 or separately provided. When it is separately provided, the rear end of the oil seal seat 18 abuts against the outer end of the axial section 9.

[0031] like Figure 3 As shown, the floating gas seal structure 2 includes, for example, a gas seal ring 21, a second spring 22, and a gas seal seat 23. The gas seal ring 21 is provided with a second circumferential protrusion 24, which is, for example, an annular protrusion arranged radially outward along the outer circumferential wall of the gas seal ring 21. The second spring 22 is fitted onto the gas seal ring 21 from one end inside and abuts against the inner end of the second circumferential protrusion 24. The gas seal ring 21 is inserted into the gas seal seat 23 from one end outside and is movably fitted into the gas seal seat 23. The gas seal seat 23 is provided with a second inner circumferential portion 25, which is, for example, along the inner circumferential wall of the gas seal seat 23. A ring-shaped protrusion is radially inwardly arranged on the circumferential wall. The second spring 22 is axially constrained between the second circumferential protrusion 24 and the second inner circumferential portion 25. The inner end of the axial segment 9 not only abuts against the outer end of the gas seal seat 23 to axially limit the gas seal seat 23, but also extends radially and blocks the outer side of the gas seal ring 21. Furthermore, the axial distance between the inner end of the axial segment 9 and the second inner circumferential portion 25 is greater than the axial length of the gas seal ring 21. Thus, the inner end of the axial segment 9 axially limits the axial movement of the gas seal ring 21 between the inner end of the axial segment 9 and the second inner circumferential portion 25. Therefore, the inner end of the axial segment 9 not only axially limits the gas seal seat 23, but also simultaneously serves as the outer limit for the axial movement space of the gas seal ring 21.

[0032] In this example, as Figure 1 , 2The oil-free screw machine shown includes a first rotor and a second rotor, and each end of the first rotor and the second rotor is provided with a gas-permeable sealing structure of the oil-free screw machine, so that four gas-permeable sealing structures of the oil-free screw machine are provided in total, and a straight communication hole 8 is provided on the shell 7 corresponding to each gas-permeable sealing structure.

[0033] Further, as shown in Figure 3 、 4 The outer ring of the bearing 27 limits the spring limiting sleeve 15, and in order to better seal, an oil retaining ring 26 is further arranged between the bearing 27 and the spring limiting sleeve 15, the oil retaining ring 26 is sleeved on the rotating shaft 3 and rotates with the rotating shaft 3, so as to reduce the oil or oil mist reaching the oil seal ring 17.

[0034] In understanding the present application, if necessary, the above structure can refer to other embodiments / attachments Figure 1 understood, and will not be repeated here.

[0035] The above is only an embodiment of the present application for illustration, so equivalent changes or modifications made according to the structure, features and principles described in the patent protection scope of the present application are included in the patent protection scope of the present application.

Claims

1. A gas permeable seal structure of an oil-free screw machine, comprising a floating oil seal structure (1) and a floating gas seal structure (2), both of which are axially fitted in a rotating shaft (3) and a shaft hole (4) of the oil-free screw machine, characterized in that, The shaft hole (4) is provided with a spacing section (5) between the floating oil seal structure (1) and the floating gas seal structure (2), an air hole (6) is arranged on the inner circumferential wall of the spacing section (5), a communication hole (8) is arranged on the housing (7) of the oil-free screw machine, the air hole (6) is communicated with the outside through the communication hole (8), the spacing section (5) is further provided with an axial section (9) for limiting the floating oil seal structure (1) and the floating gas seal structure (2) in the axial direction, a channel is arranged between the inner circumferential wall of the axial section (9) and the air hole (6), and the gas leaked from the floating gas seal structure (2) is discharged through the gap (13) between the inner circumferential wall of the axial section (9) and the rotating shaft (3), the channel, the air hole (6) and the communication hole (8).

2. A gas seal structure for an oil-free screw machine according to claim 1, wherein The axial section (9) is sequentially provided with an adjusting section (10) and a cylindrical section (11) from outside to inside, the adjusting section (10) includes a plurality of axial protrusions (12) arranged sequentially along the inner circumferential wall of the shaft hole (4), the gap (13) is formed between the inner circumferential wall of the cylindrical section (11) and the outer circumferential wall of the rotating shaft (3), and the space (14) between the adjacent axial protrusions (12) exposes the rotating shaft (3), during assembly, the axial section (9) is rotated so that the space (14) is located at the air hole (6), the outer side end of the axial protrusion (12) is arranged in the axial direction and limited by the floating oil seal structure (1), and the inner side end of the cylindrical section (11) is arranged in the axial direction and limited by the floating gas seal structure (2).

3. A gas permeable seal structure for an oil-free screw machine according to claim 1 or 2, characterized in that The communication hole (8) is a radial straight hole.

4. A gas seal for an oil-free screw machine as set forth in claim 2, wherein The adjusting section (10) and the cylindrical section (11) are integrally arranged, and the adjusting section (10) is arranged radially inward so that the outer circumferential wall of the adjusting section (10) is not in contact with the inner circumferential wall of the shaft hole (4).

5. A gas seal for an oil-free screw machine as claimed in claim 1 or 2, wherein The floating oil seal structure (1) includes a spring limiting sleeve (15), a first spring (16), an oil seal ring (17) and an oil seal seat (18), the oil seal ring (17) is provided with a first circumferential protrusion (19), the first spring (16) is sleeved on the oil seal ring (17) from the outer side of the oil seal ring (17) and abuts against the outer side end of the first circumferential protrusion (19), the oil seal ring (17) is inserted into the oil seal seat (18) from the outer side of the oil seal seat (18) and movably sleeved and matched with the oil seal seat (18), the oil seal seat (18) is provided with a first inner circumferential part (20), the spring limiting sleeve (15) limits the first spring (16) in the axial direction, the first spring (16) presses the oil seal ring (17) against the oil seal seat (18) through the cooperation of the first circumferential protrusion (19) and the first inner circumferential part (20), and the rear end of the oil seal seat (18) is integrally arranged or separately arranged with the axial section (9), when the rear end of the oil seal seat (18) is separately arranged, the rear end of the oil seal seat (18) abuts against the outer side end of the axial section (9).

6. A gas seal for an oil-free screw machine as claimed in claim 1 or 2, wherein The floating gas seal structure (2) comprises a gas seal ring (21), a second spring (22) and a gas seal seat (23), the gas seal ring (21) is provided with a second circumferential protrusion (24), the second spring (22) is sleeved on the gas seal ring (21) from one end of the inner side of the gas seal ring (21) and abuts against the inner side end of the second circumferential protrusion (24), and the gas seal ring (21) is inserted into the gas seal seat (23) from one end of the outer side of the gas seal seat (23) and movably sleeved and matched with the gas seal seat (23), the gas seal seat (23) is provided with a second inner circumferential part (25), the second spring (22) is axially limited between the second circumferential protrusion (24) and the second inner circumferential part (25), the inner side end of the axial section (9) not only abuts against the outer side end of the gas seal seat (23) to axially limit the gas seal seat (23), but also radially extends and is arranged to block the outer side of the gas seal ring (21), and the axial spacing between the inner side end of the axial section (9) and the second inner circumferential part (25) is greater than the axial length of the gas seal ring (21), so that the inner side end of the axial section (9) axially limits the gas seal ring (21) to be axially movable between the inner side end of the axial section (9) and the second inner circumferential part (25).

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