阅读说明：本技术 迷宫密封结构和螺杆压缩机 (Labyrinth seal structure and screw compressor ) 是由 毕雨时 李磊 武晓昆 刘志华 曹聪 于 2020-12-17 设计创作，主要内容包括：本公开提供一种迷宫密封结构和螺杆压缩机。其中,迷宫密封结构包括在螺杆转子轴轴向上间隔布置的多个密封齿,密封齿沿着螺杆转子轴的周向环绕设置,相邻的两个密封齿之间形成有密封槽,密封槽被配置为从螺杆转子轴的高压侧偏向螺杆转子轴的低压侧。迷宫密封结构通过将密封槽配置为从螺杆转子轴的高压侧偏向低压侧的结构,能够有效减少螺杆压缩机高压气体向排气侧轴承腔的泄漏量,又可有效降低螺杆转子轴与轴承座孔发生绞死或擦伤的风险,使得螺杆压缩机的高效可靠运行。(The present disclosure provides a labyrinth seal structure and a screw compressor. The labyrinth seal structure comprises a plurality of seal teeth which are arranged at intervals in the axial direction of the screw rotor shaft, the seal teeth are arranged around the circumference of the screw rotor shaft, a seal groove is formed between every two adjacent seal teeth, and the seal groove is configured to deviate from the high-pressure side of the screw rotor shaft to the low-pressure side of the screw rotor shaft. The labyrinth seal structure is configured into a structure which is deviated from the high-pressure side to the low-pressure side from the high-pressure side of the screw rotor shaft, so that the leakage amount of high-pressure gas of the screw compressor to the bearing cavity at the exhaust side can be effectively reduced, the risk of twisting or scratching between the screw rotor shaft and the bearing seat hole can be effectively reduced, and the screw compressor can efficiently and reliably run.)

1. A labyrinth seal structure is characterized by comprising a plurality of seal teeth (1) which are arranged at intervals in the axial direction of a screw rotor shaft (3), wherein the seal teeth (1) are circumferentially arranged along the circumferential direction of the screw rotor shaft (3), a seal groove (2) is formed between two adjacent seal teeth (1), and the seal groove (2) is configured to deviate from the high-pressure side of the screw rotor shaft (3) to the low-pressure side of the screw rotor shaft (3).

2. The labyrinth seal according to claim 1, characterized in that the angle α of the first groove face of the seal groove (2) close to the low-pressure side to the top face of the seal tooth (1) is configured such that: the included angle beta between the second groove surface of the sealing groove (2) close to the high-pressure side and the top surface of the sealing tooth (1) is configured as follows: β ═ 130 ± 5 °.

3. The labyrinth seal according to claim 1, characterized in that the spacing L1 of the top face of the seal tooth (1) from the screw rotor shaft (3) is configured such that: l1 is 0.1 mm-0.15 mm.

4. The labyrinth seal according to claim 3, characterized in that the spacing L2 of the groove bottom of the seal groove (2) from the screw rotor shaft (3) is configured such that: l2 ═ 2 ± 0.1 mm.

5. The labyrinth sealing structure as claimed in claim 1, characterized in that the sealing groove (2) comprises a wedge-shaped groove.

6. Labyrinth seal according to claim 5, characterized in that the wedge-shaped groove is tapered in a radially outward direction along the screw rotor shaft (3).

7. The labyrinth seal according to claim 1, characterized in that one or more than two of the seal grooves (2) are formed with a stop shoulder (4) at the top of the first groove face close to the low-pressure side.

8. The labyrinth seal according to claim 7, characterized in that the height of a plurality of the seal teeth (1) increases stepwise in the direction from the high-pressure side to the low-pressure side along the screw rotor shaft (3).

9. The labyrinth seal according to claim 7, characterized in that the radial height L3 of the stop shoulder (4) relative to the screw rotor shaft (3) is configured such that: l3 is more than or equal to 0.5mm, and the axial clearance L4 of the retaining shoulder (4) relative to the screw rotor shaft (3) is configured as follows: l1 is not less than L4 is not less than 1.5L 1, wherein L1 is the distance between the bottom surface of the seal groove (2) and the screw rotor shaft (3).

10. The labyrinth seal structure according to claim 1, characterized in that the plurality of seal grooves (2) includes 9 or more seal grooves (2).

11. A screw compressor comprising a screw rotor shaft (3) and a labyrinth seal according to any one of claims 1 to 10.

12. -screw compressor according to claim 11, characterised in that the screw rotor shaft (3) is of a stepped reduction in the direction along its high-pressure side to its low-pressure side.

Technical Field

The present disclosure relates to a labyrinth seal structure and a screw compressor.

Background

The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The screw compressor adopts an oil lubrication bearing, and lubricating oil enters a bearing cavity at the exhaust side to lubricate and cool the bearing and then returns to the low-pressure side of air suction, so that the pressure in the bearing cavity shown in figure 1 is close to a low-pressure state. When the screw rotor is continuously meshed, high-pressure gas can be continuously generated, and a small amount of gas can enter the bearing cavity on the exhaust side through the clearance fit position shown in the figure due to the existence of pressure difference to form leakage, so that the refrigerating capacity of the compressor is reduced, and useless work is performed.

Two approaches are commonly taken in the industry, the first being a clearance fit, with the lubricant forming an oil film therein to form a seal. The disadvantages are that: if the clearance is too large, gas leakage still exists; if the clearance is too small, the rotor shaft and the bearing housing hole are easily twisted and scratched. The second approach uses a wear-resistant material to enlarge the gap and form the seal by thermal expansion of the wear-resistant material. The disadvantages are that: the aging properties of the wear resistant material, once it fails, continues to leak.

For screw compressors, the above gap seal or material seal is adopted, and although the compressor can normally operate, the problems of energy efficiency and reliability always exist.

Disclosure of Invention

According to some embodiments of the present disclosure, a labyrinth seal structure is provided, including a plurality of seal teeth arranged at intervals in an axial direction of a screw rotor shaft, the seal teeth being circumferentially provided along a circumferential direction of the screw rotor shaft, a seal groove being formed between adjacent two of the seal teeth, the seal groove being configured to be offset from a high-pressure side of the screw rotor shaft toward a low-pressure side of the screw rotor shaft.

In some embodiments, an angle α between a first groove surface of the seal groove near the low pressure side and a top surface of the seal tooth is configured to: and alpha is 70 +/-5 degrees, and an included angle beta between a second groove surface of the sealing groove close to the high-pressure side and the top surface of the sealing tooth is configured as follows: β ═ 130 ± 5 °.

In some embodiments, the seal tooth tip face to screw rotor shaft spacing L1 is configured to: l1 is 0.1 mm-0.15 mm.

In some embodiments, the groove bottom of the seal groove is spaced apart from the screw rotor shaft by a distance L2 configured to: l2 ═ 2 ± 0.1 mm.

In some embodiments, the sealing groove comprises a wedge-shaped groove.

In some embodiments, the wedge groove tapers in a direction radially outward along the screw rotor shaft.

In some embodiments, one or more seal grooves are formed with a shoulder at the top of the first groove face near the low pressure side.

In some embodiments, the height of the plurality of seal teeth increases in steps in a direction along the high pressure side to the low pressure side of the screw rotor shaft.

In some embodiments, the radial height L3 of the shoulder relative to the screw rotor axis is configured to: l3 is more than or equal to 0.5mm, and the axial clearance L4 of the retaining shoulder relative to the screw rotor shaft is configured as follows: l4 is not less than L1 and not more than 1.5L 1, wherein L1 is the distance between the bottom surface of the seal groove and the screw rotor shaft.

In some embodiments, the plurality of seal grooves comprises more than 9 seal grooves.

According to some embodiments of the present disclosure, there is provided a screw compressor including a screw rotor shaft and the aforementioned labyrinth seal structure.

In some embodiments, the screw rotor shaft is stepped in a direction along its high pressure side to low pressure side.

Therefore, based on the technical scheme, the labyrinth seal structure of the embodiment of the disclosure can effectively reduce the leakage amount of high-pressure gas of the screw compressor to the exhaust side bearing cavity by configuring the seal groove into a structure deviated from the high-pressure side to the low-pressure side of the screw rotor shaft, and can also effectively reduce the risk of the screw rotor shaft and the bearing seat hole being twisted or scratched, so that the screw compressor can operate efficiently and reliably.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional structural schematic of some embodiments of labyrinth seals according to the present disclosure;

FIG. 2 is a partial structural schematic view of some embodiments of a labyrinth seal according to the present disclosure;

FIG. 3 is a cross-sectional structural schematic of further embodiments of labyrinth seal structures according to the present disclosure;

FIG. 4 is a partial structural schematic view of further embodiments of labyrinth seal structures according to the present disclosure.

Description of the reference numerals

1. A seal tooth; 2. a sealing groove; 3. a screw rotor shaft; 4. and (6) a shoulder.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments are to be construed as merely illustrative, and not as limitative, unless specifically stated otherwise.

The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be intervening devices between the specific device and the first device or the second device. When a particular device is described as being coupled to other devices, the particular device may be directly coupled to the other devices without intervening devices or may be directly coupled to the other devices with intervening devices.

All terms used in the present disclosure have the same meaning as understood by one of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

As shown in fig. 1 and 3, a labyrinth seal structure provided according to some embodiments of the present disclosure includes a plurality of seal teeth 1 arranged at intervals in an axial direction of a screw rotor shaft 3, the seal teeth 1 being circumferentially provided along a circumferential direction of the screw rotor shaft 3, a seal groove 2 being formed between adjacent two of the seal teeth 1, the seal groove 2 being configured to be offset from a high-pressure side of the screw rotor shaft 3 toward a low-pressure side of the screw rotor shaft 3.

In the exemplary embodiment, by configuring the seal groove 2 to be a structure deviating from the high-pressure side to the low-pressure side of the screw rotor shaft 3, the leakage amount of the high-pressure gas of the screw compressor to the bearing cavity at the exhaust side is significantly reduced compared with other shapes (such as trapezoid and triangle), the leakage of the high-pressure gas exhausted by the compressor to the bearing cavity at the low pressure is effectively prevented, the risk of the screw rotor shaft 3 and the bearing seat hole being twisted or scratched is effectively reduced, and the efficient and reliable operation of the screw compressor is ensured.

Fig. 1 to 4 are two-dimensional views, and the labyrinth seal structure is a three-dimensional structure formed by one rotation of the generatrix around the screw rotor axis in the upper view.

In accordance with a labyrinth seal configuration of the screw compressor, as shown in connection with fig. 1 and 2, in some embodiments, the seal groove 2 comprises a wedge-shaped groove. In some embodiments, the wedge grooves are tapered in a radially outward direction along the screw rotor shaft 3, ensuring leak-proof reliability.

As shown in fig. 1 and 2, in some embodiments, an included angle α between a first groove surface of the seal groove 2 near the low-pressure side and a top surface of the seal tooth 1 is configured as follows: α is 70 ± 5 °, and an angle β between a second groove surface of the seal groove 2 close to the high-pressure side and the top surface of the seal tooth 1 is configured as follows: beta is 130 +/-5 degrees, so that better leakage-proof effect is obtained, and the practicability is higher.

To ensure structural stability, as shown in fig. 2, the distance L1 between the top face of the seal tooth 1 and the screw rotor shaft 3 is configured as follows: l1 is 0.1 mm-0.15 mm. In some embodiments, the distance L2 between the groove bottom of the seal groove 2 and the screw rotor shaft 3 is configured to: l2 ═ 2 ± 0.1 mm.

In some embodiments, as shown in fig. 1 and 3, a shoulder 4 is formed at the top of the first groove surface of one or more sealing grooves 2 close to the low-pressure side, and the shoulder is arranged to change the direction of gas leakage, so that local resistance is generated, and the leakage amount is further reduced.

To ensure leak-proof reliability, in some embodiments, as shown in fig. 1 and 3, the height of the plurality of seal teeth 1 increases stepwise in a direction from the high-pressure side to the low-pressure side along the screw rotor shaft 3. The number of the blocking shoulders can be increased properly according to the structure of the compressor, and 1-2 blocking shoulders are generally arranged.

To improve the leakage-prevention reliability, as shown in fig. 4, in some embodiments, the radial height L3 of the catch 4 relative to the screw rotor shaft 3 is configured to: l3 is greater than or equal to 0.5mm, and the axial clearance L4 of the retaining shoulder 4 relative to the screw rotor shaft 3 is configured as follows: l4 is not less than L1 and not more than 1.5L 1, wherein L1 is the distance between the bottom surface of the seal groove 2 and the screw rotor shaft 3. The upper limit of L3 is determined by the actual design size of the compressor, with larger sizes being preferred.

For better sealing effect, as shown in fig. 1, in some embodiments, the plurality of sealing grooves 2 includes more than 9 sealing grooves 2. Practice proves that the number of the sealing grooves 2 is more than or equal to 9 to realize good sealing effect.

Through simulation calculation, by utilizing the labyrinth seal structure disclosed by the embodiment of the disclosure, the gas leakage amount is reduced by 30% compared with other shapes (such as trapezoids and triangles), the high-pressure gas exhausted by the compressor is effectively prevented from leaking to the low-pressure bearing cavity, and the high-efficiency and reliable operation of the compressor is ensured.

Some embodiments of the present disclosure provide a screw compressor comprising a screw rotor shaft 3 and the aforementioned labyrinth seal structure. The screw compressor has the beneficial technical effects correspondingly.

As shown in fig. 1-4, in some embodiments, the screw rotor shaft 3 is stepped in a direction from the high pressure side to the low pressure side thereof. The screw rotor shaft 3 with a stepped reduction structure is matched with the retaining shoulder 4 at the bottom of the sealing tooth 1 in an installing manner, so that the gas leakage direction is effectively changed, the local resistance is generated, and the leakage amount is further reduced.

Thus, various embodiments of the present disclosure have been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that various changes may be made in the above embodiments or equivalents may be substituted for elements thereof without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.