CN212690341U

CN212690341U - Oil-free screw compressor sealing structure

Info

Publication number: CN212690341U
Application number: CN202021293188.0U
Authority: CN
Inventors: 周坤; 马升; 王业荣; 周武彬
Original assignee: Ningbo Baosi Energy Equipment Co Ltd
Current assignee: Ningbo Baosi Energy Equipment Co Ltd
Priority date: 2020-07-03
Filing date: 2020-07-03
Publication date: 2021-03-12
Anticipated expiration: 2030-07-03

Abstract

The utility model discloses an oil-free screw compressor sealing structure, which comprises an oil sealing component and an air sealing component which are sequentially sleeved outside a rotating shaft along the axial direction, wherein the oil sealing component is arranged at one end close to a bearing; the oil seal assembly comprises an oil seal ring sleeved outside the rotating shaft, a first mounting groove is formed in a shell outside the rotating shaft, one end of the oil seal ring abuts against the bearing, and the other end of the oil seal ring is in sealing fit with the first mounting groove; the inner hole wall of the oil seal ring is provided with a thread groove extending along the axial direction; when the rotating shaft rotates, spiral sealing is formed between the outer part of the rotating shaft and the inner hole of the oil seal ring so as to prevent lubricating oil at the bearing end from entering the compression cavity. The utility model discloses an oil-free screw compressor seal structure, simple structure, sealing performance is good, can prevent effectively that lubricating oil and the atmosphere of bearing end from entering into the compression chamber.

Description

Oil-free screw compressor sealing structure

Technical Field

The utility model relates to a compressor technical field specifically is an oil-free screw compressor seal structure.

Background

The screw compressor is composed of a pair of parallel, intermeshing female and male screws, and is one of the most widely used rotary compressors. Both single screw and twin screw, and what is commonly referred to as a screw compressor is a twin screw compressor. The screw compressor can be divided into an oil-free screw compressor and an oil injection screw compressor, in the oil injection screw compressor, a large amount of lubricating liquid is injected into a compressed gas medium to play roles of lubricating, sealing, cooling and noise reduction, the oil injection screw compressor is not provided with a synchronous gear, a male rotor directly drives a female rotor to rotate, and the lubricating oil not only plays a role of reducing the exhaust temperature, but also provides lubrication for friction pairs such as bearings, mechanical seals, slide valves and the like.

In the oil-free screw compressor, the rotors are not in direct contact and have certain gaps, the male rotor drives the female rotor to rotate through the synchronous gear, and the synchronous gear also ensures the gaps of the rotors while transmitting power. The term "oil-free" as used herein means that gas does not come into contact with oil at all during compression, but the bearings and synchronous gears of the compressor still need to be lubricated with lubricating oil, so that the design of the seal structure between the lubricating cavity and the compression cavity of the bearing is particularly important in the oil-free screw compressor structure. Poor sealing performance can cause lubricating oil supplied to bearings and gears to leak into the compression cavity, so that a trace amount of lubricating oil exists in gas compressed by the oil-free screw, and the phenomenon can affect a terminal client.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: in order to overcome the defects of the prior art, the sealing structure is applied to an oil-free screw compressor, has a simple structure and good sealing performance, and can effectively prevent lubricating oil at a bearing end and atmosphere from entering a compression cavity.

The utility model adopts the technical proposal that: the oil-free screw compressor sealing structure is applied between a compressor compression cavity and a shaft end bearing, is used for preventing lubricating oil and air at the bearing end from entering the compression cavity, and comprises an oil sealing assembly and an air sealing assembly which are sequentially sleeved outside a rotating shaft along the axial direction, wherein the oil sealing assembly is arranged at one end close to the bearing; the oil seal assembly comprises an oil seal ring sleeved outside the rotating shaft, a first mounting groove is formed in a shell outside the rotating shaft, one end of the oil seal ring abuts against the bearing, and the other end of the oil seal ring is in sealing fit in the first mounting groove; the inner hole wall of the oil seal ring is provided with a thread groove extending along the axial direction; when the rotating shaft rotates, spiral sealing is formed between the outer part of the rotating shaft and the inner hole of the oil seal ring so as to prevent lubricating oil at the bearing end from entering the compression cavity.

Compared with the prior art, the utility model has the following advantage:

in the sealing structure of the utility model, a plurality of sealing structures, namely an oil sealing component and an air sealing component, are arranged between the compression cavity and the bearing end of the compressor, and the oil sealing component is arranged at one end close to the bearing, because lubricating oil is needed to be adopted for lubrication at one end of the bearing; the oil seal assembly in the structure comprises an oil seal ring, the oil seal ring is positioned between the air seal assembly and the bearing cavity, the inner hole wall of the oil seal ring is provided with a spiral groove, lubricating oil which runs out of the bearing cavity can enter the spiral groove, and liquid in the spiral groove can form a liquid nut under the high-speed rotation action of the rotating shaft, namely the non-contact dynamic seal which prevents liquid leakage in a thread form is also called spiral seal; the sealing form effectively prevents lubricating oil in the bearing cavity from entering the compression cavity; in addition, the end, close to the compression cavity, of the outer portion of the rotating shaft is further provided with a gas sealing assembly, so that gas at the bearing end and a small amount of lubricating liquid which runs out of the bearing end can be prevented from entering the compression cavity, and the sealing performance is further guaranteed.

As an improvement, a plurality of oil outlet holes communicated with the lubricating oil chamber are formed in the side wall of one end, close to the bearing, of the oil seal ring along the circumferential direction. The oil outlet hole is arranged to realize the return circulation of the lubricating oil and prevent the lubricating oil from flowing to the compression cavity along the axial direction.

The oil seal assembly further comprises an oil retainer ring, the oil retainer ring is sleeved outside the rotating shaft, an accommodating groove is formed in one end, close to the bearing, of the oil seal ring, and the outer end of the oil retainer ring is matched in the accommodating groove; the oil outlet is formed in the side wall of one end, close to the bearing, of the accommodating groove, and a gap communicated with the oil outlet is reserved between the oil retainer and the end face of the bearing.

In a further improvement, the oil slinger is provided with a tapered surface at an end thereof adjacent the bearing which tapers towards an end thereof remote from the bearing. The conical surface is arranged at one end of the oil deflector ring in the structure, so that the drainage effect is achieved, and lubricating oil can smoothly enter the oil outlet.

And the sealing assembly comprises a piston seat which is sleeved outside the rotating shaft in a sealing manner, a second mounting groove is formed in one end of the shell, close to the compression cavity, the outer end of the piston seat is assembled in the second mounting groove, a plurality of axially-arranged annular grooves are formed in the outer side wall of the piston seat, piston sealing rings are arranged in the annular grooves, and the outer end faces of the piston sealing rings are connected to the side wall of the second mounting groove to form a labyrinth type air sealing structure.

In another improvement, one end of the piston seat is abutted against the end surface of the second mounting groove, and the other end of the piston seat extends towards the position of the bearing until the oil slinger is clamped and limited between the piston seat and the end surface of the bearing; and the inner ring of the oil seal ring is sleeved outside the piston seat.

And in the improved structure, a through hole for discharging lubricating oil or gas is arranged between the piston seat and the oil seal ring on the side wall of the shell.

Drawings

Fig. 1 is a sectional view of the sealing structure of the oil-free screw compressor of the present invention.

Fig. 2 is an enlarged structural view at X in fig. 1.

The oil pump comprises a shell, a first mounting groove, a second mounting groove, a through hole, a bearing, a rotating shaft, an oil seal ring, a thread groove, an oil outlet, a containing groove, a retainer ring, a conical surface, a piston seat, an annular groove and a piston sealing ring, wherein the shell is 1, the first mounting groove is 1.1, the second mounting groove is 1.2, the through hole is 1.3, the bearing is 2, the rotating shaft is 3, the oil seal ring is 4, the thread groove is 4.1, the oil outlet is 4.2, the containing groove is 4.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the following detailed description.

In the description of the present invention, it should be noted that the terms "outside", "inner hole wall", "side wall", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. In addition, in the description of the present invention, the terms "first" and "second" are used for convenience of description and distinction, and have no specific meaning.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the term "connected" is to be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1 and 2, the utility model provides a pair of oil-free screw compressor seal structure, this structure mainly is applied to between compressor compression chamber and the axle head bearing for prevent lubricating oil and the air admission compression chamber of bearing end, it includes to establish in proper order along the axial at the outside oil seal subassembly of 3 of pivot and air seal subassembly, and oil seal subassembly establishes the one end at nearly bearing 2. Specifically, at the end of the bearing 2 of the compressor, which is located outside the rotating shaft 3, is a housing 1 for mounting various components, and an oil seal assembly and a gas seal assembly are mounted in the housing 1.

Specifically, oil seal assembly includes oil blanket circle 4, the one end of nearly bearing 2 is equipped with first mounting groove 1.1 on casing 1, the outside at pivot 3 is adorned to the inner circle suit of oil blanket circle 4, the sealed cooperation of the outer end of oil blanket circle 4 is in first mounting groove 1.1, the sealed cooperation of here indicates, be equipped with the sealing washer between the lateral wall of oil blanket circle 4 and first mounting groove 1.1 lateral wall, for the location of sealing washer, be equipped with corresponding sealing washer groove on the lateral wall of oil blanket circle 4 in this structure, the inner circle location of sealing washer is at the sealing washer inslot, the sealed laminating of the lateral wall of sealing washer is on the lateral wall of first mounting groove 1.1, the sealed cooperation of oil blanket circle 4 with first mounting groove 1.1 has been realized.

In addition, one axial end of the oil seal ring 4 is abutted against the end face of the bearing 2, and the other end of the oil seal ring is matched in the first mounting groove 1.1; the inner hole wall of the oil seal ring 4 is provided with a thread groove 4.1 extending along the axial direction; when the rotating shaft 3 rotates, spiral sealing is formed between the outer part of the rotating shaft 3 and the inner hole of the oil seal ring 4. Specifically, the spiral seal is a non-contact dynamic seal that prevents liquid leakage by using threads, and is also called a thread seal. Usually, a thread is machined on a rotating shaft at a sealing part, lubricating liquid leaked from a bearing cavity during operation fills a space contained in the thread groove 4.1 and the outer part of the rotating shaft 3 to form a 'liquid nut', and when the rotating shaft 3 rotates at a high speed, the 'liquid nut' in an inner hole of the oil seal ring 4 generates axial movement to promote the liquid to continuously return to a high-pressure end. The spiral seal is suitable for occasions with high liquid viscosity, small pressure difference and medium rotating speed, and is basically not limited by the temperature of the liquid.

A plurality of oil outlet holes 4.2 communicated with the lubricating oil chamber are formed in the side wall of one end, close to the bearing 2, of the oil seal ring 4 along the circumferential direction. In the structure, most of the lubricating liquid overflowing from the bearing cavity flows back to the lubricating chamber along the oil outlet hole 4.2 under the sealing action of the oil seal ring 4.

As shown in fig. 1 and 2, in this embodiment, the oil seal assembly further includes an oil slinger 5, the oil slinger 5 is sleeved outside the rotating shaft 3, an accommodating groove 4.3 is formed at one end of the oil seal ring 4 close to the bearing 2, and an outer end of the oil slinger 5 is fitted in the accommodating groove 4.3; the oil outlet 4.2 is established on the lateral wall of the 2 one ends of nearly bearing of storage tank 4.3, leave the clearance with oil outlet 4.2 intercommunication between oil scraper ring 5 and the 2 terminal surfaces of bearing, oil scraper ring 5 sets up the back, the lubricated liquid that overflows from the lubrication cavity reaches oil scraper ring 5 at first, under oil scraper ring 5's the effect of blockking, most lubricated liquid flows back to the lubrication chamber from oil outlet 4.2, there is a small part of lubricated liquid to pass the clearance between oil scraper ring 5 and the storage tank 4.3 and reach the hole position of oil seal circle 4, thereby under the "spiral seal" effect in oil seal circle 4 hole, further realization is to the shutoff of lubricated liquid, prevent that lubricated liquid from getting into the compression chamber.

One end of the oil deflector ring 5 close to the bearing 2 is provided with a conical surface 5.1 inclined towards one end far away from the bearing 2, and the conical surface 5.1 mainly plays a role in guiding, so that lubricating liquid coming out of the lubricating chamber quickly reaches the oil outlet 4.2 under the guiding action of the conical surface 5.1, and then most of the lubricating oil flows back to the lubricating chamber through the oil outlet.

In this embodiment, as shown in fig. 1, the air-tight sealing assembly includes a piston seat 6 hermetically sleeved outside the rotating shaft 3, one end of the casing 1 near the compression cavity is provided with a second mounting groove 1.2, the outer end of the piston seat 6 is assembled in the second mounting groove 1.2, the outer side wall of the piston seat 6 is provided with a plurality of axially arranged annular grooves 6.1, the annular grooves 6.1 are internally provided with piston sealing rings 7, and the outer end surfaces of the plurality of piston sealing rings 7 are connected to the side wall of the second mounting groove 1.2 to form a labyrinth-type air-tight structure. Specifically, the piston sealing ring 7 in the structure is made of elastic steel and other materials, and is fixed in the inner cavity of the second mounting groove 1.2 under the action of tangential elasticity and radial elasticity of the piston sealing ring after being compressed and mounted in the second mounting groove 1.2; and a sealing ring is arranged between the inner hole of the piston seat 6 and the outer side wall of the rotating shaft 3, and the sealing ring can seal the gap lubricating oil which penetrates through the oil retainer ring 5 and the rotating shaft 3 at least partially. When the main engine operates, the rotating shaft 3 and the piston seat 6 rotate together, and the labyrinth seal principle is utilized to play a role in sealing gas.

In the structure, one end of the piston seat 6 is abutted against the end surface of the second mounting groove 1.2, the other end of the piston seat extends towards the position of the bearing 2 until the oil baffle ring 5 is clamped and limited between the piston seat 6 and the end surface of the bearing 2, and after the axial compression connection, when the rotating shaft 3 rotates, the oil baffle ring 5 also rotates together. And, the inner circle cover of oil seal ring 4 in this structure is established the outside at piston seat 6. Therefore, when the main engine is in operation, the rotating shaft 3 drives the piston seat 6 to rotate together, and the spiral sealing part in the structure is formed in the gap between the outer end of the piston seat 6 and the inner hole of the oil seal ring 4.

In addition, a through hole 1.3 for discharging lubricating oil or gas is provided in the side wall of the housing 1 between the piston seat 6 and the oil seal 4.

In this structure, the flow path of the lubricating oil is: (shown by the direction of the arrows in the figure)

Lubricating oil in the lubricating chamber enters the bearing 2 to lubricate and cool the bearing 2, then flows to the oil scraper ring 5 along the axial direction, because the oil scraper ring 5 rotates together with the rotating shaft 3 under the action of centrifugal force, the lubricating oil is thrown into the oil outlet 4.2 of the oil seal ring 4, most of the lubricating oil flows back to the lubricating chamber through the oil outlet 4.2, the rest of the lubricating oil enters the oil seal ring 4, because the inner ring of the oil seal ring 4 has a thread groove 4.1, the oil is sealed again according to the principle of spiral sealing, finally, the leaked extremely small amount of oil gas is directly discharged to the atmosphere from the through hole 1.3, moreover, a piston seat 6 and a piston seal ring 7 structure are also arranged in the shell 1 and close to the compression cavity, a plurality of annular grooves arranged at the outer end part of the piston seat 6 and the piston seal ring 6 form a labyrinth seal structure, the small amount of oil gas passing through the oil seal ring 4 is sealed again, the whole process ensures that lubricating oil and air at the bearing end cannot enter the compression cavity, and the oil-free environment of the compression cavity is ensured.

While the above is directed to the preferred embodiment of the present invention, it is not intended that it be limited, except as by the appended claims. The present invention is not limited to the above embodiments, and the specific structure thereof allows for changes, all the changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

Claims

1. The utility model provides an oil-free screw compressor seal structure, is applied to between compressor compression chamber and the axle head bearing for prevent lubricating oil and the air admission compression chamber of bearing end, its characterized in that: the oil seal device comprises an oil seal assembly and an air seal assembly which are sequentially sleeved outside a rotating shaft (3) along the axial direction, wherein the oil seal assembly is arranged at one end close to a bearing (2); the oil seal assembly comprises an oil seal ring (4) sleeved outside the rotating shaft (3), a first mounting groove (1.1) is formed in the shell (1) outside the rotating shaft (3), one end of the oil seal ring (4) abuts against the bearing (2), and the other end of the oil seal ring is matched in the first mounting groove (1.1) in a sealing mode; the inner hole wall of the oil seal ring (4) is provided with a thread groove (4.1) extending along the axial direction; when the rotating shaft (3) rotates, spiral sealing is formed between the outer part of the rotating shaft (3) and the inner hole of the oil seal ring (4).

2. An oil-free screw compressor seal structure according to claim 1, characterized in that: and a plurality of oil outlet holes (4.2) communicated with the lubricating oil chamber are formed in the side wall of one end, close to the bearing (2), of the oil seal ring (4) along the circumferential direction.

3. An oil-free screw compressor seal structure according to claim 2, characterized in that: the oil seal assembly further comprises an oil retainer ring (5), the oil retainer ring (5) is sleeved outside the rotating shaft (3), an accommodating groove (4.3) is formed in one end, close to the bearing (2), of the oil seal ring (4), and the outer end of the oil retainer ring (5) is matched in the accommodating groove (4.3); the oil outlet (4.2) is formed in the side wall of the containing groove (4.3) close to one end of the bearing (2), and a gap communicated with the oil outlet (4.2) is reserved between the oil retainer ring (5) and the end face of the bearing (2).

4. An oil-free screw compressor seal structure according to claim 3, characterized in that: one end of the oil slinger (5) close to the bearing (2) is provided with a conical surface (5.1) which inclines towards one end far away from the bearing (2).

5. An oil-free screw compressor seal structure according to claim 3, characterized in that: the air-tight seal subassembly include piston seat (6) of seal cover dress in pivot (3) outside, the one end of nearly compression chamber is equipped with second mounting groove (1.2) on casing (1), the outer end of piston seat (6) is joined in marriage the dress in second mounting groove (1.2), just be equipped with ring channel (6.1) of a plurality of axial arrangements on piston seat (6) lateral wall, ring channel (6.1) in be equipped with piston seal ring (7), the outer terminal surface of a plurality of piston seal rings (7) is connected on second mounting groove (1.2) lateral wall in order to form labyrinth type air-tight seal structure.

6. An oil-free screw compressor seal structure according to claim 5, characterized in that: one end of the piston seat (6) is abutted against the end surface of the second mounting groove (1.2), and the other end of the piston seat extends towards the position of the bearing (2) until the oil slinger (5) is clamped and limited between the piston seat (6) and the end surface of the bearing (2); and the inner ring of the oil seal ring (4) is sleeved outside the piston seat (6).

7. An oil-free screw compressor seal structure according to claim 5, characterized in that: and a through hole (1.3) for discharging lubricating oil or gas is arranged on the side wall of the shell (1) and between the piston seat (6) and the oil seal ring (4).