阅读说明：本技术 一种用于罗茨泵或螺杆泵的悬臂连接结构 (Cantilever connecting structure for roots pump or screw pump ) 是由 荣易 于 2021-08-23 设计创作，主要内容包括：一种用于罗茨泵或螺杆泵的悬臂连接结构,包括外壳体、轴承端盖、主动轴转子和悬臂转子,主动轴转子与驱动定位套相连接,驱动定位套上设有圆形凸台；悬臂转子包括线性转子、过渡圆柱和悬臂转子定位圈；悬臂转子定位圈与驱动定位套固定连接；外壳体套接在悬臂转子外部,轴承端盖设置在主动轴转子外侧,轴承端盖内设置有第一台阶,主动轴转子外表面设置有第二台阶,第一台阶和第二台阶之间设有轴承腔,轴承腔内安装有轴承。本发明克服了现有技术的不足,通过悬臂转子定位圈与驱动定位套相配合,驱动定位套与主动轴转子相配合,可以确保悬臂转子的刚性和保持整体性能,并且大幅降低了其机加工的要求,并且不再需要延伸的轴与转子的嵌入配合。(A cantilever connecting structure for a roots pump or a screw pump comprises an outer shell, a bearing end cover, a driving shaft rotor and a cantilever rotor, wherein the driving shaft rotor is connected with a driving positioning sleeve, and a circular boss is arranged on the driving positioning sleeve; the cantilever rotor comprises a linear rotor, a transition cylinder and a cantilever rotor positioning ring; the cantilever rotor positioning ring is fixedly connected with the driving positioning sleeve; the outer shell is sleeved outside the cantilever rotor, the bearing end cover is arranged on the outer side of the driving shaft rotor, a first step is arranged in the bearing end cover, a second step is arranged on the outer surface of the driving shaft rotor, a bearing cavity is arranged between the first step and the second step, and a bearing is arranged in the bearing cavity. The cantilever rotor positioning ring is matched with the driving positioning sleeve, and the driving positioning sleeve is matched with the driving shaft rotor, so that the rigidity and the integral performance of the cantilever rotor can be ensured, the machining requirement is greatly reduced, and the embedded matching of the extended shaft and the rotor is not required.)

1. The utility model provides a cantilever connection structure for lobe pump or screw pump which characterized in that: the device comprises an outer shell (1), a bearing end cover (2), a driving shaft rotor (3) and a cantilever rotor (4), wherein one end of the driving shaft rotor (3) is fixedly connected with one side of a driving positioning sleeve (6) through a locking bolt (5), a circular boss (7) is arranged at the inner circle of the other side of the driving positioning sleeve (6), and a bolt hole (14) is arranged at the outer circle of the other side of the driving positioning sleeve (6);

the cantilever rotor (4) and the driving shaft rotor (3) are coaxially arranged, the cantilever rotor (4) comprises a linear rotor (41), a transition cylinder (42) and a cantilever rotor positioning ring (43), one side of the linear rotor (41) is coaxially connected with the cantilever rotor positioning ring (43) through the transition cylinder (42), a groove (44) is formed in the outer side surface of the cantilever rotor positioning ring (43), and the groove (44) is in interference fit with the circular boss (7); the outer circle of the cantilever rotor positioning ring (43) is fixedly connected with a bolt hole (14) at the outer circle of the driving positioning sleeve (6) through a fixing bolt (15);

the outer shell (1) is sleeved outside the cantilever rotor (4), the bearing end cover (2) is arranged on the outer surface of one side, close to the cantilever rotor (4), of the driving shaft rotor (3), the bearing end cover (2) is fixedly connected with the outer shell (1), a first step (9) is arranged in the bearing end cover (2), a second step (10) is arranged on the outer surface of the driving shaft rotor (3), a bearing cavity (11) is arranged between the first step (9) and the second step (10), a bearing (12) is installed in the bearing cavity (11), one side of the outer circle of the bearing (12) is abutted against the first step (9) in the axial direction, the other side of the outer circle of the bearing (12) is abutted against the bearing gland (13), the bearing gland (13) is fixed on the bearing end cover (2) through bolts, one side of the inner circle of the bearing (12) is abutted against the second step (10) in the axial direction, the other side of the inner circle of the bearing (12) is abutted against the driving positioning sleeve (6).

2. The cantilever connection structure for a roots pump or a screw pump according to claim 1, wherein: and a wave spring (8) is fixedly arranged between the outer surface of the circular boss (7) and the inner surface of the groove (44).

3. The cantilever connection structure for a roots pump or a screw pump according to claim 1, wherein: one side, close to the cantilever rotor (4), of the driving shaft rotor (3) is provided with a flat key structure, a flat key hole (61) is formed in the side surface of the driving positioning sleeve (6), and the driving positioning sleeve (6) is matched with the flat key structure through the flat key hole (61).

4. The cantilever connection structure for a roots pump or a screw pump according to claim 1, wherein: the excircle department of drive position sleeve (6) evenly is provided with two first locating pin holes (16), evenly be provided with four second locating pin holes (17) on cantilever rotor position circle (43), second locating pin hole (17) pass through the locating pin with first locating pin hole (16) and are connected.

5. The cantilever connection structure for a roots pump or a screw pump according to claim 1, wherein: the inner cavity of the outer shell (1) is provided with a sealing cover plate (18), the sealing cover plate (18) is fixedly installed on the side surface of the bearing end cover (2) through a bolt, a first sealing ring (19) and a second sealing ring (20) are arranged in the middle of the sealing cover plate (18), and the first sealing ring (19) and the second sealing ring (20) are respectively sleeved on the outer surfaces of the transition cylinder (42) and the cantilever rotor positioning ring (43).

6. The cantilever-connection structure for a roots pump or a screw pump according to claim 5, wherein: the sealing cover plate (18) is equally divided into a first cover plate (181) and a second cover plate (182) from a middle horizontal line, bolt holes are formed in the side faces of the first cover plate (181) and the second cover plate (182), and the first cover plate (181) and the second cover plate (182) are fixedly connected through bolts.

7. The cantilever connection structure for a roots pump or a screw pump according to claim 1, wherein: the linear rotor (41), the transition cylinder (42) and the cantilever rotor positioning ring (43) are designed in an integrated mode.

8. The cantilever-connection structure for a roots pump or a screw pump according to claim 5, wherein: the bearing cavity (11) is provided with protection gas channel (21) below, protection gas channel (21) are connected with outside protection gas pipeline, bearing gland (13) and drive position sleeve (6) clearance fit, sealed apron (18) and cantilever rotor (4) clearance fit.

Technical Field

The invention relates to the technical field of roots pumps, in particular to a cantilever shaft or rotor connecting structure which is used for a roots vacuum pump, a roots blower, a screw vacuum pump and a multi-stage dry vacuum pump and adopts a rotor hybrid cantilever structure or a cantilever structure. In particular to a cantilever connecting structure for a roots pump or a screw pump.

Background

Most of traditional Roots vacuum pumps, Roots blowers, screw vacuum pumps and other types of multi-stage dry vacuum pumps adopt non-cantilever structures, namely, two ends of an impeller and a shaft in a pump cavity are respectively supported by bearings, and rotation is realized. The greatest advantages of this conventional model are: the weight of the rotor is uniformly distributed and stressed on the bearings at the two ends, and the bearings at the two ends are fixed in the bearing cavities, so that the stability and the minimum jumping of the middle rotor are ensured to the maximum extent. The vacuum pump, Roots blower, screw vacuum pump and other multi-stage dry vacuum pumps are all positive displacement pumps, and two rotors are meshed with each other while rotating, so that the two ends of adjacent rotors are kept stable, the runout of two ends of any shaft of the rotors during high-speed rotation needs to be minimized, and if the end surface of any one rotor is shaken and deviated, the meshed rotors are separated from meshed contact surfaces, so that interference and collision occur.

However, this type of bearing arrangement, while ensuring minimal run-out of the shaft and rotor ends, has the significant disadvantage that once the rotor has been serviced, the bearing must be removed before the rotor and shaft can be removed from the pumping chamber, and each removal of the bearing must wear the bearing chamber and bearing. With the use of the conventional roots vacuum pump, roots blower and other types of multi-stage dry vacuum pumps of screw vacuum pumps in the industrial field, the dry vacuum pump is found to have the advantages of energy conservation and environmental protection compared with other oil-rotary vane pumps, but the pump clamping fault occurs on meshed rotors due to the fact that once the pumped substances contain dust, viscosity, hydrocarbon and corrosive media, the meshed rotors are easily adhered, remained and corroded. Many times, the rotor must be removed from the pump cavity to facilitate complete cleaning.

In particular, in the case of screw pumps and multi-stage dry vacuum pumps, the exhaust port is at a high pressure and at an atmospheric pressure, so that when the pumped gas contains dust, viscous, hydrocarbon and corrosive media and is discharged from the pump cavity after being compressed, the gas carrying the harmful media inevitably contaminates the bearing at the exhaust port, thereby making the bearing changed and easily damaged. This is also the main reason why the failure rate of the existing screw vacuum pumps, multi-stage dry vacuum pumps in chemical applications (corrosive, viscous environments) and in dusty applications is very high. Even many screw vacuum pumps adopt nitrogen gas seal, mechanical seal, lip type seals multiple protection, can't stop completely that the bearing of exhaust port side contacts harmful medium, this because its exhaust pressure is higher than atmospheric pressure, and must be higher than the pressure in the chamber of bearing, leads to the long-term operation under must have gaseous medium to contact the bearing.

After the cantilever rotor structure is adopted, the bearing can be arranged on the low vacuum degree side, so that the influence of dust, viscosity, hydrocarbon and corrosive media on the bearing on the exhaust port side can be completely eliminated. And in the bearing on the vacuum side, because the pressure of the bearing cavity is balanced and is completely higher than the air inlet pressure, harmful media cannot cause any influence on the bearing on the vacuum side at any time.

However, the most serious problem of the cantilever rotor is that, according to the principle of force arm, the end without bearing of the shaft and the rotor lacks stability, and when the rotor rotates at high speed, huge jumping easily occurs, so that adjacent rotors cannot be meshed. And the mounting means of cantilever rotor is more complicated relatively, and it will satisfy the terminal surface clearance at first, will satisfy the azimuth again, and the more common cantilever mode is a logical axle, and the impeller cover is on the axle, guarantees the azimuth through the key. At the moment, the strength of the cantilever shaft and the length of the cantilever are very critical, the cantilever is too long, the weight of the rotor is completely loaded on the shaft, the torque is larger, and the runout cannot be guaranteed necessarily when the rotor rotates. And because of the cantilever shaft, the shaft cannot adopt a larger diameter to meet the rigidity. This structure is necessarily very unstable.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a cantilever connecting structure for a roots pump or a screw pump, which overcomes the defects of the prior art, has reasonable design, the rigidity of the cantilever rotor can be ensured to the maximum extent and the integral performance can be kept through the mutual matching of the cantilever rotor positioning ring and the driving positioning sleeve and the mutual matching of the driving positioning sleeve and the driving shaft rotor, and greatly reduces the machining requirement, only needs to machine the molded line on the external meter, does not need to open a deep hole sleeve shaft in the axial direction, reduces the risk of the deviation of concentric circles of the internal and external circles, does not need to open a key slot by using linear cutting, meanwhile, the processed cantilever rotor is also convenient to be subjected to anti-corrosion treatment because the cantilever rotor only has the outer surface without the inner hole, and in installation, the azimuth degree and the fastening are ensured by means of bolts and positioning pins, and the embedded fit of the extended shaft and the rotor is not required.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a cantilever connecting structure for a roots pump or a screw pump comprises an outer shell, a bearing end cover, a driving shaft rotor and a cantilever rotor, wherein one end of the driving shaft rotor is fixedly connected with one side of a driving positioning sleeve through a locking bolt, a circular boss is arranged at the inner circle of the other side of the driving positioning sleeve, and bolt holes are respectively arranged at the outer circle of the other side of the driving positioning sleeve;

the cantilever rotor and the driving shaft rotor are coaxially arranged, the cantilever rotor comprises a linear rotor, a transition cylinder and a cantilever rotor positioning ring, one side of the linear rotor is coaxially connected with the cantilever rotor positioning ring through the transition cylinder, a groove is formed in the outer side surface of the cantilever rotor positioning ring, and the groove is in interference fit with the circular boss; the outer circle of the cantilever rotor positioning ring is fixedly connected with a bolt hole at the outer circle of the driving positioning sleeve through a fixing bolt;

the utility model discloses a cantilever rotor, including the driving shaft rotor, the shell body cup joints at the cantilever rotor outside, the bearing cap sets up the one side surface that is close to the cantilever rotor at the driving shaft rotor, just bearing cap and shell body fixed connection, be provided with first step in the bearing cap, driving shaft rotor surface is provided with the second step, be equipped with the bearing chamber between first step and the second step, install the bearing in the bearing chamber, one side of the excircle of bearing is close to with first step mutually in the axial, the opposite side and the bearing gland of the excircle of bearing are inconsistent, the bearing gland passes through the bolt fastening on the bearing cap, one side of the interior circle of bearing is close to with the second step mutually in the axial, the opposite side and the drive position sleeve of the interior circle of bearing are contradicted.

Preferably, a wave spring is fixedly arranged between the outer surface of the circular boss and the inner surface of the groove.

Preferably, one side of the driving shaft rotor, which is close to the cantilever rotor, is provided with a flat key structure, the side surface of the driving positioning sleeve is provided with a flat key hole, and the driving positioning sleeve is matched with the flat key structure through the flat key hole.

Preferably, the excircle of the driving positioning sleeve is uniformly provided with two first positioning pin holes, the cantilever rotor positioning ring is uniformly provided with four second positioning pin holes, and the second positioning pin holes are connected with the first positioning pin holes through positioning pins.

Preferably, the inner cavity of the outer shell is provided with a sealing cover plate, the sealing cover plate is fixedly installed on the side surface of the bearing end cover through a bolt, a first sealing ring and a second sealing ring are arranged in the middle of the sealing cover plate, and the first sealing ring and the second sealing ring are respectively sleeved on the outer surfaces of the transition cylinder and the cantilever rotor positioning ring.

Preferably, the sealing cover plate is equally divided into a first cover plate and a second cover plate from a middle horizontal line, bolt holes are formed in the side faces of the first cover plate and the second cover plate, and the first cover plate and the second cover plate are fixedly connected through bolts.

Preferably, the linear rotor, the transition cylinder and the cantilever rotor retainer ring are of an integrated design.

Preferably, a protective gas channel is arranged below the bearing cavity and connected with an external protective gas pipeline, the bearing gland is in clearance fit with the driving positioning sleeve, and the sealing cover plate is in clearance fit with the cantilever rotor.

The invention provides a cantilever connecting structure for a roots pump or a screw pump. The method has the following beneficial effects: the cantilever rotor positioning ring is matched with the driving positioning sleeve, the groove is in interference fit with the circular boss, so that the cantilever rotor is ensured to be in a concentric shaft with the driving shaft rotor through the driving positioning sleeve, the cantilever rotor can ensure the rigidity of the cantilever rotor and keep the integral performance to the maximum by adopting the installation mode, the machining requirement is greatly reduced, only the outer surface of the cantilever rotor is required to be machined to form a molded line, a deep hole sleeve shaft is not required to be axially arranged, the risk of the concentric circle deviation of an inner circle and an outer circle is reduced, a key groove is not required to be cut by using linear cutting, and the machined cantilever rotor is convenient to carry out anticorrosion treatment because only the outer surface of the cantilever rotor does not have an inner hole, and in installation, the azimuth and fastening are ensured by means of bolts and positioning pins, and the embedded fit of the extended shaft and the rotor is not required;

the driving shaft rotor and the driving positioning sleeve can play a reverse driving force when locked through the wave spring, so that a locking bolt of the driving positioning sleeve is locked with a thread in a bolt hole in the end face of the driving shaft rotor, the locking force is increased, and a gap in the driving shaft rotor is eliminated, so that the driving shaft rotor and the driving positioning sleeve cannot be loosened due to high-speed rotation and vibration; the end face gap of the cantilever rotor is ensured by the sealing cover plate.

Drawings

In order to more clearly illustrate the present invention or the prior art solutions, the drawings that are needed in the description of the prior art will be briefly described below.

FIG. 1 is a schematic cross-sectional view of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a schematic cross-sectional view of the drive shaft rotor as installed in accordance with the present invention;

FIG. 4 is a schematic structural view of a cantilever rotor according to the present invention;

FIG. 5 is a schematic cross-sectional view of a cantilever rotor according to the present invention;

FIG. 6 is a first schematic structural view of a driving positioning sleeve according to the present invention;

FIG. 7 is a second schematic structural view of a driving positioning sleeve according to the present invention;

FIG. 8 is a schematic structural view of a bearing cover according to the present invention;

FIG. 9 is a schematic view of the structure of the sealing cover plate of the present invention;

FIG. 10 is a schematic cross-sectional view of the sealing cover plate according to the present invention;

the reference numbers in the figures illustrate:

1. an outer housing; 2. a bearing end cap; 3. a drive shaft rotor; 4. a cantilever rotor; 5. locking the bolt; 6. driving the positioning sleeve; 7. a circular boss; 8. a wave spring; 9. a first step; 10. a second step; 11. a bearing cavity; 12. a bearing; 13. a bearing gland; 14. bolt holes; 15. fixing the bolt; 16. a first dowel hole; 17. a second dowel hole; 18. sealing the cover plate; 19. a first seal ring; 20. a second seal ring; 21. a shielding gas channel; 22. an air flow passage groove; 41. a linear rotor; 42. a transition cylinder; 43. a cantilever rotor positioning ring; 44. a groove; 61. a flat key hole; 181. a first cover plate; 182. and a second cover plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings.

In the first embodiment, as shown in fig. 1 to 10, a cantilever connection structure for a roots pump or a screw pump comprises an outer shell 1, a bearing end cover 2, a driving shaft rotor 3 and a cantilever rotor 4, wherein one end of the driving shaft rotor 3 is fixedly connected with one side of a driving positioning sleeve 6 through a locking bolt 5, a circular boss 7 is arranged at the inner circle of the other side of the driving positioning sleeve 6, and bolt holes 14 are respectively arranged at the outer circle of the other side of the driving positioning sleeve 6; the cantilever rotor 4 and the driving shaft rotor 3 are coaxially arranged, the cantilever rotor 4 comprises a linear rotor 41, a transition cylinder 42 and a cantilever rotor positioning ring 43, one side of the linear rotor 41 is coaxially connected with the cantilever rotor positioning ring 43 through the transition cylinder 42, a groove 44 is formed in the outer side surface of the cantilever rotor positioning ring 43, and the groove 44 is in interference fit with the circular boss 7; the excircle of the cantilever rotor positioning ring 43 is fixedly connected with a bolt hole 14 at the excircle of the driving positioning sleeve 6 through a fixing bolt 15; the outer casing 1 cup joints in cantilever rotor 4 outside, bearing housing 2 sets up the one side surface that is close to cantilever rotor 4 at driving shaft rotor 3, and bearing housing 2 and outer casing 1 fixed connection, be provided with first step 9 in the bearing housing 2, driving shaft rotor 3 surface is provided with second step 10, be equipped with bearing chamber 11 between first step 9 and the second step 10, install bearing 12 in the bearing chamber 11, one side of the excircle of bearing 12 is close to with first step 9 mutually in the axial, the opposite side of the excircle of bearing 12 is inconsistent with bearing gland 13, bearing gland 13 passes through the bolt fastening on bearing housing 2, one side of the interior circle of bearing 12 is close to with second step 10 mutually in the axial, the opposite side of the interior circle of bearing 12 is inconsistent with drive position sleeve 6.

The working principle is as follows:

in the present application, two ends of the driving shaft rotor 3 are respectively fixed and supported by two bearings, so that the driving shaft rotor 3 is very stable when rotating at a high speed, and the jumping amplitude can meet the meshing of adjacent impellers. By installing the bearing 12 in the bearing cavity 11 and fastening the outer circle of the bearing 12 in the bearing cavity through the bearing gland 13 and the first step 9, the axial displacement of the driving shaft rotor 3 and the bearing 12 can only be in the direction that the second step 10 is far away from the bearing 12 because the bearing end cover 2 is fixed. The driving positioning sleeve 6 is propped against the other side of the inner circle of the bearing 12 and is fastened with the bolt hole on the end face of the driving shaft rotor 3 through the locking bolt 5 of the driving positioning sleeve 6, so that the driving shaft rotor 3 is tensioned by the driving positioning sleeve 6, and the driving shaft rotor 3 is locked in the axial direction at the moment because the outer circle of the bearing 12 is firmly fixed in the bearing end cover 2 and the bearing gland 13, so that the gap between the impeller on the driving shaft rotor 3 and the bearing end cover 2 is determined; therefore, the subsequent installation of the cantilever rotor 4 does not influence the clearance between the driving shaft rotor 3 and the bearing end cover 2 in the axial direction.

Thus, one side of the driving shaft rotor 3 belongs to a fixed side, all axial gaps are fixed, and the azimuth of all shafts of the non-cantilever rotor can be quickly determined through the installation of the gear on the other side.

The cantilever rotor 4 comprises a linear rotor 41 with meshing linearity, and the linear rotor 41, a transition cylinder 42 and a cantilever rotor positioning ring 43 are designed into a whole, wherein the cantilever rotor 4 is made of a non-metal material in the application, so that the rigidity of the whole cantilever rotor is ensured; the cantilever rotor positioning ring 43 is matched with the driving positioning sleeve 6, and the groove 44 is in interference fit with the circular boss 7, so that the cantilever rotor 4 and the driving shaft rotor 3 are positioned in a concentric shaft through the driving positioning sleeve 6, and the cantilever rotor 4 can also ensure synchronous rotation of the same rotating speed and concentric circles when the driving shaft rotor 3 rotates.

The cantilever rotor 4 of this application adopts foretell mounting means, can be the biggest assurance cantilever rotor 4 the rigidity with keep the wholeness ability, and reduced its machining's requirement by a wide margin, only need be at its external appearance machine tooling molded lines, and need not open the deep hole sleeve axle in the axial, the risk of interior excircle concentric circles deviation has been reduced, it needs the keyway (this kind of mode is very inaccurate to the determination of the azimuth of rotor) not more to use the line cutting, simultaneously because cantilever rotor 4 only has the surface and does not have the interior hole, consequently also be convenient for do anticorrosive treatment to this cantilever rotor 4 after processing, and in the installation, rely on bolt and locating pin to ensure azimuth and fastening, and the embedding cooperation of the axle that no longer needs to extend and rotor.

In the second embodiment, as a further preferable scheme of the first embodiment, a wave spring 8 is fixedly installed between the outer surface of the circular boss 7 and the inner surface of the groove 44. The driving shaft rotor 3 and the driving positioning sleeve 6 can play a reverse driving force when being locked through the wave spring 8, so that the locking bolt 5 of the driving positioning sleeve 6 is locked with threads in a bolt hole on the end face of the driving shaft rotor 3, the locking force is increased, gaps in the locking bolt are eliminated, and the locking nut and the thrust washer can not be loosened due to high-speed rotation and vibration and are similar to those of a locking nut and a thrust washer in a traditional structure. In the embodiment, the locking bolt 5 adopts a hexagon socket head cap screw structure, and preferably adopts a fine-tooth bolt, so that the effect is more obvious.

In the third embodiment, as shown in fig. 6, as a further preferable scheme of the first embodiment, one side of the driving shaft rotor 3 close to the cantilever rotor 4 is provided with a flat key structure, a flat key hole 61 is formed in a side surface of the driving positioning sleeve 6, and the driving positioning sleeve 6 is matched with the flat key structure through the flat key hole 61. Utilize the flat keyway that driving shaft rotor 3 one side flat key structure constitutes to make driving shaft rotor 3 insert drive position sleeve 6 in, in driving shaft rotor 3 rotatory in-process, drive position sleeve 6 that can be better rotate together.

In a fourth embodiment, as a further preferable scheme of the first embodiment, 2 180 ° first positioning pin holes 16 are uniformly formed in the outer circle of the driving positioning sleeve 6, 4 90 ° equally-divided second positioning pin holes 17 are uniformly formed in the cantilever rotor positioning ring 43, and two adjacent driving shaft rotors 3 inevitably form a 90 ° plane angle in the gear-determined orientation (this is determined by the profile of the meshed rotors, for example, if the driving shaft rotor is a two-lobe roots rotor or a 90 ° driving shaft rotor, but if the driving shaft rotor is a three-lobe roots rotor or a 60 ° driving shaft rotor, the cantilever rotor positioning ring has 6 60 ° equally-divided positioning pin holes, and if the driving positioning sleeve is provided with only 3 120 ° positioning pin holes). And through the dislocation of locating pin, can ensure the azimuth of cantilever rotor, fasten through the bolt finally. So that the cantilever rotor is tightly fastened with the driving positioning sleeve.

And by arranging 4 90-degree-divided second positioning pin holes 17 on the cantilever rotor positioning ring 43 and only 2 180-degree first positioning pin holes 16 on the driving positioning sleeve 6, the horizontal planes of the two meshed cantilever rotors 4 are necessarily 90 degrees or 0 degrees, so that the cantilever rotors 4 are very convenient to mount (the meshed type line of the cantilever rotors is the horizontal intersection angle of 90 degrees), and in addition, when the cantilever rotors are mounted, the mounted non-cantilever rotors are not required to be adjusted again in any azimuth degree.

Fifth embodiment, as shown in fig. 9 to 10, as a further preferable embodiment of the first embodiment, for a roots vacuum pump, a roots blower, and a screw vacuum pump, the clearance of the rotor end face is an important parameter for determining the vacuum degree and the air extraction amount thereof, and if the clearance is too large, the vacuum degree is deteriorated, and the air extraction efficiency is significantly reduced. The end face of the cantilever rotor on the positioning ring is not a meshed rotor and cannot directly keep an applied clearance with the end face.

Therefore, in order to solve the above problems, a sealing cover plate 18 is arranged in the inner cavity of the outer shell 1, the sealing cover plate 18 is fixedly mounted on the side surface of the bearing end cover 2 through bolts, a first sealing ring 19 and a second sealing ring 20 are arranged in the middle of the sealing cover plate 18, and the first sealing ring 19 and the second sealing ring 20 are respectively sleeved on the outer surfaces of the transition cylinder 42 and the cantilever rotor positioning ring 43. The end-face clearance of the cantilever rotor is ensured by the sealing cover plate 18.

In a sixth embodiment, as a further preferable scheme of the fifth embodiment, when the cantilever rotor, the bolt and the nut are determined during installation, the cantilever rotor and the driving positioning sleeve are connected first, and the sealing cover plate can be installed only after installation is completed, and the sealing cover plate cannot be installed if the sealing cover plate is an integral cover plate.

Therefore, in order to solve the above problem, in the present application, the sealing cover plate 18 is equally divided into a first cover plate 181 and a second cover plate 182 from a middle horizontal line, three bolt holes are respectively opened on the side surfaces of the first cover plate 181 and the second cover plate 182, and the first cover plate 181 and the second cover plate 182 are fixedly connected by bolts.

During actual installation, the first cover plate 181 and the second cover plate 182 are separated, the first cover plate 181 and the second cover plate 182 are respectively inserted from the upper part and the lower part of the installed cantilever rotor 4, so that the outer surface of the transition cylinder 42 and the outer surface of the cantilever rotor positioning ring 43 are just in clearance fit with the first sealing ring 19 and the second sealing ring 20 in the middle of the sealing cover plate 18, the first cover plate 181 and the second cover plate 182 are locked through bolts, the two sealing cover plates are fixedly installed on the side surface of the bearing end cover 2 through the bolts under the guidance of the excircle of the cantilever rotor positioning ring 43, the clearance between the sealing cover plate 18 and the end surface of the cantilever rotor 4 is determined through a clearance gauge, and if the clearance is too large or too small, the clearance can be adjusted through an adjusting gasket or a file.

Seventh embodiment, as a further preferable solution to fifth embodiment, in order to ensure the corrosion resistance or dust of the cantilever rotor 4, especially the protection of the cantilever rotor connecting bolt holes, and the cantilever rotor connecting drive positioning sleeve 6, the bearing 12. A protective gas channel 21 is arranged below the bearing cavity 11, the protective gas channel 21 is connected with an external protective gas pipeline, the bearing gland 13 is in clearance fit with the driving positioning sleeve 6, and the sealing cover plate 18 is in clearance fit with the cantilever rotor 4.

In actual operation, the region from the bearing 12 to the cantilever rotor 4 is under negative pressure, so that the slightly pressurized or atmospheric external shielding gas fills the shielding gas channel 21 through the external shielding gas line, and then permeates through the gas flow channel groove 22 of the bearing gland 13 to fill the side of the bearing close to the cantilever rotor. Because the bearing gland 13 is in clearance fit with the driving positioning sleeve 6 and the sealing cover plate 18 is in clearance fit with the cantilever rotor 4, the protective gas can be filled into cavities of the sealing cover plate 18 along with the clearances, and the cavities are the positions for fastening the bolts of the cantilever rotor 4, so that a very good protection effect is achieved; finally, the protective gas can continuously permeate into the suction inlet of the cantilever rotor 4 and is discharged out of the pump body together with the compressed process gas, so that the protection of the bolts, the bearings and other elements which cannot be subjected to complete anti-corrosion treatment is thoroughly ensured, and the elements are prevented from being damaged by dust and corrosive gas. Because the positive pressure gas permeates into the negative pressure chamber, the operation mode of the air curtain is completely different from that of the air curtain which is used for generating positive impact on the gas at the exhaust port of the existing screw pump or Roots blower and the protective gas, and the problem that the bearing at the exhaust port side is inevitably influenced by process media in the operation process of the existing screw pump, Roots blower and multi-stage dry vacuum pump is also avoided.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.