STRUCTURE OF ROTOR CONNECTION OF MULTI-AXIAL MULTI-STAGE ROOTS PUMP

Abstract

A structure of rotor connection of multi-axial multi-stage roots pump comprises a rotor body, a rotor shaft is arranged on one end face of the rotor body, a sub-shaft cavity is opened in the rotor shaft, and the locating keyways are symmetrically opened on both sides inside the sub-shaft cavity; a sub-shaft is arranged on the other end face of the rotor body, the sub-shafts and the sub-shaft cavities of two adjacent rotor bodies are matched, locating keyways are symmetrically opened on both sides of the sub-shaft, and the keyways are installed and fixed through sub-rotor shaft keys in the locating keyways. The invention overcomes the disadvantages of the prior art, and the first-stage rotor body is limited and fixed by the bearing, while the second-stage rotor body is only radially limited by the bearing in the first-stage rotor body. The rotor shaft on the other side is also fixed and limited by the bearing, so the thermal expansion displacement and thermal stress of the second-stage rotor body are completely independent during operation. The thermal expansion displacement of the first-stage rotor body does not affect the second-stage rotor body, and it can also synchronously drive the second-stage rotor body.

Claims

1. A structure of rotor connection of multi-axial multi-stage roots pump comprising a rotor body, is characterized in that: a rotor shaft (2) is arranged on one end face of the rotor body (1); a sub-shaft cavity (7) is opened in the rotor shaft (2), and the sub-shaft cavity (7) and the rotor shaft (2) are arranged concentrically and coaxially; the locating keyways (4) are symmetrically opened on both sides inside the sub-shaft cavity (7); a sub-shaft (3) is arranged on the other end face of the rotor body (1), the sub-shaft (3) and the rotor shaft (2) are arranged concentrically and coaxially, and the sub-shafts (3) and the sub-shaft cavities (7) of two adjacent rotor bodies (1) are matched, the locating keyways (5) are symmetrically opened on both sides of the sub-shaft (3), and the keyways (5) are installed and fixed through sub-rotor shaft keys (6) in the locating keyways.

2. The structure of rotor connection of multi-axial multi-stage roots pump of claim 1, is characterized in that: the depth of the locating keyway (4) is less than that of the sub-shaft cavity (7), and the depth of sub-shaft cavity (7) is less than the length of the rotor shaft (2).

3. The structure of rotor connection of multi-axial multi-stage roots pump of claim 1, is characterized in that: the length of the keyway (5) on the surface of the sub-shaft (3) is less than that of the sub-shaft (3).

4. The structure of rotor connection of multi-axial multi-stage roots pump of claim 1, is characterized in that: both the rotor shaft (2) and the sub-shaft (3) are made of cast iron, and the sub-shaft (3) and the sub-shaft cavity (7) are interference fitted.

5. The structure of rotor connection of multi-axial multi-stage roots pump of claim 1, is characterized in that: one end side of the sub-rotor shaft key (6) is a plane end face (61), which is used for positioning with the rotor shaft (2), and the other end side of the sub-rotor shaft key (6) is an arc-shaped end face (62), which is used for the guiding and installation of the sub-shaft (3).

Description

DESCRIPTION OF DRAWINGS

[0012] In order to explain the technical solutions in the invention or in the prior art more clearly, the brief introduction of drawings required in the description of the prior art is as follows.

[0013] FIG. 1 is a structure diagram of the invention;

[0014] FIG. 2 is a cross-sectional view of the present invention;

[0015] FIG. 3 is a sectional diagram of the invention;

[0016] FIG. 4 is a sectional diagram of the sub-rotor shaft keys of the invention;

[0017] FIG. 5 is a schematic diagram of the state structure of the invention when combined;

[0018] FIG. 6 is a sectional diagram I of the invention when combined;

[0019] FIG. 7 is a sectional diagram II of the invention when combined;

[0020] the numbers in the drawings are explained as follows: [0021] 1. Rotor body; 2. Rotor shaft; 3. Sub-shaft; 4. Locating keyway; 5. Keyway; 6. Sub-rotor shaft key; 61. Plane end face; 62. Arc-shaped end face; 7. Sub-shaft cavity.

EMBODIMENTS

[0022] In order to make the objectives, technical solutions and advantages of the invention clearer, the technical solutions in the invention will be described clearly and completely combined with the drawings in the invention.

[0023] As shown in FIG. 1-7, a structure of rotor connection of multi-axial multi-stage roots pump comprises a rotor body, a rotor shaft 2 is arranged on one end face of the rotor body 1; a sub-shaft cavity 7 is opened in the rotor shaft 2, and the sub-shaft cavity 7 and the rotor shaft 2 are arranged concentrically and coaxially; the locating keyways 4 are symmetrically opened on both sides inside the sub-shaft cavity (7; a sub-shaft 3 is arranged on the other end face of the rotor body 1, the sub-shaft 3 and the rotor shaft 2 are arranged concentrically and coaxially, and the sub-shafts 3 and the sub-shaft cavities 7 of two adjacent rotor bodies 1 are matched, the locating keyways 5 are symmetrically opened on both sides of the sub-shaft 3, and the keyway 5 is arranged correspondingly to the locating keyway 4, and the keyways 5 are installed and fixed through sub-rotor shaft keys 6 in the locating keyways.

[0024] In the embodiment of the invention, an integral roots pump rotor consists of a plurality of rotor bodies 1 for combination, and the size of each rotor body 1 includes the length, outer diameter and row line structure of the rotor body 1 can be different, only requiring the inner diameter of the sub-shaft cavity 7 in the rotor shaft 2 of each rotor body 1, the outer diameter of the sub-shaft 3, the locating keyway 4 in the sub-shaft cavity 7 and the keyway 5 on the outer surface of the sub-shaft 3 are consistent. Moreover, the first-stage rotor body 1 only needs a rotor shaft, and the other end face is designed as a normal shaft, which can meet the installation of gears, bearing, lock nuts and other parts.

[0025] Before multiple rotor bodies 1 are combined, the parts at one end of the normal shaft of the first-stage rotor body 1 are firstly installed to position the first-stage rotor body 1, and the bearing can also be installed on the outer surface of the rotor shaft 2 of the first-stage rotor body 1, so that the entire first-stage rotor body 1 is limited by two bearings, and then the spacer and the sealing element are installed to seal both side end faces of the first-stage roots pump cavity, so that the first-stage rotor body 1 is within an independent roots pump cavity. And the rotor shaft 2 of the first-stage rotor body 1 is reserved on the spacer for connecting with the sub-shaft of the second-stage rotor body 1.

[0026] When multiple rotor bodies 1 is combined, two sub-rotor shaft keys 6 are firstly installed in the rotor shaft 2 of the first-stage rotor body 1, and make the rotor shaft keys 6 correspond to the locating keyways 4, and then let the keyway 5 on the surface of the sub-shaft 3 of the second-stage rotor body 1 align with the two sub-rotor shaft keys 6 already installed in the rotor shaft 2 of the first-stage rotor body 1, to ensure that the sub-shaft 3 is inserted into the rotor shaft 2, and the rotor shaft 2 and the subshaft 3 are assembled concentrically, thereby ensuring that the shafts of both rotors are on the same shaft center; at the same time, after the rotor shaft 2 and sub-shaft 3 are installed matching with the sub-rotor shaft keys 6, the shaft rotation angle of two rotor bodies 1 remains the same; and in order to further increase the rotation angle of the shaft during rotation and eliminate the accumulative error, after several rotors are meshed and assembled together, the outer circular lines of several rotor bodies 1 can be integrally machined to ensure the rotation angles of the shafts of the rotor bodies 1 are completely the same.

[0027] After the sub-shaft 3 of the second-stage rotor body 1 is inserted into the rotor shaft 2 of the first-stage rotor body 1, due to the first-stage rotor body 1 is fixed and limited by the bearing (including axial and radial directions), while it is only radially limited by the bearing in the first-stage rotor body 1, and similarly, the rotor shaft 2 on the other side of the second-stage rotor body 1 is also fixed and limited by the bearing (including axial and radial directions). So the thermal expansion displacement and thermal stress of the second-stage rotor body 1 are completely independent during the operation, and the thermal expansion displacement of the first-stage rotor body does not affect the second-stage rotor body, and it can also synchronously drive the second-stage rotor body; similarly, the sub-shaft 3 of the third-stage rotor body is inserted into the rotor shaft 2 of the first-stage rotor body 1 in the same way; each rotor body 1 of the multi-stage roots pump is independently fixed and the thermal expansion displacement is also independent without accumulative superposition. Therefore, as long as the accuracy meets the requirements, the number of stages of the multi-stage roots pump can be more, not affected by thermal expansion displacement and thermal stress.

[0028] Further, the depth of the locating keyway 4 is less than that of the sub-shaft cavity 7, and the depth of the sub-shaft cavity 7 is less than the length of the rotor shaft 2. And ensure that the excircle of the rotor shaft 2 is continuous, without notch in the arc surface of the outermost circle. Because the depth of the sub-shaft cavity 7 cannot reach the root of the rotor shaft 2, the strength of the rotor shaft 2 can be guaranteed. When driving, the rotor shaft 2 will not be tore at the root of the rotor body 1 due to the angular rotation force.

[0029] Further, the length of the keyway 5 on the surface of the sub-shaft 3 is less than that of the sub-shaft 3, and ensure that the excircle of the sub-shaft 3 is continuous, without notch in the arc surface of the outermost circle. Because the length of the keyway 5 does not reach the root of the sub-shaft 3, the strength of the sub-shaft 3 can be guaranteed. When driving, the sub-shaft 3 will not be tore at the root of the rotor body 1 due to the angular rotation force.

[0030] Further, both the rotor shaft 2 and the sub-shaft 3 are made of cast iron, and the sub-shaft 3 and the sub-shaft cavity 7 are interference fitted. Thus, it is possible to satisfy that the sub-shaft 3 is smoothly inserted into the rotor shaft 2 without adhesion.

[0031] Further, one end side of the sub-rotor shaft key 6 is a plane end face 61, which is used for positioning with the rotor shaft 2, so that when the sub-shaft key 6 is installed in the locating keyway 4, the flat end surface 61 can fit with the end faces of the locating keyway 4; and the other end side of the sub-rotor shaft key 6 is an arc-shaped end face 62, which can play a certain role in installation and guidance when the sub-shaft 3 is inserted into the rotor shaft 2; Moreover, The driving achieved by meshing with the rotor shaft 2 is to drive the upper side and top surface of both ends of the sub-rotor shaft key 6, and the driving achieved by meshing with the rotor shaft 3 is the lower side and bottom surfaces of the both ends of the sub-rotor shaft key 6.

[0032] The above embodiments are only used to explain the technical solution of the invention, but not to limit it; although referring to the aforesaid embodiments, the invention has been described in detail, those skilled in the art shall understand that the technical solutions described in the aforesaid embodiments can still be modified, or some of the technical features are equivalently replaced; and these modifications or replacements shall not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the invention.