CN219605636U

CN219605636U - Impeller and driving shaft connecting mechanism

Info

Publication number: CN219605636U
Application number: CN202320686195.4U
Authority: CN
Inventors: 严黎坚; 孙建东
Original assignee: Runa Smart Equipment Co Ltd
Current assignee: Runa Smart Equipment Co Ltd
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2023-08-29
Anticipated expiration: 2033-03-30

Abstract

The utility model provides a coupling mechanism of an impeller and a driving shaft, which comprises the driving shaft, wherein the driving shaft comprises a first cylindrical section and a second cylindrical section which are coaxially arranged, the outer diameter of the second cylindrical section is larger than that of the first cylindrical section, and an annular step surface is formed on the end surface of the second cylindrical section; an impeller, wherein an installation space is formed between the impeller and the driving shaft; and the elastic component is arranged in the installation space and is convenient for the impeller to detach. When the impeller is disassembled, the impeller can be automatically ejected from the driving shaft under the axial thrust of the elastic component, so that the impeller is easily disassembled, and the structure of the impeller is not damaged.

Description

Impeller and driving shaft connecting mechanism

Technical Field

The utility model relates to the field of centrifugal refrigeration compressors, in particular to a mechanism for connecting an impeller with a driving shaft.

Background

In the field of centrifugal compressors commonly used in the refrigeration industry, energy conservation, consumption reduction and high speed are main trends of product development. When the rotating speed of the rotor rises from below 1K rpm to 3-10K rpm, the impeller is lightened and the size is reduced by 2-3 times under the same cooling capacity. The weight and the size of the whole machine are also reduced, however, the assembly process of the impeller and the driving shaft has high accuracy, so that the impeller and the driving shaft with smaller size are not convenient to control, and the disassembly difficulty is increased.

In the prior art, the operation method of the small impeller with the outer diameter below 150mm is that: the impeller is heated to a specific temperature, and then the stud restraining the impeller and the driving shaft is slowly pushed and pulled out through the tool, so that the disassembling work between the impeller and the driving shaft is completed.

Because the impeller external diameter is less and intensity is not high, when dismantling, because the pretightning force between impeller and the drive shaft, after heating impeller to certain temperature and under the condition that the double-screw bolt continues to retrain impeller and drive shaft, the impeller can automatic axial spring a part and unload pretightning force between impeller and the drive shaft this moment, makes the screw thread of impeller screw hole damaged, leads to the impeller to scrap.

Disclosure of Invention

The utility model aims to solve the technical problem that when the impeller is a small impeller with the outer diameter below 150mm, the disassembly work of the impeller and the driving shaft is easily completed without influencing the reuse of the impeller.

In order to solve the technical problem, the utility model provides a coupling mechanism of an impeller and a driving shaft, which comprises the driving shaft, wherein the driving shaft comprises a first cylindrical section and a second cylindrical section which are coaxially arranged, the outer diameter of the second cylindrical section is larger than that of the first cylindrical section, and an annular step surface is formed on the end surface of the second cylindrical section; the impeller is sleeved on the first cylindrical section at the hollow part and is detachably and fixedly connected with the driving shaft, and an installation space is formed between the impeller and the driving shaft; and the elastic component is arranged in the installation space and is convenient for the impeller to detach.

Further, the installation space is formed by an annular downward concave surface which is axially arranged at the hollow part of the impeller and corresponds to the annular step surface, an annular bulge which is arranged on the outer circumference of the annular downward concave surface, and the annular step surface.

Further, in the state that the impeller is fixedly connected with the driving shaft, one axial end of the elastic component is abutted against the annular step surface, and the other axial end of the elastic component is abutted against the annular concave surface to have axial thrust.

Further, the elastic component is a wave spring sleeved on the first cylindrical section.

Preferably, the impeller further comprises a fastener disposed between the drive shaft and the impeller, the fastener limiting the degree of freedom in relative rotation of the impeller and the drive shaft.

Further, the fastener is a key; a groove is formed in the outer side wall of the first cylindrical section of the driving shaft; the inner side wall of the hollow part of the impeller is provided with notches which are in one-to-one correspondence with the grooves;

the key is inserted axially along the impeller with one side of the key in the groove and the other side of the key in the notch to limit rotation of the drive relative to the impeller.

Preferably, threaded holes are symmetrically formed in the front end of the first cylindrical section, and bolts limiting axial movement of the impeller relative to the driving shaft are arranged in the threaded holes.

Compared with the prior art, the utility model has the following beneficial effects:

the utility model provides a connection mechanism of an impeller and a driving shaft, which is characterized in that when the impeller is dismounted, bolts for preventing the impeller from axially moving relative to the driving shaft are firstly dismounted, then the impeller is directly heated to a required temperature under the condition that a key is not required to be dismounted, so that the impeller is automatically ejected under the axial thrust of an elastic component, and the convenient dismounting of the impeller and the driving shaft is finished.

Drawings

FIG. 1 is a schematic view of an impeller and a drive shaft;

FIG. 2 is a cross-sectional view of the impeller as removed from the drive shaft;

FIG. 3 is a schematic view of the impeller and drive shaft after installation;

fig. 4 is a cross-sectional view of the impeller after installation with the drive shaft.

In the figure: 1. a drive shaft; 11. a first cylindrical segment; 12. a second cylindrical section; 120. a circumferential step surface; 111. a groove; 2. an impeller; 20. a hollow portion; 200. a notch; 201. a concave annular surface; 202. an annular protrusion; 3. an elastic component; 30. an installation space; 4. a fastener; 5. and (5) a bolt.

Detailed Description

In order to make the technical solutions and technical effects of the present utility model more clear, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments.

As shown in fig. 1 and 2, the drive shaft 1 in the present utility model includes a first cylindrical section 11 and a second cylindrical section 12 coaxially arranged, the second cylindrical section 12 having an outer diameter larger than that of the first cylindrical section 11, and forming a circumferential step surface 120 at an end surface of the second cylindrical section 12. The outer side wall of the first cylindrical section 11 is symmetrically provided with grooves 111.

The impeller 2 in the utility model is a small impeller 2 with the outer diameter below 150mm in the refrigeration industry, the impeller 2 is detachably and fixedly connected with the driving shaft 1, the impeller 2 comprises a hollow part 20 positioned at the impeller hub, and the hollow part 20 is sleeved on the first cylindrical section 11. An annular concave surface 201 which corresponds to the annular step surface 120 and is axially arranged on the back surface of the impeller 2 corresponding to the hollow part 20, and an annular bulge 202 is arranged on the outer circumference of the annular concave surface 201. A fastener 4 is provided between the drive shaft 1 and the impeller 2, the fastener 4 limiting the degree of freedom in the relative rotation of the impeller 2 and the drive shaft 1. The inner side wall of the hollow part 20 of the impeller 2 is provided with notches 200 which are in one-to-one correspondence with the grooves 111. The fastener 4 is preferably a key, wherein the key is inserted in the axial direction of the impeller 2, wherein one side of the key is in the recess 111 and the other side of the key is in the notch 200 to limit rotation of the drive relative to the impeller 2.

When the impeller 2 is fixedly connected with the driving shaft 1, the annular concave surface 201, the annular bulge 202 and the annular step surface 120 enclose a mounting space 30, and an elastic component 3 which is convenient for the impeller 2 to be disassembled is arranged in the mounting space 30. The elastic component 3 has one axial end abutting against the annular step surface 120, and the other axial end abutting against the annular concave surface 201 to have axial thrust.

Preferably, the elastic element 3 is a wave spring which is fitted over the first cylindrical section 11. The elastic component 3 can also be a bent elastic pad.

The elastic component 4 of the present utility model is preferably a wave spring. The parameters of the used corrugated spring material are 314 stainless steel, and the thickness delta, the number of turns n, the central diameter phi and the hot-set temperature t of the stainless steel are in a certain proportional relation with the interference magnitude g of the impeller 2 assembly, namely: k.alpha.f (delta, n, phi, t)/g K is a dimensionless constant; the effective working environment of the ripple spring of this design is 0 ~ 60 ℃, and beyond this scope, no linear elasticity exists, namely: f= -Kf Δx-displacement, kf-modulus of elasticity;

the ripple spring is positioned in a mechanism formed by the impeller 2 and the driving shaft 1, has the function of a damper, and when the impeller 2 is in unstable operation, the ripple spring has 0.5-1 mm of play in the axial direction, and the damper plays a role of buffering at the moment, so that the impeller 2 is protected from being damaged.

Alternatively, the elastic component 3 and the annular step surface 120 may be fixedly connected or movably connected. Preferably, the bonding type of low-temperature gluing can be adopted, and specifically: the elastic component 3 is selected as a bent elastic pad, a proper adhesive is selected, and the elastic pad is adhered to the annular step surface 120 at low temperature; the elastic component 3 can be inclined to approach by means of the weight, and the weight is as follows: the elastic component 3 is selected as a bent elastic cushion, and the side with larger elastic cushion mass is inclined to lean against the annular step surface 120; the horizontal displacement type connection can also be adopted, and specifically comprises the following steps: the elastic member 3 is selected as a wave spring, which is horizontally placed in the installation space 30.

As shown in fig. 3, the open end of the recess 111 of the drive shaft 1 corresponds to the open end of the notch 200 of the impeller 2, and a fastener 4 is inserted into the recess, and the fastener 4 is used for limiting the circumferential rotation of the impeller 2 relative to the drive shaft 1.

In order to prevent the impeller 2 from axially moving relative to the driving shaft 1, the front end of the first cylindrical section 11 of the driving shaft 1 is symmetrically provided with threaded holes, and bolts 5 are inserted into the threaded holes.

As shown in fig. 4, after the impeller 2 is mounted on or dismounted from the drive shaft 1, the elastic assembly 3 is compressed, i.e., there is an axial thrust of the elastic assembly 3.

The impeller 2 and the driving shaft 1 are mutually restrained through interference fit and the fastening piece 4, so that a certain pretightening force exists after the impeller 2 and the driving shaft 1 are installed. The disassembly method can only be applied to a high-speed centrifugal heat pump system, the working medium is the existing refrigerants such as R22, R134A and the like, the material is aviation aluminum, the diameter of the impeller 2 is less than 100mm, and the rotating speed is 3-10 ten thousand rpm; the utility model can complete the disassembly work between the impeller 2 and the driving shaft 1 without a disassembly tool in the prior art, and the impeller 2 cannot be damaged in the morning, the utility model skillfully utilizes the pretightening force existing after the impeller 2 and the driving shaft 1 are installed, and the disassembly work of the impeller 2 is easily completed under the thrust of the elastic component 3, and the specific disassembly steps are as follows:

firstly, disassembling a bolt 5 for preventing the impeller 2 from axially moving relative to the driving shaft 1;

and secondly, heating the impeller 2 to a required temperature to enable the impeller 2 to be automatically ejected under the axial thrust of the elastic component 3, namely, completing the disassembly of the impeller 2 and the driving shaft 1.

In the utility model, when the impeller and the driving shaft are installed, the specific installation steps are as follows:

first, the elastic member 3 is installed in the installation space 30;

secondly, heating the impeller 2 to a required temperature, sleeving a hollow part 20 of the impeller 2 on the first cylindrical section 11, and pushing the impeller 2 to a preset position for interference fit;

thirdly, inserting a fastener 4 into the opening end of the notch 200 corresponding to the opening end of the groove 111, and limiting the circumferential rotation freedom degree of the impeller 2 relative to the driving shaft 1;

and fourthly, inserting a bolt 5 into the threaded hole to limit the freedom degree of axial movement of the impeller 2 relative to the driving shaft 1, namely finishing the fixation of the impeller 2 and the driving shaft 1.

Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A coupling mechanism for an impeller and a drive shaft, comprising:

-a drive shaft (1), the drive shaft (1) comprising a first cylindrical section (11) and a second cylindrical section (12) coaxially arranged, the second cylindrical section (12) having an outer diameter larger than the outer diameter of the first cylindrical section (11) and forming a circumferential step surface (120) at an end face of the second cylindrical section (12);

the impeller (2) is sleeved on the first cylindrical section (11) at the hollow part (20) of the impeller (2) and is detachably and fixedly connected with the driving shaft (1), and an installation space (30) is formed between the impeller (2) and the driving shaft (1);

and the elastic component (3) is arranged in the installation space (30) and is convenient for the impeller to be detached.

2. The coupling mechanism of an impeller and a driving shaft according to claim 1, wherein the installation space (30) is formed by a concave annular surface (201) axially opened at the hollow part (20) of the impeller (2) and corresponding to the annular step surface (120), an annular protrusion (202) set up on the outer circumference of the concave annular surface (201), and the annular step surface (120).

3. The coupling mechanism of the impeller and the driving shaft according to claim 2, wherein in a state that the impeller (2) is fixedly coupled with the driving shaft (1), one axial end of the elastic component (3) is abutted against the annular step surface (120), and the other axial end is abutted against the annular downward concave surface (201) to have axial thrust.

4. Coupling mechanism of an impeller and a drive shaft according to claim 1, characterized in that the elastic assembly (3) is a wave spring which is sleeved on the first cylindrical section (11).

5. The coupling mechanism of an impeller and a drive shaft according to claim 1, further comprising a fastener (4) arranged between the drive shaft (1) and the impeller (2), the fastener (4) limiting the degree of freedom of the relative rotation of the impeller (2) and the drive shaft (1).

6. Coupling mechanism of an impeller and a drive shaft according to claim 5, characterized in that the fastener (4) is a key; the outer side wall of the first cylindrical section (11) of the driving shaft (1) is provided with a groove (111); notches (200) which are in one-to-one correspondence with the grooves (111) are formed in the inner side wall of the hollow part (20) of the impeller (2);

the key is inserted axially along the impeller (2), wherein one side of the key is in a groove (111) and the other side of the key is in the notch (200) to limit rotation of the drive shaft (1) relative to the impeller (2).

7. Coupling mechanism of an impeller and a drive shaft according to claim 1, characterized in that the front end of the first cylindrical section (11) is symmetrically provided with threaded holes in which bolts (5) are arranged for limiting the axial play of the impeller (2) relative to the drive shaft (1).