Fastening tool for impeller

Abstract

The invention relates to a fastening tool for an impeller. The device comprises a pull nut which is used for being connected with the second end of a pressing screw rod; the end, axially away from the pressing screw, of the pull nut extends outwards in the radial direction to form a boss. The hydraulic cylinder core is sleeved outside the pull nut and comprises a first shaft section and a second shaft section which are connected with each other; the hydraulic cylinder sleeve comprises a first stepped hole; the first stepped hole comprises a first hole section I matched with the first shaft section and a first hole section II matched with the second shaft section, and a pressure cavity for introducing pressure oil is formed between the second shaft section and the bottom wall of the first hole section II; the thrust barrel is provided with a second stepped hole, the second stepped hole comprises a first hole section and a second hole section, the first end of the thrust barrel can abut against the gasket, and the second end of the thrust barrel abuts against the first end of the hydraulic cylinder sleeve. Axial thrust generated by pressure oil is used for fastening, interference of friction coefficient fluctuation on fastening force precision is effectively avoided, and therefore reliability of the fastening effect of the impeller is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal fans, and in particular to a fastening tool for an impeller. Background Art

[0002] In existing single-stage high-speed centrifugal fans, the tightening force control of the impeller and the rotating shaft is mostly achieved by controlling the torque of the compression nut (mostly using a torque wrench). Due to the influence of surface processing quality and on-site environment, the uncertain friction coefficient makes the actual tightening force differ greatly from the design value. Especially in high-pressure fans, due to the limitation of the strength of the impeller material, the safety factor of the connection between the impeller and the rotating shaft is very small, and the existing technology cannot meet its accuracy. Summary of the invention

[0003] To this end, the present invention provides an impeller fastening tool, which adopts a hydraulic control method and uses the axial thrust generated by pressure oil for fastening, effectively avoiding the interference of friction coefficient fluctuations on the fastening force accuracy, thereby significantly improving the reliability of impeller fastening.

[0004] In order to solve the above technical problems, the present invention provides a fastening tool for an impeller, wherein a rotating shaft is arranged on one axial side of the impeller, a first end of a pressing screw passes through a central through hole of the impeller and is connected to the rotating shaft, a second end of the pressing screw extends to the other axial side of the impeller and a washer and a fastening nut are arranged thereon, and the fastening tool comprises:

[0005] A pull nut is used to be connected to the second end of the compression screw; the pull nut has a boss extending radially outward from one end axially away from the compression screw;

[0006] The hydraulic cylinder core is sleeved outside the pull nut and includes a first shaft section and a second shaft section connected to each other; the diameter of the first shaft section is smaller than the diameter of the second shaft section, the second shaft section abuts against the boss and extends radially outward to a limited step;

[0007] A hydraulic cylinder sleeve, the hydraulic cylinder sleeve comprises a first end and a second end axially opposite to each other, and is provided with a first step hole; the first step hole comprises a first hole section 1 matched with the first shaft section and a first hole section 2 matched with the second shaft section, a pressure chamber for passing pressure oil is formed between the second shaft section and the bottom wall of the first hole section 2, and the second end of the hydraulic cylinder sleeve abuts against the limit step;

[0008] The thrust cylinder is provided with a second step hole, the second step hole includes a second hole segment 1 and a second hole segment 2 with different diameters, the second hole segment 1 can be sleeved outside the fastening nut, and the first shaft segment extends into the second hole segment 2; the thrust cylinder includes a first end and a second end axially oppositely arranged, the first end of the thrust cylinder can be abutted against the washer, and the second end of the thrust cylinder is abutted against the first end of the hydraulic cylinder sleeve.

[0009] In one embodiment of the present invention, the radial outer end of the hydraulic cylinder sleeve is provided with an oil filling hole connected to the pressure chamber.

[0010] In one embodiment of the present invention, the oil filling hole is a threaded hole and is connected to an outlet of a hydraulic pump.

[0011] In one embodiment of the present invention, a pressure gauge is provided at the outlet of the hydraulic pump to obtain the oil pressure value in the pressure chamber.

[0012] In one embodiment of the present invention, the end surface of the thrust cylinder is provided with a notch penetrating to the second hole section 1 to expose the fastening nut.

[0013] In one embodiment of the present invention, the central through hole of the hydraulic cylinder core is clearance-matched with the pull nut.

[0014] In one embodiment of the present invention, the first shaft segment and the first hole segment have a clearance fit; and the second shaft segment and the first hole segment have a clearance fit.

[0015] In one embodiment of the present invention, the first shaft segment and the second hole segment are clearance-matched.

[0016] In one embodiment of the present invention, a first seal is provided between the first shaft segment and the first hole segment 1; and a second seal is provided between the second shaft segment and the first hole segment 2.

[0017] In one embodiment of the present invention, under the action of the pressure oil in the pressure chamber, a first axial thrust surface is formed between the second shaft segment and the boss, and a second axial thrust surface is formed between the second end of the thrust cylinder and the first end of the hydraulic cylinder sleeve.

[0018] The above technical solution of the present invention has the following advantages compared with the prior art:

[0019] The impeller fastening tooling of the present invention overcomes the influence of machining surface quality and on-site environment on the fastening force, and controls the fastening force intuitively and accurately, thereby ensuring the reliability of safe operation of high-speed centrifugal fans, especially high-pressure fans.

[0020] The present invention utilizes the wide range of hydraulic pressure to change the hydraulic pressure to obtain different tightening forces, and is applicable to fans of all specifications. In particular, in large-size fans, when a very large tightening force is required, the superiority of the present invention is more obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0022] Figure 1 It is a schematic diagram of the fastening tooling structure of the impeller of the present invention.

[0023] Figure 2 It is a side view schematic diagram (K direction) of the fastening tooling structure of the impeller of the present invention.

[0024] Figure 3 Schematic diagram of the fastening structure between the impeller and the rotating shaft.

[0025] Figure 4 It is a schematic diagram of the use of the present invention in the impeller fastening tooling.

[0026] Description of the Figures in the Specification:

[0027] 1. Rotating shaft; 2. Compression screw; 3. Impeller; 4. Washer; 5. Fastening nut; 6. Thrust cylinder; 6a. Second hole section one; 6b. Second hole section two; 61. Notch; 62. Second axial thrust surface; 7. Hydraulic cylinder sleeve; 7a. First hole section one; 7b. First hole section two; 71. Oil filling hole; 8. First sealing element; 9. Second sealing element; 10. Pull nut; 101. First axial thrust surface; 102. Boss; 11. Hydraulic cylinder core; 11a. First shaft section; 11b. Second shaft section; 111. Limiting step; 12. Pressure chamber. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0029] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0030] In the present invention, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present invention, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0031] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0032] Reference Figure 1 , Figure 3 As shown, a fastening tool for an impeller 3 of the present invention, a rotating shaft 1 is provided on one axial side of the impeller 3, a first end of a pressing screw 2 passes through a central through hole of the impeller 3 and is connected to the rotating shaft 1, a second end of the pressing screw 2 extends to the other axial side of the impeller 3 and a washer 4 and a fastening nut 5 are provided thereon, and the fastening tool comprises:

[0033] The pull nut 10 is used to be connected to the second end of the compression screw 2 through a thread; the pull nut 10 has a boss 102 extending radially outward from one end axially away from the compression screw 2;

[0034] The hydraulic cylinder core 11 is sleeved outside the puller 10, and includes a first shaft section 11a and a second shaft section 11b connected to each other; the diameter of the first shaft section 11a is smaller than the diameter of the second shaft section 11b, and the second shaft section 11b abuts against the boss 102 and extends radially outward to form a limiting step 111;

[0035] A hydraulic cylinder sleeve 7, wherein the hydraulic cylinder sleeve 7 comprises a first end and a second end which are axially opposite to each other and is provided with a first step hole; the first step hole comprises a first hole section 1 7a which matches with the first shaft section 11a and a first hole section 2 7b which matches with the second shaft section 11b, a pressure chamber 12 for introducing pressure oil is formed between the second shaft section 11b and the bottom wall of the first hole section 2 7b, and the second end of the hydraulic cylinder sleeve 7 abuts against the limiting step 111;

[0036] The thrust cylinder 6 is provided with a second step hole, which includes a second hole section 1 6a and a second hole section 2 6b with different diameters. The second hole section 1 6a can be sleeved outside the fastening nut 5, and the first shaft section 11a extends into the second hole section 2 6b; the thrust cylinder 6 includes a first end and a second end axially oppositely arranged, the first end of the thrust cylinder 6 can be abutted against the washer 4, and the second end of the thrust cylinder 6 abuts against the first end of the hydraulic cylinder sleeve 7.

[0037] By adopting a hydraulic control method and utilizing the axial thrust generated by the pressure oil for tightening, interference of friction coefficient fluctuation on the tightening force accuracy is effectively avoided, thereby significantly improving the reliability of the tightening of the impeller 3.

[0038] Reference Figure 1 As shown, in one embodiment, the radial outer end of the hydraulic cylinder sleeve 7 is provided with an oil filling hole 71 connected to the pressure chamber 12.

[0039] The oil filling hole 71 is a threaded hole and is connected to the outlet of the hydraulic pump, and a pressure gauge is provided at the outlet of the hydraulic pump to obtain the oil pressure value (P) in the pressure chamber 12. It should be noted that the pressure gauge can be directly installed at the outlet of the hydraulic pump, or can be led to a position visible to the human eye through a pipeline.

[0040] In one embodiment, referring to Figure 2 As shown, the end surface of the thrust cylinder 6 is provided with a notch 61 penetrating to the second hole section 1 6 a , and 1 to 2 notches may be provided to expose the fastening nut 5 , so as to facilitate the rotation of the fastening nut 5 through the notch 61 .

[0041] In one embodiment, the central through hole of the hydraulic cylinder core 11 is clearance-matched with the pull nut 10 .

[0042] In one embodiment, the first shaft segment 11a is clearance-fitted with the first hole segment 1 7a; the second shaft segment 11b is clearance-fitted with the first hole segment 2 7b, one of which is a small clearance fit and the other is a larger clearance fit to prevent mutual interference.

[0043] In one embodiment, the first shaft segment 11a and the second hole segment 6b are clearance-fitted.

[0044] In one embodiment, a first sealing member 8 is disposed between the first shaft segment 11a and the first hole segment 1 7a; and a second sealing member 9 is disposed between the second shaft segment 11b and the first hole segment 2 7b.

[0045] In one embodiment, under the action of the pressurized oil in the pressure chamber 12 , a first axial thrust surface 101 is formed between the second shaft segment 11 b and the boss 102 , and a second axial thrust surface 62 is formed between the second end of the thrust cylinder 6 and the first end of the hydraulic cylinder sleeve 7 .

[0046] It should be noted that, refer to Figure 1 , Figure 4 As shown, when the oil pressure in the pressure chamber 12 is P, under the action of the first axial thrust surface 101, the axial thrust of the hydraulic cylinder core 11 on the nut 10 is F (directed to the right); under the action of the second axial thrust surface 62, the axial thrust of the cylinder sleeve on the thrust cylinder is also F (directed to the left), and at this time, the thrust of the thrust cylinder body 6 applied to the gasket 4 is also F (to the left), that is, the axial force applied to the impeller 3 is also F.

[0047] Reference Figure 4 As shown, before the impeller 3 is tightened, the tightening thread on the clamping screw 2 is not tightened. The central thread on the pull nut 10 is connected with the thread on the clamping screw 2, so that the first end (left end face) of the thrust cylinder is close to the gasket 4; the oil filling hole 71 on the hydraulic cylinder sleeve 7 is connected to the outlet of the manual hydraulic pump, and the hydraulic pump is manually operated to make the pressure gauge installed at the outlet reach the design value P. At this time, the oil pressure in the pressure chamber 12 is equal to P. Under the action of the pressure oil, a first axial thrust surface 101 is formed between the hydraulic cylinder core 11 and the pull nut 10, and the axial thrust of the hydraulic cylinder core 11 on the pull nut 10 is F (direction to the right). At the same time, a second axial thrust surface 62 is formed between the cylinder sleeve and the thrust cylinder body 6, and the axial thrust of the hydraulic cylinder sleeve 7 on the thrust cylinder is also F (direction to the left). At this time, the thrust force F (to the left) on the washer 4 by the thrust cylinder 6 is also F, that is, the axial force F on the impeller 3 is also F. Due to the action of the axial force F, the impeller 3 and the washer 4 are compressed, the pressing screw 2 is stretched, and the fastening nut 5 is separated from the washer 4. After the hydraulic pressure P is stable, the axial force F remains unchanged, and the relative axial displacement caused by compression and elongation also remains stable. At this time, the fastening nut 5 is rotated through the notch 61 on the thrust cylinder 6 to make it close to the washer 4, and then the hydraulic pump is operated to relieve the pressure, and the pull nut 10 and the entire fastening tooling are removed. The fastening force F of the impeller 3 is entirely borne by the fastening nut 5 and the pressing screw 2, that is, the entire fastening work of the impeller 3 is completed. By adopting the hydraulic control method and using the axial thrust generated by the pressure oil for fastening, the interference of the friction coefficient fluctuation on the fastening force accuracy is effectively avoided, thereby significantly improving the reliability of the fastening effect.

[0048] It should be noted that when the diameter of the first hole section 1 7a of the hydraulic cylinder sleeve 7 is d, the diameter of the first hole section 2 7b is D (D>d), and the oil pressure in the pressure chamber 12 is equal to P, F = the design tightening force of the impeller 3, then Since P can be accurately controlled and read out by a pressure gauge, a relatively accurate tightening force F of the impeller 3 can be obtained.

[0049] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A fastening tool for an impeller (3), wherein a rotating shaft (1) is arranged on one axial side of the impeller (3), a first end of a pressing screw (2) passes through a central through hole of the impeller (3) and is connected to the rotating shaft (1), a second end of the pressing screw (2) extends to the other axial side of the impeller (3) and a washer (4) and a fastening nut (5) are arranged thereon, characterized in that: The fastening tool comprises: A pull nut (10) is used to be connected to the second end of the compression screw (2); an end of the pull nut (10) axially away from the compression screw (2) is provided with a boss (102) extending radially outwards; The hydraulic cylinder core (11) is sleeved outside the puller (10), and comprises a first shaft section (11a) and a second shaft section (11b) connected to each other; the diameter of the first shaft section (11a) is smaller than the diameter of the second shaft section (11b); the second shaft section (11b) abuts against the boss (102) and extends radially outward to form a limiting step (111); A hydraulic cylinder sleeve (7), the hydraulic cylinder sleeve (7) comprising a first end and a second end axially opposite to each other, and provided with a first step hole; the first step hole comprises a first hole section 1 (7a) cooperating with the first shaft section (11a) and a first hole section 2 (7b) cooperating with the second shaft section (11b); a pressure chamber (12) for introducing pressure oil is formed between the second shaft section (11b) and the bottom wall of the first hole section 2 (7b); the second end of the hydraulic cylinder sleeve (7) abuts against the limit step (111); The thrust cylinder (6) is provided with a second stepped hole, the second stepped hole comprising a second hole section 1 (6a) and a second hole section 2 (6b) having different diameters, the second hole section 1 (6a) being capable of being sleeved outside the fastening nut (5), and the first shaft section (11a) extending into the second hole section 2 (6b); the thrust cylinder (6) comprising a first end and a second end axially oppositely arranged, the first end of the thrust cylinder (6) being capable of abutting against the washer (4), and the second end of the thrust cylinder (6) abutting against the first end of the hydraulic cylinder sleeve (7).

2. The fastening tool for an impeller (3) according to claim 1, characterized in that: An oil injection hole (71) communicating with the pressure chamber (12) is provided at the radial outer end of the hydraulic cylinder sleeve (7).

3. The fastening tool for an impeller (3) according to claim 2, characterized in that: The oil filling hole (71) is a threaded hole and is connected to the outlet of the hydraulic pump.

4. The fastening tool for an impeller (3) according to claim 3, characterized in that: The outlet of the hydraulic pump is provided with a pressure gauge to obtain the oil pressure value in the pressure chamber (12).

5. The fastening tool for an impeller (3) according to claim 1, characterized in that: The end surface of the thrust cylinder (6) is provided with a notch (61) penetrating to the second hole section 1 (6a) so as to expose the fastening nut (5).

6. The fastening tool for an impeller (3) according to claim 1, characterized in that: The central through hole of the hydraulic cylinder core (11) is clearance-matched with the pull nut (10).

7. The fastening tool for an impeller (3) according to claim 1, characterized in that: The first shaft section (11a) is clearance-matched with the first hole section 1 (7a); and the second shaft section (11b) is clearance-matched with the first hole section 2 (7b).

8. The fastening tool for an impeller (3) according to claim 1, characterized in that: The first shaft section (11a) and the second hole section (6b) are clearance-fitted.

9. An impeller (3) fastening tool according to any one of claims 1 to 8, characterized in that: A first sealing member (8) is provided between the first shaft section (11a) and the first hole section 1 (7a); and a second sealing member (9) is provided between the second shaft section (11b) and the first hole section 2 (7b).

10. An impeller (3) fastening tool according to any one of claims 1 to 9, characterized in that: Under the action of the pressure oil in the pressure chamber (12), a first axial thrust surface (101) is formed between the second shaft section (11b) and the boss (102), and a second axial thrust surface (62) is formed between the second end of the thrust cylinder (6) and the first end of the hydraulic cylinder sleeve (7).

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