A dynamic balancing fixture for a large-diameter impeller

Abstract

The utility model belongs to dynamic balance test fixture technical field discloses a kind of dynamic balance fixtures for large-rotating-diameter impeller, including balance mandrel, the middle part of balance mandrel is equipped with the elastic expansion sleeve for the self-centering type expansion of balance mandrel, a tight pull rod is passed through inside elastic expansion sleeve, the outside of elastic expansion sleeve is provided with variable-diameter type needle roller, variable-diameter type needle roller penetrates the shaft wall of balance mandrel and extends the outside of balance mandrel;The tight pull rod includes tensioning shaft portion, positioning cone shaft portion and adjusting shaft portion integrally formed in sequence, positioning cone shaft portion passes inside elastic expansion sleeve and its side wall is attached on the inner hole wall of elastic expansion sleeve;The utility model has adopted the self-centering type expansion structure of elastic clamping, solved the problem of traditional mandrel expansion damage impeller positioning hole precision.

Description

Technical Field

[0001] This utility model relates to the field of dynamic balancing test fixtures, and in particular to a dynamic balancing fixture for a large-diameter impeller. Background Technology

[0002] In motor-driven equipment, impellers with large rotation diameters and large orifices are used when handling large flow rates, high head, special media transport, or adapting to specific spatial structures. However, large rotation diameter and large orifice impellers are subject to structural limitations during machining, are prone to deformation, and require stringent process control, resulting in higher manufacturing costs.

[0003] Moreover, as a key component of the rotating parts, the high-speed rotating impeller must undergo dynamic balancing testing to ensure dynamic balancing accuracy, so as to reduce faults such as large vibrations and falling caused by the imbalance of the workpiece itself.

[0004] Traditional dynamic balancing fixtures are mainly divided into two types. One type uses a combination of fixed and movable cones, including a mandrel, a fixed cone located at one end of the mandrel and integral with the mandrel, a movable cone movably connected to the other end of the mandrel, and a fastening nut for securing the movable cone. The taper makes the impeller and the mandrel tightly connected as one unit. This requires high precision from the mandrel and also carries the risk of damaging the fit tolerance positioning accuracy of the impeller's center hole during the impeller fixing process. This will affect the dynamic balancing accuracy of the entire shaft system after the impeller is assembled, causing irreversible precision loss to the impeller. Utility Model Content

[0005] The main technical problem to be solved by this utility model is to provide a dynamic balancing fixture for impellers with large rotation diameters. It adopts a self-centering tensioning structure with elastic clamping, which solves the problem of the traditional mandrel expansion damaging the accuracy of the impeller positioning hole.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: A dynamic balancing fixture for a large-diameter impeller includes a balancing mandrel. An elastic expansion sleeve for self-centering tensioning of the balancing mandrel is installed in the middle of the balancing mandrel. A tensioning rod passes through the inside of the elastic expansion sleeve. A variable-diameter needle roller is provided on the outside of the elastic expansion sleeve. The variable-diameter needle roller penetrates the shaft wall of the balancing mandrel and extends out of the outside of the balancing mandrel. The tensioning rod includes a tensioning shaft, a positioning cone shaft, and an adjusting shaft, which are integrally formed in sequence. The positioning cone shaft passes through the interior of the elastic expansion sleeve and its sidewall is in close contact with the inner wall of the elastic expansion sleeve.

[0007] The following are further optimizations of the above technical solution by this utility model: The variable diameter needle roller includes multiple fastening blocks arranged in a ring at equal intervals around the axis of the balance mandrel.

[0008] Further optimization: The elastic expansion sleeve is provided with a tensioning block and a centering nut on both sides respectively. The tensioning block is fixed to one end inside the balance mandrel and is slidably connected to the tensioning rod. The centering nut is fixed to the other end of the balance mandrel and is threadedly connected to the tensioning rod.

[0009] Further optimization: A limit block is provided on the side of the elastic expansion sleeve away from the centering nut, and the end face of the elastic expansion sleeve is pressed against the side wall of the limit block.

[0010] Further optimization: A tensioning deformation gap is formed between the outer wall of the elastic expansion sleeve and the inner wall of the balance mandrel.

[0011] Further optimization: The inner wall of the variable diameter needle roller is fixedly connected to the outer wall of the elastic expansion sleeve, and the outer wall of the variable diameter needle roller is adapted to the positioning hole of the impeller.

[0012] Further optimization: The diameter of the tensioning shaft is the same as the diameter of the small diameter end of the positioning cone shaft and extends through the tensioning block; the diameter of the adjusting shaft is the same as the diameter of the large diameter end of the positioning cone shaft and is connected to the centering nut.

[0013] Further optimization: The centering nut is sleeved and fixed to the end of the balance spindle, the adjusting shaft passes through and extends out of the outside of the centering nut, and the adjusting shaft is installed on the centering nut by means of a threaded connection.

[0014] The present invention adopts the above-mentioned technical solution and has the following beneficial effects: The present invention adopts the above-mentioned technical solution, which is ingeniously conceived and reasonably structured. By cooperating with the inner conical hole of the elastic expansion sleeve and the conical shaft of the tensioning rod, a self-centering and reliable fixation of the impeller is achieved, thereby greatly reducing the process requirements for the consistency of the impeller positioning hole and avoiding irreversible damage to the accuracy of the impeller positioning hole during the fixing process. Thus, it solves the problem of the traditional mandrel expansion damaging the accuracy of the impeller positioning hole. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure in an embodiment of this utility model.

[0017] In the diagram: 1. Balance mandrel; 2. Elastic expansion sleeve; 3. Tensioning rod; 301. Tensioning shaft; 302. Positioning cone shaft; 303. Adjusting shaft; 4. Variable diameter needle roller; 5. Tensioning block; 6. Centering nut; 7. Limiting block. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] A dynamic balancing fixture for a large-diameter impeller includes a balancing mandrel 1, wherein an elastic expansion sleeve 2 for self-centering tensioning of the balancing mandrel 1 is installed in the middle of the balancing mandrel 1.

[0020] In this embodiment, the elastic expansion sleeve 2 can be made of a rubber-like material with excellent elastic properties, such as polyetheretherketone composite material.

[0021] Compared with traditional rigid dynamic balancing fixtures, this invention has high coaxiality stability after assembly with the impeller, reduces fluctuations in dynamic balancing test data, and improves the repeatability of the impeller's positioning accuracy.

[0022] Moreover, the elastic expansion sleeve 2 used in this invention can suppress vibration and improve the reliability of dynamic balance detection under high-speed rotation (speed ≥ 5000 rpm).

[0023] Preferably, a tensioning rod 3 passes through the inside of the elastic expansion sleeve 2, and a variable diameter needle roller 4 is provided on the outside of the elastic expansion sleeve 2. The variable diameter needle roller 4 passes through the shaft wall of the balance mandrel 1 and extends out of the outside of the balance mandrel 1.

[0024] This invention utilizes the elastic retractable mechanism of the elastic expansion sleeve 2 to achieve adaptive compensation for the machining accuracy of the impeller positioning hole, significantly reducing the dependence of the dynamic balancing fixture on the machining accuracy of the impeller positioning hole, reducing the stringent requirements for the consistency of the impeller positioning hole size, and significantly improving the yield rate of the impeller production process.

[0025] Preferably, the tensioning rod 3 includes a tensioning shaft 301, a positioning cone shaft 302 and an adjusting shaft 303 integrally formed in sequence. The positioning cone shaft 302 passes through the interior of the elastic expansion sleeve 2, and the inner wall of the elastic expansion sleeve 2 is tightly attached to the shaft wall of the positioning cone shaft 302.

[0026] In this embodiment, the inner hole of the elastic expansion sleeve 2 is a tapered hole that matches the taper of the positioning cone shaft portion 302.

[0027] In this embodiment, the tension rod 3 is rotated to drive its movement, so that the outer conical surface of the positioning cone shaft 302 is in deep engagement with the inner conical hole of the elastic expansion sleeve 2. The outer diameter of the elastic expansion sleeve 2 is elastically expanded by mechanical extrusion, which can simultaneously drive the variable diameter needle roller 4 to expand radially.

[0028] This invention constructs a self-centering tensioning structure by using the tapered fit between the inner hole of the elastic expansion sleeve 2 and the positioning cone shaft 302. When the positioning cone shaft 302 is screwed into the elastic expansion sleeve 2, it can cause the radial dimension of the elastic expansion sleeve 2 to expand uniformly and make the positioning hole of the impeller and the variable diameter needle roller 4 form a gapless fit, thereby ensuring the coaxiality of the impeller and the balance mandrel 1 and providing a stable mechanical reference for dynamic balancing and weight removal testing.

[0029] Preferably, the variable diameter needle roller 4 includes a plurality of fastening blocks arranged in a ring at equal intervals around the axis of the balance mandrel 1.

[0030] In this embodiment, the spacing between adjacent fastening blocks can change with the outer diameter of the elastic expansion sleeve 2, so that the radial dimension of the variable diameter needle roller 4 can be adjusted within a certain range.

[0031] Meanwhile, the extensibility of the elastic expansion sleeve 2 gives the radial dimension of the variable diameter needle roller 4 dynamic adjustability, solving the assembly problem caused by the dimensional tolerance fluctuation of the impeller positioning hole.

[0032] Moreover, the elastic tensioning structure used in this invention can absorb minor dimensional errors and avoid scratching the impeller surface due to hard contact, thereby solving the problem of irreversible precision loss of the impeller positioning hole after the dynamic balancing fixture is assembled with the impeller.

[0033] Preferably, a tensioning block 5 and a centering nut 6 are respectively provided on both sides of the elastic expansion sleeve 2. The tensioning block 5 is fixed to one end inside the balance spindle 1 and is slidably connected to the tensioning rod 3. The centering nut 6 is fixed to the other end of the balance spindle 1 and is threadedly connected to the tensioning rod 3.

[0034] Preferably, a limiting block 7 is provided on the side of the elastic expansion sleeve 2 away from the centering nut 6, and the end face of the elastic expansion sleeve 2 is pressed against the side wall of the limiting block 7.

[0035] In this embodiment, the limiting block 7 serves to limit the elastic expansion sleeve 2. As the positioning cone shaft 302 of the tensioning rod 3 continuously enters the elastic expansion sleeve 2, it also applies a thrust in the axial direction to the elastic expansion sleeve 2.

[0036] The limiting block 7 is located behind the pushing force on the elastic expansion sleeve 2, which can reliably limit the elastic expansion sleeve 2 at this position and ensure the tightening reliability of the elastic expansion sleeve 2.

[0037] Preferably, a tensioning deformation gap is formed between the outer wall of the elastic expansion sleeve 2 and the inner wall of the balance mandrel 1.

[0038] In this embodiment, the setting of the tension deformation gap allows the outer diameter of the elastic expansion sleeve 2 to deform within a small range during the tensioning process, so as to push the variable diameter needle roller 4 outward and press it against the inner wall of the positioning hole of the impeller, thereby realizing the self-centering tensioning and fixing of the impeller.

[0039] Preferably, the inner wall of the variable diameter needle roller 4 is fixedly connected to the outer wall of the elastic expansion sleeve 2, and the outer wall of the variable diameter needle roller 4 is adapted to the positioning hole of the impeller.

[0040] Preferably, the diameter of the tensioning shaft 301 is the same as the diameter of the small diameter end of the positioning cone shaft 302 and extends through the tensioning block 5, and the diameter of the adjusting shaft 303 is the same as the diameter of the large diameter end of the positioning cone shaft 302 and is connected to the centering nut 6.

[0041] Preferably, the centering nut 6 is sleeved and fixed to the end of the balance spindle 1, and the adjusting shaft 303 passes through and extends out of the outside of the centering nut 6. The adjusting shaft 303 is installed on the centering nut 6 by means of a threaded connection.

[0042] The process of fixing the impeller using this invention is as follows: S1. Pass one end of the present invention with the tensioning block 5 through the positioning hole on the impeller, and make the position of the impeller correspond to the position of the variable diameter needle roller 4. S2. After placing the balance mandrel 1 on the dynamic balancing test bench, the tension rod 3 is driven to move continuously toward the direction of the tension block 5 by rotating the tension rod 3. S3. During the movement of the tensioning rod 3, the outer conical surface of the positioning cone shaft 302 is in deep fit with the inner conical hole of the elastic expansion sleeve 2. Through mechanical extrusion, the outer diameter of the elastic expansion sleeve 2 expands elastically, which can simultaneously drive the variable diameter needle roller 4 to expand radially, so that the outer diameter of the variable diameter needle roller 4 is pressed against the inner wall of the impeller positioning hole, thereby fixing the impeller. S4. Perform dynamic balancing tests on the impeller using a dynamic balancing test bench; S5. After completing the dynamic balance test, the tension rod 3 is driven to move continuously away from the tension block 5 by rotating it in the opposite direction. S7. During the movement of the tensioning rod 3, the outer conical surface of the positioning cone shaft 302 and the inner conical hole of the elastic expansion sleeve 2 disengage from each other. Under the elastic contraction of its own elasticity, the outer diameter of the elastic expansion sleeve 2 is elastically reduced, which can simultaneously drive the variable diameter needle roller 4 to radially reduce, so that the outer diameter of the variable diameter needle roller 4 is separated from the inner wall of the impeller positioning hole, thus unlocking the impeller. S9. The unlocked impeller can be directly removed from the balance spindle 1 to prepare for the clamping and fixing of the next impeller.

[0043] Although embodiments of the present invention 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 to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dynamic balancing fixture for a large-diameter impeller, characterized in that, Includes a balance mandrel (1), wherein an elastic expansion sleeve (2) for self-centering tensioning of the balance mandrel (1) is installed in the middle of the balance mandrel (1), a tensioning rod (3) passes through the inside of the elastic expansion sleeve (2), and a variable diameter needle roller (4) is provided on the outside of the elastic expansion sleeve (2), the variable diameter needle roller (4) passes through the shaft wall of the balance mandrel (1) and extends out of the outside of the balance mandrel (1); The tensioning rod (3) includes a tensioning shaft (301), a positioning cone shaft (302) and an adjusting shaft (303) integrally formed in sequence. The positioning cone shaft (302) passes through the interior of the elastic expansion sleeve (2), and the inner wall of the elastic expansion sleeve (2) is tightly attached to the shaft wall of the positioning cone shaft (302).

2. The dynamic balancing fixture for a large-diameter impeller according to claim 1, characterized in that, The variable diameter needle roller (4) includes multiple fastening blocks arranged in a ring at equal intervals around the axis of the balance mandrel (1).

3. The dynamic balancing fixture for a large-diameter impeller according to claim 1, characterized in that, The elastic expansion sleeve (2) is provided with a tension block (5) and a centering nut (6) on both sides respectively. The tension block (5) is fixed to one end inside the balance spindle (1) and is slidably connected to the tensioning rod (3). The centering nut (6) is fixed to the other end of the balance spindle (1) and is threadedly connected to the tensioning rod (3).

4. A dynamic balancing fixture for a large-diameter impeller according to claim 3, characterized in that, The elastic expansion sleeve (2) is provided with a limiting block (7) on the side away from the centering nut (6), and the end face of the elastic expansion sleeve (2) is pressed against the side wall of the limiting block (7).

5. A dynamic balancing fixture for a large-diameter impeller according to claim 1, characterized in that, A tensioning deformation gap is formed between the outer wall of the elastic expansion sleeve (2) and the inner wall of the balance mandrel (1).

6. A dynamic balancing fixture for a large-diameter impeller according to claim 1, characterized in that, The inner wall of the variable diameter needle roller (4) is fixedly connected to the outer wall of the elastic expansion sleeve (2), and the outer wall of the variable diameter needle roller (4) is adapted to the positioning hole of the impeller.

7. A dynamic balancing fixture for a large-diameter impeller according to claim 3, characterized in that, The diameter of the tensioning shaft (301) is the same as the small diameter of the positioning cone shaft (302) and extends through the tensioning block (5). The diameter of the adjusting shaft (303) is the same as the large diameter of the positioning cone shaft (302) and is connected to the centering nut (6).

8. A dynamic balancing fixture for a large-diameter impeller according to claim 7, characterized in that, The centering nut (6) is sleeved and fixed to the end of the balance spindle (1), and the adjusting shaft (303) passes through and extends out of the outside of the centering nut (6). The adjusting shaft (303) is installed on the centering nut (6) by means of threaded connection.

Images