Anti-loosening device and method for small pump impeller

Abstract

The invention relates to an anti-loosening device and method, in particular to an anti-loosening device and method for a small pump impeller. The invention aims to solve the problems that a thin-wall hollow shaft of a mechanical pump cannot be impacted and damaged by a large external force to prevent loosening and cannot be prevented from loosening by using thread anti-loosening glue due to long-term soaking in a liquid working medium. The structure comprises a locking screw and a motor shaft, the locking screw is characterized in that a cylindrical section is arranged between the screw head and the threaded section of the locking screw, and two notches are symmetrically formed in the screw head of the locking screw; and a column platform section matched with the cylindrical section is arranged in the inlet of the inner hole of the motor shaft. The invention belongs to the technical field of spacecraft space micro pumps.

Description

Technical Field

[0001] The invention relates to an anti-loosening device and method, belonging to the technical field of spacecraft space micro pumps. Background Art

[0002] It is used to drive the circulation of perfluorotriethylamine medium and realize load thermal control. It is the first pump aerospace product undertaken by our institute. When the mechanical pump is working, its rated speed is 8000r / min. The anti-loosening effect of the impeller will directly affect the service life and reliability of the mechanical pump. In the development stage of the mechanical pump prototype and prototype, in order to prevent the locking screw from loosening, we have tried to open a hole on the side wall of the locking screw and use a sample punch to forcefully destroy the thread morphology, open a hole on the side wall of the locking screw and use electron beam welding to melt the internal thread of the motor shaft and destroy the thread morphology, and use electron beam welding along the axis of the motor from the fan-shaped notch at the top of the locking screw to remelt the thread mating surface of the locking screw and the motor shaft. However, the test results were not ideal, and finally the only way to prevent loosening was to apply thread anti-loosening glue. However, the bonding strength of the thread anti-loosening glue will decrease after being immersed in the perfluorotriethylamine medium for a long time, and there is a risk that the thread glue will crack and affect the anti-loosening effect, and the glue layer will fall off to form excess. Summary of the invention

[0003] The present invention aims to solve the problem that the thin-walled hollow shaft of a mechanical pump cannot be prevented from loosening by destroying the thread tooth type through a large external force impact and cannot be prevented from loosening by using thread anti-loosening glue due to long-term immersion in liquid working medium, and further proposes an anti-loosening device and method for a small pump impeller.

[0004] The technical solution adopted by the present invention to solve the above-mentioned problem is: the anti-loosening device of a small pump impeller described in the present invention includes a locking screw and a motor shaft; a cylindrical section is provided between the screw head and the threaded section of the locking screw, and two notches are symmetrically provided on the screw head of the locking screw; a column base section matching the cylindrical section is provided at the entrance of the inner hole of the motor shaft.

[0005] Furthermore, the notch is a fan-shaped notch.

[0006] The steps of the method for preventing a small pump impeller from loosening according to the present invention include:

[0007] Step 1: Put the impeller on the front end of the motor shaft;

[0008] Step 2: Insert the locking screw through the through hole in the center of the impeller into the inner hole of the motor shaft;

[0009] Step 3: The cylindrical section of the locking screw is tightly matched with the column section at the entrance of the inner hole of the motor shaft;

[0010] Step 4: Electron beam welding is performed on the notch of the locking screw to fix the locking screw and the motor shaft together. The locking screw also fixes the impeller at the front end of the motor shaft.

[0011] Furthermore, the welding method at the notch of the locking screw is spot welding.

[0012] The beneficial effects of the present invention are as follows: the present invention changes the structural form of the locking screw and the motor shaft, reserves two fan-shaped notches on the screw head of the locking screw, adds a cylindrical section between the screw head and the threaded section, and also adds a cylindrical section at the entrance of the inner hole of the motor shaft. Finally, electron beam welding is used to spot weld the locking screw and the matching surface of the cylindrical section of the motor shaft from the end face, thereby achieving the purpose of preventing loosening.

[0013] The present invention adds a cylindrical section between the screw head and the threaded section of the locking screw. Correspondingly, a cylindrical section is also added at the entrance of the inner hole of the motor shaft. The two cylindrical sections are in close contact. Subsequently, electron beam welding is used to perform spot welding on the end surface to achieve the connection between the locking screw and the motor shaft, thereby preventing loosening. At the same time, the spot welding area is small and has almost no effect on the dynamic balance of the rotor system.

[0014] The present invention can effectively solve the problem of preventing high-speed rotating products from loosening by means of an ingeniously designed thread pair structure without adding any parts.

[0015] The welding test of the formal product has verified that the mechanical pump impeller adopting the present invention has a good anti-loosening effect. The present invention does not change the product size and does not increase the number of product parts. It is particularly practical for precision mechanical pumps and other high-speed rotating products with smaller structural sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the locking screw and the motor shaft;

[0017] Figure 2 is a top view of the locking screw head;

[0018] Figure 3 It is a three-dimensional structural schematic diagram of the present invention;

[0019] Figure 4 It is a schematic diagram of the traditional impeller compression structure;

[0020] Figure 5 It is a schematic diagram of the impeller pressing structure of the present invention;

[0021] Figure 6 It is a schematic diagram of the structure of the impeller;

[0022] Figure 7 Schematic diagram comparing a conventional shaft head and the shaft head of the present invention;

[0023] Figure 7 a is a schematic diagram of a traditional shaft head;

[0024] Figure 7 b is a schematic diagram of the shaft head of the present invention;

[0025] Figure 8 It is a schematic diagram of a conventional compression screw;

[0026] Fig. 9 It is a schematic diagram of the clamping screw of the present invention. DETAILED DESCRIPTION

[0027] Specific implementation method 1: Figure 1 and Figure 2 As shown, a small pump impeller anti-loosening device includes a locking screw 1 and a motor shaft 2; a cylindrical section 101 is provided between the screw head and the threaded section of the locking screw 1, and two notches 102 are symmetrically provided on the screw head of the locking screw 1; a column base section 201 matching the cylindrical section 101 is provided at the entrance of the inner hole of the motor shaft 2.

[0028] The positions of the two fan-shaped notches 102 are symmetrical with respect to the axis of the locking screw 1 , thereby ensuring the symmetry of the electron beam welding area and reducing the influence of welding on the dynamic balance.

[0029] Specific implementation method 2: Figure 1 and Figure 2 As shown, a method for preventing a small pump impeller from loosening comprises the following specific steps:

[0030] Step 1, put the impeller 3 on the front end of the motor shaft 2;

[0031] Step 2, the locking screw 1 passes through the through hole in the center of the impeller 3 and is inserted into the inner hole of the motor shaft 2;

[0032] Step 3, the cylindrical section 101 of the locking screw 1 is tightly matched with the column base section 201 in the entrance of the inner hole of the motor shaft 2;

[0033] Step 4: Electron beam welding is performed at the notch 101 of the locking screw 1 to fix the locking screw 1 and the motor shaft 2 together. The locking screw 1 also fixes the impeller 3 at the front end of the motor shaft 2.

[0034] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A small pump impeller anti-loosening device, comprising a locking screw (1) and a motor shaft (2); characterized in that: A cylindrical section (101) is provided between the screw head and the threaded section of the locking screw (1), and two notches (102) are symmetrically provided on the screw head of the locking screw (1); a column base section (201) matching the cylindrical section (101) is provided at the entrance of the inner hole of the motor shaft (2).

2. The anti-loosening device for a small pump impeller according to claim 1, characterized in that: The notch (102) is a fan-shaped notch.

3. A method for preventing a small pump impeller from loosening, characterized in that: The specific steps include: Step 1: Sleeve the impeller (3) onto the front end of the motor shaft (2); Step 2: The locking screw (1) passes through the through hole in the center of the impeller (3) and is then inserted into the inner hole of the motor shaft (2); Step 3: The cylindrical section (101) of the locking screw (1) is tightly matched with the column base section (201) at the entrance of the inner hole of the motor shaft (2); Step 4: Electron beam welding is performed at the notch (101) of the locking screw (1) to fix the locking screw (1) and the motor shaft (2) together. The locking screw (1) also fixes the impeller (3) at the front end of the motor shaft (2).

4. A method for preventing a small pump impeller from loosening according to claim 3, characterized in that: The welding method at the notch (101) of the locking screw (1) is spot welding.

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