Impeller press-fitting device of double-press structure

Abstract

The utility model provides an impeller press-fitting device of a double-press structure, which comprises an upper press head and a lower press head which are oppositely arranged, the upper press head is provided with a displacement sensor I and a displacement sensor II, the vertical distance between the mounting positions of the displacement sensor I and the displacement sensor II is a known constant h, and the known constant h is equal to the known constant h. The lower pressing head is used for supporting the lower end of the rotating shaft and applying upward pre-tightening force F, and the upper pressing head is used for driving the impeller to move downwards so that the impeller and the rotating shaft can be subjected to press fitting; the first displacement sensor is used for detecting the vertical distance H1 from the installation position of the impeller to the upper surface of the impeller when the impeller is pressed, and the second displacement sensor is used for detecting the vertical distance H2 from the installation position of the impeller to the upper datum plane of the shell when the impeller is pressed. The finally obtained impeller press-fitting height is not affected by dimensional tolerance and assembly tolerance of related parts, so that products with high press-fitting consistency can be obtained, and the performance consistency of electronic water pump finished products is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of electronic water pump assembly technology, specifically to an impeller pressing device with a dual-pressor structure. Background Technology

[0002] The electric water pump is a core component of the automotive cooling system, responsible for driving the circulation of coolant. The overall performance of the electric water pump is strongly correlated with the clearance of the impeller rings; this clearance has a significant impact on its performance. A clearance that is too large or too small will negatively affect the electric water pump's efficiency, flow rate, pressure, wear, noise, vibration, temperature control, and energy consumption. Besides proper design of the impeller ring clearance, its size is also closely related to the final press-fit height H of the impeller; therefore, improving the impeller press-fit accuracy and consistency is crucial.

[0003] Existing impeller pressing devices such as Figure 1 As shown, the impeller and shaft are assembled by using a support fixture to hold the shaft in place and a pressure head pressing down on the impeller to fix its displacement. This method is simple and efficient, but it can only guarantee the consistency of the height difference between the lower ends of the impeller and shaft. Because the gasket assembly (including ceramic gaskets and rubber damping pads) and shaft are clearance-fitted, during operation, the shaft, rotor core assembly, and gasket assembly will float upwards under the axial force of the fluid until the gasket assembly is in contact with the housing. Due to the influence of housing thickness tolerance, shaft height tolerance, gasket assembly height tolerance, and rotor core assembly assembly tolerance, the cumulative tolerance range for the impeller press-fit height is large. Therefore, when the impeller press-fit height accuracy requirement of the electronic water pump is too high, this press-fitting scheme cannot guarantee the consistency of the press-fitting results.

[0004] In summary, there is an urgent need for a dual-press impeller pressing device to solve the problems existing in the prior art. Utility Model Content

[0005] The purpose of this utility model is to provide an impeller pressing device with a dual-press structure, which aims to solve the problem that existing impeller pressing methods cannot guarantee the consistency of pressing results when the pressing height accuracy requirements of electronic water pump impellers are too high. The specific technical solution is as follows:

[0006] A dual-press impeller pressing device includes an upper pressing head and a lower pressing head arranged opposite to each other. The upper pressing head is equipped with a displacement sensor one and a displacement sensor two. The vertical distance between the installation positions of the displacement sensor one and the displacement sensor two is a known constant h. The lower pressing head is used to support the lower end of the rotating shaft and apply an upward preload F. The upper pressing head is used to move the impeller downward to press the impeller and the rotating shaft together. The displacement sensor one is used to detect the vertical distance H1 from the installation position of the impeller to the upper surface of the impeller during pressing, and the displacement sensor two is used to detect the vertical distance H2 from the installation position of the impeller to the reference surface on the housing during pressing.

[0007] Preferably, both displacement sensor one and displacement sensor two are contact displacement sensors or non-contact displacement sensors.

[0008] Preferably, the maximum measuring stroke of the displacement sensor one The following condition must be met: After the impeller is installed on the upper pressure head, the distance H1 from the upper surface of the impeller to the installation position of the displacement sensor is less than or equal to...

[0009] Preferably, the maximum measuring stroke of the displacement sensor two It must meet the following requirement: During the downward movement of the upper pressure head, when the displacement sensor two first acquires the vertical distance H2 from its installation position to the reference plane, the vertical distance H of the current impeller upper surface from the reference plane is calculated based on H1, h, and the first acquired H2. d It must be greater than or equal to H; where H is the final target pressing height of the impeller.

[0010] Preferably, it also includes a servo control system, which is used to control the movement of the upper and lower pressure heads.

[0011] Preferably, the servo control system is connected to a display screen, which is used to display the movement stroke of the upper pressure head and the lower pressure head, as well as the applied force.

[0012] The application of the technical solution of this utility model has the following beneficial effects:

[0013] This invention can calculate the vertical distance H between the upper surface of the impeller and the reference surface of the housing in real time using displacement sensor one and displacement sensor two. d When H is satisfied dWhen the final press height H is equal to the target press height, press-fitting is stopped. The preload F applied to the shaft by the lower press head ensures that the gasket assembly fits snugly against the housing. This eliminates the adverse effects of housing thickness tolerance, shaft height tolerance, gasket assembly height tolerance, and rotor core assembly assembly tolerance on the final impeller press height. In other words, the final impeller press height is not affected by the dimensional tolerances and assembly tolerances of the relevant parts. Therefore, products with high press-fitting consistency can be obtained, thus ensuring the consistent performance of the finished electronic water pump.

[0014] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0016] Figure 1 This is a structural schematic diagram of an existing impeller pressing device;

[0017] Figure 2 This is a schematic diagram of the impeller pressing device of this utility model;

[0018] Figure 3 This is a schematic diagram of the intermediate pressing state of the impeller pressing device of this utility model;

[0019] Figure 4 This is a schematic diagram of the impeller pressing device of this utility model in the completed pressing state;

[0020] Among them, 1. Impeller, 2. Housing, 2.1. Reference surface, 3. Rotary shaft, 4. Rotor core assembly, 5. Ceramic gasket, 6. Rubber damping pad, 7. Upper pressure head, 8. Support fixture, 9. Displacement sensor one, 10. Displacement sensor two, 11. Lower pressure head. Detailed Implementation

[0021] To facilitate understanding of this invention, a more comprehensive description is provided below, along with preferred embodiments. However, this invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this invention.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0023] Example:

[0024] The specific structure of the electronic water pump is existing technology. For ease of understanding, this embodiment only provides a simple description of the electronic water pump's structure. For details not described in detail, please refer to existing technology. The electronic water pump generally includes an impeller 1, a housing 2, a rotating shaft 3, a rotor core assembly 4, and a gasket assembly. The rotating shaft 3 is rotatably mounted on the housing 2. The rotor core assembly 4 is mounted on the rotating shaft 3 and located inside the housing. The impeller 1 is press-fitted to the end of the rotating shaft 3 and located outside the housing. The gasket assembly is mounted on the rotating shaft 3 and located inside the housing, near the impeller and close to the inner wall of the housing. The gasket assembly generally includes ceramic gaskets 5 and rubber shock-absorbing pads 6. The rotor core assembly 4 rotates synchronously with the rotating shaft 3, while the gasket assembly does not rotate synchronously with the rotating shaft.

[0025] Figure 1 This is a schematic diagram of an existing impeller pressing device. The existing impeller pressing device includes an upper pressing head 7 and a supporting fixture 8, which are arranged opposite to each other. During impeller pressing, the supporting fixture 8 holds the lower end of the rotating shaft 3, and the upper pressing head 7, carrying the impeller 1, presses it down to fix it, completing the assembly of the impeller 1 and the rotating shaft 3 (the specific structure of the impeller mounted on the upper pressing head is described in existing technology, generally a snap-fit ​​type). This method is simple and has high pressing efficiency, but it can only ensure the consistency of the height difference between the lower ends of the impeller 1 and the rotating shaft 3. Because the gasket assembly (which includes a ceramic gasket 5 and a rubber shock-absorbing pad 6) and the rotating shaft 3 have a clearance fit, when the electronic water pump is working, under the action of the axial force of the fluid, the rotating shaft 3, the rotor core assembly 4, and the gasket assembly will float up as a whole until the gasket assembly is in contact with the housing 2. Due to the influence of the thickness tolerance of the housing 2, the height tolerance of the shaft 3, the height tolerance of the gasket assembly, and the assembly tolerance of the rotor core assembly 4, the cumulative tolerance range of the impeller press-fit height is relatively large. Therefore, when the accuracy requirement of the final press-fit height H of the electric water pump impeller is too high, this press-fitting scheme cannot guarantee the consistency of the press-fitting results, thus making it impossible to guarantee the consistency of the gap size of the wear ring. The final press-fit height H of the impeller refers to the height distance between the upper surface of the impeller and the reference surface 2.1 on the housing 2 after press-fitting, where the reference surface refers to the upper surface of the housing 2.

[0026] To address the problems existing in current impeller pressing devices, this embodiment provides an impeller pressing device with a dual-press structure, such as... Figure 2As shown. The pressing device in this embodiment includes an upper pressing head 7 and a lower pressing head 11 arranged opposite to each other. The upper pressing head 7 is equipped with a displacement sensor 9 and a displacement sensor 10. The vertical distance between the installation positions of the displacement sensor 9 and the displacement sensor 10 is a known constant h. The lower pressing head 11 is used to support the lower end of the rotating shaft 3 and apply an upward preload F. The displacement sensor 9 is used to detect the vertical distance H1 from the installation position of the impeller to the upper surface of the impeller 1 during the pressing process. The displacement sensor 10 is used to detect the vertical distance H2 from the installation position of the impeller to the reference surface 2.1 on the housing 2 during the pressing process.

[0027] Preferably, during the pressing process, the vertical distance H between the current upper surface of the impeller and the reference plane can be calculated based on H1, H2, and h. d According to H d The final target pressing height H of the impeller can be used to calculate the stroke H that the upper pressure head needs to continue pressing down. x =H d -H, control the upper pressure head to continue pressing down H x This ensures that the final press-fit height of the impeller is H; where H should satisfy... d ≥H.

[0028] Furthermore, the vertical distance H d The calculation can be obtained based on the actual installation of displacement sensor 9 and displacement sensor 10. If the installation position of displacement sensor 9 is h higher than the installation position of displacement sensor 10, then H... d =H2 + h - H1; If the installation position of displacement sensor 9 is h lower than the installation position of position sensor 10, then H d =H2-h-H1.

[0029] Preferred, such as Figure 2 As shown, in this embodiment, displacement sensor 9 and displacement sensor 10 are installed on the same horizontal plane of the upper pressure head, that is, the installation positions of the two displacement sensors are on the same horizontal plane (i.e., h = 0). At this time, H d =H2-H1.

[0030] Preferably, both displacement sensor 9 and displacement sensor 10 are contact or non-contact displacement sensors; that is, displacement sensor 9 and displacement sensor 10 can be arbitrarily selected as contact or non-contact displacement sensors, and it is not required that they be selected as the same type of displacement sensor.

[0031] Preferably, the maximum measuring stroke of the displacement sensor 9 The following condition must be met: After the impeller is installed on the upper pressure head 7, the distance H1 from the upper surface of the impeller to the installation position of the displacement sensor 9 is less than or equal to... Since the relative position between the impeller 1 and the upper pressure head 7 will not change after the impeller 1 is installed on the upper pressure head 7, the maximum measurement stroke (maximum measurement range) of the displacement sensor 9 only needs to be able to measure the vertical distance from its installation position to the upper surface of the impeller 1 (i.e., ensure that H1 can be obtained).

[0032] Preferably, the maximum measuring stroke of the displacement sensor 10 It must meet the following requirement: During the downward pressing process of the upper pressure head, when the displacement sensor 10 first obtains the vertical distance H2 from its installation position to the reference plane, the vertical distance H of the current impeller upper surface from the reference plane is calculated based on H1, h, and the first obtained H2. d It must be greater than or equal to H to prevent the impeller upper surface from being less than H but not yet obtaining H2, which would result in an excessive impeller pressing depth and affect the mouth ring clearance.

[0033] Furthermore, in order to address the problem that the cumulative tolerance range of the impeller pressing height is large due to the influence of the shell thickness tolerance, shaft height tolerance, gasket assembly height tolerance, and rotor core assembly assembly tolerance, resulting in the inability to guarantee the consistency of the pressing results, in this embodiment, the lower pressing head 11 applies an upward pressing force F to the shaft 3 from below, so that the ceramic gasket 5 in the gasket assembly fits against the shell 2, thereby eliminating the influence of the shell thickness tolerance, shaft height tolerance, gasket assembly height tolerance, and rotor core assembly assembly tolerance on the impeller 1 assembly.

[0034] Since the rubber damping pad 6 will be compressed when the rotating shaft is pushed upward, considering the differences in the material, thickness, and fit of the rubber damping pad 6, this embodiment assumes that the reference value of the tightening force F is a constant value F0, and calculates the compensation force F for dynamic compensation of F0. 补偿 The final clamping force output by the downward pressure head 11 is obtained as F = F0 + F 补偿 The specific method is as follows:

[0035] A1. Fix the housing and control the lower pressure head 11 to rise and press against the lower end of the rotating shaft 3. Gradually increase the preload F' applied by the lower pressure head to the rotating shaft. Obtain the linear equation between F' and the lower pressure head stroke S (i.e. the deformation of the rubber damping pad) in the linear deformation section of the rubber damping pad 6, and obtain the slope K of the linear equation.

[0036] A2. Based on the slope K and the compensation coefficient α n Calculate the compensating force F 补偿 According to F 补偿 The clamping force F is calculated from F0; where F 补偿 =K×α n F = F0 + F 补偿 F0 is a given baseline value.

[0037] Specifically, the compensation coefficient α n The method for determining it is as follows:

[0038] Given a step size of m N, the compensation coefficient α n Perform 2n+1 value selections, and control the output clamping force F of the pressure head according to the value of the compensation coefficient each time to press the impeller. Measure the final impeller pressing height (referring to the distance from the upper surface of the impeller to the reference surface after the impeller is pressed) under different values ​​of the compensation coefficient, and select the compensation coefficient with the highest accuracy of the impeller pressing height as the optimal value.

[0039] Furthermore, the compensation coefficient α n The values ​​of are: -n×m, -(n-1)×m, ..., -2×m, -m, 0, m, 2m, ..., (n-1)×m, n×m.

[0040] The impeller is press-fitted by applying a clamping force F through the pressure head 11, controlling the linear deformation region of the rubber damping pad 6 to eliminate the influence of shell thickness tolerance, shaft height tolerance, gasket assembly height tolerance, and rotor core assembly assembly tolerance on the impeller 1 assembly. Preferably, the given reference value F0 can be selected within the range of [F1', F2'], and further preferred... Where: F1' is the minimum preload applied by the lower pressure head to the rotating shaft in the linear deformation section of the rubber damping pad 6, and F2' is the maximum preload applied by the lower pressure head to the rotating shaft in the linear deformation section of the rubber damping pad 6.

[0041] Preferably, the pressing device in this embodiment further includes a servo control system, which is used to control the movement of the upper pressing head and the lower pressing head. The servo control system is connected to a display screen, which is used to display the movement stroke of the upper pressing head and the lower pressing head and the applied force, respectively.

[0042] Preferably, there can be only one servo control system, that is, one servo control system controls the upper pressure head and the lower pressure head; alternatively, there can be two servo control systems, with the upper pressure head and the lower pressure head controlled by their respective servo control systems, and both servo control systems connected to a display screen to display data information.

[0043] The method for pressing the impeller using the pressing device of this embodiment is as follows:

[0044] The impeller is mounted on the upper pressure head, and the displacement sensor 9 detects the vertical distance H1 from its installation position to the upper surface of the impeller 1.

[0045] The housing is fixed and the pressure head is pressed against the lower end of the rotating shaft. The pressure head applies a preload force F to the rotating shaft, so that the gasket assembly fits into the housing and the housing and the rotating shaft are in a relatively fixed state.

[0046] The upper pressure head, carrying the impeller, presses it downwards to press it against the rotating shaft. Displacement sensor 210 detects the vertical distance H2 from its installation position to the reference surface 2.1 on the housing 2.

[0047] Calculate the vertical distance H from the reference plane to the current upper surface of the impeller based on H1, H2, and h. d ,like Figure 3 As shown;

[0048] According to H d The final target pressing height H of the impeller is calculated to determine the next stroke H that the upper pressure head needs to continue pressing down. x H x =H d -H;

[0049] Control the upper pressure head to continue pressing down H x The final press-fit height of the impeller is H, such as Figure 4 As shown;

[0050] Once the pressing is complete, the upper and lower press heads retract.

[0051] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A double-press structure impeller press-fitting device, characterized by comprising: The device comprises upper and lower pressing heads arranged oppositely, the upper pressing head is provided with displacement sensor one and displacement sensor two, the vertical distance between the installation positions of the two displacement sensors is a known constant h, the lower pressing head is used for supporting the lower end of the rotating shaft and applying an upward pre-tightening force F, the upper pressing head is used for bringing the impeller downward to press-fit the impeller with the rotating shaft; the displacement sensor one is used for detecting the vertical distance H1 from the installation position thereof to the upper surface of the impeller during the press-fitting of the impeller, and the displacement sensor two is used for detecting the vertical distance H2 from the installation position thereof to the upper reference surface of the housing during the press-fitting of the impeller.

2. The double-press structure's impeller press-fitting device according to claim 1, characterized in that, The displacement sensor one and the displacement sensor two are both contact or non-contact displacement sensors.

3. The double-press structure impeller press-fitting device according to claim 1, characterized by The maximum measuring stroke of the displacement sensor one The following conditions must be met: after the impeller is installed on the upper pressing head, the distance H1 from the upper surface of the impeller to the installation position of the displacement sensor one is less than or equal to 4. The double-press structure impeller press-fitting device according to claim 1, characterized by The maximum measuring stroke of the displacement sensor two It is required that during the descending of the upper pressing head, when the displacement sensor two first obtains the vertical distance H2 from the installation position to the reference plane, the vertical distance H of the upper surface of the impeller from the reference plane is calculated according to H1, h and the first obtained H2 d It is required to be greater than or equal to H; wherein H is the final target pressing height of the impeller.

5. The double-press structure impeller press-fitting device according to claim 1, characterized by The device further comprises a servo control system used for controlling the actions of the upper and lower pressing heads.

6. The double-press structure's impeller press-fitting device according to claim 5, characterized in that, The servo control system is connected with a display screen used for displaying the movement stroke and the applied force of the upper and lower pressing heads respectively.

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