Rotor shaft weight center centering apparatus and method therefor

Abstract

The present invention discloses a centering machining method for a rotor shaft, wherein the method comprises: a step of mounting the rotor shaft on a jig; a step of measuring a deviation amount by comparing the actual center line of the rotor shaft with a preset centering line; a step of determining whether the deviation amount is zero or below an allowable threshold; and a step of terminating the centering machining operation if the deviation amount is zero or below the threshold, and performing an outer diameter machining process to cut the outer diameter of the rotor shaft if the deviation amount exceeds the threshold. The invention also discloses a centering machining method and a centering machining apparatus for performing the same.

Description

Technology Field

[0001] The present invention relates to an apparatus and method for centering the center of gravity of a rotor shaft for electric vehicles. As the electric vehicle market expands, competition regarding the performance of drive motors is intensifying. The present invention is a technology designed to reduce processing costs and process time in order to secure the competitiveness of rotor shafts for electric vehicles. Background Technology

[0002] In an electric vehicle motor, the cores of the rotor and stator are mounted around a rotor shaft. As the electric vehicle motor is a module that generates rotational power for the electric vehicle, and the internal rotor shaft transmits rotational force to the transmission, the selection of the manufacturing process and precision machining within that process are critical.

[0003] In Patent No. 10-2751782, the applicant disclosed a technology for manufacturing a rotor shaft (1') as shown in FIG. 6 through a hollow material composite forging process for a rotor shaft for an electric vehicle. The rotor shaft (1') includes a sleeve (10') with a constant diameter, a second joint (110a') integrally formed at one end of the sleeve (10'), a first shaft tube (13a') integrally formed at the second joint (110a), and a flange (14'). Additionally, at the opposite end, it includes a joint (110') and a shaft tube (13') integrally formed at the joint (110').

[0004] However, since the rotor shaft is a high-speed rotating component, managing the concentricity of the inner and outer diameters and quality control of the balance weights are crucial. During the pipe manufacturing process, deviations in the center of gravity in the rotational direction may occur due to inner and outer diameter eccentricity or concentric deformation during the forging process.

[0005] To manage deformed centering, a manufacturing method that minimizes the amount of imbalance by machining both the inner and outer diameters is required. However, machining the inner and outer diameters simultaneously requires a significant amount of time and cost.

[0006] The present invention has been devised to resolve the problems of the prior art described above all at once. The problem to be solved

[0007] Therefore, the objective of the present invention is to provide a centering machining device and method capable of producing a final product precisely and quickly by aligning it with the center of gravity of a rotor shaft. means of solving the problem

[0008] To achieve the above-mentioned objective, the present invention provides a centering method for a rotor shaft, wherein the method comprises: a step of mounting the rotor shaft on a jig; a step of measuring a deviation amount by comparing the actual center line of the rotor shaft with a preset centering line; a step of determining whether the deviation amount is zero or below an allowable threshold; and a step of terminating the centering operation if the deviation amount is zero or below the threshold, and performing an outer diameter machining process to cut the outer diameter of the rotor shaft if the deviation amount exceeds the threshold.

[0009] The step of cutting the outer diameter of the rotor shaft may involve cutting the outer diameter of the sleeve at one end of the rotor shaft or the outer diameter of the sleeve at the other end opposite to the one end.

[0010] In addition, the present invention provides a centering machine device for a center of gravity of a rotor shaft, wherein the device comprises a rotor shaft and a jig on which the rotor shaft is mounted, and the jig comprises a center of gravity measuring part having at least one roller that is rotatable in contact with the rotor shaft at a point where the center of gravity is located on the rotor shaft and accommodates the weight of the rotor shaft and the reaction force and vibration received from the rotor shaft, and a centering machine tool for machining the outer diameter portions of a first sleeve and a second sleeve are respectively arranged opposite to a first sleeve at one end of the rotor shaft and a second sleeve at the opposite end.

[0011] Each central processing tool is formed as a housing, and each first sleeve or second sleeve is accommodated in the empty space provided by the housing, and at least one cutting tool for cutting the outer diameter of each sleeve may be installed on the inner surface of the space.

[0012] The above centering machining device further includes a control unit connected to a jig, and balance data measured by the center of gravity measuring unit is transmitted to the control unit, and the control unit calculates the deviation amount by comparing it with the actual center line of the rotor shaft currently being measured based on a predetermined centering line (L), and can transmit machining data according to the deviation amount to the control unit of the center machining tool. Effects of the invention

[0013] The present invention provides a centering machining device and method capable of producing a final product precisely and quickly by aligning it with the center of gravity of a rotor shaft. Brief explanation of the drawing

[0014] FIG. 1 is a flowchart illustrating each step of the rotor shaft center of gravity centering method of the present invention. FIG. 2 is a schematic diagram illustrating the principle of centering the center of gravity of the rotor shaft of the present invention. FIG. 3 is a drawing of a center machining tool for machining the outer diameter portion of the present invention. Figure 4 is an overall configuration diagram of the rotor shaft center of gravity centering machining system of the present invention. Figure 5 is a diagram illustrating the concepts of the centering line (L) and the center line (C). Figure 6 is a drawing of the applicant's prior patent rotor shaft. Specific details for implementing the invention

[0015] The present invention is capable of various modifications and may have various embodiments. Specific embodiments are illustrated in the drawings and described in detail in the specific details for carrying out the invention. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0016] FIG. 1 is a flowchart illustrating each step of the rotor shaft center of gravity centering method of the present invention.

[0017] First, the rotor shaft (1) is mounted on the jig (2) (S10).

[0018] Next, the center of gravity of the rotor shaft (2) is measured using the center of gravity measuring part (4) installed on the jig (2) (S12).

[0019] Next, based on the ideal centering line, the deviation amount is measured by comparing this with the actual center line of the rotor shaft (1) (S14).

[0020] Next, determine whether the deviation amount in step (S14) is zero or below an allowable threshold (S16).

[0021] If the deviation amount is zero or below the threshold in step (S16), the process proceeds to step (S20) and the centering operation is completed. This is the case where the product is judged to be of high quality as there is no error. However, if the deviation amount is above the threshold in step (S16), an outer diameter machining process is performed to cut the outer diameter of the rotor shaft (1) (S18).

[0022] Subsequently, the process of returning to step (S12) to calculate the deviation between the actual center line and the centering line after the outer diameter machining process and determining whether it is within the allowable range is repeated until a high-quality product is produced. Returning to step (S12) does not necessarily have to be performed after the outer diameter machining process; instead, the deviation between the center line and the centering line can be displayed in real-time, for example, on a display, allowing the operator to perform the outer diameter machining process once.

[0023] FIG. 2 is a schematic diagram illustrating the principle of centering the center of gravity of the rotor shaft (1) of the present invention.

[0024] The rotor shaft (1) has the same shape as the applicant's prior patent, but this is not intended to limit the present invention. The rotor shaft (1) is largely composed of a long first sleeve (12) on the right, a relatively short second sleeve (14) on the left, and a main body (16) with the largest diameter in the center.

[0025] The point (O) where the ideal center of gravity is located on the rotor shaft (1) is a point slightly to the right in the longitudinal direction relative to the main body (16). At this point (O), a first roller (40) with a large diameter is positioned at the upper center of the rotor shaft (1), and two second rollers (42) with small diameters are positioned symmetrically on both the left and right sides at the bottom. These rollers form a center of gravity measuring unit (4) and support the rotor shaft (1) in a balanced manner at three points. These rollers and the rotor shaft (1) rotate simultaneously, and at this time, the weight of the rotor shaft (1) and the reaction force and vibration received from the rotor shaft (1) are transmitted to the control unit (3) to serve as a reference for calculating the deviation amount between the center of gravity and the actual center line.

[0026] In the present invention, the part processed to achieve balance is the outer diameter portion (A, A') that primarily forms the exterior, indicated by the red line. The outer diameter portion (A) on the right is shaped like an inverted "C" and forms the exterior of the outer end of the first sleeve (12), which is long on the rotor shaft (1). In the present invention, the outer diameter portion (A) should be interpreted in a broad sense, not only as the outer part corresponding to the outside of the inner diameter portion, but also including the vertical end surface and the part that is slightly recessed from the end surface but exposed to the outside, as illustrated. The outer diameter portion (A') on the left is shaped like a "C" and forms the exterior of the outer end of the second sleeve (14), which is short on the rotor shaft (1).

[0027] Each outer diameter part can be machined to the same shape and dimensions, but as long as the center of gravity is centered, it does not exclude machining to different shapes or dimensions.

[0028] In addition, if the center of gravity is biased to the left from the current point (O), only the outer diameter (A') can be machined to reduce the weight on the left, and conversely, if the center of gravity is biased to the right from the current point (O), only the outer diameter (A) can be machined to reduce the weight on the right, and simultaneous machining of the two sleeves is not mandatory.

[0029] The present invention is characterized by processing only the “outer diameter” as described above, and since the inner diameter processing process can be eliminated, the center of gravity centering operation is rapid, efficient, and more economical.

[0030] FIG. 3 is a drawing of a center machining tool (20) for machining the outer diameter portions (A, A') of the present invention. Since the center machining tool (20) has the same structure on both sides, the explanation will be based on the structure on the right.

[0031] The central machining tool (20) includes an inverted “U” shaped housing (21) and a rotating part at the rear of the housing (21). The outer diameter portion (A) of the first sleeve (12) is inserted into the empty space formed by the housing (21). A first bit (23) is installed in the middle of the front wall behind the space of the housing (21), a second bit (24) is installed on the upper part of the front (left) side wall, and a third bit (25) is installed on the front wall adjacent to the first bit (23). When the central machining tool (20) rotates, each bit also rotates around the first sleeve (12) and cuts the corresponding part of the outer diameter portion (A) that contacts it.

[0032] It can be understood that the installation position and number of each bit (23, 24, 25) are aligned with the shape of the outer diameter (A). The second bit (24) is intended to machine the outer surface that occupies most of the outer diameter (A), and the first and third bits (23) are intended to cut the ends of the outer diameter (A). The center machining tool (20) on the left also has bits installed to match the shape of the outer diameter (A'), and a detailed description is omitted.

[0033] It will be understood that the number and position of the cutting tool in the center machining tool (20) may vary depending on the shape and size of the rotor shaft (1).

[0034] Figure 4 is an overall configuration diagram of the rotor shaft center of gravity centering machining system of the present invention.

[0035] The machining system includes a jig (2) and a control unit (3). A rotor shaft (1) is mounted on the jig (2). A center of gravity measuring unit (4) and a center machining tool (20) are installed on the jig (2).

[0036] The control unit (3) includes a data transmission / reception unit (30), a deviation amount measurement unit (32), a center machining tool drive unit (34), and a display (36). Balance data measured by the center of gravity measurement unit (4) is transmitted to the control unit (3) through the data transmission / reception unit (30). The deviation amount measurement unit (32) calculates the deviation amount by comparing the centering line (L) with the actual center line (C) of the rotor shaft (1) based on the centering line (L).

[0037] The centering line (L) is an ideal measurement reference line predetermined according to the weight and shape of the rotor shaft (1). The centering line (L) data is stored in advance in the memory of the control unit (3). The actual center line (C) is an actual center line set based on the center of gravity of the rotor shaft (1) currently being measured, based on the transmitted data of the center of gravity measuring unit (4).

[0038] FIG. 5 is a diagram illustrating the concepts of a centering line (L) and a center line (C). In a model such as the rotor shaft (1) in FIG. 5, the ideal centering line (L) is a horizontal line extending through the center of the longitudinal direction as illustrated. If the actual rotor shaft (1) is manufactured ideally, the center line (C) indicated based on the data transmitted by the center of gravity measuring unit (4) will coincide with the centering line (L). However, in the illustrated example, the upper sleeve at both ends of the rotor shaft (1) is thicker than the lower sleeve, resulting in vertical asymmetry, and the center line (C) is indicated slightly above the centering line (L) (red). Therefore, a subsequent processing step is required to align the two lines. The deviation measurement unit (32) calculates the bias position and bias weight to align the two lines, converts this into processing data, and transmits it to the center processing tool driving unit (34). The central processing tool drive unit (34) transmits processing data to the control unit of the central processing tool (20) via the data transmission and reception unit (30) and simultaneously turns on the driver of the central processing tool (20).

[0039] Accordingly, as described above, the center machining tool (20) machines the outer diameter portions (A, A') of the rotor shaft (1). During the above operation, the centering line (L) and the center line (C) are displayed in real time on the display (36) based on the shape of the rotor shaft (1), and the operator continuously monitors the machining accuracy and deviation amount. When the two lines match, the operator stops the operation, and a high-quality product can be obtained easily, quickly, and automatically.

[0040] Point (O) in Fig. 2 is the position where the center of gravity should ideally be located, and since the center line (C) according to the actual center of gravity of the current rotor shaft (1) is measured and displayed based on this position, the deviation amount between the centering line and the center line corresponds to logically accurate processing data.

[0041] Although preferred embodiments of the present invention have been described above, various changes and modifications are possible to the present invention, and it is obvious that the scope of the present invention extends to the same or equivalent scope as the claims described below.

Claims

Claim 1 delete Claim 2 delete Claim 3 A centering machine for a rotor shaft, wherein the machine comprises a rotor shaft and a jig on which the rotor shaft is mounted, and the jig comprises a center of gravity measuring part having at least one roller that is rotatable in contact with the rotor shaft at a point where the center of gravity is located on the rotor shaft and accommodates the weight of the rotor shaft and the reaction force and vibration received from the rotor shaft, and a centering machine tool for machining the outer diameter portions of the first sleeve and the second sleeve are respectively arranged opposite to the first sleeve at one end of the rotor shaft and the second sleeve at the opposite end. Claim 4 A centering machining device according to claim 3, wherein each centering machining tool has a main body formed by a housing, each first sleeve or second sleeve is accommodated in the empty space provided by the housing, and at least one cutting tool for cutting the outer diameter of each sleeve is installed on the inner surface of the space. Claim 5 In claim 4, the centering machining device further includes a control unit connected to a jig, balance data measured by a center of gravity measuring unit is transmitted to the control unit, the control unit calculates a deviation amount by comparing a predetermined centering line (L) with the actual center line of the rotor shaft currently being measured, and transmits machining data according to the deviation amount to the control unit of the center machining tool. Claim 6 A centering method for a rotor shaft using a centering machine for a rotor shaft according to claim 3, wherein the method comprises: a step of mounting a rotor shaft on a jig; a step of measuring a deviation amount by comparing a preset centering line with the actual center line of the rotor shaft; a step of determining whether the deviation amount is zero or below an allowable threshold; and a step of terminating the centering machine operation if there is no deviation amount or it is below the threshold, and performing an outer diameter machining process to cut the outer diameter of the rotor shaft if it exceeds the threshold; wherein the step of cutting the outer diameter of the rotor shaft is to cut the outer diameter of a sleeve at one end of the rotor shaft or the outer diameter of a sleeve at the other end opposite to the one end.

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