CN114413725A

CN114413725A - Method for judging stator assembly qualification on motor stator hot jacket assembly line

Info

Publication number: CN114413725A
Application number: CN202210092635.3A
Authority: CN
Inventors: 刘平; 郭雪成; 蔡央
Original assignee: Zhuzhou Gear Co Ltd
Current assignee: Zhuzhou Gear Co Ltd
Priority date: 2022-01-26
Filing date: 2022-01-26
Publication date: 2022-04-29
Anticipated expiration: 2042-01-26
Also published as: CN114413725B

Abstract

The invention discloses a method for judging whether a stator is assembled on a motor stator shrink fit assembly line, which is characterized in that a calculation formula and a clearance qualified value range between a stator and a rotor for reference are pre-established, when the stator is assembled in a motor shell, the maximum deviation of the end part of the stator relative to the rotor can be obtained through measurement and calculation by using the calculation formula, and then whether a product is qualified or not is judged by comparing the obtained maximum deviation with the clearance qualified value range. The method has the advantages that a circle concentric with the stator is drawn along the upper end face of the stator before the stator is pressed on the motor shell, a measuring tool is used for finding a highest point and a lowest point on the circle by height measurement after the stator is pressed on the motor shell, the heights of the two points are measured, the calculation can be carried out by using the created calculation formula, and the product can be judged to be qualified or not by substituting the calculation result into the judgment formula. If an empirical formula is obtained by the inverse operation, the judgment can be made only by calculating the difference value between the highest point and the lowest point.

Description

Method for judging stator assembly qualification on motor stator hot jacket assembly line

Technical Field

The invention relates to a method for judging stator assembly qualification on a motor stator hot jacket assembly line, and belongs to the technical field of motor detection.

Background

The motor is used as a power source of the electric automobile and is a core part of the electric automobile. Therefore, the quality of the motor can affect the quality of the electric automobile. The quality of the motor is determined by design, and the quality of the motor is greatly influenced by the assembly process. The most difficult to control is that the cylindrical stator is inclined when being sheathed on a motor shell in a shrink fit mode, the coaxiality of the central line of the stator and the central line of the shell is low after the shrink fit is formed, so that one side of the upper end and the other side of the lower end of a rotor in the space in the cylindrical stator are always attached to or close to the inner wall of the stator respectively, and the chamber sweeping phenomenon known in the industry occurs when the rotor rotates.

Generally, whether the clearance between the stator and the rotor meets the design requirement can be judged by measuring the coaxiality of the center line of the stator and the center line of the shell or the verticality of the end face of the stator and the center line of the shell. But the measurement of the coaxiality and the verticality can be measured by the three-coordinate equipment. Since the three-coordinate device is expensive and inefficient, and cannot be applied to a production line, and in addition, no other simple and feasible detection method has been found, it is inevitable that defective products are detected during final testing, but assembly in other aspects is completed at this time, and a large cost is paid.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: how to in time discharge the motor that has the risk of sweeping the thorax on producing the line, effectively improve the problem of motor assembly qualification rate.

Aiming at the problems, the technical scheme provided by the invention is as follows:

a method for judging whether stator assembly is qualified on a motor stator shrink fit assembly line is characterized in that a calculation formula and a clearance qualified value range between a stator and a rotor for reference are pre-established, when the stator is assembled in a motor shell, the maximum deviation of the end part of the stator relative to the rotor can be obtained through measurement and calculation by using the calculation formula, and whether a product is qualified or not is judged by comparing the obtained maximum deviation with the clearance qualified value range.

Has the advantages that: the method is characterized in that a circle concentric with the stator is drawn along the upper end face of the stator before the stator is pressed on the motor shell, a measuring tool is used for finding a highest point and a lowest point on the circle by height measurement after the stator is pressed on the motor shell, the height of the two points is measured (the distance between the two points is the diameter of the circle and can be considered to be known), the created calculation formula can be used for calculation, and the calculation result is substituted into the judgment formula to judge whether the product is qualified.

If the inverse operation is carried out according to the calculation formula established by the specification, an empirical formula for detecting the product of the specification can be established, whether the product is qualified or not can be judged only by calculating the difference value between one highest point and one lowest point during application, and the detection is simpler and more convenient.

Drawings

FIG. 1 is a geometric view for calculation in combination with the motor housing, stator, rotor structure;

fig. 2 is a schematic top view of the upper end surface of the stator.

In the figure: 1. a motor housing; 2. a stator; 3. a rotor; 4. and (4) a circle.

Detailed Description

The invention is further described with reference to the following examples and figures:

as shown in fig. 1, the motor includes a rotor 3 having a cylindrical shape, a stator 2, and a motor housing 1. Stator 2 has the cylindrical cavity, and stator 2 pressure equipment is in the motor housing, and rotor 3 installs in the cylindrical cavity of stator 2, has the clearance between the periphery of rotor 3 and the 2 inner walls of stator.

According to the shrink fit process of the stator 2, the stator 2 is pressed into the motor shell 1 at a high temperature, and due to the difference between the thermal deformation property and the installation angle of the material, the complete coincidence of the shaft axis M of the stator 2 after the press fitting and the common shaft axis N of the rotor 3 and the motor shell 1 is difficult to ensure, namely the stator 2 is installed partially during the press fitting.

During press fitting, the stator 2 is severely assembled, so that the rotor 3 is swept in a cavity of the stator 2. The upper end face of the offset stator 2 is higher on one side and lower on the other side relative to the upper end face of the motor housing 1. The rotor 3 is swept in the cavity of the stator 2 to occur at the lower end of the side where the upper end surface of the stator 2 is high and at the upper end of the side where the upper end surface is low.

Since it is difficult to determine the coaxiality of the axial line M of the stator 2 and the axial line N common to the rotor 3 and the motor case 1 on the shrink fit assembly line, the present application places the key to solve the problem on how to know the maximum deviation amount of the upper end face of the stator 2 from the rotor 3.

Example one

The invention provides a method for judging stator assembly qualification on a motor stator shrink fit assembly line, which is characterized in that a calculation formula and a clearance qualification value range between a stator 2 and a rotor 3 for reference are pre-established, when the stator 2 is assembled in a motor shell, the maximum deviation of the end part of the stator 2 relative to the rotor 3 can be obtained through measurement and calculation by using the calculation formula, and then whether a product is qualified or not is judged by comparing the obtained maximum deviation with the clearance qualification value range.

The pre-established calculation formula and the range of acceptable gap values between the stator 2 and the rotor 3 for reference comprise the following steps:

step one, drawing a geometric view for calculation combined with a product structure:

step two, establishing a maximum deviation calculation formula;

introducing a minimum safety factor, and determining a qualified judgment formula containing a clearance qualified value range;

step four, initial inspection;

and fifthly, rechecking and adjusting the range of the qualified value of the clearance.

As shown in fig. 1, the geometric view for calculation combined with the motor structure drawn in the step one is an axial sectional view of the motor housing 1, the stator 2, and the rotor 3, in which the stator axis M and the rotor axis N are taken in cross section, and the highest side and the lowest side of the upper end surface of the biased stator 2 with respect to the upper end surface of the motor housing 1 are respectively on both sides of the sectional view; setting a measuring point A on the end surface of the stator 2 on the lowest side, and setting a measuring point B on the end surface of the stator 2 on the highest side; making a straight line X connecting the upper end surfaces of the two sides of the motor shell 1, making perpendicular lines AD and BE of the straight line X by passing through a point A and a point B, and making a straight line BC perpendicular to the straight line AD by passing through the point B; the included angle between the line segment AB and the CB is less than 1; the deflection included angle of the stator axial lead M relative to the rotor axial lead N is less than 2; respectively marking points H and K at the upper end and the lower end of a lateral line of the inner wall of the lowest side of the stator 2; a lower end setpoint J of the side edge line of the rotor 3 near the lowermost side of the stator 2; drawing a parallel JF of the line segment KH from the point J, so that the length of the line segment KH is equal to that of the line segment JF; taking a vertical line FG of the side edge where the point J of the rotor 3 is located from the point F; the deflection included angle between the line segment FJ and the line segment GJ is less than 3.

Step two, the calculation formula for establishing the maximum deviation comprises the following sub-steps:

a) setting: the length of the AC is L1, the heights of line segments AD and BE are h1 and h2 respectively, the length of line segment AB is L2, the length of line segment FJ is L3, and the length of line segment FG is L4;

b) establishing a first calculation formula according to the substep a: l1= h1-h2

h1, h2 are obtained by measurement;

c) establishing a second calculation formula according to the substep b: sin < 1= L1/L2

L2 was obtained by measurement;

d) establishing a third calculation formula according to the substep c: less than 3= &1 = &2

The

angles

1, 2 and 3 are the same angles of the same object rotating in the same direction, so that the angles are equal;

e) establishing a fourth calculation formula according to the substep d: l4= sin ≈ 3 × L3

L3 is the height of the known stator;

the L4 is the maximum deviation of the end of the stator 2 relative to the rotor 3.

It should be noted here that L4 represents the length of the line FG for convenience of drawing and calculation, and in practice, L4 represents the deviation from the point H on the upper end surface of the stator 2 to the point I on the rotor 3, and since the distance from the point H to the point I is the maximum distance from the upper end surface of the stator 2 to the rotor 3, the deviation from the point H on the upper end surface of the stator 2 to the point I on the rotor 3 is the maximum deviation of the end of the stator 2 from the rotor 3 as described herein.

Step three, introducing the lowest safety factor, and establishing a qualified judgment formula comprises the following sub-steps:

f) given that σ is the ideal gap for design (the gap where the distance between the outer periphery of the rotor 3 and the inner wall of the stator 2 is equal everywhere), a minimum safety factor n is introduced, n ∈ (0, 1) is set, and the value of n is typically set to 0.3, 0.4, 0.5.

g) Determining a qualification judgment formula: L4E [ sigma, n x sigma ]

And when the L4 value falls into the clearance qualified value range [ sigma, n multiplied by sigma ], judging that the product is qualified.

The initial inspection comprises the following sub-steps:

i) measurement: respectively measuring line segments AD, BE and AB to obtain values of h1, h2 and L2;

j) and (3) calculating: calculating the value of the maximum deviation L4 by using a first calculation formula, a second calculation formula, a third calculation formula and a fourth calculation formula in sequence according to the values of h1, h2 and L2 measured in the step i and the known value of L3;

k) and (4) qualification judgment: and (4) comparing the values of L4 obtained in the substep j by using a judgment formula L4 epsilon [ sigma, n multiplied by sigma ], wherein if the value of L4 falls into the clearance qualified value range [ sigma, n multiplied by sigma ], the initial detection product is qualified, otherwise, the initial detection product is unqualified.

In n ∈ (0, 1), () means that both values are excluded, i.e., 0 and 1 are excluded, as is the case throughout.

In [ σ, nxσ ], the term [ ] is meant to include both values, i.e., σ and nxσ, and the term [ ] is used throughout.

As shown in fig. 1 and 2, the line segments AD, BE, AB are measured respectively in the step i of the fourth step, and the values of h1, h2, L2 are obtained, before assembly, a circle 4 is drawn on the end face of the stator 2, so that the center of the circle is located on the axial center line of the stator 2, and the diameter of the circle 4 is accurately measured; after the stator 2 is pressed and assembled, different points are selected on the circle 4 by a measuring tool to measure the vertical height from the points to the top end face of the motor shell 1, and the measured point with the maximum height value h1 is the lowest point A of the circle 4; the measurement point of the minimum height value h2 is taken as the highest point B of the circle 4; since points a and B are the lowest and highest points, respectively, on the circle, a line segment from point a to point B must pass through the center of circle 4, with the length L2 of line segment AB being the diameter of circle 4.

Fifthly, rechecking, namely rechecking the products subjected to the primary inspection in the step four by using three-coordinate equipment, and increasing the value of the lowest safety coefficient n when unqualified products are missed for inspection; and when qualified products are regarded as unqualified products, the value of the lowest safety factor n is reduced, so that a reliable clearance qualified value range for reference in assembly line detection is obtained.

Through the steps, calculation formulas I, II, III, IV and judgment formulas which can be directly used are obtained, and the clearance qualified value range in the judgment formulas is a reliable clearance qualified value range determined through rechecking.

During actual application, firstly, the measurement is carried out according to the method, namely before assembly, a circle 4 is drawn on the end face of the stator 2, the center of the circle is positioned on the axis of the stator 2, and the diameter of the circle 4 is accurately measured; after the stator 2 is pressed and assembled, a measuring tool, preferably a high-precision measuring tool with data display, is used for measuring the lowest point A and the highest point B on the circle 4, and then the heights h1 and h2 of the point A and the point B relative to the upper end surface of the motor shell are measured respectively; the length L2 from point a to point B is the diameter of circle 4. Thus, we obtained values for h1, h2, L2. And then, whether the stator assembly is qualified or not can be judged on the motor stator hot jacket assembly line by utilizing the calculation formulas I, II, III, IV and the judgment formula.

For products with the same specification, the size of the circle 4 drawn on the end face of the stator 2 can be fixed before assembly, so that the diameter is measured only once, the value of L2 is directly obtained in subsequent application, and only the lowest point A and the highest point B are measured to obtain the values of h1 and h2, so that the detection is very convenient.

Example two

As shown in fig. 1 and 2, a method for determining stator assembly qualification on a stator shrink fit assembly line of a motor is different from the first embodiment in that: according to the clearance qualified value range [ sigma, nxsigma ] of the L4 determined after the retest, inverse operation is carried out by utilizing the obtained first calculation formula, the second calculation formula, the third calculation formula and the fourth calculation formula, and an empirical formula for simplifying the operation is obtained, wherein the empirical formula comprises the following steps:

step 1: l4= n × σ is calculated by using calculation formula four, calculation formula three, calculation formula two, and calculation formula one in this order, and L1= x is obtained.

Calculating L4= σ by using calculation formula four, calculation formula three, calculation formula two, and calculation formula one in this order to obtain L1= y;

step 2: creating a qualified value range [ x, y ] of L1 according to step 1;

and 3, step 3: since L1= h1-h2, an empirical formula is created from the step 2 qualified value range [ x, y ]:

h1 - h2∈[x，y]

and when the values of h1-h2 fall into the qualified value range [ x, y ], judging that the product is qualified, otherwise, judging that the product is unqualified.

The above steps are briefly described as follows:

sin∠3=L3/L4

∠1=∠2=∠3

L1=sin∠1× L2

since L1= h1-h2

h1 – h2=sin∠1× L2

When sin < 1 × L2 is n × σ and is substituted into L4 in sin < 3= L3/L4, the value obtained by calculation is x,

h1 – h2=x；

when sin < 1 × L2 is sigma and substituted into L4 in sin < 3= L3/L4, the value obtained by calculation is y,

h1 – h2=y，

that is, the product was acceptable when h1-h 2= x,

the product is qualified when h1-h 2= y,

since n belongs to (0, 1), and x and y are both positive values, x is obtained by substituting n x sigma, y is obtained by substituting sigma,

therefore, x < y,

a range of qualifying values x, y for h1-h2 can thus be created,

thus obtaining an empirical formula for judging the product to be qualified: h1-h 2E [ x, y ]

Compared with the first embodiment, the embodiment only needs to measure and obtain the values of h1 and h2, and can perform calculation detection by using empirical formulas h1-h2 epsilon [ x, y ], so that multiple operations in the first embodiment are omitted, and the detection is more convenient. However, the empirical formula h1-h2 ∈ [ x, y ] in this embodiment is obtained by inverse operation of the calculation formula in the first embodiment, and thus the first embodiment and the second embodiment are inseparable in operation relationship.

Meanwhile, the qualified value range [ x, y ] of the second embodiment is determined by the technical parameters of a product with a certain specification, and can only be applied to the detection of the product. That is, products of different specifications need to be respectively subjected to inverse operation to obtain a qualified value range [ x, y ], because technical parameters of products of different specifications are different, such as a value of the stator height L3.

The above-described embodiments are intended to illustrate the invention more clearly and should not be construed as limiting the scope of the invention covered thereby, any modification of the equivalent should be considered as falling within the scope of the invention covered thereby.

Claims

1. A method for judging whether a stator is assembled on a motor stator shrink fit assembly line is characterized in that a calculation formula and a clearance qualified value range between a stator (2) and a rotor (3) for reference are established in advance, when the stator (2) is assembled in a motor shell, the maximum deviation of the end part of the stator (2) relative to the rotor (3) can be obtained through measurement and calculation by using the calculation formula, and whether a product is qualified or not is judged by comparing the obtained maximum deviation with the clearance qualified value range.

2. The method for determining stator assembling qualification on the motor stator shrink fit assembly line according to claim 1, wherein the pre-established calculation formula and the range of the qualified gap value between the stator (2) and the rotor (3) for reference comprise the following steps:

step two, establishing a maximum deviation calculation formula;

step four, initial inspection;

3. The method for determining stator assembling qualification on the motor stator shrink fit assembling line according to claim 2, wherein the step one of drawing the geometric view for calculation combined with the product structure is drawing an axial sectional view of the motor housing (1), the stator (2) and the rotor (3) with the stator axis M and the rotor axis N in section, and making the highest side and the lowest side of the upper end face of the stator (2) to be offset relative to the upper end face of the motor housing (1) on both sides of the sectional view respectively; setting a measuring point A on the end surface of the stator (2) on the lowest side, and setting a measuring point B on the end surface of the stator (2) on the highest side; making a straight line X connecting the upper end surfaces of the two sides of the motor shell (1), making perpendicular lines AD and BE of the straight line X by passing a point A and a point B, and making a straight line BC perpendicular to the straight line AD by passing the point B; the included angle between the line segment AB and the CB is less than 1; the deflection included angle of the stator axial lead M relative to the rotor axial lead N is less than 2; respectively marking points H and K at the upper end and the lower end of a lateral line of the inner wall of the lowest side of the stator (2); a lower end set point J at a side edge line of the rotor (3) near a lowermost side of the stator (2); drawing a parallel JF of the line segment KH from the point J, so that the length of the line segment KH is equal to that of the line segment JF; taking a vertical line FG of the side edge where the point J of the rotor (3) is located from the point F; the deflection included angle between the line segment FJ and the line segment GJ is less than 3.

4. The method for determining stator assembling qualification on the stator shrink fit assembling line of the motor according to claim 3, wherein the step two of establishing the maximum deviation calculation formula comprises the following sub-steps:

h1, h2 are obtained by measurement;

L2 was obtained by measurement;

The angles 1, 2 and 3 are the same rotating angles of the same object in the same direction;

L3 is the height of the known stator;

the L4 is the maximum deviation of the end of the stator (2) relative to the rotor (3).

5. The method for judging stator assembling qualification on the motor stator shrink fit assembly line as claimed in claim 4, wherein the step three of introducing the lowest safety factor and establishing the qualification judgment formula comprises the following sub-steps:

f) knowing σ as the ideal gap for design, introducing a minimum safety factor n, setting n ∈ (0, 1)

g) Determining a qualification judgment formula: L4E [ sigma, n x sigma ]

6. The method for judging stator assembling qualification on the motor stator shrink fit assembling line as claimed in claim 5, wherein the step four of the initial inspection comprises the following substeps:

k) and (4) qualification judgment: and (4) comparing the value of L4 obtained in the substep j by using a judgment formula L4 epsilon [ sigma, n multiplied by sigma ], if the value of L4 falls into the clearance qualified value range [ sigma, n multiplied by sigma ], the product is qualified in the initial inspection, otherwise, the product is not qualified in the initial inspection.

7. The method for judging whether the stator assembly is qualified on the motor stator hot jacket assembly line according to claim 6, wherein in the step five, the rechecking is carried out, the gap qualified value range is adjusted, namely, products subjected to the primary inspection in the step four are rechecked by using three-coordinate equipment, and when unqualified products are missed, the value of the lowest safety factor n is increased; and when qualified products are regarded as unqualified products, the value of the lowest safety factor n is reduced, so that a reliable clearance qualified value range for reference in assembly line detection is obtained.

8. The method for determining the stator assembling qualification in the stator shrink fit assembling line of the motor according to claim 7, wherein the step of determining whether the product is qualified by comparing the obtained maximum deviation amount with the range of the clearance qualification value is performed by using a qualification formula L4 ∈ [ σ, nxσ ], wherein [ σ, nxσ ] is a reliable range of the clearance qualification value determined by the re-inspection.

9. The method for determining stator assembling qualification in the stator shrink fit assembling line of the motor according to claim 6, wherein the step i of dividing the four steps into four steps is that the line segments AD, BE and AB are respectively measured to obtain the values of h1, h2 and L2, before assembling, a circle (4) is drawn on the end face of the stator (2), the center of the circle is located on the axis of the stator (2), and the diameter of the circle (4) is accurately measured; after the stator (2) is pressed and assembled, different points are selected on the circle (4) by using a measuring tool to measure the vertical height from the points to the top end face of the motor shell (1), and the measured point with the maximum height value h1 is the lowest point A of the circle (4); the measuring point of the minimum height value h2 is taken as the highest point B of the circle (4); the line segment from point a to point B passes through the center of the circle (4), and the length L2 of the line segment AB is the diameter of the circle (4).

10. The method for determining stator assembling qualification in a stator shrink fit assembling line of an electric machine according to claim 7, wherein the obtained first, second, third and fourth calculation formulas are used to perform inverse operation according to the determined clearance qualification range [ σ, n × σ ] of L4 after the retest, thereby obtaining an empirical formula for simplified operation, and the method comprises the following steps:

step 1: calculating L4= nxσ by using a calculation formula four, a calculation formula three, a calculation formula two, and a calculation formula one in this order to obtain L1= x;

step 2: creating a qualified value range [ x, y ] of L1 according to step 1;

h1 - h2∈[x，y]

and when h1-h2 falls into the qualified value range [ x, y ], determining that the product is qualified, otherwise, determining that the product is unqualified.