阅读说明：本技术 将轴承单元的脉冲环的磁中心定中心在旋转中心上的方法 (Method for centering the magnetic center of the impulse ring of a bearing unit on the center of rotation ) 是由 伊夫·安德烈·利弗拉托 奥利维尔·韦伯 于 2021-05-20 设计创作，主要内容包括：一种用于将轴承单元的脉冲环的磁中心定中心在轴承单元的轴承的旋转中心上的方法,轴承单元包括能够相对于彼此同心地旋转的第一圈和第二圈,脉冲环设置有包括多对磁极的靶以及固定到轴承的第一圈的固定套筒,方法包括：a)将脉冲环在轴向上插入第一圈与固定套筒之间,第一圈和固定套筒被构造为在轴承的轴向方向上保持脉冲环；在脉冲环与固定套筒之间保持径向间隙,b)在脉冲环的一个机械转圈上记录角信号,角信号是由被构造为与多对磁极配合的检测部件产生的,c)基于角信号确定脉冲环的总节距偏差向量；d)将脉冲环在轴承的径向方向上移位,移位的幅值和移位的方向由是根据总节距偏差向量而确定的,及e)相对于第一圈固定脉冲环。(A method for centering a magnetic center of an impulse ring of a bearing unit on a rotational center of a bearing of the bearing unit, the bearing unit comprising a first ring and a second ring concentrically rotatable relative to each other, the impulse ring being provided with a target comprising a plurality of pairs of magnetic poles and a fixation sleeve fixed to the first ring of the bearing, the method comprising: a) inserting an impulse ring in an axial direction between a first ring and a fixed sleeve, the first ring and the fixed sleeve being configured to hold the impulse ring in an axial direction of the bearing; maintaining a radial gap between the impulse ring and the stationary sleeve, b) recording an angle signal on one mechanical revolution of the impulse ring, the angle signal being generated by a detection member configured to cooperate with a plurality of pairs of magnetic poles, c) determining a total pitch deviation vector of the impulse ring based on the angle signal; d) displacing the impulse ring in the radial direction of the bearing, the magnitude of the displacement and the direction of the displacement being determined from the total pitch deviation vector, and e) fixing the impulse ring relative to the first ring.)

1. Method for centering the magnetic centre (C4) of an impulse ring (7) of a bearing unit (4) on the rotational centre of a bearing (6) of the bearing unit, the bearing unit comprising a first ring (8) and a second ring (9) concentrically rotatable in relation to each other, the impulse ring (7) being provided with a target (14) comprising a plurality of pairs of poles (N1, S1, N2, S2, N3, S3, N4, S4, N5, S5, N6, S6, N7, S7, N8, S8) and a fixing sleeve (15) fixed to the first ring (8) of the bearing, the method comprising:

-a) inserting an impulse ring (7) axially between the first ring (8) and the fixed sleeve (15), wherein the first ring and the fixed sleeve are configured to hold the impulse ring in the axial direction of the bearing; maintaining a radial gap (g7) between the impulse ring (7) and the fixed sleeve (15),

-b) recording the angular signal (S) on a mechanical revolution of the impulse ring (7)_DE) Said angular signal being generated by a detection member (5) configured to cooperate with said pairs of magnetic poles;

-c) determining a total pitch deviation vector of the impulse ring (7) based on the angle signal

-d) displacing the impulse ring (7) in the radial direction of the bearing, the magnitude of the displacement and the direction of the displacement being determined from the total pitch deviation vector, an

-e) fixing the impulse ring (7) with respect to the first ring (8).

2. Method according to claim 1, characterized in that the total pitch deviation vector of the impulse ring (7) is determinedComprises the following steps:

-determining a single pitch deviation value (SPD) for each interval, said each interval being defined as the angular distance between two nearest poles of the same polarity;

-selecting a maximum single pitch deviation value and a minimum single pitch deviation value;

-determining a first single pitch deviation vector associated with the maximum single pitch deviation valueAnd a second single pitch deviation vector associated with the minimum single pitch deviation valueAnd

-calculating a vector difference between the first vector and the second vector, the total pitch deviation vector being equal to the resulting vector.

3. Method according to claim 2, characterized in that the step of determining the single-pitch deviation value (SPD) for one interval comprises:

-determining the actual period (preal (i)) of the angular signal with respect to said interval measured by the detection means (5);

-determining a theoretical period of the angular signal (ptheo (i)) for the interval; and

-calculating the single pitch deviation as a percentage of the theoretical period of the angle signal of the difference between the theoretical period of the angle signal and the actual period of the angle signal.

4. Method according to any of claims 1 to 3, characterized in that the amplitude (A) of the displacement is determined_SH) And direction (D)_SH) Comprises the following steps:

-determining a deviation vector of the magnitude of the shift from the total pitchModulo (F) of_link)，

-calculating said amplitude value using said relation,

the direction of the shift is the opposite direction of the total pitch deviation vector.

5. Method according to claim 4, characterized in that the relation (F) of the magnitude of the shift to the modulus of the total pitch deviation vector is associated_link) Is determined mathematically or empirically.

6. The method according to any one of claims 1 to 5, wherein steps a), b), c) and d) are performed; repeating steps b) and c) to determine a new total pitch deviation vector; and if the modulus of the new total pitch vector is less than or equal to a threshold value, performing step e).

7. The method according to any one of claims 1 to 5, wherein steps a), b), c) and d) are performed; repeating steps b) and c) to determine a new total pitch deviation vector; repeating step d) if the modulus of the new total pitch vector is greater than a threshold, the magnitude of the shift and the direction of the shift being determined from the new total pitch deviation vector; and performing step e) when the modulus of said new total pitch vector is less than or equal to a threshold value.

8. Method according to any of claims 1 to 6, characterized in that the impulse ring (7) is fixed by welding, gluing or riveting.

9. A method according to any one of claims 1-8, characterised in that the fixing sleeve (15) is fixed to the inner ring (8) of the bearing.

10. Bearing unit (4) manufactured according to any of the preceding claims.

Technical Field

The present invention relates to a magnetic sensor comprising a bearing unit cooperating with a detection member, and more particularly to a method for centering an impulse ring of such a bearing unit.

Background

The magnetic sensors deliver analog sinusoidal signals that are related to the angular position of the rotor. More precisely, such a sensor comprises a rotor formed by a pulsed ring fitted with poles and a stator fitted with detection means able to detect the magnetic field of each pole.

When rotation is applied to the rotor, the magnetic poles pass in front of the detection member in succession. A current is induced in the sensing member based on the distance of the sensing member from the magnetic pole. The current forms a time function of a sinusoidal periodic signal, wherein the strength of the signal depends on the distance between the detection member and the magnetic pole. The time dependence can be converted to an angular dependence based on the known geometry of the sensor and the rotation speed. Thus, time may be associated with the angular position of the rotor, and a sinusoidal signal may be obtained that associates intensity with angular position.

Such a magnetic sensor is generally used in motor control. In the particular case of belt starter generators, the requirement for accuracy of the sensor output signal is increasingly important because the machine torque needs to be controlled appropriately with a minimum amount of noise. Furthermore, the level of the oscillating current of the battery must be kept below a fixed limit so as not to degrade the overall performance of the vehicle.

One source of inaccuracy in the sensor output is in the impulse ring itself, since the impulse ring cannot produce a perfect image of the rotor position.

Due to the misalignment of the different components of the bearing unit, the impulse ring is not perfectly aligned with the detection member, so that the induced current is not a picture of the exact angular position. The magnetic center of the impulse ring and the mechanical center of the rotor are not coincident.

A common solution for reducing the misalignment of the different components consists in increasing the precision of the manufacturing operations in order to produce more precise components.

However, improving manufacturing operations generally involves lengthening manufacturing operation cycle times and increasing production costs.

Disclosure of Invention

It is desirable to avoid at least some of the aforementioned disadvantages, in particular by reducing misalignment (misalignment) of the impulse ring in the bearing unit without the need to improve the accuracy of the bearing unit assembly.

According to an aspect, a method for centering a magnetic center of an impulse ring of a bearing unit on a rotational center of a bearing of the bearing unit is proposed, wherein the bearing unit comprises a first ring and a second ring which are concentrically rotatable with respect to each other.

The impulse ring is provided with a target comprising a plurality of pairs of poles and a fixed sleeve fixed to a first ring of the bearing, the method comprising:

-a) inserting the impulse ring axially between the first ring and the fixed sleeve, the first ring and the fixed sleeve being configured to hold the impulse ring in the axial direction of the bearing; a radial gap is maintained between the impulse ring and the fixed sleeve,

-b) an angular signal recorded (over one mechanical turn) on one mechanical revolution of the impulse ring, said angular signal being generated by a detection means configured to cooperate with said plurality of pairs of poles;

-c) determining a total pitch deviation vector (total pitch deviation vector) of the impulse ring based on the angle signal;

-d) shifting (shifting) the impulse ring in a radial direction of the bearing, the magnitude of the shift and the direction of the shift being determined from the total pitch deviation vector; and

-e) fixing the impulse ring relative to the first ring.

Advantageously, the step of determining the total pitch deviation vector of the impulse ring comprises:

-determining a single pitch deviation value for each interval defined as the angular distance between two nearest poles of the same polarity;

-selecting a maximum single pitch deviation value and a minimum single pitch deviation value;

-determining a first single-pitch deviation vector associated with the largest single-pitch deviation value and a second single-pitch deviation vector associated with the smallest single-pitch deviation value; and

-calculating a vector difference between the first vector and the second vector, the total pitch deviation vector being equal to the resulting vector.

Preferably, the step of determining the single-pitch deviation value for an interval comprises:

-determining the actual period of the angular signal measured by the detection means with respect to the interval;

-determining a period of the angle signal with respect to the interval; and

-calculating the single pitch deviation as a percentage of the theoretical period of the angle signal of the difference between the theoretical period of the angle signal and the actual period of the angle signal.

Advantageously, the step of determining the magnitude and direction of said shift comprises:

-determining a relation relating the magnitude of the shift to the modulus of the total pitch deviation vector,

-calculating the amplitude (amplitude) using the relation,

the direction of the shift is the opposite direction of the total pitch deviation vector.

Preferably, the relationship relating the magnitude of the shift to the modulus of the total pitch deviation vector is determined mathematically or empirically.

Advantageously, steps a), b), c) and d) are performed; repeating steps b) and c) to determine a new total pitch deviation vector, and if the modulus of said new total pitch vector is less than or equal to a threshold value, performing step e).

Preferably, steps a), b), c) and d) are performed; repeating steps b) and c) to determine a new total pitch deviation vector; repeating step d) if the modulus of the new total pitch vector is greater than a threshold, the magnitude of the shift and the direction of the shift being determined from the new total pitch deviation vector; and performing step e) when the modulus of said new total pitch vector is less than or equal to a threshold value.

Advantageously, the impulse ring is fixed by welding, gluing or riveting.

Preferably, the fixed sleeve is fixed to the inner race of the bearing.

According to another aspect, the bearing unit is manufactured according to the method as described above.

Drawings

Further advantages and features of the invention will emerge without any limitation upon examination of the detailed description of embodiments and the accompanying drawings, in which:

FIG. 1 is an axial sectional view of a bearing unit mounted on a rotating shaft according to an example of the present invention;

FIG. 2 schematically illustrates an embodiment of a pulse loop;

FIG. 3 shows a first embodiment of a method for centering the magnetic center of a pulser ring according to the invention;

figure 4 shows the insertion of the impulse ring axially between the first ring and the fixed sleeve;

FIG. 5 shows an example of an angle signal;

FIG. 6 schematically shows a magnetic center and a mechanical center displaced by a distance;

FIG. 7 shows a shifting vector; and

fig. 8 shows a second embodiment of the method according to the invention for centering the magnetic center of the pulse ring.

Detailed Description

Referring to fig. 1, a longitudinal cross-section of a device 1 is shown, wherein the device 1 comprises a rotation shaft 2, a bearing unit 4 and a detection member 5.

The detection means comprises, for example, a coil.

The shaft 2 and the bearing unit 4 are centered on the central axis X1 of the device 1.

The bearing unit 4 includes a bearing 6 mounted on the shaft 2 and a magnetic impulse ring (magnetic impulse ring)7 mounted on the bearing 6.

The detection means 5 are associated with the impulse ring 7 to track the rotation of the rotation axis 2.

The bearing 6 comprises a rotating inner ring 8 and a non-rotating outer ring 9 centered on an axis X1. The bearing 6 further comprises rolling elements 10, such as balls, between the inner ring 8 and the outer ring 9.

The inner ring 8 includes a cylindrical hole 11 and a cylindrical groove 12 formed in the hole 11. With reference to the axis X1, the diameter of the cylindrical hole 11 is smaller than the diameter of the cylindrical groove 12.

The pulser ring 7 includes a target holder 13, a target 14, and a fixing sleeve 15.

Away from the central axis X1, the target holder 13 includes an inner periphery 16, a radial portion 17, and an outer periphery 18. The inner periphery 16 defines an inner bore of the target holder 13 and is fixed to the rotating inner ring 8 of the bearing 6 by a fixing sleeve 15. The radial portion 17 extends substantially radially from the inner periphery 16 towards the outside of the bearing 6. The outer periphery 18 of the radial portion 17 is located radially outside the outer ring 9.

A gap g17 is provided in the axial direction between the radial portion 17 of the target holder 13 and the side surface (/ lateral surface) of the outer ring 9.

The outer periphery 18 of the target holder 13 includes an outer tubular portion 19 extending in the axial direction from the radial portion 17. The outer tubular portion 19 extends parallel to the axis X1 and is located radially above the outer ring 9 of the bearing 6.

The target 14 is held by the outer tubular portion 19 of the target holder 13 radially outside the outer ring 9 with respect to the axis X1.

The target 14 and the detection member 5 cooperate to track the rotation of the impulse ring 7, the target holder 13, the inner ring 6 and the shaft 2 about the central axis X1. A gap g5 is provided in the radial direction between the surface and the detection member 5.

The target 14 comprises a series of magnetic poles of opposite polarity, such that the sensing member 5 induces a current as the poles pass in front of the sensing member in succession.

Alternatively, the detection member 5 and the pulse ring 7 may use any other suitable technique instead of the magnetic technique. For example, inductive or optical techniques may be implemented within the bearing unit 4 of the device 1.

The inner periphery 16 of the target holder 13 is fixed to the rotating inner ring 8 of the bearing 6 by a fixing sleeve 15.

The fixed sleeve 15 comprises an annular tubular portion 20 extending in an axial direction parallel to the axis X1.

The tubular portion 20 is fitted in the groove 12 of the rotating inner ring 8.

The fixing sleeve 15 further comprises a radial collar 21 extending radially outwards from the end of the annular tubular portion 20.

The radial collar 21 overlaps the inner periphery 16 of the radial extension of the target holder 13. The radial collar 21 presses the inner periphery 16 in the axial direction against the side of the inner ring 8 in order to prevent any relative rotation between the fixing sleeve 15, the target holder 13 and the inner ring 8.

Fig. 2 schematically shows an example of an embodiment of the impulse ring 7 and the detection member 5 mounted on the shaft 2.

The target 14 comprises, for example, 8 north magnetic poles, named N1 to N8, alternating with 8 south magnetic poles, named S1 to S8, forming 8 pole pairs, denoted Npp.

In another embodiment, the impulse ring 7 comprises more or less than 8 pole pairs.

The magnetic centre of the impulse ring 7 is named C4 and does not coincide with the centre of rotation of the bearing 6, which is located on the axis X1, the two centres being separated by a distance e.

The detection unit 5 generates an angle signal S_DEWherein the angle signal S_DEComprising an induced current I (over one mechanical turn) over one mechanical revolution (one mechanical turn) of the impulse ring 7_induced。

The interval i is defined as the two nearest poles N of the same polarity_iAnd S_iWherein i varies from 1 to 8.

Each pole pair S in front of the detection member 5 when rotation is applied to the rotary shaft 2_i、N_iInduced current I_real(i) So that:

for example by the processing unit PU to a diagonal signal S_DEAnd (6) processing.

Fig. 3 shows a first embodiment of a method for centering the magnetic center C4 of the impulse ring 7 on the rotational center of the bearing 6.

In step 30, the impulse ring 7 is inserted between the inner ring 8 and the fixed sleeve 15, wherein the inner ring 8 and the fixed sleeve 15 are configured to hold the impulse ring 7 in the axial direction X1 of the bearing 6.

As shown in fig. 4, a radial gap g7 is maintained between the target holder 13 of the pulser ring 7 and the fixed sleeve 15.

A radial gap g7 is maintained between the fixed sleeve 15 and the bore of the target holder.

Then, in step 31, the detection means generate an angle signal S on one mechanical revolution of the impulse ring 7 (/ about one mechanical revolution of the impulse ring 7)_DE。

In step 32, the processing unit PU bases on the angle signal S_DEDetermining the total pitch deviation vector (total pitch deviation vector) of the pulse ring 7

First, the single pitch deviation value SPD for each interval i is calculated based on the following formula:

wherein:

P_Theo(i) the method comprises the following steps Theoretical period (/ time period) of the angle signal for interval i (Theoretical period)

P_real(i) The method comprises the following steps The actual period of the angle signal for interval i.

It should be noted that the actual period P_real(i) Will be determined between poles of the same sign (i.e., between north poles or between south poles). Similarly, the actual period P_real(i) Will be on the same class of signal edges(signal edge), i.e. between rising edges or between falling edges.

FIG. 5 shows the inclusion of a current I on a mechanical turn_real(i) Induced current I of_inducedTheoretical period P_Theo(i) And the actual period P_real(i) Wherein i varies from 1 to 8.

Then, the processing unit PU selects the maximum single-pitch deviation value SPDmax and the minimum single-pitch deviation value SPDmin and determines a first single-pitch deviation vector associated with the maximum single-pitch deviation valueAnd a second single pitch offset vector associated with the minimum single pitch offset value

First single pitch offset vectorIs defined by a maximum single-pitch deviation value SPDmax (e.g., equal to 0.16%), and the direction of the vector is defined by the angular position of the maximum single-pitch deviation value SPDmax in a mechanical turn (e.g.,or 315.07 deg.).

Similarly, a second single pitch offset vectorIs defined by the minimum single pitch deviation value SPDmin (e.g., equal to-0.13%), and the direction of the vector is defined by the angular position of the minimum single pitch deviation value SPDmin in the mechanical revolution (e.g.,or 135.03 deg.).

The processing unit PU calculates a vector difference, a pitch deviation, between the first vector and the second vector(Vector)Equal to the vector as the final result.

Using the above values, pitch deviation vectorIs defined as having a modulus TPD equal to 0.20% and an angular position D_TPDEqual to-85.55 deg..

Then, in step 33 (fig. 3), the pulse ring 7 is displaced (shifted) in the radial direction of the bearing 6.

According to total pitch deviation vectorDetermining the amplitude A of the shift_SHAnd the direction of displacement D_SHBy the amplitude A_SHAnd direction D_SHFeature-wise shift vectorIndicating a shift.

Is named as F_linkWill shift by an amplitude A_SHDeviation vector from total pitchAre associated with each other and shifted in the direction D_SHAnd vectorIn the opposite direction.

Relationship F_linkAre determined empirically or mathematically.

Now a mathematically determined relationship F is given_linkThe method of (1).

FIG. 6 schematically shows the magnetic center C4 and the mechanical center X1 separated by a distance e.

The circumference C1 of the impulse ring 7 is equal to the diameter D of the impulse ring 7 in front of the detection member 5 multiplied by pi.

An electrical degree (electrical degree) equal toBy 360 and the number N of pole pairs_PPThe product of the multiplications removes (devided) perimeter C1.

As shown in FIG. 6, a displacement of magnitude equal to the distance e of the mechanical center X1 from the magnetic center C4 yields a magnetic sector angle magnitude of angle α times 2, approximating the position magnitude of distance e times 2.

Relationship F_linkEqual to:

amplitude A_SHAnd circumference in millimeters, and die TPD in percent.

For example, assume that the diameter D is equal to 63 mm.

The amplitude of the shift A when the modulus TPD is equal to 0.2%_SHEqual to 0.025 mm.

Shift vectorIs defined as amplitude A_SHEqual to 0.025mm and direction D_SHEqual to 94.45 ° (-85.55 ° plus 180 °).

FIG. 7 shows a first single pitch offset vectorSecond single pitch offset vectorPitch deviation vectorAnd a shift vector

Then in step 34 (fig. 3), the impulse ring 7 is locked in the radial direction such that it is fixed to the inner ring 9 of the bearing 6 both in the radial direction and in the axial direction.

The impulse ring 7 is locked, for example by welding, gluing or riveting.

Fig. 8 shows a second embodiment of a method for centering (centering) the magnetic center C4 of the impulse ring 7 on the rotational center of the bearing 6.

Step 30, step 31 and step 32 are performed.

If steps 30, 31 and 32 are performed for the first time (step 35), step 33 is performed and then steps 31 and 32 are repeated to determine a new total pitch deviation vector.

When a new total pitch deviation vector is determined, the modulus of the new total pitch deviation vector is compared to a threshold value (step 36). The value of the threshold is for example equal to 0.30%.

If the new total pitch deviation vector modulo is less than or equal to the threshold value, step 34 is performed.

If the modulus of the new total pitch deviation vector is greater than the threshold, step 33 is performed to determine a shift vector, wherein the magnitude of the shift and the direction of the shift are determined from the new total pitch deviation vector.

The method allows to compensate for the misalignment of the different components of the bearing unit 2 by adjusting the impulse ring 7 according to the value of the total pitch deviation vector TPD without the need to increase the precision of the bearing unit components, so that the magnetic center of the impulse ring and the mechanical center of the bearing unit substantially coincide, in order to improve the quality of the detection of the angular position of the rotor.

In the example shown, the sensor bearing unit is provided with a rolling bearing comprising a row of rolling elements. As a further alternative, the rolling bearing may comprise at least two rows of rolling elements. In the example shown, the rolling elements are balls. Alternatively, the rolling bearing may comprise other types of rolling elements, such as rollers. In another variant, the rolling bearing can also be provided with a plain bearing without rolling elements.

In addition, in the example shown, the first ring of the rolling bearing is the inner ring 8 and the second ring is the outer ring 9. Alternatively, an arrangement may be provided in which the first opposed turns form the outer turn and the second turn forms the inner turn. In this case, the pulse ring is fixed to the outer ring.