KR20070022056A - Rolling bearing unit with load measuring unit - Google Patents

Abstract

The hub 4 is fixedly supported by the hub 4 concentrically with the encoder 12 whose characteristics are alternately alternating with respect to the circumferential direction and at equal intervals. The detection part of the sensor 13 supported by the said outer ring 3 is made to oppose the detected surface of this encoder 12 in close proximity. The width dimension of the 1st, 2nd both to-be-detected part formed in this to-be-detected surface changes continuously in the direction to which the load which should be detected acts. Since the pattern which the output signal of the said sensor 13 changes with this change of load changes, the said load is calculated | required by observing this pattern. The output signal obtains the rotational speed of the hub 4 and is also used for the control of ABS and TCS.

Description

Rolling bearing unit with load measuring device {ROLLING BEARING UNIT WITH LOAD MEASURING UNIT}

The rolling bearing unit having a load measuring unit according to the present invention, for example, supports the axle of a vehicle (car) so as to be rotatable with respect to a suspension device, and at the same time measures the magnitude of the load to be used for securing stable running of the vehicle. do. In addition, such a rolling bearing unit having a load measuring unit according to the present invention is installed in a rolling bearing unit that supports the main shafts of various machine tools, and measures the load applied to the main shafts to appropriately adjust the feed speed of the tool and the like. To be used.

For example, in order to rotatably support the wheel of a vehicle with respect to the suspension, a rolling bearing unit is used. In addition, in order to secure the running stability of the vehicle, a driving state stabilization device of a vehicle such as an anti lock brake system (ABS) or a traction control system (TCS) is widely used. According to these running state stabilization devices, such as ABS and TCS, it is possible to stabilize the running state of a vehicle at the time of braking or acceleration. However, in order to secure this stability under more stringent conditions, a lot of information affecting the running stability of the vehicle must be taken in and the brake and the engine must be controlled.

That is, in the case of the conventional driving condition stabilization device such as ABS or TCS, so-called feedback control is performed to detect the slip between the tire and the road surface to control the brake or the engine. There is a temporary delay. In other words, to improve performance under strict conditions, so-called feedforward control ensures that slippage does not occur between the tire and the road surface, or that the brake actuation of the left and right wheels is extremely different. One-sided activation cannot be prevented. Further, in a truck or the like, it is not possible to prevent the running stability from being poor as the loading state is poor.

In order to cope with such a problem, in order to perform the feedforward control or the like, one or both of the radial load and the axial load applied to the wheel are measured on the rolling bearing unit for supporting the wheel with respect to the suspension device. Load measuring device can be built in. As a wheel bearing rolling bearing unit having a load measuring device that can be used in this case, Japanese Patent Application Laid-Open No. JP-A-2001-21577 (hereinafter referred to as Patent Document 1) and Japanese Laid-Open Patent Publication JP-A-3 -209016 (hereinafter referred to as Patent Document 2), JP-A-2004-3918 (hereinafter referred to as Patent Document 3), JP-B-62-3365 (hereinafter referred to as Patent Document 4) is known.

Among these, Patent Document 1 describes a rolling bearing unit having a load measuring device capable of measuring a radial load. In the case of the first example of the conventional structure, a non-rotational displacement sensor measures the displacement in the radial direction between the outer ring that does not rotate and the hub that rotates on the inner diameter side of the outer ring, thereby applying between these outer rings and the hub. Losing radial loads are detected. The detected radial load is used not only to control the ABS appropriately but also to inform the driver of the poor loading condition.

In addition, Patent Literature 2 describes a structure for measuring an axial load applied to a rolling bearing unit. In the case of the 2nd example of the conventional structure of this patent document 2, the screw hole which screws the bolt for engaging this fixed side flange to a knuckle in the several inner side surfaces of the fixed side flange formed in the outer peripheral surface of the outer ring. The load sensor is provided in each of the surrounding portions. These load sensors are placed between the outer surface of the knuckle and the inner surface of the fixed side flange while the outer ring is fixed to the knuckle. In the case of the load measuring device of the rolling bearing unit of the second example of the conventional structure as described above, the axial load applied between the wheel and the knuckle is measured by the respective load sensors.

In addition, Patent Document 3 provides a displacement sensor attached to four circumferential positions of the outer ring and an L-shaped to-be-detected ring fitted to the hub and fixed at the four positions to provide the hub with respect to the outer ring. The structure which detects the displacement of a radial direction and thrust direction, and detects the direction of the load applied to this hub, and its magnitude | variety according to the detected value of each part is described.

Further, in Patent Document 4, a strain gauge for detecting dynamic deformation is provided in the outer ring equivalent member which lowered some rigidity, and the revolution speed of the rolling element is determined from the passing frequency of the rolling element detected by the strain gauge. The method of obtaining the revolution speed and measuring the axial load applied to the rolling bearing from this idle speed is described.

In the case of the 1st example of the prior art structure of patent document 1 mentioned above, the load applied to a rolling bearing unit is measured by measuring the radial displacement of an outer ring and a hub by a displacement sensor. However, since the radial displacement amount is not large, it is necessary to use a high precision sensor as the displacement sensor in order to accurately measure this load. Since the high precision non-contact sensor is expensive, the cost of the entire rolling bearing unit with the load measuring device is inevitable.

Moreover, in the case of the 2nd example of the conventional structure of patent document 2, it is necessary to provide the load sensor of the same number as the bolt which fixes an outer ring with respect to a knuckle. For this reason, not only the load sensor itself is expensive, but also the cost as a whole of the rolling bearing unit with a load measuring device is inevitably high. Moreover, since the structure of patent document 3 installs a sensor in four circumferential positions of an outer ring, cost becomes higher than the structure of patent document 1 above. Moreover, since the rigidity of a part of outer ring equivalent member must be low in the method of patent document 4, securing of durability of this outer ring equivalent member may become difficult.

Moreover, in the structure or method as described in any one of patent documents l-4, the exclusive mechanism is provided in order to measure the load applied to a rolling bearing unit. For this reason, an increase in cost and weight cannot be avoided.

As a technique related to the present invention, in Japanese Patent Application Laid-Open No. JP-A-2004-77159 (hereinafter referred to as Patent Document 5), this encoder is obtained by using an encoder in which N poles and S poles are alternately arranged on the surface to be detected. A structure for detecting run-out of an inner ring supporting a is described. However, Patent Document 5 does not describe a technique for detecting a load applied to the rolling bearing unit using the encoder, even if a technique suggesting such a technique is considered together.

Problems to be Solved by the Invention

An object of the present invention is to provide a rolling bearing unit having a load measuring device that can be compact and lightweight, and can measure the load applied to the rolling bearing unit.

According to the first aspect of the present invention, a rolling bearing unit having a load measuring device includes a rolling bearing unit and a load measuring device.

The rolling bearing unit includes a stationary side raceway wheel that does not rotate in the state of use, a rotating side raceway wheel that rotates in the state of use, and a stationary side existing on the circumferential surface of the stationary raceway raceway and the rotating side raceway wheel. It is provided with the some cloud element formed between the track | orbit and a rotational track | orbit.

The load measuring device further includes an encoder in which a part of the rotating raceway wheel is concentrically supported with the rotating raceway wheel, and the characteristics of the surface to be detected are alternately changed along the circumferential direction, and the detection unit detects the detected raceway. Supported by an unrotated portion (for example, the stationary raceway wheel or a part of the suspension or housing supporting and fixing the stationary raceway wheel) in a state facing the surface, in response to the characteristic change of the surface to be detected. And a sensor for changing the output signal, and a calculator for calculating the load applied between the stationary track wheel and the rotary track wheel in accordance with the output signal.

In addition, the pitch or phase in which the characteristic of the surface to be detected varies along the circumferential direction is continuously changed in correspondence with the operating direction of the load to be detected.

The calculator has a function of calculating the load according to a pattern in which the output signal of the sensor changes.

The rolling bearing unit with the load measuring device of the present invention configured as described above acts as follows, and the load acting between the stationary track wheel and the rotary track wheel is obtained. First, when a load acts between these race tracks, both race tracks are displaced relative to the stationary side, the rotating side raceways, and the elastic deformation of each rolling element. As a result, the positional relationship of the detection surface of the encoder supported by the rotating track wheel and the detection part of the sensor supported by a part of said stationary track wheel or suspension device changes.

The pitch or phase in which the characteristic of the detected surface of the encoder changes with respect to the circumferential direction changes continuously along the direction of action of the detected load. Therefore, when the two raceway wheels are relatively displaced in accordance with this load, the pattern (cycle or magnitude or phase of change) of the output signal of the sensor changes with the rotation of the rotational raceway wheel. Since there is a correlation between the degree of change of this pattern and the magnitude of the load, the magnitude of this load is obtained according to this pattern.

The combination of the encoder and the sensor is also necessary in order to control ABS or TCS or to detect the rotational speed of the rotary raceway wheel (when such a combination is performed in relation to the wheel bearing rolling bearing unit). In addition, even when such a combination is performed with respect to the machine tool, it is necessary to detect the rotational speed of the spindle. The rolling bearing unit having the load measuring device of the present invention can be configured such that the load can be detected by devising a structure necessary for detecting such a rotational speed, and it is not necessary to install a new part in the rolling bearing unit part. For this reason, the structure used for measuring the load applied to this rolling bearing unit can be comprised with a small size and light weight.

According to the second aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the load to be detected is a radial load acting in the radial direction between the stationary raceway wheel and the rotating side raceway wheel, The surface to be detected includes an axial side of the encoder, and on the surface to be detected, the first and second portions to be detected having different characteristics are alternately and evenly arranged in the circumferential direction, and these two skins Among the widths in the circumferential direction of the detection unit, the width of the first detected part is wider toward the radially outer side, and the width of the second detected part is wider toward the radially inner side.

According to the third aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the load to be detected is a radial load acting in the radial direction between the stationary raceway wheel and the rotating side raceway wheel, The surface to be detected includes an axial side surface of the encoder, on which the first and second detected portions having different characteristics are alternately and evenly aligned in the circumferential direction, and the first to The boundary between the detection unit and the second detected unit is inclined with respect to the radial direction of the encoder, and the inclined direction with respect to the radial direction of the boundary is opposite to each other with respect to the radial middle portion of the encoder. The detection part of 1 pair of sensors provided in the position spaced apart in the radial direction of this encoder across an intermediate part opposes the to-be-detected surface of this encoder.

According to the fourth aspect of the present invention, in the rolling bearing unit having the load measuring device according to the second or third aspect, the encoder is made of a permanent magnet, and one of the first to be detected portion and the second to be detected portion is N It is a pole and the other part to be detected is an S pole.

According to the fifth aspect of the present invention, in the rolling bearing unit having the load measuring device according to the second or third aspect, one of the first to be detected portion and the second to be detected portion is a through hole or a concave hole, and the other The to-be-detected part of is an interim portion located between the through-holes or recessed holes which adjoin the circumferential direction.

According to the sixth aspect of the present invention, in the rolling bearing unit having the load measuring device according to the second or third aspect, one of the first to be detected portion and the second to be detected portion is a convex portion, and the other to be detected portion is Is a recess located between the convex parts adjacent in the circumferential direction.

According to the seventh aspect of the present invention, in the rolling bearing unit having the load measuring device of the fifth or sixth aspect, the encoder is made of a magnetic material, and the sensor corresponds to a change in the magnetic characteristics of the detected surface of the encoder. In order to change the output signal, non-changing portions are provided at both ends of the encoder in the radial direction so that the pitch with respect to the rotational direction of the first detected portion or the second detected portion does not change with respect to the radial direction.

According to the eighth aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the load to be detected is a radial load acting in the radial direction between the stationary raceway wheel and the rotating side raceway wheel, A plurality of combinations to be detected includes a pair of unique portions having a axial side surface of the encoder and each having a characteristic different from that of the other portion, wherein the surfaces to be detected are equally spaced in the circumferential direction. The intervals in the circumferential direction between the pair of unique parts constituting each of the detection portions to be detected are continuously changed in the same direction in the radial direction in the entire detection portions.

According to the ninth aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the load to be detected is an axial load acting in the axial direction between the stationary track wheel and the rotary track wheel, The surface to be detected includes the circumferential surface of the encoder, and on the surface to be detected, the first and second to-be-detected portions having different characteristics are alternately and equidistantly arranged in the circumferential direction. Among the widths in the circumferential direction of the detection unit, the width of the first detected part is wide toward one end in the axial direction, and the width of the second detected part is wide toward the other end in the axial direction.

According to the tenth aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the load to be detected is an axial load acting in the axial direction between the stationary raceway wheel and the rotating side raceway wheel, The to-be-detected surface includes the peripheral surface of the encoder, on which the first to-be-detected portion and the second to-be-detected portion having different characteristics are alternately arranged at equal intervals with respect to the circumferential direction, and the first to The boundary between the detection unit and the second detected unit is inclined with respect to the axial direction of the encoder, and the inclination direction with respect to the axial direction of the boundary is opposite to each other at the boundary of the axial middle portion of the encoder. The detection part of a pair of sensors provided in the position spaced apart in the axial direction of this encoder across an intermediate part opposes the to-be-detected surface of this encoder.

According to the eleventh aspect of the present invention, in the rolling bearing unit having the load measuring device of the ninth or tenth aspect, the encoder is made of a permanent magnet, the first to be detected is an N pole, and the second to be detected is an S pole. to be.

According to a twelfth aspect of the present invention, in the rolling bearing unit having the load measuring device of the ninth or tenth aspect, the first detected portion is a through hole or a concave hole, and the second detected portion is a through hole adjacent to the circumferential direction. It is the middle part between the hole or the concave hole.

According to a thirteenth aspect of the present invention, in the rolling bearing unit having the load measuring device of the ninth or tenth aspect, the first to-be-detected part is a convex part, and the second to-be-detected part is located between the convex parts adjacent in the circumferential direction. It is a recess that exists.

According to a fourteenth aspect of the present invention, in the rolling bearing unit having the load measuring device of the twelfth or thirteenth aspect, the encoder is made of a magnetic material, and the sensor corresponds to a change in the magnetic properties of the detected surface of the encoder. To change the output signal, and at both ends in the axial direction of the encoder, a non-changing portion is provided in which the pitch with respect to the rotational direction of the first detected portion or the second detected portion does not change with respect to the axial direction.

According to a fifteenth aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the load to be detected is an axial load acting in the axial direction between the stationary track wheel and the rotary track wheel, A plurality of combinations for detection include a circumferential surface of the encoder and a pair of unique portions each having different characteristics from the other portions, aligned with the detected surface at equal intervals in the circumferential direction. The space | interval regarding the circumferential direction of a pair of unique part which comprises each of these to-be-detected combination parts changes continuously in the same direction of an axial direction in the whole to-be-detected combination part.

According to the sixteenth aspect of the present invention, in the rolling bearing unit having the load measuring devices of the first to fifteenth aspects, the detection portions of the sensors are respectively opposed to three or more different positions in the circumferential direction among the detected surfaces of the encoder. The calculator has a function of calculating the moment load applied between the stationary track wheel and the rotary track wheel by comparing the output signals of these sensors.

According to a seventeenth aspect of the present invention, in the rolling bearing unit having the load measuring device of the sixteenth aspect, the detected surface of the encoder includes the circumferential surface of the encoder, and the detection portion of each sensor is the circumference of the circumferential surface of the encoder The directions are opposed to the equally spaced positions.

According to an eighteenth aspect of the present invention, in the rolling bearing unit having the load measuring device of the sixteenth aspect, the detected surface of the encoder includes the axial side of the encoder, and the detection portion of each sensor is the axial side of the encoder. Oppose the circumferential equidistant positions of.

According to a nineteenth aspect of the present invention, in the rolling bearing unit having the load measuring device of the first to eighteenth aspects, the rolling bearing unit is a rolling bearing unit for wheel support, and in use, the stationary track wheel is suspended. Is fixed to the wheel, and the rotating raceway wheel supports the wheel to rotate together with the wheel.

According to a twentieth aspect of the present invention, in the rolling bearing unit having the load measuring device of the first to eighteenth aspects, the rolling bearing unit rotatably supports the main axis of the machine tool to the housing, and in the use state, the stationary side The outer ring, which is the raceway ring, is internally fitted and fixed to this housing or a portion fixed to the housing, and the inner ring, which is the rotating side raceway ring, is fixed to the outer raceway to the main shaft or a portion that rotates with the main shaft.

According to the twenty-first aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the rolling bearing unit is a rolling bearing unit for wheel support, and in use, an outer ring, which is a stop raceway wheel, is supported by the suspension device. A fixed and fixed hub supporting the wheel and rotating together with the wheel, each of which is located on the inner circumferential surface of the outer ring and is located on the outer circumferential surface of the hub, each of which is a stationary track, A plurality of rolling elements are provided for each row between the double-row inner raceways, which are the rotational raceways, and a flange for supporting the wheels is provided at the axial outer end of the hub, and concave on the outer circumferential surface, which is the surface to be detected. An encoder in which parts and convex parts are alternately aligned is fixed to an axial inner end of the hub or to an intermediate portion of the inner ring raceway of the double row, and the load to be detected is Concave formed on the surface to be detected of the encoder, which is an axial load acting in the axial direction between the outer ring and the hub and opposes the detection portion of the sensor in the radial direction at an upper portion of the surface to be detected that exists on the outer circumferential surface of the encoder. The width | variety with respect to the circumferential direction of the recessed part in a part and a convex part is wide in the axial direction inner end side, and narrow in the axial direction outer end side.

According to the twenty-second aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the rolling bearing unit is a rolling bearing unit for wheel support, and in use, the outer ring, which is a stop side raceway wheel, is supported by the suspension device. A fixed, hub, which is a rotating raceway wheel, supports and secures the wheel and rotates with the wheel, and is located on the inner circumferential surface of the outer ring, each of which is located on the outer circumferential surface of the hub and a double-row outer raceway, each of which is a stationary raceway; A plurality of rolling elements are provided for each row between the double-row inner raceways, which are the rotational raceways, and a flange for supporting the wheels is provided at the axial outer end of the hub, and concave on the outer circumferential surface, which is the surface to be detected. An encoder in which parts and convex parts are alternately aligned is fixed to an axial inner end of the hub or to an intermediate portion of the inner ring raceway of the double row, and the load to be detected is It is an axial load acting axially between the outer ring and the hub, and the detection part of the sensor is opposed to the lower part of the detected surface existing on the outer circumferential surface of the encoder in the radial direction, and is formed on the detected surface of the encoder. The width | variety with respect to the circumferential direction of the recessed part in a recessed part and a convex part is wide at the outer side of an axial direction, and narrow at the inner side of an axial direction.

According to a twenty-third aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the rolling bearing unit is a rolling bearing unit for wheel support, and in use, an outer ring, which is a stop raceway wheel, is supported by the suspension device. A fixed, hub which is a rotating raceway wheel supports and secures the wheel and rotates with the wheel, and is located on the inner circumferential surface of the outer ring, each of which is located on an outer circumferential raceway of a double row, which is a stationary raceway, and an outer circumferential surface of the hub, A plurality of rolling elements are provided in each row between the double-row inner raceways, each of which is a rotational track, and a flange for supporting the wheels is provided at the axial outer end of the hub, and the inner surface in the axial direction is a detected surface. An encoder in which concave portions and convex portions are alternately aligned on the side surface is fixed to the axially inner end of the hub, and a load to be detected is axial between the outer ring and the hub. An axial load acting in the direction of the axial load, and the detection part of the sensor is opposed to the upper part of the detected surface existing on the inner surface of the encoder in the axial direction, and the concave portion and the convex portion formed on the detected surface of the encoder are axially opposed. The width | variety with respect to the circumferential direction of the recessed part in the inside is wide at a radial outer end side, and narrow at a radial inner end side.

According to a twenty-fourth aspect of the present invention, in the rolling bearing unit having the load measuring device of the first aspect, the rolling bearing unit is a rolling bearing unit for wheel support, and in use, the outer ring, which is a stop raceway wheel, is supported by the suspension device. A fixed and fixed hub supporting the wheel and rotating together with the wheel, each of which is located on the inner circumferential surface of the outer ring and is located on the outer circumferential surface of the hub, each of which is a stationary track, A plurality of rolling elements are provided in each row between the double-row inner raceways, which are the rotational raceways, and a flange for supporting the wheels is provided at the axial outer end of the hub, and the inner surface in the axial direction, which is the detected surface. An encoder in which concave portions and convex portions are alternately aligned on the side surface is fixed to the axially inner end of the hub, and the load to be detected is axially between the outer ring and the hub. It is an axial load which acts as a axial load, and the lower part of the to-be-detected surface which exists in the axial-inner side of the said encoder opposes a detection part of a sensor in the axial direction, The width | variety with respect to the circumferential direction of a recessed part is wide at a radial inner end side, and is narrow at a radial outer end side.

1 is a cross-sectional view showing Embodiment 1 of the present invention.

FIG. 2 is a view of the encoder main body, seen from the right side of FIG. 1; FIG.

FIG. 3 is a view similar to FIG. 2 showing a scanning portion of the detected surface of the encoder scanned by the detection portion of the sensor; FIG.

4 is a diagram showing an output signal of a sensor that changes with a change in radial load, respectively.

5 is a diagram showing a first example of the relationship between the radial displacement of the outer ring and the hub and the radial load;

6 is a perspective view and a front view of a second example of an encoder provided in Embodiment 2 of the present invention.

7 is a cross-sectional view showing Embodiment 3 of the present invention.

8 is a perspective view of principal parts each showing a third example of an encoder provided in Embodiment 4 of the present invention;

Fig. 9 is a view of the detected surface of the encoder as viewed from the axial direction, showing the scanning portion of the detected surface of the encoder scanned by the detection portion of the sensor;

10 is a diagram showing a sensor output signal that changes with a change in radial load, respectively.

Fig. 11 is a sectional view showing Embodiment 5 of the present invention.

12 is a perspective view illustrating a raw material and an assembled state of the encoders respectively provided in the fifth embodiment;

Fig. 13 is a diagram showing an output signal of a sensor that changes with the variation of the axial load, respectively.

14 is a sectional view showing a sixth embodiment of the present invention;

Fig. 15 is a perspective view each showing a raw material and an assembled state of an encoder provided in Embodiment 7 of the present invention.

Fig. 16 is a sectional view showing Embodiment 8 of the present invention.

17 is a partial perspective view of an encoder provided in Embodiment 8;

Fig. 18 is a diagram showing an output signal of a sensor that changes with the variation of the axial load, respectively.

Fig. 19 is a sectional view showing Embodiment 9 of the present invention.

20 is a perspective view of an encoder provided in Embodiment 9;

Fig. 21 is a diagram showing an output signal of a sensor that changes with the variation of the axial load, respectively.

Fig. 22 is a sectional view showing Embodiment 10 of the present invention.

23 is a front view of the encoder provided in the tenth embodiment;

Fig. 24 is a partial sectional view showing Embodiment 11 of the present invention.

25 is a sectional view showing a twelfth embodiment of the present invention;

Fig. 26 is a schematic cross sectional view showing a state of being fitted between a suspension device and a wheel;

27 is a diagram for explaining a variation of an output signal of a sensor in response to a displacement;

Fig. 28 is a sectional view showing Embodiment 13 of the present invention.

Fig. 29 is a sectional view showing Embodiment 14 of the present invention.

Fig. 30 is a sectional view showing Embodiment 15 of the present invention.

Fig. 31 is a sectional view showing Embodiment 16 of the present invention.

32 is a sectional view showing a seventeenth embodiment of the present invention;

33 is a perspective view of an encoder provided in a seventeenth embodiment;

34 is an exploded view of an encoder provided in the seventeenth embodiment;

35 is a diagram showing an output signal of a sensor that changes with the variation of the axial load, respectively.

Fig. 36 is a sectional view showing Embodiment 18 of the present invention.

37 is a perspective view of an encoder provided in the eighteenth embodiment;

38 is an exploded view of an encoder provided in an eighteenth embodiment;

39 is a diagram showing an output signal of a sensor that changes with the variation of the axial load, respectively.

* Description of the symbols for the main parts of the drawings *

1, 1a: rolling bearing unit for wheel support

2: load measuring device

3, 3a: paddle

4, 4a, 4b: hub

5, 5a: cloud element

6, 6a: paddle track

7: Fitted Mount

8: hub body

9: inner ring

10: flange

11, lla: inner ring track

12, 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j, 12k, 12A, 12B: encoder

13, 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, 13i, 13A, 13B, 13C: sensor

14, 14a, 14b, 14c: support plate

15, 15a: encoder body

16: wheel

17: cylindrical part

18, 18a: cover

19: bottom plate

20, 20a: fitting mounting hole

21, 21a, 21b: through hole

22, 22a, 22b: interim portion

23: wheel

24: combination part for detection

25: Unique part

26: cylindrical part

27, 27a: convex

28, 28a: concave

29a, 29b: parallel part

30a, 30b: parallel part

31a, 31b: non-changing part

32a, 32b: non-changing part

33a, 33b: through hole

34a, 34b: column

35: Limbu

Best Mode for Carrying Out the Invention

In the case of practicing the present invention, for example, as described in the second or third aspect, the load to be detected is a radial load acting in the radial direction between the stationary track wheel and the rotating track wheel. do.

In this case, the surface to be detected is the axial side of the encoder, and the first and second portions to be detected having different characteristics are arranged alternately and at equal intervals in the circumferential direction. .

In the case of the invention described in the second aspect, among the widths in the circumferential direction of the two detected portions, the width of the first detected portion is made wider toward the radially outer side, and the width of the second detected portion is made radially inner. Wide towards.

In the case of adopting such a configuration, if the central axis of the rotating raceway wheel is eccentric with respect to the central axis of the stationary raceway wheel in response to the change in the radial load, the radial direction of the portion of the sensor facing the detection part of the detected surface is opposed. The position changes. Therefore, when the radial position of the part of the sensor facing the detection part changes in the detected surface according to the change in the radial load, the circumference of one of the first and second detected parts opposite to the detection part is detected. Direction length becomes long, and the circumferential length of the other to-be-detected part becomes short. In addition, the period in which the output signal of the sensor changes or the magnitude of the change varies depending on the circumferential lengths of the first and second to-be-detected portions facing each other. Therefore, when the ratio of the period or magnitude of the change corresponding to the first detected part and the period or magnitude of the change corresponding to the second detected part is determined during the change of the output signal of the sensor, the centers of the two track wheels are determined. The extent to which the axis is eccentric in the radial direction, and furthermore, the magnitude of the radial load acting between the two raceway rings is obtained.

In the case of the invention described in the third aspect, the boundary between the first and second detected parts is inclined with respect to the radial direction of the encoder, and the inclination direction with respect to the radial direction of the boundary is determined. The radial middle portions of the encoders are reversed from each other at the boundary. Moreover, the detection part of 1 pair of sensors provided in the position spaced apart in the radial direction of this encoder is inserted so that this detection part of this encoder may be opposed.

In the case of adopting such a configuration, if the central axis of the rotating raceway wheel is eccentric with respect to the central axis of the stationary track wheel, the detection unit of the pair of sensors faces the detected surface. The radial position of the part to be changed. Therefore, when the radial position of the portion of the detected surfaces opposing to the detection portions of the two sensors changes according to the radial load change, the phase of the detection signal of one sensor advances and the detection of the other sensor is performed. The phase of the signal is slow. Therefore, when the phase shift of the output signals of the two sensors is found, the degree to which the central axes of the two race tracks are eccentric in the radial direction, and further, the magnitude of the radial load acting between the race tracks is determined.

In the case of carrying out the invention described in the second or third aspect as described above, for example, as described in the fourth aspect, the encoder is made of a permanent magnet. Therefore, one to-be-detected part of a 1st detected part and a 2nd to-be-detected part is made into N pole, and the other to-be-detected part is made into S pole. Therefore, the permanent magnet is magnetized in the axial direction and the magnetization direction is alternately changed in the circumferential direction. In this case, one of the N poles and the S poles is made into a fan shape (or trapezoid) whose width is increased in the circumferential direction toward the radially outer side of the encoder, and the other pole is the radius of the encoder. It is set as an inverse sector shape (or an inverted trapezoidal shape) which becomes wide with respect to the circumferential direction toward a direction inner side.

In addition, the sensor combined with such a permanent magnet encoder is an active magnetic sensor provided with magnetic detection elements, such as a hall element and a magnetoresistance element.

When a permanent magnet encoder and an active sensor are combined, the period (for example, the time at which the output signal is shifted in a predetermined direction with respect to the reference potential) of the reference signal (for example, 0 V) of the output signal of the sensor is As the width of the sector or inverted sector becomes wider, it becomes longer. Similarly, the variation (magnitude of change) with respect to the reference voltage becomes larger as the width of the sector becomes larger.

In addition, when implementing the invention described in the second or third aspect as described above, for example, as described in the fifth or sixth aspect, the first to-be-detected portion and the second to-be-detected portion formed on the detected surface of the encoder are described. It is also preferable to use one to-be-detected part as a through hole, a concave hole, or a convex part in a to-be-detected part, and to make the other to be the inter-part or concave part which exists between the through hole or concave hole adjacent to a circumferential direction. As described in the fourth aspect, it is also effective to use the encoder as a permanent magnet. In the case of detecting the load with higher accuracy, it is preferable to use an encoder having the structure described in the fifth or sixth aspect.

This reason is as follows. First, in order to obtain the permanent magnet encoder described in the fourth aspect, the specific area of the surface to be detected of the encoder is magnetized. In this case, the shapes of the N poles and the S poles present on the surface to be detected are made into a fan shape or an inverse fan shape, and in order to strictly regulate the magnetization area, a high magnetization technique is required. For this reason, the manufacturing cost of an encoder made of a permanent magnet is increased. In contrast, the structure described in the fifth or sixth aspects can be manufactured by simply molding the encoder by machining, press molding, or injection molding (including die casting), which ensures shape accuracy and dimensional accuracy. It is easy. Thus, the manufacturing cost of the encoder can be made relatively low. Therefore, when cost reduction is considered, the structure described in the fifth or sixth aspect is superior to the structure described in the fourth aspect.

In this case, the material constituting the encoder is selected by the type of sensor. For example, when this sensor is an active magnetic sensor provided with a permanent magnet and magnetic detection elements, such as a hall element or a magnetoresistance element, the said encoder is made from magnetic metals, such as a steel plate. Even in such a structure, as in the case of using the above-mentioned permanent magnet encoder, the output signal of the sensor changes according to the change in the radial position of the portion where the detection portion of the sensor opposes in the detected surface of the encoder. do.

In contrast, when the sensor is optical and the one to be detected part is a through hole, the encoder may be formed of a material that blocks light. In this case, the period in which the output signal of the sensor changes in accordance with the change in the radial position of the portion of the encoder to which the detection portion of the sensor opposes changes (the magnitude of the change does not change).

In the case of carrying out the invention described in the fifth or sixth aspect as described above, preferably, as described in the seventh aspect, the encoder is made of a magnetic material, and the sensor is formed on the magnetic surface of the detected surface of the encoder. The output signal is changed in response to the change in characteristics. Further, at both ends of the encoder in the radial direction, a non-changing portion is provided in which the pitch with respect to the rotational direction of the first or second detected portion does not change with respect to the radial direction.

This configuration stabilizes the flow of magnetic flux between these detection sections and the detected surface, while the detection section of the sensor faces the widthwise end (outer diameter side end or inner diameter side end) of the detected surface of the encoder. The output signal of the sensor can be stabilized.

In the case of carrying out the present invention, for example, as described in the eighth aspect, the load to be detected is a radial load acting in the radial direction between the stationary side raceway wheel and the rotational side raceway wheel.

In this case, the surface to be detected is the axial side of the encoder, and in the circumferential direction, a plurality of combinations to be detected are composed of a pair of unique parts each having different characteristics from other portions. Place at equal intervals over.

The space | interval regarding the circumferential direction between a pair of unique part which comprises each of these to-be-detected combination parts changes continuously in the same direction with respect to a radial direction in all the to-be-detected combination parts.

In this configuration, the output signal of the sensor having the detection unit facing the detected surface of the encoder changes at the instant of opposing each of the unique parts, but the changing interval (period) changes so that the detection unit of the sensor opposes. It changes with the change in the radial position of the part.

Further, in the case of practicing the present invention, as described in the ninth or tenth aspect, the axial direction in which the load to be detected acts in the axial direction between the stationary track wheel and the rotary track wheel It is a load.

In this case, the to-be-detected surface is made into the circumferential surface of an encoder, and the to-be-detected surface and the to-be-detected part which have a different characteristic are arrange | positioned alternately and at equal intervals with respect to the circumferential direction.

In the case of the invention described in the ninth aspect, the width of the first to-be-detected part is wide toward the one end in the axial direction, and the width of the second to-be-detected part is toward the other end in the axial direction, among the widths in the circumferential direction of the two detected parts. Widen.

In such a configuration, when the relative positions of the stationary raceway wheel and the rotational raceway wheel are shifted in the axial direction according to the variation of the axial load, the axial position of the portion of the detection surface that faces the detection unit of the detected surface. Changes.

Therefore, the magnitude | size of the axial load acting between the said track wheels is calculated | required similarly to the case where the radial load as described in the 2nd aspect mentioned above is calculated | required.

In the case of the invention described in the tenth aspect, the boundary between the first and second detected parts is inclined with respect to the axial direction of the encoder, and the inclination direction with respect to the axial direction of the boundary is determined. The intermediate portions in the axial direction are opposite to each other at the boundary. In addition, a pair of sensors provided at a position in which the axial intermediate portion is isolated in the axial direction of the encoder is opposed to the detected surface of the encoder.

In the case of adopting such a configuration, when the rotational raceway wheel is displaced in the axial direction with respect to the stationary raceway wheel in response to the variation in the axial load, the portion of the pair of detection parts facing each other in the detected surface is opposed. The axial position of changes. Therefore, when the axial position of the portion of the detected surfaces opposing to the detection portions of the two sensors changes according to the change in the axial load, the phase of the detection signal of one sensor advances and the detection of the other sensor is performed. The phase of the signal is slow. Therefore, when the phase shift of the output signals of the two sensors is found, the magnitude of the axial load acting between the two raceway wheels and, moreover, between the two raceway wheels is determined.

Also in the case of carrying out the invention described in the ninth or tenth aspect described above, as described in the eleventh aspect, for example, the encoder is a permanent magnet, the first to-be-detected portion is the N pole, and the second is the second. Let the detected part be the S pole.

Alternatively, as described in the twelfth or thirteenth aspect, one of the first to be detected portion and the second to be detected portion is a through hole or a concave hole or a convex portion, and the other to be detected portion is penetrated adjacent to the circumferential direction. It is also preferable to set it as the intermediate part or recessed part which exists between a hole or a recessed hole. The reason for this is as described in the structural part described in the fifth or sixth aspect described above, and a high-precision encoder can be manufactured at low cost as compared to the permanent magnet encoder described in the eleventh aspect. It is because the structure which can detect a load precisely can be manufactured at low cost.

In the case of carrying out the invention described in the twelfth or thirteenth aspect as described above, preferably, as described in the fourteenth aspect, the encoder is made of a magnetic material, and the sensor is formed on the detected surface of the encoder. The output signal is changed in response to the change in the magnetic characteristics. At both ends of the encoder in the axial direction, unchanged portions are provided in which the pitches of the first and second detected parts are not changed in the axial direction.

In such a configuration, in the state where the detection portion of the sensor faces the widthwise end portion (both axial ends) of the detected surface of the encoder, the flow of magnetic flux between these detection portions and the detected surface is stabilized, and the sensor Can stabilize the output signal.

In the case of carrying out the present invention, for example, as described in the fifteenth aspect, the load to be detected is an axial load acting in the axial direction between the stationary track wheel and the rotary track wheel. .

In this case, the detection surface is the peripheral surface of the encoder, and the detection surface includes a plurality of combinations to be detected, each of which is composed of a pair of unique parts having different characteristics from the other portions, over the circumferential direction. Place at equal intervals.

The space | interval regarding the circumferential direction between 1 pair of unique parts which comprise each said to-be-detected combination part changes continuously in the same direction with respect to an axial direction in the whole to-be-detected combination part.

In such a configuration, although the output signal of the sensor having the detection unit opposed to the detected surface of the encoder changes at the instant of opposing the respective unique parts, the changing interval (period) is determined by the detection unit of the sensor. It changes with the change of the axial position of the opposing part.

Moreover, when implementing this invention, Preferably, as described in 16th aspect, the to-be-detected part of a sensor opposes three or more positions which differ in the circumferential direction among the to-be-detected surface of an encoder. In addition, the calculator has a function of calculating the moment load applied between the stationary track wheel and the rotary track wheel by comparing the output signals of these sensors.

In this case, for example, as described in the seventeenth aspect, the detected surface of the encoder is the circumferential surface of the encoder, and the detection section of each sensor is opposed to the circumferential equal intervals of the circumferential surface of the encoder.

Alternatively, as described in the eighteenth aspect, the detection surface of the encoder is used as the axial side of the encoder, so that the detection portions of each sensor are opposed to the circumferential equal interval positions of the axial side of the encoder.

If such a configuration is adopted, the moment loads applied between the two orbital wheels are also determined, not only among the radial load component and the axial load component, among the loads applied between the stationary track wheel and the rotary track wheel. Become.

Further, in order to implement the present invention, as described in, for example, the nineteenth aspect, the rolling bearing unit is used as the wheel bearing rolling bearing unit. The wheels are fixed to the track wheels, and the rotary side track wheels are rotated together with the wheels.

In such an embodiment, the magnitude of the load applied to the wheel can be measured, and the control for improving the stable running of the vehicle can be improved.

In another embodiment, as described in the twentieth aspect, the rolling bearing unit is used to rotatably support the main shaft of the machine tool to the housing. In this case, in use, the outer ring, which is the stationary raceway wheel, is internally fitted and fixed to this housing or a portion fixed to the housing, and the inner ring, which is the rotational raceway ring, is rotated together with the main axis or the main axis. Secure the outside fitting on the

In this aspect, it is installed in the rolling bearing unit supporting the main shaft of various machine tools, the load applied to the main shaft is measured, and the feed speed of the tool is appropriately adjusted to improve the quality of the workpiece and the processing efficiency. Can secure both.

Moreover, when implementing this invention, for example, as described in the twenty-first to twenty-fourth aspects, the rolling bearing unit is a rolling support rolling bearing unit, and in use, suspends an outer ring which is a stop raceway wheel. It is assumed that the hub, which is a rotating side raceway wheel, supports and secures the wheel and rotates with the wheel. In addition, a plurality of rolling elements are formed in each row between the outer ring raceway, each of which is a stationary side track, and the inner ring raceway of the double row, each of which is a rotational raceway, existing on the inner circumferential surface of the outer ring. At the same time, a flange is formed to support the wheel at the axial outer end of the hub.

In the case of the invention described in the twenty-first aspect or the twenty-second aspect, an encoder in which recesses and convex portions are alternately arranged on an outer circumferential surface, which is a surface to be detected, includes an axial inner end portion of the hub or an intermediate portion of the inner ring raceway of the double row. And the load to be detected is an axial load acting axially between the outer ring and the hub.

In the case of the invention described in the twenty-first aspect, the detection unit of the sensor is opposed to the upper part of the detected surface existing on the outer circumferential surface of the encoder in the radial direction. Moreover, the width | variety with respect to the circumferential direction of the recessed part in the unevenness | corrugation formed in the to-be-detected surface of the said encoder is made wide at the inner end side of an axial direction, and narrow at the outer end side.

In the case of the invention described in the twenty-second aspect, in the concave portion and the convex portion formed on the detected surface of the encoder, the detection portion of the sensor is opposed to the lower portion of the detected surface existing on the outer circumferential surface of the encoder. The width of the concave portion is widened at the axial outer end side and narrowed at the axial inner end side.

On the other hand, in the case of the invention described in the twenty-third aspect or the twenty-fourth aspect, an encoder in which concave portions and convex portions are alternately arranged on the axially inner side surface, which is the surface to be detected, is fixed to the axially inner end of the hub and should be detected. The load is an axial load acting between the outer ring and the hub.

In the case of the invention described in the twenty-third aspect, the detection unit of the sensor is opposed in the axial direction to the upper part of the detected surface existing on the axially inner side of the encoder. Moreover, the width | variety with respect to the circumferential direction of the recessed part formed in the to-be-detected surface of the said encoder and the convex part is made wide at the radial outer end side, and narrows at the radial inner end side.

In the case of the invention described in the twenty-fourth aspect, the detection unit of the sensor is opposed to the lower part of the surface to be detected that exists on the inner side of the encoder in the axial direction. Moreover, the width | variety with respect to the circumferential direction of the recessed part formed in the to-be-detected surface of the said encoder and the convex part is made wide at the radial inner end side, and narrows at the radial outer end side.

With this arrangement, the variation in the detection signal of the sensor caused by the variation in the load acting between the stationary raceway wheel and the rotating raceway wheel can be increased, and the measurement accuracy of the load can be improved.

On the other hand, the recessed part mentioned in the invention which concerns on 21st-24th aspect mentioned above includes the through-hole formed by punching a metal plate. In this case, the convex portions refer to intermediate portions of the through holes adjacent in the circumferential direction.

Embodiment 1

1-5 show Embodiment 1 of this invention corresponding to Claims 1, 2, 4, and 19. FIG. The rolling bearing unit with a load measuring device of the present embodiment includes a rolling bearing unit 1 for a wheel support and a load measuring device 2 provided with a function as a rotational speed detecting device.

Among these, the wheel support rolling bearing unit 1 is provided with the outer ring 3, the hub 4, and some rolling elements 5 and 5, as shown in FIG. Among these, the outer ring 3 is a stationary raceway wheel supported and fixed to the suspension device in use, and has the same shape as the outward flange that engages the outer ring tracks 6 and 6 of the double row on the inner circumferential surface and the suspension on the outer circumferential surface. Each has a fitting mounting portion 7. The hub 4 is a rotating side raceway wheel that supports and secures the wheel in use and rotates with the wheel, and is formed by combining the hub body 8 and the inner ring 9 in combination. In such a hub 4, a flange 10, which is used to support the wheels, is provided at the axial outer end of the outer circumferential surface (an end that becomes the widthwise outer side of the vehicle body when fitted to the suspension), Inner ring raceways 11, 11 are provided on the intermediate portion of the axial hub and on the outer circumferential surface of the inner ring 9, respectively. Each of the rolling elements 5 and 5 is provided so as to be freely clouded between the respective inner ring raceways 11 and 11 and the outer ring raceways 6 and 6, respectively, freely and on the inner diameter side of the outer ring 3. The hub 4 is supported by the outer ring 3 so as to rotate freely concentrically. In the example of the city, the ball is used as the cloud element. In the case of a rolling bearing unit for wheel support of a heavy vehicle, tapered rollers may be used as the rolling elements. The shifting of the structure using the ball as the rolling element can increase the amount of displacement between the outer ring and the hub as compared with the structure using the tapered roller as the rolling element. However, even in the case of the structure using the tapered roller as the rolling element, the displacement is small but the displacement is generated. Thus, the unit using tapered rollers can also be the subject of the present invention.

As shown in FIG. 1, the load measuring device 2 includes an encoder 12, a sensor 13, and a calculator (not shown).

Among these, the encoder 12 consists of the support plate 14 and the encoder main body 15. As shown in FIG. Among them, the support plate 14 is formed by bending the magnetic metal plate such as a mild steel plate, thereby continuing the circular wheel portion 16 and the cylindrical portion 17 through the inclined portion. The said support plate 14 is made into substantially J shape in cross section, and makes the whole annular. The encoder main body 15 is made of permanent magnets such as rubber magnets, plastic magnets, and the like as a whole. The encoder main body 15 is fixed to the axially inner side surface of the cylindrical portion 16 concentrically with the cylindrical portion 17.

The permanent magnets constituting the encoder main body 15 are magnetized in the axial direction, and their magnetization directions are alternately and evenly spaced in the circumferential direction. Therefore, the N pole and the S pole are alternately arranged at equal intervals on the axially inner side surface of the encoder main body 15 which is the surface to be detected. In the case of this embodiment, the part to be magnetized by these N poles and the part magnetized by the S pole are the 1st detected part and 2nd detected part which have a different characteristic which exist in the to-be-detected surface of the said encoder 12. Corresponds to. The width of the magnetized portion of the N pole and the width of the portion magnetized to the N pole and the portion magnetized to the S pole are widened toward the outer side in the radial direction. Widen radially inward.

The encoder 12 configured as described above is fitted with a cylindrical portion 17 of the support plate 14 by a shrink fit to an axially inner end of the inner ring 9. Thus, the encoder 12 made in this way is fastened concentrically with the hub 4 in the axial inner ring portion of the hub 4. In this state, the axially inner side surface of the encoder main body 15 is located on an imaginary plane orthogonal to the central axis of the hub 4.

The sensor 13 is supported and fixed to the axially inner end of the outer ring 3 via a cover 18. The cover 18 is formed in a cylindrical shape with a bottom by injection molding a synthetic resin or by drawing into a metal plate. The cover 18 is fitted and fixed to the inner end of the outer ring 3 in a state of blocking the inner end opening of the outer ring 3. The mounting hole 20 is located in the vicinity of the outer diameter side and opposes the surface to be detected of the encoder 12 and constitutes the bottom plate portion 19 constituting such a cover 18. It is formed in the state penetrating to a direction.

The sensor 13 is supported and fixed to the bottom plate portion l9 in a state where the fitting hole 20 is inserted through the axially inward direction outward. Therefore, the detection part provided in the uppermost end surface (left end surface of FIG. 1) of the said sensor 13 is closely opposed to the to-be-detected surface of the said encoder 12 through the measurement interval of about 0.5-2 mm. Moreover, as an active magnetic sensor, magnetic detection elements, such as a Hall element and a magnetoresistance element, are formed in the detection part of the said sensor 13. As shown in FIG. The characteristic of such a magnetic detection element changes in the state which opposes the N pole, and the state which opposes the S pole. Therefore, when the encoder 12 rotates together with the hub 4, the characteristics of the magnetic detection element change, and the output signal of the sensor 13 changes.

In this way, the period (frequency) at which the output signal of the sensor 13 changes is changed corresponding to the rotational speed of the hub 4. Specifically, the faster the rotational speed is, the shorter the period during which the output signal changes, and the higher the changing frequency. For this reason, when this output signal is sent to the controller (not shown) provided in the vehicle body side etc., the rotational speed of the wheel which rotates with the encoder 12 can be calculated | required, and ABS or TCS can be controlled. This point is the same as the conventionally known technique.

In particular, in the case of this embodiment, the pattern by which the said output signal changes according to the magnitude | size of the radial load which acts between the said hub 4 and the said outer ring 3 changes. Therefore, the radial load can be obtained by observing this pattern. This point will be described with reference to FIGS. 3 to 5.

First, the premise that the radial load is obtained will be described. As described in Patent Document 1, the relative position with respect to the radial direction of the outer ring 3 and the hub 4 is determined by the radial load applied between the outer ring 3 and the hub 4. Varies with size The reason is that, according to this radial load, the respective outer ring raceways 6 and 6 and the respective inner rings in which the rolling surfaces of the respective rolling elements 5 and 5 and the rolling surfaces of the respective rolling elements 5 and 5 are in rolling contact with each other. This is because the elastic deformation amounts of the tracks 11 and 11 change. In the prior art described in Patent Document 1, the radial load between the outer ring and the hub is determined by directly measuring a displacement about the radial direction between the outer ring and the hub by a displacement sensor. In contrast, in the present embodiment, the magnitude of the radial load applied between the outer ring 3 and the hub 4 is determined according to the relative displacement of the encoder 12 and the sensor 13. Doing. This point is demonstrated below.

When a standard radial load (standard value) is applied between the outer ring 3 and the hub 4, the detection portion of the sensor 13 is radially centered on the surface to be detected of the encoder 12. Assume that you are facing. In this case, the detection part of the said sensor 13 is shown by the dashed-dotted line (alpha) in FIG. 3, and scans the center part of the to-be-detected surface. In this radial center part, since the width | variety with respect to the circumferential direction of the part magnetized by the said N pole and the width | variety with respect to the circumferential direction of the part magnetized by the S pole are mutually the same, the output signal of the said sensor 13 is FIG. As shown in (A) of FIG. 2, the oscillation is performed at the same amplitude on both sides about a reference voltage (for example, 0 V). That is, the period T _{H at} which the voltage of the output signal becomes higher than this reference voltage And cycle lowered T _L Are equal to each other (T _H = T _L ). Further, the difference ΔV _H between the maximum value of the voltage of the output signal and the reference voltage And the difference ΔV _L between the minimum value of the voltage of the output signal and the reference voltage are also equal to each other (ΔV _H = ΔV _L ).

In contrast, when the radial load applied between the outer ring 3 and the hub 4 is larger than the standard value, the position of the outer ring 3 with respect to the hub 4 is shifted downward. Therefore, the detection part of the said sensor 13 opposes the part located close to the radial inside inside of the to-be-detected surface of the encoder 12. In this case, the detection part of the said sensor 13 is shown by the dashed-dotted line (beta) in FIG. 3, and scans the part located in the radial direction inner side of the to-be-detected surface. In this radially biased portion, the width of the circumferential direction of the portion magnetized by the N pole is smaller than the width of the circumferential direction of the portion magnetized by the S pole, so that the output signal of the sensor 13 is shown in FIG. 4. As shown in (B), it vibrates to the low position side centering on a reference voltage (for example, 0V). That is, the period T _{L at} which the voltage of the output signal becomes lower than this reference voltage becomes larger (T _H <T _L ) than the period T _{H at} which it becomes high. Further, the difference ΔV _L between the minimum value of the voltage of the output signal and the reference voltage The, difference △ V _H of the maximum value and the reference voltage of the output signal voltage Greater than (△ V _L > ΔV _H ).

Contrary to the case described above, when the radial load applied between the outer ring 3 and the hub 4 is smaller than the standard value, the position of the outer ring 3 with respect to the hub 4 is shifted upward. Therefore, the detection part of the said sensor 13 opposes the part located close to the radially outer side of the to-be-detected surface of the encoder 12. As shown in FIG. In this case, the detection part of the said sensor 13 is shown by the dashed-dotted line (gamma) in FIG. 3, and scans the part located near the radially outer side of the to-be-detected surface. In the portion located close to the radially outer side, the width of the circumferential direction of the portion magnetized by the N pole is wider than the width of the circumferential direction of the portion magnetized by the S pole, so that the output of the sensor 13 As shown in Fig. 4C, the signal vibrates largely toward the high position centering on the reference voltage (for example, 0 V). That is, the period T _H at which the voltage of the output signal becomes higher than this reference voltage becomes larger than the period T _{L at} which the output T becomes low (T _H > T _L ). Further, the difference ΔV _H between the maximum value of the voltage of the output signal and the reference voltage is larger than the difference ΔV _L between the minimum value of the voltage of the output signal and the reference voltage (ΔV _H > ΔV _L ).

Therefore, when the pattern of the output signal of the sensor 13 is monitored, the degree of shift (radial displacement) between the central axis of the outer ring 3 and the central axis of the hub 4 can be obtained. Specifically, if the ratio "T _H / T _L " between the period T _{H at} which the voltage of this output signal becomes higher than the reference voltage and the period T _{L at} which it is lowered is observed, the central axis of the outer ring 3 and the hub ( (4) The degree to which the central axis of 4) is shifted (radial displacement) can be obtained. In addition, by observing the maximum value and the reference with the difference △ V _H and the voltage ratio "△ V _H / △ V _L" with the difference △ V _L of the minimum value and the reference voltage of the output signal voltage of the voltage of the output signal Also, the radial displacement amount can be obtained. Since the relationship between these ratios "T _H / T _L ", "ΔV _H / ΔV _L " and the radial displacement amount is almost linear with respect to any ratio, it is easily obtained. Thus, the obtained relationship is loaded into the software that is installed in a calculator (not shown, microcomputer) used to calculate the radial load.

Furthermore, the relationship between the radial displacement amount and the radial load is obtained by calculation or experiment. In the case of obtaining the relationship by calculation, the specifications of the rolling bearing unit 1 are used, that is, the radius of curvature of the cross sections of the respective outer ring raceways 6 and 6 and the respective inner ring raceways 11 and 11, the angle In addition to the number and diameter of the rolling elements 5, 5, based on the material of the outer ring 3 and the hub 4, it is obtained according to the theory well known in the art of rolling bearing units. In addition, in the case of obtaining the above relationship by experiment, the outer ring 3 and the hub 4 are applied while the radial loads of different sizes, which are already known, are applied between the outer ring 3 and the hub 4. Measure the relative displacement with respect to the radial direction. Either side, the relationship as shown in Fig. 5 is obtained with respect to the radial displacement amount and the magnitude of the radial load, and is incorporated in the software.

Since this embodiment is comprised as mentioned above, it is not necessary to incorporate new components, such as a displacement sensor, in the rolling bearing unit 1 part, and the said radial load can be calculated | required. That is, the combination of the encoder 12 and the sensor 13 should control ABS and TCS, and is also necessary to detect the rotational speed of the hub 4. The rolling bearing unit with a load measuring device of this embodiment is a structure which calculate | requires the said radial load by devising the structure required in order to detect such a rotation speed. Therefore, the structure used for measuring the radial load applied to the rolling bearing unit can be made compact and lightweight.

As can be seen from Fig. 4, in the present embodiment, the period T _{H at} which the voltage of the output signal of the sensor 13 is higher than the reference voltage and the period T _L at which the voltage is lower than the reference voltage change depending on the magnitude of the radial load. do. Therefore, in order to accurately determine the rotational speed of the hub 4 irrespective of the variation in the radial load, the rotational speed is calculated according to the sum "T _H + T _L " of both cycles. The sum "T _H + T _L " is equal to the radial displacement even when the portion magnetized to the N pole and the portion magnetized to the S pole are either fan-shaped or inverted-shape as shown in Figs. It remains almost constant regardless. Therefore, in this embodiment, the rotation speed is exactly obtained.

Embodiment 2

6A shows Embodiment 2 of the present invention corresponding to claims 1, 2, and 5. In the case of this embodiment, the through-holes 21 and 21 are formed at equal intervals along the circumferential direction in the radial direction middle part of the circular-shaped encoder 12a. In the case of this embodiment, each of these through-holes 21 and 21 becomes an inverse fan shape (or an inverted trapezoid) in which the width of the circumferential direction becomes narrow gradually toward the radially outward direction of the said encoder 12a. In addition, the intermediate portions 22, 22 between the through holes 21, 21 adjacent to the circumferential direction have a fan shape (or trapezoid) in which the width of the circumferential direction becomes wider toward the radially outward direction. Therefore, in the case of this embodiment, each said intermediate part 22, 22 turns into the 1st detected part of Claim 2, and each said through hole 21, 21 part becomes a 2nd detected part similarly. In contrast to the above case, as shown in FIG. 6B, the widths of the through holes 21a and 21a are gradually increased toward the radially outward direction, and the widths of the intermediate portions 22a and 22a are radially. It may become smaller toward the outer direction.

In any case, by combining with an appropriate sensor, as in the case of the first embodiment described above, the center axis of the stationary raceway wheel such as the outer ring supporting the sensor and the rotation of the hub or the like supporting the encoder 12a are fixed. The displacement amount with respect to the radial direction with respect to the central axis of the side race ring is obtained. Thus, the radial load acting between these stationary raceway wheels and the rotational raceway wheels is obtained. Here, the material which comprises the encoder 12a is selected according to the kind of sensor.

For example, when this sensor is an active magnetic sensor provided with a permanent magnet and magnetic detection elements, such as a hall element or a magnetoresistance element, the said encoder 12a is made from magnetic metals, such as a steel plate. The sensor is made as in the case of a passive magnetic sensor comprising a permanent magnet, a pole piece, and a coil, and an encoder 12a is similarly manufactured. Even in such a structure, the output signal of this sensor changes with the change of the radial position of the part which the detection part of the said sensor faces among the to-be-detected surface of this encoder 12a like the case of the said Embodiment 1. In the case of using a magnetic sensor, instead of a through hole, a concave or convex portion of a fan shape or an inverted shape may be formed on the detected surface of the encoder. In the case of encoders made of permanent magnets in which the N pole and the S pole are arranged on the surface to be detected, the magnetic flux intensity becomes uneven, so that the detection accuracy of the load may deteriorate. In such a case, if an encoder having a through hole or a concave portion or a convex portion is formed in the magnetic metal does not cause such a problem, it is easy to secure the detection accuracy of the load.

In contrast, when the sensor is optical, the structures of one of the first and second detected portions formed on the surface to be detected of the encoder 12a are limited to through holes. In this case, the material which comprises this encoder 12a should just be a material which covers light. In the case of using an optical sensor, the period in which the output signal of the sensor changes in accordance with the change in the radial position of the portion of the encoder 12a that the detection portion of the sensor opposes changes (changes The size does not change).

Since the structure and operation | movement of parts other than the encoder 12a are the same as that of Embodiment 1 mentioned above, illustration and description regarding an equivalent part are abbreviate | omitted.

Embodiment 3

7 shows Embodiment 3 of the present invention corresponding to claims 1, 2, and 19. FIG. In the case of this embodiment, the encoder 12b is externally fitted and fixed between the rolling elements 5 and 5 arrange | positioned in multiple rows at the axial middle part of the hub 4a. This encoder 12b is provided with the support plate 14a which formed the annular shape whole in the cross-section L shape. Therefore, the encoder main body 15 made of a permanent magnet as shown in Figs. 2 and 3 described above is attached to one side of the circular wheel portion 23 of the support plate 14a, or the above-described circular wheel portion 23 is attached. Through holes 21, 21a or recesses as shown in FIG. As a result, this circular-wheel part 23 itself has a function as an encoder.

The sensor 13a combined with such an encoder 12b is formed in the fitting mounting hole 20a formed in the middle part of the outer ring raceway 6, 6 of a double row at the axial middle part of the outer ring 3, and this outer ring 3 ) Is inserted inward from the radially outer side. And the detection part formed in the side surface of the uppermost end part of the said sensor 13a is attached to the to-be-detected surface of the encoder main body 15 which attached to the axial side surface of the said circular-wheel part 23, or this side surface of this circular-wheel part 23 itself. Place it close.

The displacement between the center axis of the hub 4a and the center axis of the outer ring 3 is obtained according to the pattern of the output signal of the sensor 13a, and from this displacement between the hub 4a and the outer ring 3 About the point which calculates the radial load acting on, it is the same as that of Embodiment 1 or Embodiment 2 mentioned above. Therefore, redundant description is omitted.

Embodiment 4

8-10 has shown 4th Embodiment of this invention corresponding to Claims 1 and 8. FIG. In the case of this embodiment, the several to-be-detected combination part 24, 24 is arrange | positioned at equal intervals along the circumference direction in the axial direction side surface of the encoder 12c which is a to-be-detected surface. Each of these to-be-detected combination parts 24 and 24 is comprised by the pair of unique part 25 and 25 different from each other in the characteristic. As each of these unique parts 25 and 25, the slit-shaped long hole as shown to FIG. 8A, similarly to the recessed hole as shown to FIG. 8B, similarly to FIG. Convex portions on bank-like as shown are employable. Regardless of which hole is used for each of the unique portions 25 and 25, the intervals in the circumferential direction of the pair of unique portions 25 and 25 constituting each of the detected portions 24 and 24 are In the combined parts 24 and 24 to be detected, they are continuously changed in the same direction along the radial direction. In the example of illustration, the space | interval regarding the circumferential direction between the pair of unique parts 25 and 25 which comprise each detection part 24 and 24 for each detected direction is radially outward of the said encoder 12c. The space | interval regarding the circumferential direction between the digitization parts 25 and 25 which comprise each to-be-detected combination part 24 and 24 adjacent to each other in a circumferential direction becomes small toward the radially outer side of the said encoder 12c. It is inclined in the direction.

As shown in FIG. 10, the output signal of the sensor which opposes the detection part to the to-be-detected surface of the encoder 12c as mentioned above changes at the instant which opposes each said unique part 25,25. Thus, the changing interval (period) changes in accordance with the change in the radial position of the portion where the detection portion of the sensor opposes.

For example, when a standard radial load (standard value) is applied between a stationary raceway wheel such as an outer ring and a rotational raceway wheel such as a hub, the detection unit of the sensor is indicated by dashed lines α in FIGS. 9 and 10. The center portion of the surface to be detected is scanned. In this case, the output signal of the sensor changes as shown in Fig. 10B.

On the other hand, if the radial load applied between the stationary track wheel and the rotary track wheel is larger than the standard value, the detection unit of the sensor is represented by a dashed line β in Figs. 9 and 10, for example, Scan the part located close to the radially inner side. In this case, the output signal of the sensor changes as shown in Fig. 10A.

Further, when the radial load applied between the stationary track wheel and the rotary track wheel is smaller than the standard value, the detection unit of the sensor is shown, for example, by dashed lines γ in FIGS. 9 and 10, and the detected object is detected. Scan the part located close to the radially outer side of the face. In this case, the output signal of the sensor changes as shown in Fig. 10C.

Therefore, also in the present embodiment, when looking at the pattern (interval of change) of the output signal of the sensor, the degree of displacement (radial displacement amount) between the central axis of the stationary raceway wheel and the central axis of the rotational raceway wheel ), And from the degree of this displacement, it is possible to measure the radial load applied between these two orbital wheels.

Embodiment 5

11-13 has shown Embodiment 5 of this invention corresponding to Claims 1, 9, 11, and 19. FIG. In the case of this embodiment, the encoder 12d is externally fitted and fixed to the intermediate | middle part of the rolling elements 5 and 5 arrange | positioned in multiple rows at the axial middle part of the hub 4a. This encoder 12d is comprised as shown to FIG. 12 (B) by making a strip | belt-shaped material round, as shown to FIG. 12 (A). The cylindrical encoder main body 15b is attached and fixed to the outer peripheral surface of the cylindrical support plate 14b over the perimeter.

The encoder main body 15b is made of permanent magnets such as rubber magnets and plastic magnets, and is magnetized in the radial direction. The magnetization directions are alternately alternated at equal intervals in the entire circumferential direction. Accordingly, the N poles and the S poles are alternately arranged at equal intervals on the outer circumferential surface of the encoder main body 15b which is the surface to be detected. Among these, the width | variety with respect to the circumferential direction of the part magnetized by the N pole which is a 1st to-be-detected part is wide at the one end of the axial direction of the said encoder main body 15b, and is narrow at the other end. On the other hand, the width | variety with respect to the circumferential direction of the part magnetized by the S pole which is a 2nd to-be-detected part is narrow at one end of the axial direction of the said encoder main body 15b, and is widened to the other end.

The sensor 13b used with such an encoder 12d is formed in the fitting mounting hole 20a formed in the middle portion of the outer ring raceways 6 and 6 of the double row at the axial middle portion of the outer ring 3, and the outer ring ( 3) is inserted inward from the radially outward direction. And the detection part formed in the upper end cross section of the said sensor 13b is located near the outer peripheral surface of the said encoder main body 15b.

In the present embodiment having the above-described configuration, the relative positions of the outer ring 3 and the hub 4a in the axial direction in accordance with the variation in the axial load applied between the outer ring 3 and the hub 4a. If it is displaced, the axial position of the part of the outer peripheral surface of the encoder main body 15b which the detection part of the sensor 13b opposes changes. As a result, similarly to the first embodiment described above, the pattern in which the output signal of the sensor 13b changes is changed as shown in FIG. The relationship between the pattern in which the output signal of the sensor 13b as shown in FIG. 13 changes and the magnitude of the axial load applied between the outer ring 3 and the hub 4a are also described in the first embodiment. It is obtained by calculation or experiment in the same manner as the relation between the radial load at and the change of the output signal pattern. Therefore, by observing the change of the pattern of this output signal, the magnitude | size of the said axial load can be calculated | required.

Embodiment 6

14 shows Embodiment 6 of the present invention corresponding to claims 1, 9, 11, and 19. In the case of this embodiment, the encoder 12e is externally fitted and fixed to the axial inner end part of the hub 4a. This encoder 12e is provided with the support plate 14c. And the permanent magnet encoder body which alternately arrange | positioned the N pole and S pole on the inner peripheral surface of the cylindrical part 26 of this support plate 14c in the state magnetized in the range of fan shape or trapezoid shape, respectively. Or by forming a fan-shaped or trapezoidal through hole in the cylindrical portion 26, the cylindrical portion 26 itself has a function as an encoder. And the detection part of the sensor 13c supported by the cover 18a fixed to the inner opening part of the outer ring 3 is located near the inner peripheral surface of the said encoder 12e which is a to-be-detected surface.

Also in this case of this embodiment, the magnitude of the axial load acting between the outer ring 3 and the hub 4a can be obtained by observing the change in the pattern of the output signal of the sensor 13c.

Embodiment 7

15 shows Embodiment 7 of the present invention corresponding to claims 1 and 15. This embodiment applies the structure of Embodiment 4 shown to FIGS. 8-10 mentioned above in order to calculate the magnitude | size of an axial load. That is, in the case of this embodiment, the several to-be-detected combination part 24, 24 is arrange | positioned at equal intervals in the circumferential direction on the outer peripheral surface (or inner peripheral surface) of the cylindrical encoder 12f which is a to-be-detected surface. Doing. Each of these to-be-detected combination parts 24 and 24 is comprised by the pair of unique part 25 and 25 different from each other in the characteristic. As each of these unique parts 25 and 25, the slit-shaped long hole is employ | adopted in this embodiment.

The encoder 12f having such unique portions 25 and 25 rounds a strip-shaped magnetic metal plate formed by punching the respective long holes in advance as shown in Fig. 15A. This is done by welding the edges of both ends of the circumferential direction together. As each of the said unique parts 25 and 25, the concave hole as shown in FIG. 8 (B) mentioned above, and similarly the bank-shaped convex part as shown in FIG. 8 (C) are employable. Also in the case of this embodiment, similarly to the case of the said Embodiment 4, the space | interval regarding the circumferential direction of the pair of unique part 25, 25 which comprises each said to-be-detected combination part 24 and 24 is And the combined portions 24 and 24 for detection are continuously changed in the same direction with respect to the axial direction. That is, the space | interval with respect to the circumferential direction of the pair of unique part 25, 25 which comprises each detection part 24 and 24 for each detected is axial one end of the said encoder 12f (lower-right in FIG. 15). ), And the distance between the circumferential directions of the unique portions 25, 25 constituting each of the detection portions 24, 24 adjacent to the circumferential direction is the other end in the axial direction of the encoder 12f. It is inclined in the direction which becomes small toward (the upper left of FIG. 15).

As shown in FIG. 10, the output signal of the sensor which faced the detection part to the outer peripheral surface (or inner peripheral surface) which is the detected surface of the encoder 12f mentioned above is the same as the case of Embodiment 4 mentioned above. It changes at the moment facing the unique part 25,25. And the changing interval (period) changes with the change of the axial position of the part which the detection part of the said sensor opposes. Therefore, also in the present embodiment, when looking at the pattern of the output signal of the sensor, the degree of axial displacement (axial displacement) of the stationary raceway wheel and the rotational raceway wheel is obtained, and from these degrees of displacement, these are obtained. The axial load applied between both track wheels can be obtained. The technique for obtaining the load from the pattern of the output signal of the sensor is the same as that of the fourth embodiment except that the load to be obtained is changed from the radial load to the axial load.

In this case, the structure corresponding to claim 12 is not shown. However, as the structure of the cylindrical encoder 12c shown in FIG. 8A is applied to the cylindrical encoder 12f shown in FIG. 15B, the cylindrical encoder 12a shown in FIG. Applying the structure to a cylindrical encoder results in a structure corresponding to the above claim 12.

Embodiment 8

16-18 show Embodiment 8 of this invention corresponding to Claims 1, 9, 13, and 19. FIG. This embodiment has shown about the case where this invention was implemented by the drive wheel support rolling bearing unit 1a. In addition, in consideration of being mounted on a heavy vehicle, tapered rollers are used as the rolling elements 5a and 5a. In the case of such a present embodiment, the encoder 12g as shown in FIG. 17 is externally mounted and fixed to the middle part of the inner ring raceway 11a, 11a of a double row in the axial middle part of the hub 4b. The encoder 12g is formed in a toroidal shape by a magnetic metal material, and the convex portions 27 and 27 serving as the first to be detected and the concave portions 28 and 28 serving as the second to be detected are circumferentially formed on the outer circumferential surface thereof. Alternately, they are formed at equal intervals.

In the present embodiment having the above-described configuration, the outer ring 3a having the double row outer ring raceways 6a and 6a formed on the inner circumferential surface thereof and the outer ring in accordance with the variation in the axial load applied between the hub 4b. When the relative position of 3a and hub 4b is displaced in the axial direction, of the part of the outer peripheral surface of the encoder 12g which the detection part of the sensor 13d supported by the axial middle part of this outer ring 3a opposes, The axial position changes. As a result, similarly to the fifth embodiment described above, the pattern (duty ratio) in which the output signal of the sensor 13d changes is changed as shown in FIG. Embodiment 5 also shows the relationship between the pattern in which the output signal of the sensor 13d as shown in FIG. 18 changes and the magnitude of the axial load applied between the outer ring 3a and the hub 4b. In the same manner as, it is obtained by calculation or experiment. Therefore, by observing the pattern of the change of this output signal, the magnitude | size of the said axial load can be calculated | required.

If the structure in which the frustum or inverted trapezoidal concave and convex portions are alternately arranged in the circumferential direction as in this embodiment is applied to an encoder in which the surface to be detected is formed on the axial side, the present embodiment is a cloud. It can also be used to measure the radial load on the bearing unit.

Embodiment 9

19-21 shows Embodiment 9 of this invention corresponding to Claims 1, 9, 13, 14, and 19. FIG. This embodiment is based on the structure of Embodiment 8 mentioned above, and the convex parts 27a and 27a and the concave part 28a which were formed in the outer peripheral surface of the encoder 12h which are externally fitted and fixed to the intermediate part of the hub 4b are shown. , By devising the shape of 28a, the output signal of the sensor 13d is stabilized. That is, in the case of this embodiment, the width dimension regarding the circumferential direction of the said encoder 12h is the encoder 12h in the axial direction both ends of each said convex part 27a, 27a and the recessed part 28a, 28a, respectively. Is a parallel portion (29a, 29b, 30a, 30b) which does not change with respect to the axial direction. Therefore, the pitch at which the characteristic of the outer circumferential surface, which is the surface to be detected of the encoder 12h, changes with respect to the circumferential direction, In the axial middle part of this outer peripheral surface, it fluctuates by an axial position, but it does not fluctuate regardless of an axial position in both axial directions.

In the case of this embodiment, the reason why the output signal of the said sensor 13d is stabilized by forming each said parallel part 29a, 29b, 30a, 30b is as follows. As described above, by using a magnetic material as an encoder and having an uneven portion formed on the surface to be detected, the pitch of the characteristic change of the surface to be detected can be made higher than that of the permanent magnet encoder. However, in the case of the structure of Embodiment 8 described above, the pitch of this characteristic change should be shortened, and if the gap between the concave portion and the convex portion is shortened, the detection portions of the sensor are both widthwise ends (both axial ends) of the detected surface of the encoder. In the state facing)), the flow of magnetic flux flowing between these detection portions and the surface to be detected becomes unstable, and the output of the sensor tends to be unstable. For example, in the encoder 12g shown in FIG. 17, when the pitch between the convex parts 27 and 27 and the concave parts 28 and 28 is shortened, the convex parts 27 and 27 of the frustum adjacent to the circumferential direction are made. ) Bases are close to each other. In particular, even when the encoder 12g and the sensor 13d are greatly displaced in the axial direction, the rotational speed of the hub 4b should be able to be detected, and the axial direction permitted between these encoders 12g and the sensor 13d is allowed. When the height dimension of the frustum shape is enlarged in order to secure the relative displacement amount with respect to, as described above, the tendency of the bottom edges of the convex portions 27 and 27 of the frustum adjacent to the circumferential direction to become prominent is remarkable.

On the other hand, in the case of this embodiment, as the said parallel parts 29a, 29b, 30a, and 30b are formed, the low sides of the convex parts 27a and 27a of the frustums adjacent in the circumferential direction are too close to each other. Can be prevented. And even when the detection part of the said sensor 13d opposes the part corresponding to the base of the said convex part 27a, 27a at the axial end of the outer peripheral surface of the encoder 12h, The output of the sensor 13d can be stabilized by stabilizing the flow of magnetic flux flowing between the detected surfaces of the encoder 12h. In addition, even if the amount of displacement in the axial direction between the hub 4b and the outer ring 3a is slightly increased, the rotation speed of the hub 4b is detected by the sensor 13d.

Although the shape of the both circumferential edges of the said parallel part 29a, 29b, 30a, 30b is a straight line, the shape of this part may not necessarily be a straight line. For example, the sensor 13d may be slightly inclined with respect to the axial direction depending on the sensitivity and the sensitivity accommodation range (spot diameter), or may have an arc shape with a large radius of curvature.

In addition, as long as the structure of the sensor 13d combined with the encoder 12h includes a permanent magnet, the type thereof is not particularly limited. That is, a coil is wound around a pole piece for guiding the flow of magnetic flux emitted from the permanent magnet, and even a so-called passive type can be used even if it is a so-called active type incorporating a magnetic detection element that changes characteristics according to the density of magnetic flux. Can be. However, as shown in FIG. 21, the said convex part 27a which exists in the outer peripheral surface of this encoder 12h in the state which the detection part of the said sensor 13d opposes the axial middle part of the said encoder 12h is shown. Since the ratio of the length dimension with respect to the rotation direction of 27a) and the said recessed part 28a, 28a should be detected, the smaller the spot diameter of the said sensor 13d is preferable at the point which calculates this ratio with high precision.

Since the structure and operation of the other parts are the same as those of the eighth embodiment described above, redundant descriptions are omitted.

Embodiment 10

22 and 23 show a tenth embodiment of the present invention corresponding to claims 1, 2, 5, 7, 19. In the present embodiment, by devising the shape of the encoder shown in FIG. 6 (A), the detection portion of the sensor 13e is positioned near the inner diameter or the portion located near the outer diameter of the detected surface of the encoder. Even when facing the part, the output of the sensor 13e is stabilized. That is, in the case of this embodiment, the non-change parts 31a and 31b in the inner diameter side and the outer diameter side both ends of the through-holes 21b and 21b and the intermediate part 22b and 22b which were formed in the encoder 12i made from the magnetic metal plate , 32a, 32b are formed. The circumferential opposite end edges of each of the non-change parts 31a, 31b, 32a, and 32b are respectively present in the radial direction of the encoder 12i. Therefore, in each of the non-change parts 31a, 31b, 32a, and 32b, the pitch of the characteristic change with respect to the rotational direction of the axially inner side of the encoder 12i, which is the surface to be detected, does not change with respect to the radial direction.

In the case of this embodiment, it is the same as that of Embodiment 2 shown in FIG. 6 mentioned above about measuring a radial load, and it is the point which stabilizes the flow of magnetic flux, and stabilizes the output of the sensor 13e. Since it is the same as that of Embodiment 9 mentioned above, overlapping description is abbreviate | omitted.

Embodiment 11

24 shows Embodiment 11 of the present invention corresponding to claims 1, 16. In the case of this embodiment, the detection parts of the sensors 13f, 13g, 13h are opposed to three positions of the circumferential equal intervals of the outer circumferential surface of the encoder 12j which is the detected surface. Thus, by each of these sensors 13f, 13g, 13h, the rotational speed of the hub 4a (e.g., see FIG. 11) and between this hub 4a and the outer ring 3 (e.g., FIG. 11) The axial load applied and the moment load applied between these hubs 4a and the outer ring 3 can be measured. The moment load calculated | required by this embodiment is a moment around the virtual axis orthogonal to the center axis of the said hub 4a and the outer ring 3.

In this case of this embodiment, not only the axial load applied between the hub 4a and the outer ring 3, but also the moment load applied between the hub 4a and the outer ring 3 can be measured. . That is, when a moment load is applied between these hub 4a and the outer ring 3, when the center axis of these hub 4a and the center axis of the outer ring 3 are shift | deviated, these hub 4a and outer ring 3 The displacement in the axial direction that occurs between the portions is different for each of the portions in which the detection portions of the sensors 13f, 13g, and 13h face each other. Therefore, the pattern (the magnitude relationship between the output signals of these sensors 13l, 13g, 13h) different from the output signals of these sensors 13f, 13g, 13h differs according to the direction of the moment load. Further, as the moment load becomes larger, the difference in the output signal of each sensor 13f, 13g, 13h becomes larger. Therefore, if the magnitude relationship between the output signal of each of these sensors 13f, 13g, 13h and the relationship between the direction and magnitude of the action of the moment load are calculated in advance by calculation or experiment, and input into the calculation formula of software to be installed in the calculator, In addition to the axial load applied between the hub 4a and the outer ring 3, the moment load applied between the hub 4a and the outer ring 3 can be measured.

For example, the axial load applied to each part is measured according to the output signals of the respective sensors 13f, 13g, 13h, and from the axial load of each of these parts and the diameter of the encoder 12j, Calculate the moment load. The axial load is calculated based on the average value of the output signals of the respective sensors 13f, 13g, 13h, or calculated by averaging the axial load calculated according to the output signals of the respective sensors 13f, 13g, 13h. do. The signals indicative of the axial load and the moment load and the rotational speed of the hub 4a thus obtained are sent to the controller of the ABS or the TCS, as in the case of the other embodiments, and used for the control for stabilizing the attitude of the vehicle. do.

Since the structure and operation of other parts are the same as, for example, Embodiment 5 shown in FIGS. 11 to 13 described above or Embodiment 8 shown in FIGS. 16 to 18 described above, overlapping descriptions are omitted.

Embodiment 12

25-27 shows Embodiment 12 of this invention corresponding to Claims 1, 19, and 21. FIG. This embodiment aims at improving the measurement accuracy of the axial load acting between the outer ring 3a and the hub 4b by devising the mounting positions of the encoder 12g and the sensor 13A. First, the reason why the structure which considered this point is needed is demonstrated.

As described above, as shown in Fig. 17, as the encoder, by forming the uneven portion on the surface to be detected made of magnetic material, the pitch of the characteristic change of the surface to be detected can be made highly accurate as compared to the encoder made of the permanent magnet. However, even when a magnetic encoder (12g) made of magnetic materials formed by alternately forming convex portions 27 and 27 and concave portions 28 and 28 on the surface to be detected, and a magnetic sensing sensor, The amount of change in the duty ratio (ratio of the high level period and the low level period of the output signal voltage) of the output signal of this sensor becomes small. Even in this case, even if the variation in the duty ratio is small, in order to accurately calculate the load according to the output signal of the sensor, noise components included in the output signal must be corrected (removed), and a low-pass filter, Data processing by filters such as notch filters and adaptive filters is required. Since data processing other than the adaptive filter in these data processing involves a response delay, it is unpreferable from the point of performing more accurately the running state stabilization control of a vehicle. In addition, the response filter has no response delay but increases in cost.

In consideration of these, it is desirable to avoid post-processing by a filter as much as possible to reduce the level of noise components included in the output signal, thereby causing a response delay or increasing the cost. In order to make the level of the noise component relatively small (large S / N ratio), the degree of change in the duty ratio of the output signal by the displacement based on the load to be detected may be increased. For this purpose, it is considered to increase the inclination angle with respect to the axial direction of the boundary part (step difference part) of each said convex part 27 and 27 and each said recessed part 28 and 28. When the inclination angle is increased, the amount of change in the duty ratio per unit displacement can be increased with respect to the axial displacement of the encoder 12g. However, when the inclination angle is increased, the number of the convex portions 27 and 27 and the concave portions 28 and 28, which can be alternately formed in the entire circumference of the encoder 12g, is small (in accordance with the characteristic change). The width of one pitch is increased), and the number of times (the number of pulses) of the output signal of the sensor 13A changes while the encoder 12g is rotated one time. As a result, since the load acting between the outer ring 3a and the hub 4b is disadvantageously obtained in real time, it cannot be used depending on the conditions.

In view of the above-described situation, the present embodiment does not increase the inclination angle with respect to the axial direction of the boundary portion, but rather the duty ratio of the output signal of the sensor 13A per unit displacement of the encoder 12g. The change is made large, and it is designed in the situation where the displacement of this encoder 12g, and also the said axial load must be measured with precision.

In view of the above-described situation, in the present embodiment, the encoder 12g in which the convex portions 27 and 27 and the concave portions 28 and 28 are alternately arranged on the outer circumferential surface as the detected surface. Is fitted to the axially inner end of the hub 4b, which is a rotating raceway wheel. Moreover, the sensor 13A supported by the part which does not rotate, such as the outer ring 3a and the knuckle which comprises the suspension apparatus, is arrange | positioned above the said encoder 12g, and the detection part of this sensor 13A is this encoder ( 12g) is opposed to the upper end of the outer circumferential surface in the radial direction. Moreover, among the said convex parts 27 and 27 and each said recessed part 28 and 28 formed in the outer peripheral surface of this encoder 12g, the width | variety with respect to the circumferential direction of each said recessed part 28 and 28 is axle. It is widening to the direction inner edge side (right side of FIG. 25), and narrowing to outer edge side (left side of FIG. 25) similarly. In the case of the present embodiment, by such a configuration, the change in the duty ratio of the output signal of the sensor 13A per unit displacement of the encoder 12g can be increased, and the displacement of this encoder 12g, and furthermore, Can accurately measure the axial load.

That is, as shown in FIG. 26, since a predetermined height (wheel radius) exists between the road surface and the wheel bearing rolling bearing unit 1a, the axial direction generated between the outer circumferential surface of the wheel (tire) of the vehicle and the road surface. The load acts on the wheel bearing rolling bearing unit 1a as a load including a moment load. Therefore, a relative displacement is generated between the hub 4b and the outer ring 3a by the load including the moment load. For example, when an axial load acts on the vehicle body inward direction (right direction in Fig. 25) on the road surface, the hub 4b as a whole is displaced in the vehicle body inward direction, and the hub 4b is driven by the moment load. Tends to swing in the counterclockwise direction in FIG. As a result, the said encoder 12g is displaced to the right direction of FIG. 25, and also to an upward direction. In this manner, the axial load is applied between the hub 4b and the outer ring 3a as a load including a moment load, so that the hub 4b and the outer ring 3a are relatively displaced. In this case, the direction of the relative displacement between the encoder 12g and the sensor 13A induced based on the moment load, and of the encoder 12g and the sensor 13A based on the axial load Matching the directions of the relative displacements is effective in terms of increasing the variation in the duty ratio of the output signal. This embodiment is invented from such a viewpoint.

As can be seen from the description of the eighth embodiment shown in FIG. 16 to FIG. 18 described above, the duty ratio of the output signal of the sensor 13A changes as the encoder 12g is displaced in the right direction. At the same time, the duty ratio also changes when the encoder 12g is displaced upward. Thus, the state which this duty ratio changes because the encoder 12g displaces upwards is demonstrated by FIG. 27 represents the relative displacement of the detection part of the said sensor 13A and the outer peripheral surface (detection surface) of the encoder 12g. However, the vertical axis in FIG. 27 may be the magnetic flux density. In either case, when shear drop or chamfer exists at the boundary between the convex portions 27 and 27 and the concave portions 28 and 28 present on the outer circumferential surface of the encoder 12g, or When the diameter (spot diameter) of the detection portion of the sensor 13A is large, the waveform of the output signal of the sensor 13A is not a perfect rectangular waveform but a waveform close to a sine wave.

If the waveform of this output signal is such a sinusoidal waveform, if the threshold value identifying the leading edge and the trailing edge of the output signal is constant, the encoder 12g is When displaced toward the sensor 13A side, the waveform shown in Fig. 27 is entirely offset. That is, by shortening the distance between the detected surface of these encoder 12g and the detection part of the sensor 13A, the voltage level of an output signal becomes high as a whole. In this state, as can be seen from the intersection of the upper curve of FIG. 27 and the threshold value level, the proportion of the portions recognized as the convex portions 27 and 27 that occupy one period of the output signal increases. Thus, the duty ratio is changed. That is, even if it is not displaced in the axial direction (horizontal direction), the duty ratio of the output signal of the sensor 13A changes.

As can be seen from the above description, as shown in Fig. 25, when the sensor 13A is disposed above the encoder 12g, the encoder 12g is displaced upwards, and the When the distance (gap) of the outer peripheral surface and the detection part of the sensor 13A becomes small, the ratio of the part recognized as the said convex parts 27 and 27 corresponding to one period of the output signal of this sensor 13A increases. Therefore, the displacement of the encoder 12g based on the axial load toward the axially inner side (right side in FIG. 25), which acts as a load including the moment load, is such that the ratio of the convex portions 27 and 27 is different. If this encoder 12g is mounted in the direction to become large, these encoders 12g based on the direction of the relative displacement of the said encoder 12g based on the said moment load, and the said sensor 13A, and the said axial load. ) And the relative displacement of the sensor 13A can be matched to increase the duty ratio of the output signal. The case where the axial load acts on the vehicle body outward direction (left direction in FIG. 25) on the road surface is also the same except that the directions are reversed in the above description.

Embodiment 13

28 shows Embodiment 13 of the present invention corresponding to claims 1, 19, and 22. In the case of this embodiment, the sensor 13A is arrange | positioned under the encoder 12g, and the detection part of this sensor 13A opposes the lower end part of the outer peripheral surface of this encoder 12g which is a to-be-detected surface. And about the circumferential direction of the convex parts 27 and 27 formed in the outer peripheral surface of this encoder 12g, and the recessed parts 28 and 28 in each recessed part 28 and 28 (refer FIG. 17, FIG. 27). The width is made wider at the axial outer end side and narrower at the inner end side. That is, in the case of this embodiment, while the installation position of the said sensor 13A is reversed up and down with the above-mentioned Embodiment 12, the arrangement | positioning of each said recessed part 28 and 28 is reversed inside and outside this Embodiment 12. do.

Also in this case of this embodiment, the relative displacement of the encoder 12g and the sensor 13A based on the moment load, and the relative displacement of these encoder 12g and the sensor 13A based on the axial load. By varying the directions of, the variation in the duty ratio of the output signal of this sensor 13A can be increased. As in the present embodiment, when the sensor 13A is provided below the encoder 12g, the direction of the transverse displacement due to the axial load and the transverse displacement due to the moment load coincides with each other. It is preferable at the point of ensuring measurement accuracy. However, when the sensor 13A is provided below the encoder 12g, the sensor 13A is likely to be damaged by foreign matter such as a stone in which a wheel springs up. Therefore, in consideration of the strength and the like of the sensor 13A, the installation position and the installation direction of each component 13A and 12g are determined.

Embodiment 14

29 shows Embodiment 14 of the present invention corresponding to claims 1, 19, and 23. In the case of this embodiment, the encoder 12A which alternately arrange | positioned the recessed part and the convex part in the axial direction inner side surface which is a to-be-detected surface is being fixed to the axial inner end part of the hub 4b which is a rotation side track wheel. The detection part of the sensor 13B opposes the axial direction in the upper part of the to-be-detected surface which exists in the axial direction inner surface of this encoder 12A. Moreover, the width | variety with respect to the circumferential direction of the recessed part in the unevenness | corrugation formed in the to-be-detected surface of the said encoder 12A is made wide at the radially outer end side, and is narrowing at the inner end side similarly.

In order to measure the axial load applied to the wheel bearing rolling bearing unit 1a from the wheel, as shown in Figs. 25 to 28, the detection surface existing on the circumferential surface of the cylindrical encoder 12g is used. It is preferable to face the sensor 13A in the radial direction and to detect a change in the duty ratio of the output signal of the sensor 13A in accordance with the axial load. However, the encoder 12g and the sensor 13A cannot be provided due to restrictions on the installation space, and as shown in FIG. 29, the sensor 13B may be opposed to the encoder 12A in the axial direction. . As described above, the axial load applied to the wheel bearing rolling bearing unit 1a at the contact portion between the outer circumferential surface of the wheel and the road surface is a load including a moment load, which is the wheel bearing rolling bearing unit 1a. ) Therefore, as mentioned above, even if it is a structure which opposes the sensor 13B with respect to the encoder 12A in the axial direction, the said axial load can be calculated | required.

In such a structure, when the axial load from the road surface, for example, from the road surface toward the axially inward direction (right side in Fig. 29), the encoder 12A is based on the axial load. Displaced to the right direction, the distance between the surface to be detected of this encoder 12A and the detection portion of the sensor 13B becomes small. At the same time, this encoder 12A is displaced upward by the moment load. Therefore, the duty ratio changes due to the direction (trend) in which the duty ratio of the output signal of the sensor 13B changes due to the upward displacement based on the moment load, and the decrease in the distance based on the axial load. If the directions are the same, the duty ratio as a whole can be increased.

  As described above, if the distance is made small, the proportion of the portion recognized as the convex portion occupying one period of the output signal increases. Therefore, if the unevenness formed in the inner surface of the encoder 12A is set so that the ratio of the portion recognized as the convex portion is increased by the displacement of the encoder 12A upward, the (including the moment load) The change in the duty ratio of the output signal of the sensor 13B can be increased in accordance with the change in the axial load. As in the present embodiment, the sensor 13B is provided above the encoder 12A, and the width of the width of the recessed portion in the concave-convex portion in the uneven surface formed on the detected surface of the encoder 12A is radial. If wider at the outer end side and narrower at the inner end side, the encoder 12A based on the moment load and the encoder 12A based on the axial load and the encoder 12A based on the axial load By changing the direction of the relative displacement of the sensor 13B with each other, the change in the duty ratio of the output signal can be increased.

Embodiment 15

30 shows Embodiment 15 of the present invention corresponding to claims 1, 19, and 24. In the case of this embodiment, the detection part of the sensor 13B opposes the axial direction in the lower part of the to-be-detected surface which exists in the axial direction inner side surface of the encoder 12A. In addition, the width | variety with respect to the circumferential direction of the recessed part in the unevenness | corrugation formed in the to-be-detected surface of the said encoder 12A is made wide at the inner end side in radial direction, and is narrowing at the outer end side similarly. That is, in this embodiment, the installation position of the said sensor 13B is reversed up and down with Embodiment 14 mentioned above, and the arrangement | positioning of each said recessed part is made inverted inside and outside with respect to this Embodiment 14 and a radial direction. .

Also in this case of this embodiment, the direction of the relative displacement of the encoder 12A and the sensor 13B based on the moment load, and the relative displacement of these encoders 12A and the sensor 13B based on the axial load. By varying the directions of, the variation in the duty ratio of the output signal of this sensor 13B can be increased.

Embodiment 16

31 shows Embodiment 16 of the present invention corresponding to claims 1, 9, 13, and 19. FIG. As in the structure of this embodiment, when the sensor 13d is provided between the rolling elements 5a and 5a arranged in a double row at the axial middle part of the outer ring 3a, the detected surface of the encoder 12g is provided. The effect by regulating the direction of the concave portion and the convex portion existing in the is not as remarkable as in the case where the encoder 12g is provided in the axial inner end portion. In this case, in order to make the duty ratio of the output signal of the sensor 13d even a little larger, it is preferable to restrict the direction. The regulatory direction in this case is as follows.

First, when the sensor is disposed upward with respect to the cylindrical encoder 12g having the outer circumferential surface as the detected surface, and the detection unit of the sensor is radially opposed to the outer circumferential surface of the encoder 12g, the encoder 12g. The width | variety with respect to the circumferential direction of the recessed part among the recessed part and convex part which exist in the outer peripheral surface of the () is made large toward the axial direction inner side (right side of FIG. 31). On the contrary, when the sensor is disposed downward with respect to the cylindrical encoder 12g and the detection unit of the sensor is radially opposed to the outer circumferential surface of the encoder 12g, the concave existing on the outer circumferential surface of the encoder 12g is used. The width | variety with respect to the circumferential direction of the recessed part of a part and a convex part becomes large toward an axial outer side (left side of FIG. 31). If comprised in this way, similarly to Embodiment 12 or Embodiment 13 mentioned above, these encoder 12g and sensor based on the axial load, and the direction of the relative displacement of the said encoder 12g and the sensor based on the moment load, By changing the relative displacement directions, the variation in the duty ratio of the output signal of this sensor can be increased.

Here, in the case where the sensor is installed at the axial outer end of the wheel bearing rolling bearing unit, the structure in which the installation position and the inclination direction of each part are reversed is the direction of relative displacement between the encoder and the sensor based on the moment load. And the relative displacement direction of these encoders based on the axial load and the sensor are matched, so that the change in the duty ratio of the output signal of the sensor is increased. However, since there is little possibility of installing in the axial outer end of the wheel bearing rolling bearing unit due to the space constraint, it is not very meaningful.

On the contrary, the sensor is often provided between the rolling elements arranged in a row in the axial middle part of the wheel bearing rolling bearing unit. In this case, when a load in which the axial load and the moment load are mixed is applied from the wheel to the hub of the rolling bearing unit for supporting the wheel, the encoder 12g is displaced laterally by the axial load. Moreover, the hub 4b tends to rotate by the moment load. However, this center of rotation is between the rolling elements 5a and 5a arranged in a double row, which are the installation positions of the encoder 12g, so that the vertical position of the encoder 12g is changed by the moment load. There is very little to do.

In this case, since the encoder 12g is somewhat displaced in the vertical direction by the influence of the vertical load change, when the encoder 12g is disposed between the rolling elements 5a and 5a arranged in the double row. Even if there is an optimal installation direction with respect to this encoder 12g. For example, on the road surface, the axial load acts toward the inner side of the vehicle body, which is the outer wheel when the automobile is turning, and in this case, the vertical load (radial load) is increased due to the centrifugal force. many. On the contrary, for example, the lateral load acts toward the vehicle body outward direction on the road surface, which is the inner wheel when the automobile is turning, and the up and down load is often reduced at this time.

In view of such a point, in the structure shown in FIG. 31, the encoder 12g is provided with a detection part of the sensor 13d provided on the lower side (road surface side) between the rolling elements 5a and 5a arranged in the above rows. To the lower end of the outer circumferential surface. For example, when an axial load toward the hub 4b is applied to the hub 4b on the road surface, the encoder 12g is moved in the vehicle body outward direction (left direction in FIG. 31) by the axial load. Displace. At the same time, since the up-and-down load decreases, the distance (gap) between the detection part of the sensor 13d and the encoder 12g becomes small, albeit somewhat. As described above, when this distance decreases, the proportion of the portion recognized as the convex portion occupying one period of the detection signal of the sensor 13d increases. Therefore, in the present embodiment, the encoder is increased so that the width in the circumferential direction of the concave portion increases toward the vehicle body outer side so that the ratio recognized as the convex portion increases when the encoder 12g is displaced in the vehicle body outer direction. 12g is arrange | positioned.

Embodiment 17

32-35 shows Embodiment 17 of this invention corresponding to Claims 1, 10, 11. In the case of this embodiment, the encoder 12k made of a permanent magnet is externally attached and fixed to the intermediate part of the hub 4a similarly to Embodiment 5 shown in FIGS. 11-13 mentioned above. On the outer circumferential surface of this encoder 12k, which is the surface to be detected, a portion magnetized to the N pole corresponding to the first detected portion and a portion magnetized to the S pole corresponding to the second detected portion alternately and the like in the circumferential direction. It is arranged at intervals. In particular, in the present embodiment, the boundary between the portion magnetized by the N pole and the portion magnetized by the S pole corresponding to the first and second detected parts is the same angle with respect to the axial direction of the encoder 12k. At the same time, the inclination direction with respect to this axial direction is made to reverse each other at the boundary of the axial middle part of this encoder 12k. Thus, the portion magnetized to the N pole and the portion magnetized to the S pole have a 'ku' shape (dogleg shape) in which the axial middle portion protrudes most (or concave) with respect to the circumferential direction.

On the other hand, a pair of sensors 13i and 13i are provided in the middle part of the rolling elements 5 and 5 arranged in a double row at the axial middle part of the outer ring 3, and the detection part of these sensors 13i and 13i is provided. It is located close to the outer circumferential surface of the encoder 12k. The position where the detection part of these sensors 13i and 13i oppose the outer peripheral surface of this encoder 12k is the same position with respect to the circumferential direction of this encoder 12k. In other words, the detection parts of the both sensors 13i and 13i are arranged on an imaginary straight line parallel to the central axis of the outer ring 3. Further, in the state in which no axial load is applied between the outer ring 3 and the hub 4a, most protrudes about the circumferential direction at the axial middle portion of the magnetized portion of the N pole and the magnetized portion of the S pole. The installation position of each member 12k, 13i, 13i is restrict | limited so that one part (part in which the inclination direction of a boundary changes) exists in the exact center position between the detection parts of both said sensors 13i and 13i.

In the present embodiment configured as described above, when an axial load acts between the outer ring 3 and the hub 4a, the phases in which the output signals of the sensors 13i and 13i change are shifted. That is, in the state where the axial load is not acting between the outer ring 3 and the hub 4a, the detection portions of the both sensors 13i and 13i are solid lines (a) and ((A) of FIG. a) It opposes the part which shifted | deviated by the same in the axial direction from the above, ie, the said most protruding part. Therefore, the phases of the output signals of the above sensors 13i and 13i coincide with each other as shown in Fig. 35C. On the other hand, when downward axial load is applied to the hub 4a which fixed the said encoder 12k in FIG. 35 (A), the detection part of the said both sensors 13i and 13i will be carried out in FIG. On the dashed lines (b) and (b) of A), that is, the deviation in the axial direction from the most protruding portion opposes the different portions. In this state, the phases of the output signals of the above-described sensors 13i and 13i are shifted as shown in Fig. 35B. In addition, when an axial load directed upward in FIG. 35A acts on the hub 4a to which the encoder 12k is fixed, the detection units of the both sensors 13i and 13i are shown in FIG. The shift in the axial direction from the dashed-dotted lines (c) and (c) of (A), that is, from the most protruding portion, opposes the different portions in the reverse direction. In this state, the phases of the output signals of the above sensors 13i and 13i are shifted as shown in Fig. 35D.

As described above, in the present embodiment, the phases of the output signals of the both sensors 13i and 13i are shifted in the direction along the direction of the axial load applied between the outer ring 3 and the hub 4a. . The degree to which the output signals of the sensors 13i and 13i are out of phase due to this axial load increases as the axial load increases. Therefore, in the case of this embodiment, between the outer ring 3 and the hub 4a according to the direction and the magnitude | size in the presence or absence of the phase shift of the output signal of the said both sensors 13i and 13i, and a shift exists. The direction and magnitude of the axial load acting on can be obtained.

Embodiment 18

Here, as in the seventeenth embodiment described above, the invention in which the axial load is obtained by combining an encoder and a pair of sensors which have changed the inclination direction of the boundary between the first and second portions to be detected midway is as shown. This can be done without being limited to encoders made of the same permanent magnet. That is, one detected part between the first detected part and the second detected part is a convex part existing between the through hole or the concave hole, and the other detected part is present between the through hole or the concave hole adjacent to the circumferential direction. An axial load can also be measured by combining the encoder which used the intermediate | middle part or recessed part, and the sensor according to the characteristic and shape of this encoder appropriately. Further, a pair of sensors are arranged to be offset in the radial direction so as to face one axial direction, which is the surface to be detected of the encoder, and the first and second to-be-detected portions disposed on the surface to be detected are arranged in the radial direction of the encoder. The radial load can also be measured with the structure in which the inclination direction is changed along the way while the inclination is inclined.

36-38 show Embodiment 18 of this invention considered according to the above-mentioned situation. In the case of this embodiment, the magnetic metal plate encoder 12B is externally attached and fixed to the intermediate part of the hub 4a. On the outer circumferential surface of this encoder 12B, which is the surface to be detected, the slit-type through holes 33a and 33b corresponding to the first detected portion and the column portions 34a and 34b corresponding to the second detected portion are circumferential. Alternately in the direction and at equal intervals. In this case, although the pitch between the through-holes 33a and 33b adjacent to the circumferential direction, or the pillar parts 34a and 34b is the same, the width | variety with respect to the circumferential direction of each through-hole 33a, 33b, and each pillar The widths in the circumferential direction of the sections 34a and 34b need not be the same. In particular, in the case of the present embodiment, the encoder 12B includes the respective through holes 33a and 33b corresponding to the first to-be-detected part and the pillars 34a and 34b corresponding to the second to-be-detected part. The inclination direction with respect to this axial direction is made to reverse each other on the boundary of the axial middle part of this encoder 12B, while inclining only the same angle with respect to the axial direction. In other words, the encoder 12B of this embodiment forms the through-holes 33a and 33a which are inclined by the same amount in the predetermined direction with respect to the said axial direction at one half of the axial direction, and at the other half of the axial direction. And through holes 33b and 33b that are inclined by the same angle in the opposite direction to the predetermined direction.

On the other hand, a pair of sensors 13C and 13C are provided in the middle part of the rolling elements 5 and 5 arranged in a double row at the axial middle part of the outer ring 3, and the detection part of these both sensors 13C and 13C. Is located close to the outer circumferential surface of the encoder 12B. The position where the detection part of these sensors 13C, 13C oppose the outer peripheral surface of this encoder 12B is selected as the same position regarding the circumferential direction of this encoder 12B. Further, in the state where no axial load is applied between the outer ring 3 and the hub 4a, a rim portion 35 positioned between each of the through holes 33a and 33b and continuous to the entire circumference thereof. ) Restricts the installation positions of the members 12B, 13C, and 13C so that they are located at exactly the center positions between the detection units of the sensors 13C and 13C.

In the present embodiment configured as described above, if an axial load acts between the outer ring 3 and the hub 4a, the same as in the above-described embodiment 17, the two sensors 13C, 13C The phase in which the output signal changes is shifted. That is, in the state where the axial load is not acting between the outer ring 3 and the hub 4a, the detection units of the above-mentioned amount sensors 13C and 13C are solid lines (a) in FIG. (a) It opposes the above part, ie, the part which shifted | deviated by the same part in the axial direction from the said rim part 35. FIG. Therefore, the phases of the output signals of the above sensors 13C and 13C coincide with each other as shown in Fig. 39C. On the other hand, when downward axial load is applied to the hub 4a which fixed the said encoder 12B in FIG. 39 (A), the detection part of the said both sensors 13C, 13C is shown in FIG. ), The deviation in the axial direction from the broken line (b), ie, (b), that is, from the rim portion 35 opposes the different portions. In this state, the phases of the output signals of the above-described sensors 13C and 13C are shifted as shown in Fig. 39B. In addition, when an upward axial load acts on the hub 4a which fixed the said encoder 12B to FIG. 39 (A), the detection part of the said both sensors 13C, 13C is (A) of FIG. ), The shift | deviation with respect to the axial direction from the dashed-dotted line (c), (c) of () from the said rim part 35 opposes another part in reverse direction. In this state, the phases of the output signals of both the sensors 13C and 13C are shifted as shown in Fig. 39D.

Also in the present embodiment as described above, as in the case of the seventeenth embodiment, the axis of the output signal of the both sensors 13C, 13C is applied between the outer ring 3 and the hub 4a. The direction shifts along the direction of the load. The degree to which the output signals of the sensors 13C and 13C are out of phase due to this axial load increases as the axial load increases. Therefore, also in the present embodiment, when the presence or absence of phase shift of the output signal of the said both sensors 13C, 13C exists, and between the outer ring 3 and the hub 4a according to the direction and magnitude | size, The direction and magnitude of the axial load acting on is required.

In all embodiments, the smaller the area (spot diameter) of the detection part of the sensor is preferable. This reason is to make it possible to read this pattern change with high precision, in order to obtain the change of the pattern of the characteristic change of the detected surface of the encoder according to the load fluctuation. In addition, the structure of the said sensor is not specifically limited, such as a magnetic type and an optical type. However, a magnetic one is preferable from the point that it is easy to obtain the sensor which has the precision required at low cost. In the case of using a magnetic sensor, any of a passive type and an active type can be used. However, an active sensor can be preferably used from the point that the spot diameter can be made small and the measurement can be performed with high accuracy, and the measurement can be performed from low rotation. In addition, in the case of an active sensor, magnetic sensors having various structures can be used, including a unipolar type that switches the output (ON / OFF) in response to a change in the density of the magnetic flux passing through the detection element. have.

Those skilled in the art will appreciate that various modifications and changes can be made in the disclosed preferred embodiments of the invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover all modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

This application is directed to Japanese Patent Application No. 2004-156014, filed May 26, 2004, Japanese Patent Application No. 2004-231369, filed August 6, 2004, and Japanese Patent Application No. 27, 2004. Priority is given to 2004-279755, which is incorporated by reference.

Claims (24)

With rolling bearing unit and load measuring device, The rolling bearing unit includes a stationary side raceway wheel that does not rotate in the state of use, a rotating side raceway wheel that rotates in the state of use, and a stop which exists on mutually opposing circumferential surfaces of these stationary raceway raceways and the rotational side raceway wheel. With a plurality of rolling elements provided between the side track and the rotating track, The load measuring device is a state in which a part of the rotating raceway wheel is supported concentrically with the rotating raceway wheel, and the encoder is configured to alternately change the characteristics of the surface to be detected along the circumferential direction, and the surface to be detected. A sensor which is supported on a portion which does not rotate at and which changes an output signal in response to a characteristic change of the detected surface, and calculates a load applied between the stationary track wheel and the rotary track wheel in accordance with the output signal. It is equipped with an operator to The pitch or phase in which the characteristic of the surface to be detected varies along the circumferential direction is continuously changed corresponding to the direction of action of the load to be detected, The calculator has a rolling bearing unit having a load measuring device having a function of calculating the load according to a pattern in which the output signal of the sensor changes. The method of claim 1, The load to be detected is a radial load acting radially between the stationary raceway wheel and the rotating raceway ring, and the surface to be detected includes the axial side of the encoder, and the detected surface has different characteristics. The first to-be-detected part and the second to-be-detected part are alternately arranged at equal intervals in the circumferential direction, and among the widths with respect to the circumferential direction of these two detected parts, the width of the first to-be-detected part is wide toward the radially outer side, Rolling bearing unit with a load measuring device, the width of the second detected portion is wide toward the radially inward. The method of claim 1, The load to be detected is a radial load acting radially between the stationary raceway wheel and the rotating raceway wheel, and the surface to be detected includes the axial side of the encoder, and the detected surface has different characteristics. The first to be detected part and the second to be detected part are alternately arranged at regular intervals in the circumferential direction, and the boundary between the first to be detected part and the second to be detected part is inclined with respect to the radial direction of the encoder, The inclination direction with respect to the radial direction of this boundary is mutually opposite to the radial middle part of this encoder, and the detection part of l pair of sensors provided in the position spaced apart in the radial direction of this encoder along this radial direction middle part, Rolling bearing unit with a load measuring device opposing the detected surface of the encoder. The method of claim 2 or 3, A rolling bearing unit with a load measuring device, wherein the encoder is made of a permanent magnet, one to be detected among the first to be detected and the second to be detected is the N pole, and the other to be detected is the S pole. The method of claim 2 or 3, One to-be-detected part of a 1st detected part and a 2nd to-be-detected part is a through hole or a concave hole, and the other to-be-detected part is an intermediate part located between the through holes or concave holes which adjoin a circumferential direction, and a load. Rolling bearing unit with measuring device. The method of claim 2 or 3, One to-be-detected part of a 1st detected part and a 2nd detected part is a convex part, and the other to-be-detected part is a recessed part located between the convex parts adjacent to the circumferential direction, The rolling bearing unit with a load measuring apparatus. The method according to claim 5 or 6, The encoder is made of magnetic material, and the sensor changes the output signal in response to the change in the magnetic characteristics of the detected surface of the encoder, and on both ends of the encoder, rotation of the first detected part or the second detected part Rolling bearing unit with a load measuring device, provided with an unchanged portion in which the pitch with respect to the direction does not change with respect to the radial direction. The method of claim 1, As long as the load to be detected is a radial load acting radially between the stationary raceway wheel and the rotating raceway wheel, the surface to be detected includes the axial side of the encoder, and the characteristics are different from each other. A plurality of combinations for detection including a pair of unique portions are arranged on the surface to be detected at equal intervals in the circumferential direction, and the circumference between the pair of unique portions constituting each of the combinations for detection is formed. The rolling bearing unit with a load measuring device in which the distance with respect to a direction changes continuously in the same direction of radial direction in the whole to-be-detected combination part. The method of claim 1, The load to be detected is an axial load acting in the axial direction between the stationary track wheel and the rotating track wheel, and the surface to be detected includes the circumferential surface of the encoder, and the surface to be detected has different characteristics. The first and second to-be-detected portions are alternately and equidistantly arranged in the circumferential direction, and among the widths with respect to the circumferential direction of these two to-be-detected portions, the width of the first to-be-detected portion is wide toward one end in the axial direction. The rolling bearing unit with a load measuring device, wherein the width of the second detected part is wide toward the other end side in the axial direction. The method of claim 1, The load to be detected is an axial load acting in the axial direction between the stationary track wheel and the rotating track wheel, and the surface to be detected includes the circumferential surface of the encoder, and the surface to be detected has different characteristics. The first and second to-be-detected parts are alternately and equidistantly aligned with respect to the circumferential direction, and the boundary between the first and second to-be-detected parts is inclined with respect to the axial direction of the encoder, The inclination direction with respect to the axial direction of this boundary is opposite to each other on the basis of the axial middle part of this encoder, and the detection part of a pair of sensors provided in the position spaced apart in the axial direction of this encoder along this axial middle part, Rolling bearing unit with a load measuring device opposing the detected surface of the encoder. The method according to claim 9 or 10, A rolling bearing unit with a load measuring device, wherein the encoder is made of a permanent magnet, the first to be detected is the N pole, and the second to be detected is the S pole. The method according to claim 9 or 10, A rolling bearing unit with a load measuring device, wherein the first to-be-detected portion is a through hole or a concave hole, and the second to-be-detected portion is an intermediate portion existing between the through or concave holes adjacent to the circumferential direction. The method according to claim 9 or 10, A rolling bearing unit with a load measuring device, wherein the first detected portion is a convex portion, and the second detected portion is a concave portion existing between the convex portions adjacent in the circumferential direction. The method according to claim 12 or 13, The encoder is made of magnetic material, and the sensor changes the output signal in response to the change in the magnetic characteristics of the detected surface of the encoder, and the rotation of the first to be detected portion or the second to be detected portion is axially at both ends of the encoder. Rolling bearing unit with a load measuring device, provided with an unchanged portion in which the pitch with respect to the direction does not change with respect to the axial direction. The method of claim 1, The load to be detected is an axial load acting in the axial direction between the stationary raceway wheel and the rotational raceway ring, and the detected surface includes the circumferential surface of the encoder, each of which has different characteristics from the other portions. A plurality of combinations to be detected composed of a unique portion of the plurality is arranged on the detected surface at equal intervals over the circumferential direction, and relates to the circumferential direction of a pair of unique portions constituting each of the detected portions to be detected The gap is a rolling bearing unit with a load measuring device, wherein the gap is continuously changed in the same direction in the axial direction in the entire portion to be detected. The method according to any one of claims 1 to 15, The detection units of the sensors are respectively opposed to three or more different positions in the circumferential direction among the detected surfaces of the encoder, and an arithmetic unit is applied between the stationary track wheel and the rotary track wheel by comparing the output signals of these sensors. Rolling bearing unit with load measuring device, having the function of calculating the losing moment load. The method of claim 16, A rolling bearing unit with a load measuring device, wherein the detected surface of the encoder includes the circumferential surface of the encoder, and the detection portion of each sensor is opposed to the circumferential equally spaced position of the circumferential surface of the encoder. The method of claim 16, A rolling bearing unit with a load measuring device, wherein the detected surface of the encoder includes the axial side of the encoder, and the detection portion of each sensor faces the circumferential equidistant position of the axial side of the encoder. The method according to any one of claims 1 to 18, The rolling bearing unit is a rolling bearing unit for wheel support, and in use, the stationary raceway wheel is supported and fixed to the suspension device, and the rotating side raceway wheel supports and fixes the wheel and rotates with the wheel. Rolling bearing unit. The method according to any one of claims 1 to 18, The rolling bearing unit rotatably supports the main shaft of the machine tool to the housing, and in use, the outer ring, which is the stationary raceway wheel, is internally fitted and fixed to this housing or a part fixed to the housing, and the inner ring, which is the rotational raceway ring A rolling bearing unit having a load measuring device, which is externally mounted and fixed to the main shaft or a portion rotating with the main shaft. The method of claim 1, The rolling bearing unit is a rolling bearing unit for wheel support, and in use, the outer ring, which is the stationary raceway wheel, is supported by the suspension device, and the hub, which is the rotating side raceway, supports the wheels and rotates with the wheel, and the outer ring A plurality of cloud elements are provided for each row between a double-row outer ring raceway, each of which is a stationary side track, and a double-row inner raceway, each of which is a rotational track, located on the inner circumferential surface of the hub. And an flange for supporting the wheel at the axial outer end of the hub, and an encoder having alternately aligned concave and convex portions on an outer circumferential surface of the hub to be axially inner end of the hub or the inner ring raceway of the double row. The load to be fixed at the middle portion of the shaft is an axial load acting axially between the outer ring and the hub, and the outer circumferential surface of the encoder The detection part of the sensor is opposed to the upper part of the to-be-detected surface which exists in the radial direction, and the width | variety with respect to the circumferential direction of the recessed part and the recessed part in the convex part which were formed in the to-be-detected surface of the said encoder is wide at the axial inner end side. Rolling bearing unit with load measuring device, narrow at the axial outer side. The method of claim 1, The rolling bearing unit is a rolling bearing unit for wheel support, and in use, the outer ring, which is the stationary side raceway wheel, is supported by the suspension device, and the hub, which is the rotating side raceway ring, supports the wheel and rotates with the wheel, and the outer ring A plurality of cloud elements are provided for each row between a double-row outer ring raceway, each of which is a stationary side track, and a double-row inner ring raceway, each of which is a rotational track, located on the inner circumferential surface of the hub. And an flange for supporting the wheel at the axial outer end of the hub, and an encoder having alternately aligned concave and convex portions on an outer circumferential surface of the hub to be axially inner end of the hub or the inner ring raceway of the double row. The load to be fixed at the middle portion of the shaft is an axial load acting in the axial direction between the outer ring and the hub, and the outside of the encoder The lower part of the detected surface existing on the main surface is opposed to the detection part of the sensor in the radial direction, and the width of the concave portion formed in the detected surface of the encoder and the circumferential direction of the concave portion in the convex portion is at the axial outer end side. Rolling bearing unit with a load measuring device that is wide and narrow at the axial end. The method of claim 1, The rolling bearing unit is a rolling bearing unit for wheel support, and in use, the outer ring, which is the stationary raceway wheel, is supported and fixed to the suspension device, and the hub, which is the rotating side raceway wheel, supports and secures the wheel and rotates with the wheel, A plurality of rolling elements are provided for each row between the double-row outer raceway tracks located on the inner circumferential surface of the outer ring and the double-row inner raceway tracks respectively located on the outer circumferential surface of the hub, respectively, the rotational tracks. And a flange for supporting the wheel at the axial outer end of the hub, and an encoder in which the concave portion and the convex portion are alternately aligned on the axial inner side, the surface to be detected, is fixed to the axial inner end of the hub. And a load to be detected is an axial load acting in the axial direction between the outer ring and the hub and is detected on the inner side of the encoder in the axial direction. The upper part of the sensor is opposed to the detection part of the sensor in the axial direction, and the width of the concave portion formed on the surface to be detected of the encoder and the circumferential direction of the concave portion in the convex portion is wide at the radial outer end side and narrow at the radial inner end side. Rolling bearing unit with load measuring device. The method of claim 1, The rolling bearing unit is a rolling bearing unit for supporting the wheel, and in use, the outer ring, which is the stationary raceway wheel, is supported and fixed to the suspension device, and the hub, which is the rotating side raceway, supports the wheel and rotates with the wheel, and the outer ring A plurality of cloud elements are provided for each row between a double-row outer ring raceway, each of which is a stationary side track, and a double-row inner ring raceway, each of which is a rotational track, located on the inner circumferential surface of the hub. And a flange for supporting the wheel at the axial outer end of the hub, and an encoder in which the concave portion and the convex portion are alternately aligned on the axially inner surface, the surface to be detected, is fixed to the axial inner end of the hub. And a load to be detected is an axial load acting in the axial direction between the outer ring and the hub, and among the detected surfaces existing on the axially inner surface of the encoder. The detection part of the sensor is opposed to the lower part in the axial direction, and the width | variety with respect to the circumferential direction of the recessed part formed in the to-be-detected surface of the said encoder and the convex part in the convex part is wide at a radial inner end side, and narrow at a radial outer end side. Rolling bearing unit with load measuring device.

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