JP2005156507A - Load measurement device for rolling bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase reliability in detection of a revolution speed and a rotation speed for improvement in reliability of load measurement in a structure finding a load applied between a hub 2b and an outer ring 1 based on the revolution speed of rolling elements 9a and 9b in respective races and the rotation speed of the hub 2b. <P>SOLUTION: In this load measurement device, a sensor unit 21a having revolution speed detecting sensors 23a and 23b and a rotation speed detecting sensor 15a is inserted into a mounting hole 10b attached slantingly to the outer ring 1. Revolution speed detecting encoders 25a' and 25b' arranged in holders 24a' and 24b' holding the rolling elements 9a and 9b in the respective races are tilted by the same angle in the same direction as the mounting hole 10b. A front end face 32 of the sensor unit 21a is tilted to the center axis of the sensor unit 21a. In this way, the respective sensors 23a, 23b, and 15a can be set to be parallel to detected faces of the encoders 25a', 25b', and 13a, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  A load measuring device for a rolling bearing unit that is an object of the present invention is, for example, a load (one or both of a radial load and an axial load) applied to a rolling bearing unit for supporting wheels of a vehicle such as an automobile or a railway vehicle. ) Is measured and used to ensure the running stability of the vehicle.

  For example, an automobile wheel is rotatably supported by a double row angular rolling bearing unit with respect to a suspension device. In order to ensure the running stability of automobiles, vehicle running stabilizers such as an antilock brake system (ABS), a traction control system (TCS), and a vehicle stability control system (VSC) are used. . In order to control such various vehicle running stabilizers, signals such as the rotational speed of the wheels and the acceleration in each direction applied to the vehicle body are required. In order to perform higher-level control, it may be preferable to know the magnitude of a load (one or both of a radial load and an axial load) applied to the rolling bearing unit via the wheel.

  In view of such circumstances, Patent Document 1 describes a rolling bearing unit with a load measuring device capable of measuring a radial load. The rolling bearing unit with a load measuring device of the first example of this conventional structure measures a radial load and is configured as shown in FIG. A hub 2 for coupling and fixing the wheel is supported on the inner diameter side of the outer ring 1 supported by the suspension device. The hub 2 has a hub body having a rotation-side flange 3 for fixing a wheel at an outer end thereof (an end portion on the outer side in the width direction when assembled to a vehicle, and a left end portion in each drawing excluding FIG. 6). 4 and the inner end portion of the hub body 4 (the end portion on the center side in the width direction in the assembled state in the vehicle, the right end portion of each drawing excluding FIG. 6) and are held down by the nut 5. And an inner ring 6. A plurality of rolling rings are provided between the double row outer ring raceways 7 and 7 formed on the inner peripheral surface of the outer ring 1 and the double row inner ring raceways 8 and 8 formed on the outer peripheral surface of the hub 2. The moving bodies 9a and 9b are arranged to freely rotate the hub 2 on the inner diameter side of the outer ring 1.

  A mounting hole 10 that diametrically penetrates the outer ring 1 is formed in a substantially vertical direction at an upper end portion of the outer ring 1 in a portion between the double row outer ring raceways 7 and 7 at an intermediate portion in the axial direction of the outer ring 1. Yes. In the mounting hole 10, a circular rod-shaped (round bar-shaped) displacement sensor 11, which is a load measuring sensor, is mounted. This displacement sensor 11 is a non-contact type, and the detection surface provided on the front end surface (lower end surface) is closely opposed to the outer peripheral surface of the sensor ring 12 fitted and fixed to the intermediate portion in the axial direction of the hub 2. When the distance between the detection surface and the outer peripheral surface of the sensor ring 12 changes, the displacement sensor 11 outputs a signal corresponding to the amount of change.

  In the case of the conventional rolling bearing unit with a load measuring device configured as described above, the load applied to the rolling bearing unit can be obtained based on the detection signal of the displacement sensor 11. That is, the outer ring 1 supported by the vehicle suspension device is pushed downward by the weight of the vehicle, whereas the hub 2 supporting and fixing the wheel tends to stop at the same position. For this reason, the greater the weight, the greater the deviation between the center of the outer ring 1 and the center of the hub 2 based on the elastic deformation of the outer ring 1, the hub 2, and the rolling elements 9a, 9b. The distance between the detection surface of the displacement sensor 11 and the outer peripheral surface of the sensor ring 12 provided at the upper end of the outer ring 1 becomes shorter as the weight increases. Therefore, if the detection signal of the displacement sensor 11 is sent to the controller, the radial load applied to the rolling bearing unit in which the displacement sensor 11 is incorporated can be obtained from a relational expression or a map obtained beforehand through experiments or the like. Based on the load applied to each rolling bearing unit thus obtained, the ABS is appropriately controlled and the driver is informed of the poor loading state.

  In the conventional structure shown in FIG. 3, in addition to the load applied to the rolling bearing unit, the rotational speed of the hub 2 can also be detected. For this purpose, the rotational speed detecting encoder 13 is fitted and fixed to the inner end of the inner ring 6, and the rotational speed detecting sensor 15 is supported on the cover 14 attached to the inner end opening of the outer ring 1. Yes. And the detection part of this rotational speed detection sensor 15 is made to oppose the to-be-detected part of the said encoder 13 for rotational speed detection through the measurement clearance gap.

  When the rolling bearing unit incorporating the rotational speed detecting device as described above is used, the rotational speed detecting encoder 13 is rotated together with the hub 2 to which the wheel is fixed, and the detected portion of the rotational speed detecting encoder 13 is rotated as described above. When traveling in the vicinity of the detection unit of the speed detection sensor 15, the output of the rotation speed detection sensor 15 changes. The frequency at which the output of the rotational speed detection sensor 15 changes in this way is proportional to the rotational speed of the wheel. Therefore, if the output signal of the rotational speed detection sensor 15 is sent to a controller (not shown), ABS and TCS can be controlled appropriately.

  The rolling bearing unit with a load measuring device of the first example of the conventional structure as described above is for measuring the radial load applied to the rolling bearing unit, but the structure for measuring the axial load applied to the rolling bearing unit is also, It is described in Patent Document 2 and the like and has been conventionally known. FIG. 4 shows a rolling bearing unit with a load measuring device for measuring an axial load described in Patent Document 2. As shown in FIG. In the case of the second example of this conventional structure, the rotation side flange 3a for supporting the wheel is fixed on the outer peripheral surface of the outer end portion of the hub 2a. A fixed-side flange 17 is fixed to the outer peripheral surface of the outer ring 1a for supporting and fixing the outer ring 1a to a knuckle 16 constituting a suspension device. A plurality of rolling rings are respectively provided between the double row outer ring raceways 7 and 7 formed on the inner peripheral surface of the outer ring 1a and the double row inner ring raceways 8 and 8 formed on the outer peripheral surface of the hub 2a. By providing the moving bodies 9a and 9b so as to be able to roll, the hub 2a is rotatably supported on the inner diameter side of the outer ring 1a.

  Further, a load sensor 20 is attached to a part surrounding the screw hole 19 for screwing the bolt 18 for connecting the fixed side flange 17 to the knuckle 16 at a plurality of positions on the inner side surface of the fixed side flange 17. Has been established. Each load sensor 20 is sandwiched between the outer side surface of the knuckle 16 and the inner side surface of the fixed-side flange 17 in a state where the outer ring 1 a is supported and fixed to the knuckle 16.

  In the case of the load measuring device of the rolling bearing unit of the second example having such a conventional structure, when an axial load is applied between a wheel (not shown) and the knuckle 16, the outer surface of the knuckle 16 and the fixed side flange 17 The inner surface strongly presses the load sensors 20 from both sides in the axial direction. Therefore, the axial load applied between the wheel and the knuckle 16 can be obtained by summing up the measured values of the load sensors 20. Although not shown, Patent Document 3 describes a method of obtaining the revolution speed of the rolling element from the vibration frequency of a member corresponding to an outer ring having a reduced rigidity, and measuring the axial load applied to the rolling bearing. ing.

  In the case of the first example of the conventional structure shown in FIG. 3 described above, the load applied to the rolling bearing unit is measured by measuring the displacement in the radial direction between the outer ring 1 and the hub 2 by the displacement sensor 11. However, since the displacement amount in the radial direction is small, it is necessary to use a highly accurate displacement sensor 11 in order to obtain this load with high accuracy. Since high-precision non-contact sensors are expensive, it is inevitable that the cost of the entire rolling bearing unit with a load measuring device increases.

  In the case of the second example of the conventional structure shown in FIG. 4 described above, it is necessary to provide as many load sensors 20 as the number of bolts 18 for supporting and fixing the outer ring 1a to the knuckle 16. For this reason, coupled with the fact that the load sensor 20 itself is expensive, it is inevitable that the cost of the entire load measuring device of the rolling bearing unit is considerably increased. Further, the method described in Patent Document 3 requires that the rigidity of a part of the outer ring equivalent member be lowered, and it may be difficult to ensure the durability of the outer ring equivalent member. Further, since the revolution speed of the rolling element is obtained from the vibration frequency of the outer ring equivalent member, there is a problem that the revolution speed cannot be measured accurately.

  In view of such circumstances, the present inventors have previously described this rolling bearing unit based on the revolution speed of a pair of rolling elements (balls) constituting a rolling bearing unit which is a double row angular ball bearing. An invention relating to a load measuring device for a rolling bearing unit that measures a radial load or an axial load applied to the bearing is performed (Japanese Patent Application Nos. 2003-171715 and 172483). FIG. 5 shows a load measuring device for a rolling bearing unit according to the present invention. In the case of the structure according to the previous invention, the sensor unit 21 is inserted into the mounting hole 10a formed in the portion between the double-row outer ring raceways 7 and 7 at the intermediate portion in the axial direction of the outer ring 1 (outer ring equivalent member). The front end portion 22 of the outer ring 1 protrudes from the inner peripheral surface of the outer ring 1. The tip portion 22 is provided with a pair of revolution speed detection sensors 23a and 23b and one rotational speed detection sensor 15a.

  And the detection part of each revolution speed detection sensor 23a, 23b of these is provided in each retainer 24a, 24b which hold | maintained each rolling element 9a, 9b arrange | positioned in a double row freely, The revolution speed detection The revolving speeds of the rolling elements 9a and 9b are made freely detectable by being close to and facing the encoders 25a and 25b. Further, the rotational speed of the hub 2 can be detected by making the detection part of the rotational speed detection sensor 15a close to and opposed to the rotational speed detection encoder 13a externally fitted and fixed to the intermediate part of the hub 2 which is an inner ring equivalent member. It is said. According to the load measuring device for a rolling bearing unit according to the prior invention having such a configuration, a load (a radial load and a load) applied between the outer ring 1 and the hub 2 regardless of fluctuations in the rotational speed of the hub 2. Axial load) is required.

That is, in the case of the load measuring device for a rolling bearing unit according to the above-described prior invention, an arithmetic unit (not shown) performs the outer ring 1 and the hub 2 based on the detection signals sent from the sensors 23a, 23b, 15a. One or both of a radial load and an axial load applied between the two are calculated. For example, when the radial load is obtained, the computing unit obtains the sum of the revolution speeds of the rolling elements 9a and 9b of the respective rows detected by the revolution speed detection sensors 23a and 23b, and the sum and the rotation speed. The radial load is calculated based on the ratio to the rotational speed of the hub 2 detected by the detection sensor 15a. The axial load is obtained by calculating the difference between the revolution speeds of the rolling elements 9a and 9b in the respective rows detected by the revolution speed detection sensors 23a and 23b, and the difference between the difference and the rotation speed detection sensor 15a. Calculation is based on the ratio to the rotational speed of the hub 2. This point will be described with reference to FIG. In the following description, it is assumed that the contact angles α _a and α _b of the rolling elements 9a and 9b in both rows in the state where the axial load Fy is not applied are the same.

FIG. 6 schematically shows the wheel bearing rolling bearing unit shown in FIG. 5 described above and shows the action state of the load. Preloads F ₀ and F ₀ are applied to the rolling elements 9 a and 9 b arranged in a double row between the double row inner ring raceways 8 and 8 and the double row outer ring raceways 7 and 7. Further, a radial load Fz is applied to the rolling bearing unit during use due to the weight of the vehicle body or the like. Further, an axial load Fy is applied due to centrifugal force applied during turning. These preloads F ₀ , F ₀ , radial load Fz, and axial load Fy all affect the contact angles α (α _a , α _b ) of the rolling elements 9a, 9b. Then, the contact angle alpha _a, the alpha _b is changed, these rolling elements 9a, the revolution speed n _c of 9b changes. The pitch circle diameter of each of these rolling elements 9a, 9b is D, the diameter of each of these rolling elements 9a, 9b is d, the rotational speed of the hub 2 provided with both the inner ring raceways 8, 8 is n _i , When the rotational speed of the outer race 1 provided with the outer ring raceway 7, 7 and n _o, the revolution speed n _c is expressed by the following equation.
n _c = {1− (d · cos α / D) · (n _i / 2)} + {1+ (d · cos α / D) · (n _o / 2)}

As is evident from this equation, the rolling elements 9a, revolution speed n _c of 9b, these rolling elements 9a, the contact angle α (α _a, α _b) of 9b varies in response to changes in, the above-described Similarly, the contact angles α _a and α _b vary according to the radial load Fz and the axial load Fy. Thus the revolution speed n _c is changed according to these radial load Fz and the axial load Fy. In this example, the hub 2 is rotated, since the outer ring 1 is not rotated, specifically, with respect to the radial load Fz, the revolution speed n _c is slow enough to increase. As for the axial load Fy, the revolution speed of the row that supports the axial load Fy is increased, and the revolution speed of the row that does not support the axial load Fy is decreased. Therefore, on the basis of the revolution speed n _c, it will be asked to the radial load Fz and the axial load Fy.

However, the contact angle α which leads to a change in the revolution speed n _c, as well as the radial load Fz and the axial load Fy changes while associated with each other, also vary according to the preload F _0, F _0. Also, the revolution speed n _c is changed in proportion to the rotational speed n _i of the hub 2. Therefore, these radial load Fz, the axial load Fy, the preload F _0, F _0, to be considered in conjunction all the rotational speed n _i of the hub 2, it is impossible to correctly determine the revolution speed n _c. Of these, the preloads F ₀ and F ₀ do not change according to the operating state, so it is easy to eliminate the influence by initial setting or the like. The radial load Fz with respect to this, the axial load Fy, the rotational speed n _i of the hub 2, since the constantly changing depending on the operating conditions, it is impossible to eliminate the influence by such initialization.

In the case of the prior invention in view of such circumstances, as described above, when the radial load Fz is obtained, the rolling elements 9a, 9b of the respective rows detected by the respective revolution speed detection sensors 23a, 23b are detected. By determining the sum of the revolution speeds, the influence of the axial load Fy is reduced. Further, when the axial load Fy is obtained, the influence of the radial load Fz is reduced by obtaining the difference between the revolution speeds of the rolling elements 9a and 9b in both rows. Furthermore, in any case, possible to calculate the radial load Fz or the axial load Fy on the basis of the ratio of the above sum or difference, the rotational speed detecting sensor 15a is a rotational speed n _i of the hub 2 for detecting way, by eliminating the influence of the rotational speed n _i of the hub 2. However, the axial load Fy, when calculating on the basis of the ratio of the revolution speed of the both rows of rolling elements 9a, 9b, the rotational speed n _i of the hub 2 is not necessarily required.

  There are various other methods for calculating one or both of the radial load Fz and the axial load Fy based on the signals of the revolution speed detection sensors 23a and 23b. This method is described in detail in the aforementioned Japanese Patent Application Nos. 2003-171715 and 172483, and is not related to the gist of the present invention.

  When the load measuring device for a rolling bearing unit according to the invention as described above is implemented, the mounting hole 10a may not necessarily be provided in a direction perpendicular to the central axis of the outer ring 1 as shown in FIG. It is done. That is, the mounting hole 10b is formed obliquely with respect to the central axis of the outer ring 1 as shown in FIG. 7 due to the shape of the hub 2 and the space problem when the outer ring 1 is attached to the knuckle 16 (FIG. 4). There are cases where you must do this. When the same sensor unit 21 as that inserted into the mounting hole 10a formed in the diameter direction of the outer ring 1 is assembled to the mounting hole 10b inclined in this way, as shown in FIG. Similarly, the revolution speed detection sensors 23a and 23b provided at the tip 22 of the sensor unit 21 and the revolution speed detection encoders 25a and 25b provided on the side surfaces of the cages 24a and 24b are not mutually connected. Become parallel.

  Incidentally, the structure shown in FIG. 5 described above incorporates a load measuring device in a rolling bearing unit for a driven wheel (a front wheel of an FR vehicle, an MR vehicle, an RR vehicle, and a rear wheel of an FF vehicle). The structure shown in FIG. 7 incorporates a load measuring device in a rolling bearing unit for driving wheels (FR wheel, MR wheel, rear wheel of RR vehicle, front wheel of FF vehicle, all wheels of 4WD vehicle). For this purpose, a spline hole 26 is formed at the center of the hub 2b. Further, the inner end surface of the inner ring 6 fitted on the inner end portion of the hub 2b protrudes from the inner end surface of the hub 2b. The outer end surface of the housing attached to the constant velocity joint in the assembled state hits the inner end surface of such an inner ring 6 to prevent the hub 2b and the inner ring 6 from being separated. Further, a combination seal ring 27 is provided between the inner end portion outer peripheral surface of the inner ring 6 and the inner end inner peripheral surface of the outer ring 1, and the inner end opening portion of the space 28 in which the rolling elements 9a and 9b are installed is provided. It is blocking. In the case of such a rolling bearing unit for driving wheels, based on the presence of the housing attached to the constant velocity joint, as shown in FIG. In particular, it is necessary to be inclined. However, even in the case of the rolling bearing unit for the driven wheel shown in FIG. 5, it may be necessary to incline the mounting hole for the sensor unit.

  In any case, when the revolution speed detection sensors 23a, 23b and the revolution speed detection encoders 25a, 25b are not parallel to each other as described above, the revolution speed detection encoders 25a, 25b are not parallel to each other. The magnetic flux emitted from the detected surface does not flow perpendicularly to the magnetic detection elements provided in the detection portions of the two revolution speed detection sensors 23a and 23b. For this reason, changes in the detection signals of the revolution speed detection sensors 23a and 23b become unstable, and it becomes difficult to ensure the reliability of the revolution speed detection of the rolling elements 9a and 9b in each row.

  Further, since the tip portion 22 of the sensor unit 21 protrudes in a radially inward direction from the inner peripheral surface of the outer ring, the two cages 24a and 24b are swung due to the influence of a pocket gap or the like. When rotating, the detection surfaces of the two revolution speed detection encoders 25a and 25b and the detection parts of the two revolution speed detection sensors 23a and 23b (in the structure shown in FIG. There is a possibility that the detected surface of the encoder 25b and the end of the detecting portion of the revolution speed detecting sensor 23b are in contact with each other. In the case of contact, the possibility of damaging one or both of the detected surfaces of the two revolution speed detection encoders 25a and 25b and the detection parts of the two revolution speed detection sensors 23a and 23b increases. Of course, the damage can be prevented by sufficiently separating the detected surfaces of the respective revolution speed detecting encoders 25a and 25b from the detection parts of the two revolution speed detecting sensors 23a and 23b. The magnetic flux that reaches is reduced, and it becomes increasingly difficult to ensure the reliability of revolution speed detection.

JP 2001-21577 A Japanese Patent Laid-Open No. 3-209016 Japanese Patent Publication No.62-3365

  In view of the circumstances as described above, the present invention provides a load for a rolling bearing unit capable of ensuring both reliability of revolution speed detection and preventing damage to each part even when the sensor unit is mounted in an inclined state with respect to the outer ring. Invented to realize a measuring apparatus.

The load measuring device of the rolling bearing unit of the present invention includes an outer ring equivalent member, an inner ring equivalent member, a plurality of rolling elements, a cage, a revolution speed detection encoder, a mounting hole, a revolution speed detection sensor, And an arithmetic unit.
Of these, the outer ring equivalent member has an outer ring raceway on the inner peripheral surface, and does not rotate during use.
The inner ring equivalent member is disposed concentrically with the outer ring equivalent member on the inner diameter side of the outer ring equivalent member, has an inner ring raceway on the outer peripheral surface, and rotates during use.
Each of the rolling elements is provided with a contact angle between the inner ring raceway and the outer ring raceway.
Moreover, the said holder | retainer hold | maintains each said rolling element so that rolling is possible.
The revolving speed detection encoder is provided on the axial side surface of the cage over the entire circumference, and the characteristics of the surface to be detected existing on the axial side surface are alternately shown in the circumferential direction. And it is changed at equal intervals.
The mounting hole is provided in the outer ring equivalent member.
In addition, the revolution speed detection sensor is provided at the tip of a sensor unit having an insertion portion to be inserted into the mounting hole, and by making the detection portion face the detected surface of the revolution speed detection encoder, The revolution speed of the rolling element is detected.
The computing unit calculates a load applied between the outer ring equivalent member and the inner ring equivalent member based on a detection signal sent from the revolution speed detection sensor.
Further, the mounting hole is provided in a direction inclined with respect to the radial direction of the outer ring equivalent member, and the revolution speed detecting encoder is inclined on the side surface in the axial direction of the cage in the same direction as the mounting hole. The detected surface of the revolution speed detection encoder and the detection part of the revolution speed detection sensor are arranged substantially parallel to each other.

The load measuring device of the rolling bearing unit of the present invention configured as described above can measure the load applied to the rolling bearing unit by detecting the revolution speed of the rolling element. That is, when a load is applied to a rolling bearing unit such as a ball bearing, the contact angle of the rolling elements (balls) changes, and the revolution speed of each rolling element changes. Therefore, if this revolution speed is detected, a load acting between the outer ring equivalent member and the inner ring equivalent member can be obtained.
Furthermore, according to the load measuring device of the rolling bearing unit of the present invention, since the mounting hole is provided in a direction inclined with respect to the radial direction of the outer ring equivalent member, the shape of the inner ring equivalent member and the outer ring equivalent member are suspended. The sensor unit can be assembled in the mounting hole regardless of the space problem when mounting to the apparatus. Further, even if it becomes necessary to insert / remove the sensor unit into / from the mounting hole with the outer ring equivalent member attached to the suspension device for repair or the like, this operation can be easily performed.
Even in this case, since the detection surface of the revolution speed detection encoder and the detection part of the revolution speed detection sensor are arranged substantially in parallel, the change of the detection signal of the revolution speed detection sensor is stabilized and the rotation speed detection sensor is changed. Ensuring the reliability of detecting the revolution speed of moving objects. Further, even when the cage swings due to the influence of the pocket gap, etc., the detected surface of the revolution speed detection encoder and the detection part of the revolution speed detection sensor are difficult to come into contact with each other. It is possible to make it difficult to damage the detection surface and the detection part of the revolution speed detection sensor. As a result, it becomes easy to detect the revolution speed and to ensure the reliability of the load measurement.

When the present invention is implemented, preferably, as described in claim 2, a double row outer ring raceway is provided on the inner peripheral surface of the outer ring equivalent member, and a double row inner ring raceway is provided on the outer peripheral surface of the inner ring equivalent member. At the same time, a plurality of rolling elements are provided between the outer ring raceways and the inner ring raceways with contact angles in opposite directions. A pair of revolution speed detection encoders are provided on the axial side surfaces of the pair of cages that hold the rolling elements of each row in a freely rolling manner. Further, a mounting hole is provided at a portion between the outer ring raceways at an intermediate portion in the axial direction of the outer ring equivalent member, and is provided on a side surface opposite to each other with respect to the axial direction of the outer ring equivalent member at the tip portion of the sensor unit. The detection portions of the revolution speed detection sensors are opposed to the detected surfaces of the both revolution speed detection encoders.
Thus, if it comprises so that the revolution speed of the rolling element arrange | positioned in a double row may be detected, the load which acts between the said outer ring equivalent member and the said inner ring equivalent member will be calculated | required more accurately. Further, by obtaining the load based on the ratio between the revolution speed of one row and the revolution speed of the other row, this load can be obtained even when the rotational speed of the inner ring equivalent member changes.

When carrying out the invention described in claim 2 as described above, preferably, as described in claim 3, the intermediate ring-corresponding member is positioned at the intermediate portion in the axial direction between the pair of inner ring tracks. An encoder for detecting rotational speed having an outer peripheral surface as a detection surface is provided. And the detection part of the rotational speed detection sensor installed in the front end surface of the said sensor unit is made to oppose the to-be-detected surface of the said rotational speed detection encoder.
If comprised in this way, the measurement precision of the said load in case the rotational speed of the said inner ring | wheel equivalent member will change can be improved.
When the invention described in claim 3 is carried out, it is more preferable that the tip surface of the sensor unit is inclined with respect to the central axis of the sensor unit as described in claim 4. The tip surface is substantially parallel to the axial direction of the inner ring equivalent member. The detection unit of the rotation speed detection sensor and the detected surface of the rotation speed detection encoder are arranged substantially in parallel.
With this configuration, since the magnetic flux flows orthogonally through the detection part of the sensor, the change in the detection signal of the rotational speed detection sensor is stabilized, and the rotational speed of the inner ring equivalent member is detected. It is possible to ensure the reliability of the load measurement acting between the equivalent member and the inner ring equivalent member.

  FIG. 1 shows a first embodiment of the present invention corresponding to claims 1 to 3. The feature of this embodiment is that the mounting hole 10b formed in the portion between the pair of outer ring raceways 7 and 7 at the intermediate portion in the axial direction of the outer ring 1 is also inclined with respect to the central axis of the outer ring 1. The detection units of the revolution speed detection sensors 23a and 23b and the detected surfaces of the revolution speed detection encoders 25a ′ and 25b ′ are substantially (= substantially = excluding assembly errors, etc.) In fact) in parallel points. The basic configuration and operation of the rolling bearing unit and the load measuring device are the same as the structure according to the previous invention shown in FIG. In addition, the structure that is different due to the use of the rolling bearing unit for the drive wheel is the same as the structure shown in FIG. Therefore, the same components as those shown in FIG. 7 or FIG. 5 are denoted by the same reference numerals and redundant description will be omitted, and the characteristic portions of the present embodiment will be mainly described below.

  In the case of the present embodiment, the mounting hole 10b is formed in a portion between the double row outer ring raceways 7 and 7 in the axial intermediate portion of the outer ring 1 in the direction toward the outer side in the axial direction toward the outer side in the radial direction. It is provided in an inclined state with respect to the central axis of the outer ring 1. The portion surrounding the opening of the mounting hole 10b on the outer peripheral surface of the outer ring 1 is a mounting surface 29 that exists in a direction perpendicular to the central axis of the mounting hole 10b. The one side of the outward flange-shaped attachment portion 30 provided at the base end portion of the base plate is freely abutted. Of the tip 22 of the sensor unit 21 projecting radially inward from the inner peripheral surface of the outer ring 1, the two revolution speed detecting sensors 23a and 23b are provided on both sides of the outer ring 1 in the axial direction. Is provided. Magnetic detecting elements such as Hall elements and magnetoresistive elements that constitute the detecting portions of the revolution speed detecting sensors 23 a and 23 b are arranged in parallel to the central axis of the sensor unit 21. Therefore, this magnetic detection element is provided in an inclined state with respect to the central axis of the outer ring 1.

  Further, a pair of retainers 24a 'and 24b' that rotatably hold the rolling elements 9a and 9b arranged in a double row are provided with the respective rim portions 31a and 31b facing each other. . Side surfaces of the rim portions 31a and 31b that face each other are partially conical convex surfaces (an axially outer retainer 24a) that are inclined by the same angle as the mounting hole 10b in the radially outward direction. 'In the case of the rim portion 31a) or a partially conical concave surface (in the case of the rim portion 31b of the cage 24b' on the inner side in the axial direction). Revolution speed detecting encoders 25a 'and 25b' are provided on the side surfaces of the rim portions 31a and 31b facing each other. The thicknesses of the two revolution speed detecting encoders 25a 'and 25b' in the axial direction are uniform over almost the entire width in the radial direction (except for the pole portions of the inner and outer peripheral edges). Accordingly, the detected surfaces of the two revolution speed detecting encoders 25a ′ and 25b ′ are inclined by the same angle as the mounting hole 10b in the direction of the outer side in the radial direction. As a result, the detection portions of the revolution speed detection sensors 23a and 23b and the detected surfaces of the revolution speed detection encoders 25a ′ and 25b ′ are parallel to each other.

  According to the load measuring device of the rolling bearing unit of the present embodiment configured as described above, since the mounting hole 10b is provided in a direction inclined with respect to the radial direction of the outer ring 1, the shape of the hub 2b, Regardless of the shape of the constant velocity joint coupled and fixed to the hub 2b, and the space problem when the outer ring 1 is attached to the knuckle 16 (see FIG. 4) constituting the suspension device, the sensor is inserted into the attachment hole 10b. The unit 21 can be assembled. Further, even if it becomes necessary to insert / remove the sensor unit 21 into / from the mounting hole 10b while the outer ring 1 is mounted on the knuckle 16 for repair or the like, this operation can be easily performed.

  Even when the mounting hole 10b is inclined in order to obtain such actions and effects, the detection surfaces of the two revolution speed detection encoders 25a 'and 25b' and the two revolution speed detection sensors 23a and 23b are detected. Are arranged substantially parallel to each other, so that the magnetic flux emitted from the detected surfaces of the two revolution speed detection encoders 25a 'and 25b', each of which is made of a permanent magnet, becomes the two revolution speed detection sensors 23a, It flows in a direction substantially orthogonal to the detection unit 23b. For this reason, it is possible to stabilize the change in the detection signals of both the revolution speed detection sensors 23a and 23b and to ensure the reliability of the revolution speed detection of the rolling elements 9a and 9b. Further, even when the cages 24a 'and 24b' are swung around due to the influence of pocket gaps, etc., the detected surfaces of the two revolution speed detecting encoders 25a 'and 25b' and the both revolution speed detecting sensors 23a, It becomes difficult for the detection part of 23b to contact. As a result, the detection surfaces of the two revolution speed detection encoders 25a 'and 25b' and the detection parts of the two revolution speed detection sensors 23a and 23b can be hardly damaged, and the revolution speed detection and the load measurement can be performed. It is easy to ensure reliability.

  It should be noted that the structure in which the detection surfaces of both the revolution speed detection encoders are inclined so that the detection surface of the both revolution speed detection encoders and the detection part of the both revolution speed detection sensors are substantially parallel to each other is the same. This can also be realized by making the thickness in the axial direction of the speed detection encoder different in the radial direction. That is, instead of using a general cage as shown in FIG. 5 or FIG. 7 as a cage for holding each rolling element, a radially outer side is provided on the axially inner side surface of the cage outside in the axial direction. It is possible to provide a revolution speed encoder whose thickness dimension decreases as it goes in the direction, and a revolution speed encoder whose thickness dimension increases as it goes outward in the radial direction on the axially outer surface of the cage inside in the axial direction. The above structure can be realized. Even if the sensor unit cannot be installed between the outer ring raceways of the double row due to some problem such as space, it is necessary to provide a revolution speed detection sensor at the end of the outer ring. In the configuration, it is effective for improving the reliability of load detection to make the detected surface of the revolution speed detection encoder parallel to the detection portion of the revolution speed detection sensor.

FIG. 2 shows a second embodiment of the present invention corresponding to claims 1 to 4. In the case of the present embodiment, the front end surface 32 of the sensor unit 21a is inclined with respect to the central axis of the sensor unit 21a so that the front end surface 32 is substantially parallel to the axial direction of the hub 2b. And it is a to-be-detected surface of the rotational speed detection encoder 13a made of a permanent magnet, which is externally fixed to the detection part of the rotational speed detection sensor 15a and the intermediate part of the hub 2b. The outer peripheral surface is parallel.
In the case of the present embodiment, with this configuration, the magnetic flux emitted from the outer peripheral surface of the rotational speed detection encoder 13a flows almost orthogonally through the detection portion of the rotational speed detection sensor 15a. The change of the detection signal of the speed detection sensor 15a is stabilized to ensure the reliability of the rotation speed detection of the hub 2b, and further the measurement of the load acting between the outer ring 1 and the hub 2b.
Since the configuration and operation of the other parts are the same as those in the first embodiment described above, a duplicate description is omitted.

FIG. 2 is a half sectional view showing Example 1 of the present invention. FIG. 6 is a half sectional view showing the second embodiment. Sectional drawing of the rolling bearing unit which incorporated the sensor for radial load measurement known conventionally. Sectional drawing of the rolling bearing unit which incorporated the sensor for axial load measurement conventionally known. Sectional drawing of the load measuring apparatus of the rolling bearing unit which concerns on a prior invention. The schematic diagram for demonstrating the reason for which the load added to a rolling bearing unit is calculated | required. Sectional drawing of the half part for demonstrating the problem at the time of inclining the insertion direction of a sensor unit with the structure of a prior invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a Outer ring 2, 2a Hub 3, 3a Rotation side flange 4 Hub main body 5 Nut 6 Inner ring 7 Outer ring raceway 8 Inner ring raceway 9a, 9b Rolling element 10, 10a, 10b Mounting hole 11 Displacement sensor 12 Sensor ring 13, 13a Rotational speed Detection encoder 14 Cover 15, 15a Rotational speed detection sensor 16 Knuckle 17 Fixed side flange 18 Bolt 19 Screw hole 20 Load sensor 21, 21a Sensor unit 22 Tip 23a, 23b Revolution speed detection sensor 24a, 24b, 24a ', 24b 'Cage 25a, 25b, 25a', 25b 'Revolution speed detection encoder 26 Spline hole 27 Combination seal ring 28 Space 29 Mounting surface 30 Mounting portion 31a, 31b Rim portion 32 Tip surface

Claims (4)

  An outer ring equivalent member having an outer ring raceway on the inner peripheral surface and an outer ring equivalent member arranged on the inner diameter side of the outer ring equivalent member concentrically with the outer ring equivalent member and having an inner ring raceway on the outer peripheral surface and rotating during use. An inner ring equivalent member, a plurality of rolling elements provided with a contact angle between the inner ring raceway and the outer ring raceway, a cage that holds each of the rolling bodies in a freely rollable manner, and this holding A revolving speed detecting encoder provided on the entire axial side surface of the vessel, wherein the characteristics of the detected surface existing on the axial side surface are changed alternately at equal intervals in the circumferential direction, and the outer ring By providing the mounting hole provided in the corresponding member and the tip of the sensor unit having the insertion portion inserted into the mounting hole, by making the detection portion face the detection surface of the revolution speed detection encoder, For detecting the revolution speed of the rolling element A rotation speed detection sensor, and a calculator for calculating a load applied between the outer ring equivalent member and the inner ring equivalent member based on a detection signal sent from the revolution speed detection sensor, The revolution speed detecting encoder is provided on the side surface in the axial direction of the cage in a state inclined in the same direction as the mounting hole. A load measuring device for a rolling bearing unit in which a detected surface of a speed detecting encoder and a detecting portion of the revolution speed detecting sensor are arranged substantially in parallel.   A double row outer ring raceway is provided on the inner peripheral surface of the outer ring equivalent member, and a double row inner ring raceway is provided on the outer peripheral surface of the inner ring equivalent member. A plurality of outer ring raceways are provided between the outer ring raceway and the inner ring raceway. The rolling elements are provided with contact angles in opposite directions, and a pair of revolution speeds on opposite axial side surfaces of a pair of cages that hold the rolling elements of each row in a freely rolling manner. An encoder for detection is provided, and the mounting hole is provided at an intermediate portion in the axial direction of the outer ring equivalent member at a portion between the outer ring raceways. The load measurement of the rolling bearing unit according to claim 1, wherein detection parts of a pair of revolution speed detection sensors provided on opposite side surfaces are opposed to the detection surfaces of the two revolution speed detection encoders, respectively. apparatus.   A rotation speed detection encoder having an outer peripheral surface as a detected surface is provided at a portion between the pair of inner ring raceways in the axial intermediate portion of the inner ring equivalent member, and the rotation speed installed on the front end surface of the sensor unit. The load measuring device for a rolling bearing unit according to claim 2, wherein a detection portion of the detection sensor faces a detection surface of the rotation speed detection encoder.   By tilting the front end surface of the sensor unit with respect to the central axis of the sensor unit, the front end surface is made substantially parallel to the axial direction of the inner ring equivalent member, and the detection unit of the rotation speed detection sensor and the rotation speed detection encoder The load measuring device for a rolling bearing unit according to claim 3, wherein the surface to be detected is arranged substantially in parallel.

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