JP2005114710A - Load-measuring instrument for rolling bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize structure capable of measuring revolution speeds of respective rolling elements 9a, 9b to measure a load applied onto an outer ring 1 and hub 2b, irrespective of the spacing between the rollers 9a, 9b arranged in a double row. <P>SOLUTION: Dimensions in the axial-directional of rim parts 28, 28 of holders 29a, 29b for holding the respective rolling elements 9a, 9b are made large. Revolution speed measuring encoders 25a, 25b are provided respectively on faces opposed to each other in the respective rim parts 28, 28. Detecting parts for revolving speed detecting sensors 23a, 23b held in a single sensor unit 21 are proximity-faced on detected faces of the respective revolving speed measuring encoders 25a, 25b. According to this constitution, the revolving speeds of respective rolling elements 9a, 9b are measured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  A load measuring device for a rolling bearing unit according to the present invention relates to an improvement of a rolling bearing unit for supporting wheels of a moving body such as an automobile, a railway vehicle, and various transport vehicles. One or both of radial load and axial load) is measured and used to ensure the stability of operation of the moving body.

  For example, an automobile wheel is rotatably supported by a double row angular rolling bearing unit with respect to a suspension device. Also, in order to ensure the running stability of automobiles, anti-brake brake system (ABS), traction control system (TCS), and vehicle stability control system (VSC) are used. ing. In order to control such various vehicle running state stabilization devices, 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. This conventional rolling bearing unit with a load measuring device according to the first example 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 rotation side flange 3 for fixing the wheel outside (the outside in the axial direction is the outside in the width direction in the assembled state in the vehicle, the left side of each figure. The same applies to the hub body 4 at the end, and the inside of the hub body 4 (the inside in the axial direction is the side that is the center side in the width direction when assembled to the vehicle, and the right side of each figure. And an inner ring 6 that is externally fitted to the end and held down by a nut 5. 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) 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. 29, the rotation speed of the hub 2 can be detected in addition to the load applied to the rolling bearing unit. 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. 30 shows a rolling bearing unit with a load measuring device described in Patent Document 2 for measuring an axial load. 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 first example of the conventional structure shown in FIG. 29 described above, the displacement sensor 11 measures the displacement in the radial direction between the outer ring 1 and the hub 2 to measure the load applied to the rolling bearing unit. 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. 30 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. Furthermore, it is considered that it is difficult to accurately obtain the load applied to the rolling bearing unit because the measurement accuracy of the revolution speed of the rolling element cannot be sufficiently secured.

  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. 31 shows a load measuring device for a rolling bearing unit according to the present invention. In the case of the structure according to the prior 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, and the tip 22 of the sensor unit 21 is connected to the sensor unit 21. The outer ring 1 protrudes from the inner peripheral surface. 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. In addition, the rotational speed of the hub 2 can be detected by making the detection portion of the rotational speed detection sensor 15a close to and opposed to the rotational speed detection encoder 26 that is externally fitted and fixed to the intermediate portion of the hub 2. 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. Thrust load).

  In order to detect the revolution speed of the rolling elements 9a and 9b in each row in order to obtain the load applied between the outer ring 1 and the hub 2 by the load measuring device of the rolling bearing unit according to the above-mentioned prior invention. Needs to make the detection parts of the revolution speed detection sensors 23a, 23b close to and face the revolution speed detection encoders 25a, 25b. In the case of the structure according to the prior invention shown in FIG. 31, each of the revolution speed detection sensors 23a and 23b is embedded and supported in the holder 27 together with the rotation speed detection sensor 15a to constitute a single sensor unit 21, The tip 22 of the sensor unit 21 is inserted between the pair of cages 24a and 24b.

  On the other hand, there are various types of rolling bearing units for supporting the wheels, the specifications of which differ, and the intervals between the rolling elements 9a, 9b provided in double rows, and thus the rolling elements 9a in each of these rows, The distance between the pair of holders 24a and 24b holding 9b is also different. For example, in the case of a rolling bearing unit for a relatively large automobile, this interval is large, and in the case of a rolling bearing unit for a small automobile, this interval is narrow. On the other hand, the size required for the sensor unit 21 is not so different between the case of a large automobile and the case of a small automobile.

  Accordingly, when the distance between the pair of cages 24a and 24b is large (for example, 20 mm or more) in a rolling bearing unit for a large automobile, the tip of the sensor unit 21 is simply between the cages 24a and 24b. If only 22 is inserted, the distance between the detection portions of the pair of revolution speed detection sensors 23a and 23b and the detected surfaces of the pair of revolution speed detection encoders 25a and 25b may not be appropriately set. Specifically, the distance between the detected surface of each of the revolution speed detecting encoders 25a and 25b and the detecting portion of each of the revolution speed detecting sensors 23a and 23b is too large, and the rolling elements 9a and 9b in the respective rows are arranged. There is a possibility that the reliability of the detection of the revolution speed is impaired. In this case, the width dimension of the sensor unit 21 in the axial direction of the outer ring 1 may be increased to increase the interval between the detection portions of the pair of revolution speed detection sensors 23a and 23b held in the sensor unit 21. Conceivable. However, in this case, it is necessary to enlarge the mounting hole 10a formed in the outer ring 1 so that the sensor unit 21 can be inserted, which is disadvantageous in terms of securing the strength of the outer ring 1.

  On the other hand, when the distance between the pair of retainers 24a and 24b is narrow (for example, 11 mm or less) in a rolling bearing unit for a small automobile, both of these retainers are retained in the structure according to the prior invention shown in FIG. There is a possibility that the tip 22 of the sensor unit 21 cannot be inserted between the devices 24a and 24b. In this case, it is also conceivable that the detection surface of the revolution speed detection encoder is the outer peripheral surface, and the detection surface and the detection portion of the revolution speed detection sensor are opposed to each other in the radial direction (radial direction). However, such a structure is not preferable because the degree of freedom in designing the load measuring device for the rolling bearing unit is limited, for example, it is difficult to arrange the revolution speed detection sensor.

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 makes it possible to detect the revolution speed of the rolling elements arranged in a double row regardless of the distance between the pair of cages, and to apply the load between the outer ring and the hub. It was invented to realize a load measuring device for a rolling bearing unit capable of measuring the above.

Each of the load measuring devices of the rolling bearing unit of the present invention includes an outer ring, a hub, a plurality of rolling elements, a pair of retainers, a pair of revolution speed detection sensors, and a computing unit.
Among these, the outer ring has a double row outer ring raceway on the inner peripheral surface, and does not rotate during use.
The hub is disposed concentrically with the outer ring on the inner diameter side of the outer ring, and rotates when in use. The hub has double-row inner ring raceways on the outer peripheral surface.
In addition, each of the rolling elements is divided into a plurality of rows between the inner ring raceways and the outer ring raceways, and a plurality of each of the rows is provided, and the direction of the contact angle is reversed between the rows. And can be rolled freely.
Each of the cages is for holding the rolling elements of each row in a freely rollable manner.
Each revolution speed detection sensor detects the revolution speed of the rolling elements in each row as the rotation speed of each cage.
The calculator calculates a load applied between the outer ring and the hub based on a detection signal sent from each revolution speed detection sensor.

  In the case of the rolling bearing unit load measuring device described in claims 1 and 2, the pair of revolution speed detecting sensors is held by a single sensor unit. The sensor unit is formed in a single mounting hole provided in a state where the outer ring passes through the outer ring in the radial direction of the outer ring at a portion between the double row outer ring raceways in the axially intermediate portion of the outer ring. Has been inserted.

  Further, in the rolling bearing unit load measuring device according to claim 1, each of the cages is provided with the respective rim portion positioned on the sensor unit side. At least one rim portion of the rim portions extends in the axial direction toward the sensor unit beyond the length originally required for the rim portion. And the characteristic of the to-be-detected surface which is the one axial side surface which opposes the said sensor unit is changed alternately and equidistantly with respect to the circumferential direction on the axial direction end surface which mutually opposes among the rim | limb parts of each said holder | retainer. The revolution speed detection encoder is provided, and the distance between the detected surface of each revolution speed detection encoder and the detection portion of each revolution speed detection sensor is regulated to an appropriate value.

  On the other hand, in the case of the load measuring device for a rolling bearing unit according to claim 2, each of the cages is provided with its rim portion positioned on the sensor unit side. Revolution speed detection encoder in which the characteristics of the surface to be detected, which is one side surface in the axial direction facing the sensor unit, are alternately and equally spaced in the circumferential direction on the axial end surfaces of the rim portions facing each other. Is provided. Then, by making the thickness dimension in the axial direction of at least one of the revolution speed detection encoders of these revolution speed detection encoders larger than the thickness dimension originally required for the encoder, each of the revolution speed detection encoders. The distance between the detected surface of the speed detection encoder and the detection part of each revolution speed detection sensor is regulated to an appropriate value.

  In the rolling bearing unit load measuring device according to the third aspect, the pair of revolution speed detection sensors are held by a pair of independent sensor units. Each of these sensor units is provided in a pair of mounting holes provided in a state of penetrating the outer ring in the radial direction of the outer ring at two positions apart from each other in the axial direction of the outer ring. Has been inserted. A detected surface whose characteristics are alternately changed at equal intervals in the circumferential direction on one axial side surface of the revolution speed detecting encoder provided on the axial end surface of the rim portion of each cage, and each sensor The distance with the detection part of each said revolution speed detection sensor hold | maintained at the unit is controlled to an appropriate value.

The load measuring device of the rolling bearing unit of the present invention configured as described above is loaded on the rolling bearing unit by detecting the revolution speeds of a pair of rolling elements with different contact angle directions. The load can be measured. That is, when a load is applied to a rolling bearing unit such as a double row angular type ball bearing or a double row tapered roller bearing, the contact angle of the rolling element (ball) changes, and the revolution speed of the rolling element changes. Therefore, if this revolution speed is detected as the rotational speed of the cage, a load acting between the outer ring and the hub can be obtained.
Furthermore, the load measuring device of the rolling bearing unit of the present invention can detect the revolution speed of the rolling elements arranged in double rows regardless of the distance between the pair of cages. Accordingly, the load applied between the outer ring and the hub can be measured regardless of the specifications of the rolling bearing unit.

When the invention described in claim 3 is carried out, a structure such as that described in claims 4 to 6 can be preferably employed.
In the case of the structure described in claim 4, a pair of mounting holes are provided in a portion between the pair of outer ring raceways at the axially intermediate portion of the outer ring. And the to-be-detected surface of a pair of revolution speed detection encoder provided in the rim | limb part of a pair of holder | retainer is arrange | positioned on the mutually opposing side.
With this configuration, even when the distance between the rim portions of a pair of cages is wide like a large rolling bearing unit, the revolution speed of the double row rolling elements is set as the rotational speed of each cage. It can be detected.

  Further, in the case of the structure described in claim 5, a pair of mounting holes are provided at a portion between a pair of outer ring raceways and both end surfaces in the axial direction of the outer ring at both ends in the axial direction of the outer ring. And the to-be-detected surface of a pair of revolution speed detection encoder provided in the rim | limb part of a pair of holder | retainer is arrange | positioned on the opposite side. If comprised in this way, even when a space | interval of a pair of retainers is narrow like a small rolling bearing unit, the revolution speed of a double row rolling element can be detected as a rotational speed of each of these retainers.

Further, in the case of the structure described in claim 6, the pair of mounting holes are provided with a portion between the pair of outer ring raceways in the axial intermediate portion of the outer ring and one outer ring raceway at one axial end portion of the outer ring. And a portion between the outer ring and one end surface in the axial direction. And the to-be-detected surface of a pair of revolution speed detection encoder provided in the rim | limb part of a pair of holder | retainer is arrange | positioned mutually on the same side regarding an axial direction.
Such a structure is effective when a relatively small rolling bearing unit is used, and the distance between the rolling elements arranged in double rows in the axial direction is narrow enough to accommodate only one revolution speed detection sensor. It is. That is, the revolution speed of the double-row rolling elements can be detected as the rotational speed of the two cages while using the space between the rolling elements of both rows.

When carrying out the invention described in claims 3 to 6, preferably, as described in claim 7, a pair of mounting holes are formed in parallel to each other. Further, the base end portions of a pair of sensor units provided in parallel with each other, which are respectively inserted into these mounting holes, are integrally connected to each other by a connecting portion provided on the outer diameter side of the outer ring.
If comprised in this way, the workability | operativity of attachment of the said both sensor units with respect to the said outer ring will improve.

Preferably, as described in claim 8, a ball is used as each rolling element, and a double-row angular outer ring raceway formed on the inner peripheral surface of the outer ring and a multi-row formed on the outer peripheral surface of the hub. A contact angle of the back combination type is given to a plurality of balls provided between the inner ring raceway of the row angular type.
If comprised in this way, the said load can be measured with sufficient precision with a highly rigid rolling bearing unit.

Preferably, as described in claims 9 and 10, a rotational speed supported by a part of the outer ring on a detected surface of a rotational speed detection encoder provided concentrically with the hub in a part of the hub. By making the detection portions of the detection sensors face each other, the rotational speed of the hub can be detected freely.
Then, the computing unit determines whether the outer ring and the hub are located on the basis of the ratio between the revolution speed of the rolling elements in one row and the revolution speed of the rolling elements in the other row and the rotation speed of the hub. The radial load applied to is calculated (in the case of the invention described in claim 9). Alternatively, the axial force applied between the outer ring and the hub is based on the ratio between the revolution speed of the rolling elements in one row and the revolution speed of the rolling elements in the other row and the rotational speed of the hub. The load is calculated (in the case of the invention described in claim 10).
If comprised in this way, the load (radial load and thrust load) applied to a rolling bearing unit can be calculated | required correctly irrespective of the fluctuation | variation of the rotational speed of the said hub. If the axial load is calculated based on the ratio of the revolution speeds of a pair of rolling elements (in the case of the invention described in claim 11), this rotational speed can be obtained without obtaining the rotational speed of the hub. Regardless of the change, the axial load can be accurately obtained.

  1 to 4 show a first embodiment of the present invention corresponding to claims 1 and 8 to 11. In this embodiment, the loads (radial load and axial load) applied to the rolling bearing unit for supporting the driving wheels of the automobile (the rear wheel of the FR vehicle, the RR vehicle, the MR vehicle, the front wheel of the FF vehicle, and all the wheels of the 4WD vehicle). ) Is measured when the present invention is applied to a load measuring device for a rolling bearing unit. A hub 2b for coupling and fixing the wheels is supported on the inner diameter side of the outer ring 1 supported by the suspension device. The hub 2b includes a hub main body 4a having a rotation side flange 3 for fixing a wheel at an outer end in the axial direction, and an inner ring 6 fitted on the inner end in the axial direction of the hub main body 4a. A spline hole 31 for inserting a spline shaft attached to a constant velocity joint (not shown) is formed at the center of the hub body 4a. The inner end surface of the inner ring 6 is in contact with the outer end surface of the housing of the constant velocity joint in a state where the hub 2b is coupled and fixed to the constant velocity joint, thereby preventing the inner ring 6 from coming off from the hub body 4a.

Between the double-row angular inner ring raceways 8 and 8 formed on the outer peripheral surface of the hub 2b and the double-row angular outer ring raceways 7 and 7 formed on the inner peripheral surface of the outer ring 1, respectively. By dividing the moving bodies (balls) 9a, 9b into double rows (two rows) and providing a plurality of them for each row while being held by the retainers 29a, 29b, the inner diameter of the outer ring 1 is provided. The hub 2b is rotatably supported on the side. In this state, the rolling elements 9a and 9b in each row are provided with contact angles α _a and α _b (FIG. 4) in opposite directions and in the same direction, and are combined with a back row type double row angular contact. Configures a ball bearing. Sufficient preload is applied to the rolling elements 9a and 9b in each row so as not to be lost due to an axial load applied during use. When such a rolling bearing unit is used, the outer ring 1 is supported and fixed to a suspension device, and a braking disk and a wheel of a wheel are supported and fixed to the rotation side flange 3 of the hub 2b.

  A state in which a single mounting hole 10a is penetrated in the radial direction through the outer ring 1 between the double row outer ring raceways 7 and 7 at the axially intermediate portion of the outer ring 1 constituting the rolling bearing unit as described above. It is formed with. A single sensor unit 21 is inserted into the mounting hole 10a from the radially outer side of the outer ring 1 to the inner side, and the tip 22 of the sensor unit 21 is projected from the inner peripheral surface of the outer ring 1. ing. The tip portion 22 is provided with a pair of revolution speed detection sensors 23a and 23b and one rotational speed detection sensor 15a.

  Of these, the revolution speed detecting sensors 23a, 23b are for measuring the revolution speed of the rolling elements 9a, 9b arranged in the double row, and the axial direction of the hub 2b in the tip portion 22 is measured. Each detection surface is arrange | positioned on the both side surfaces regarding (the left-right direction of FIGS. 1-2). In this embodiment, the revolution speed detection sensors 23a and 23b detect the revolution speeds of the rolling elements 9a and 9b arranged in the double row as the rotation speeds of the cages 29a and 29b. For this reason, in the case of the present embodiment, the rim portions 28, 28 constituting the respective retainers 29a, 29b are arranged on the sides facing each other. Then, revolving speed detection encoders 25a and 25b each having a ring shape are attached and supported on the surfaces of the rim portions 28 and 28 facing each other over the entire circumference. The characteristics of the detected surfaces of the revolution speed detecting encoders 25a and 25b are changed alternately and at equal intervals in the circumferential direction, and the rotational speeds of the cages 29a and 29b are changed to the revolution speed detecting sensors. Detection is possible by 23a and 23b.

  For this purpose, the detection surfaces of the revolution speed detection sensors 23a and 23b are made to face each other in close proximity to the surfaces that are the detection surfaces of the revolution speed detection encoders 25a and 25b. The distance (measurement gap) between the detected surface of each revolution speed detecting encoder 25a, 25b and the detection surface of each revolution speed detecting sensor 23a, 23b is the inner surface of the pocket of each retainer 29a, 29b. And larger than a pocket gap, which is a gap between the rolling elements 9a and 9b, and preferably 2 mm or less. If the measurement gap is equal to or less than the pocket gap, there is a possibility that the detected surface and the detection surface may rub against each other when the cages 29a and 29b are displaced by the pocket gap. On the contrary, if the measurement gap exceeds 2 mm, it becomes difficult to accurately measure the rotations of the revolution speed detecting encoders 25a and 25b by the revolution speed detection sensors 23a and 23b.

In this embodiment, the distance (measurement gap) between the detected surface of each of the revolution speed detection encoders 25a and 25b and the detection surface of each of the revolution speed detection sensors 23a and 23b is limited to the appropriate range as described above. In this case, the rim portions 28 and 28 of the retainers 29 a and 29 b are extended in the axial direction toward the sensor unit 21. That is, the axial dimensions of the rim portions 28, 28 are made larger than necessary for securing the strength of the retainers 29a, 29b. Therefore, the distance D28 between the pair of rim portions 28, ₂₈ is larger than that in the case where the general cages 24a, 24b are incorporated in the rolling bearing unit of this embodiment as shown in FIG. It is getting shorter. Therefore, in the case of the present embodiment, although the distance between the inner ring raceways 8 and 8 and the distance between the outer ring raceways 7 and 7 are wider than those in the structure according to the prior invention shown in FIG. The distance D ₂₈ between the pair of rim portions 28, ₂₈ is substantially the same as that of the structure according to the present invention. Therefore, despite the large spacing between the inner ring raceways 8 and 8 and the spacing between the outer ring raceways 7 and 7, the rotational speed of the retainers 29a and 29b, and thus the rolling elements 9a and 9a, The reliability of the revolution speed detection of 9b can be ensured. Further, since it is not necessary to increase the inner diameter of the mounting hole 10a, it is possible to suppress a decrease in the strength of the outer ring 1.

  On the other hand, the rotational speed detection sensor 15a is for measuring the rotational speed of the hub 2b, and its detection surface is arranged on the distal end surface of the distal end portion 22, that is, the radially inner end surface of the outer ring 1. doing. A cylindrical rotational speed detecting encoder 26 is externally fitted and fixed between the double-row inner ring raceways 8 and 8 at the intermediate portion of the hub 2b. The detection surface of the rotation speed detection sensor 15a is opposed to the outer peripheral surface, which is the detection surface of the rotation speed detection encoder 26. The characteristics of the surface to be detected of the rotational speed detecting encoder 26 are changed alternately and at equal intervals in the circumferential direction so that the rotational speed of the hub 2b can be detected by the rotational speed detecting sensor 15a. The measurement gap between the outer peripheral surface of the rotational speed detection encoder 26 and the detection surface of the rotational speed detection sensor 15a is also suppressed to 2 mm or less.

  As the encoders 25a, 25b, and 26, those of various structures that have been used for detecting the rotational speed of the wheel in order to obtain ABS and TCS control signals can be used. For example, as each of the encoders 25a, 25b, and 26, as shown in FIG. 3, a multi-pole magnet made by alternately arranging N poles and S poles on the detection surface (side surface or outer peripheral surface) at equal intervals. Can be preferably used. However, a simple encoder made of a magnetic material can also be used. Regardless of which structure is used as each of the encoders 25a, 25b, and 26, the output signal of each rotational speed detection sensor changes at a frequency proportional to the rotational speed.

  In the case of the present embodiment, each of the revolution speed detecting encoders 25a and 25b is an annular permanent magnet in which S poles and N poles are alternately arranged at equal intervals on the side surface in the axial direction, which is the detected surface. Is used. Such revolving speed detecting encoders 25a and 25b are bonded and fixed to the side surfaces of the rim portions 28 and 28 of the holders 29a and 29b separately manufactured, or these holders 29a and 29b are bonded. When injection molding is performed, insert molding is performed by setting the revolving speed detection encoders 25a and 25b in the cavity. Alternatively, two-color molding may be performed, or magnetic powder may be mixed into the synthetic resin or the like constituting each of the cages 29a and 29b to magnetize them. Which method is adopted is selected according to the cost, the required bond strength, and the like.

  Further, as each of the revolution speed detection sensors 23a and 23b and the rotation speed detection sensor 15a, which are sensors for detecting the rotation speed, magnetic rotation speed detection sensors can be preferably used. As the magnetic rotational speed detection sensor, an active sensor incorporating a magnetic detection element such as a Hall element, Hall IC, magnetoresistive element (MR element, GMR element), or MI element can be preferably used. . Such a magnetic detection element is preferably formed as an IC package. In this case, the IC package may be SMT or lead type. In order to construct an active type rotational speed detection sensor incorporating such a magnetic detection element, for example, one side surface of the magnetic detection element is directly or via a stator made of a magnetic material, the magnetization direction of the permanent magnet. Abut against one end surface (when a magnetic material encoder is used) and the other side surface of the magnetic detection element directly or via a magnetic material stator to the detection surface of each encoder 25a, 25b, 26 Make them face each other. In this embodiment, a permanent magnet encoder is used, so that no permanent magnet on the sensor side is necessary.

In the case of the load measuring device of the rolling bearing unit of the present embodiment, which includes the sensor unit 21 incorporating the sensors 23a, 23b, 15a as described above, the detection signals of the sensors 23a, 23b, 15a are: It inputs into the calculator which is not illustrated through the cable 30. FIG. Then, based on the detection signals sent from the sensors 23a, 23b, 15a, the arithmetic unit applies one or both of a radial load and an axial load applied between the outer ring 1 and the hub 2b. Is 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 in each row 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. Further, the axial load is obtained by calculating the difference between the revolution speeds of the rolling elements 9a and 9b in each row detected by the revolution speed detection sensors 23a and 23b, and this difference and the rotational speed detection sensor 15a are detected. Calculation is based on the ratio to the rotational speed of the hub 2b. 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 9 a and 9 b in each row are the same in a state where the axial load F _a is not applied.

FIG. 4 schematically shows the rolling bearing unit for supporting the wheel shown in FIG. 1 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 F _r is applied to the rolling bearing unit during use due to the weight of the vehicle body or the like. Further, by the centrifugal force or the like applied during cornering, applied is the axial load F _a. These preloads F ₀ , F ₀ , radial load F _r , and axial load F _a 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 2b provided with each of 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 (1).
n _c = {1− (d · cos α / D) · (n _i / 2)} + {1+ (d · cos α / D) · (n _o / 2)} (1)

As is clear from this equation (1), the rolling elements 9a, the 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 As described above, the contact angles α _a and α _b change according to the radial load F _r and the axial load F _a . Thus the revolution speed n _c is changed according to these radial load F _r and axial load F _a. In this embodiment, the hub 2b is rotated, since the outer ring 1 is not rotated, specifically, with respect to the radial load F _r, the revolution speed n _c is slow enough to increase. Further, with respect to the axial load F _a, the revolution speed of the column that supports the axial load F _a faster, revolution speeds of the columns that do not support this axial load F _a is delayed. Therefore, the radial load F _r and the axial load F _a can be obtained based on the revolution speed n _c .

However, the contact angle α which leads to a change in the revolution speed n _c, as well as the radial load F _r and the axial load F _a is changed while associated with each other, also varies the preload F _0, F ₀ To do. Also, the revolution speed n _c is changed in proportion to the rotational speed n _i of the hub 2b. Therefore, if the radial load F _r , the axial load F _a , the preload F ₀ , F ₀ , and the rotational speed n _i of the hub 2b are not considered in relation to each other, the revolution speed n _c can be obtained accurately. Can not. 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. On the other hand, the radial load F _r , the axial load F _a , and the rotational speed n _i of the hub 2b constantly change according to the operating state, and therefore the influence cannot be eliminated by initial setting or the like.

In the case of the present embodiment in view of such circumstances, as described above, when the radial load F _r is obtained, the rolling elements 9a of the respective rows detected by the respective revolution speed detecting sensors 23a, 23b, by obtaining the sum of the revolution speeds of 9b, it is less affected in the axial load F _a. Further, when determining the axial load F _a , the influence of the radial load F _r is reduced by determining the difference in revolution speed between the rolling elements 9 a and 9 b in each row. Further calculation, in any case, and the sum or difference, the radial load F _r or the axial load F _a on the basis of the ratio between the rotational speed n _i of the hub 2b of the rotational speed detecting sensor 15a detects by and by eliminating the influence of the rotational speed n _i of the hub 2b. However, the axial load F _a, when calculating on the basis of the rolling elements 9a, 9b ratio of the revolution speed of said each row, the rotational speed N _i of the hub 2b is not necessarily required.

There are various other methods for calculating one or both of the radial load F _r and the axial load F _a based on the signals of the revolution speed detection sensors 23a and 23b. Such a method is described in detail in the above-mentioned Japanese Patent Application Nos. 2003-171715 and 172484, and is not related to the gist of the present invention.

In the case of the above-described first embodiment, a pair of revolution speeds provided on the side surfaces of the rim portions 28 and 28 by increasing the axial dimension of the rim portions 28 and 28 of the pair of retainers 29a and 29b. The interval between the detection surfaces of the detection encoders 25a and 25b is appropriately regulated. On the other hand, although not shown, as described in claim 2, by increasing the thickness dimension in the axial direction of each revolution speed detection encoder, the detected surface of each revolution speed detection encoder is detected. It is also possible to make the interval between each other appropriate.
Furthermore, even when the axial dimension of the rim portions 28, 28 is increased, or when the thickness dimension in the axial direction of each revolution speed detecting encoder is increased, the axial dimension of either one of the rim portions 28 or the encoder is increased. You can also enlarge only. In this case, the other axial dimension remains at the normal value. Further, the position of the mounting hole of the sensor is restricted so that the sensor can be brought closer to the other side.

  5 to 6 show a second embodiment of the present invention corresponding to claims 3, 4 and 8. In the case of the present embodiment, the pair of revolution speed detection sensors 23a and 23b are held in the tip portions 34a and 34b of the pair of sensor units 32a and 32b that are independent from each other. In order to mount each of these sensor units 32a and 32b, a pair of mounting holes 33a and 33b are provided at two positions spaced apart in the axial direction between the pair of outer ring raceways 7 and 7 in the middle portion of the outer ring 1 in the axial direction. Are provided in the radial direction of the outer ring 1 so as to penetrate the outer ring 1. Each of the sensor units 32a and 32b is inserted into the pair of mounting holes 33a and 33b from the outer diameter side to the inner diameter side of the outer ring 1, and the respective tip end portions 34a and 34b are arranged in the middle of the outer ring 1. It protrudes from the inner peripheral surface. Revolution speed detecting encoders 25a provided on the axial end surfaces of the rim parts of the retainers 24a and 24b with the detection parts of the revolving speed detection sensors 23a and 23b held at the tip parts 34a and 34b, It is made to oppose to the to-be-detected surface which is one side surface of 25b through the measurement gap. The measurement gap is larger than the pocket gap and is 2 mm or less.

  As described above, in this embodiment, a pair of revolution speed detection sensors 23a and 23b are held by a pair of independent sensor units 32a and 32b, and each of these sensor units 32a and 32b is a pair of independent ones. Are inserted into the mounting holes 33a and 33b. Accordingly, the cages 24a and 24b are ordinary ones whose rim portions are not particularly large in the axial direction. And the said measurement gap is controlled appropriately. Other configurations and operations are the same as those of the first embodiment.

  7 to 8 show a third embodiment of the present invention corresponding to claims 3, 5 and 8. In the case of the present embodiment, a rolling bearing unit for measuring the load applied to the rolling bearing unit for supporting the driven wheel of the automobile (the front wheel of the FR vehicle, the RR vehicle, the MR vehicle, the rear wheel of the FF vehicle). A case where the present invention is applied to a load measuring device is shown. In the case of this embodiment, in order to connect and fix the inner ring 6 to the hub body 4b constituting the hub 2c, the cylindrical portion 35 formed at the inner end of the hub body 4b is plastically deformed radially outward. The inner end surface of the inner ring 6 is held down by the portion 36. Other configurations of the rolling bearing unit are the same as those of the conventional structure shown in FIG. 29 and the structure according to the prior invention shown in FIG.

  In particular, in the case of the present embodiment, as in the second embodiment described above, the pair of revolution speed detection sensors 23a and 23b are arranged in the tip portions 34a and 34b of the pair of sensor units 32a and 32b that are independent from each other. Hold on. In order to mount the sensor units 32a and 32b, a pair of mounting holes are formed in a portion between the pair of outer ring raceways 7 and 7 and both end surfaces in the axial direction of the outer ring 1 at both ends in the axial direction of the outer ring 1. 33a and 33b are provided in a state of penetrating the outer ring 1 in the radial direction of the outer ring 1, respectively. Each of the sensor units 32a and 32b is inserted into the pair of mounting holes 33a and 33b from the outer diameter side to the inner diameter side of the outer ring 1, and the tip portions 34a and 34b are respectively connected to both ends of the outer ring 1. It protrudes from the inner peripheral surface.

  In accordance with the arrangement of the sensor units 32a and 32b at both ends of the outer ring 1 as described above, in the case of the present embodiment, a retainer 38a for holding the rolling elements 9a and 9b, The rim portions 37a and 37b of 38b are arranged on the opposite sides. Revolution speed detecting encoders 25a and 25b are respectively provided on one side surfaces of the rim portions 37a and 37b located on opposite sides. Then, the detection portions of the revolution speed detection sensors 23a and 23b held at the tip portions 34a and 34b are measured on the detected surface which is one side surface in the axial direction of the revolution speed detection encoders 25a and 25b. It is opposed through a gap. The measurement gap is larger than the pocket gap and is 2 mm or less.

  As described above, in the case of the present embodiment, a pair of revolution speed detection sensors 23a and 23b are held by a pair of independent sensor units 32a and 32b, and the rolling elements 9a and 9b arranged in double rows are arranged. The pair of retained cages 38a and 38b are inserted into a pair of mounting holes 33a and 33b which are provided so as to be sandwiched from both sides in the axial direction. Therefore, even if there is not enough space for the sensor unit to enter between the rolling elements 9a and 9b arranged in the double row, the rotational speed of the cages 38a and 38b, The revolution speed of each rolling element 9a, 9b can be detected.

  FIG. 9 shows Embodiment 4 of the present invention corresponding to claims 3, 4, and 8. In the present embodiment, the structure of the second embodiment shown in FIGS. 5 to 6 is changed to a driven wheel and the rotational speed of the hub 2 can be detected. In the case of the present embodiment, since it is for a driven wheel, a spline hole as in the second embodiment is not provided at the center of the hub 2. Further, in order to detect the rotational speed of the hub 2, a base of a substantially cylindrical cored bar 39 that constitutes a rotational speed detecting encoder 13 a is formed on the inner ring 6 provided near the inner end of the hub 2 in the axial direction. An end portion (an outer end portion in the axial direction, the left end portion in FIG. 9) is fitted and fixed. Then, the S pole and the N pole are formed on the inner peripheral surface of the permanent magnet 40 provided on the inner peripheral surface of the tip end portion (the inner end portion in the axial direction, the right end portion in FIG. 9) of the core bar 39 over the entire circumference. These are arranged alternately and at equal intervals in the circumferential direction. On the other hand, the rotational speed of the hub 2 is detected by making the detection part of the rotational speed detection sensor 15b supported by the cover 41 covering the inner end opening of the outer ring 1 close to the inner peripheral surface of the permanent magnet 40. It is free. Since other configurations and operations are the same as those in the second embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 10 shows Embodiment 5 of the present invention corresponding to claims 3, 4 and 8. In the case of the present embodiment, as in the case of the first embodiment shown in FIGS. 1 and 2 described above, the rotational speed detecting encoder 26 is fitted and fixed to the outer peripheral surface of the intermediate portion of the hub 2. In the case of the present embodiment, among the pair of sensor units 32a ′ and 32b, the revolution speed detecting sensor 23a and the rotational speed detecting sensor 15a are disposed at the tip end portion 34a ′ of the sensor unit 32a ′ on the outer side in the axial direction. And holding. The rotational speed of the hub 2 can be detected by making the detecting portion of the rotational speed detecting sensor 15a out of these faces the outer peripheral surface of the rotational speed detecting encoder 26. The rotational speed detecting encoder 26 is provided with a back yoke made of a magnetic material on the inner diameter side thereof, so that the magnetizing strength is improved and the press-fitting to the hub 2 can be facilitated. However, when viewed only from the aspect of securing the magnetizing strength, the back yoke can be omitted if the hub 2 is made of a magnetic material. If omitted, a magnetized (dummy) back yoke is installed when magnetizing the rotational speed detection encoder 26, and after the magnet is removed, the rotational speed detection encoder 26 26 may be fitted on the hub 2. Further, the magnetizing operation may be performed before the outer fitting to the hub 2 or after the outer fitting. When performing after external fitting, the dummy back yoke is not necessary. Since other configurations and operations are the same as those of the fourth embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 11 shows Embodiment 6 of the present invention corresponding to claims 3, 4, and 8. In the present embodiment, the inside and outside in the axial direction are reversed from the above-described embodiment 5. That is, in the case of the present embodiment, among the pair of sensor units 32a and 32b ′, the revolution speed detection sensor 23b and the rotation speed detection sensor 15a are disposed at the tip end portion 34b ′ of the sensor unit 32b ′ on the inner side in the axial direction. And holding. Since other configurations and operations are the same as those of the fifth embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 12 shows Embodiment 7 of the present invention corresponding to claims 3, 6 and 8. In the case of the present embodiment, a pair of mounting holes 33 a and 33 b are formed at the intermediate portion in the axial direction of the outer ring 1 and between the pair of outer ring raceways 7 and 7 and at the inner end in the axial direction of the outer ring 1. It is provided in a portion between the outer ring raceway 7 on the inner side in the direction and the inner end face in the axial direction of the outer ring 1. In addition, the rim portions 44 and 44 of the cages 24a and 24b holding the rolling elements 9a and 9b in each row are both positioned on the inner side in the axial direction. Revolution speed detecting encoders 25a and 25b are attached to the inner side surfaces in the axial direction of the rim portions 44 and 44, respectively. In addition, a rotational speed detecting encoder 26 is externally fitted and fixed to the outer peripheral surface of the intermediate portion of the hub 2.

  The detection unit of the revolution speed detection sensor 23a held at the tip 34a 'of the sensor unit 32a' inserted into the mounting hole 33a formed between the pair of outer ring raceways 7 and 7 is used as the revolution speed detection encoder. Similarly, the detecting portion of the rotational speed detecting sensor 15a is opposed to the outer peripheral surface of the rotational speed detecting encoder 26 on the inner side surface of the axial direction 25a. Further, the detecting portion of the revolution speed detecting sensor 23b held at the tip end portion 34b of the sensor unit 32b inserted into the mounting hole 33b at the axially inner end portion is opposed to the inner side surface in the axial direction of the revolution speed detecting encoder 25b. ing. Since the configuration and operation other than the formation positions of the mounting holes 33a and 33b and the installation positions of the revolution speed detection encoders 25a and 25b are the same as those of the fifth embodiment shown in FIG. And redundant description is omitted.

  FIG. 13 shows an eighth embodiment of the present invention corresponding to the third, sixth, and eighth aspects. In the present embodiment, the inner and outer portions in the axial direction are reversed from the seventh embodiment described above. That is, in the case of the present embodiment, the rim portions 44, 44 of the cages 24a, 24b that hold the rolling elements 9a, 9b in each row are both positioned on the outer side in the axial direction, and the rim portions 44, Revolution speed detecting encoders 25a and 25b are attached to the outer surface of the shaft 44 in the axial direction. The detection unit of the revolution speed detection sensor 23b held at the tip 34b 'of the sensor unit 32b' inserted into the mounting hole 33b formed between the pair of outer ring raceways 7 and 7 is used as the revolution speed detection encoder. Similarly, the detection portion of the rotational speed detection sensor 15a is opposed to the outer peripheral surface of the rotational speed detection encoder 26 on the outer surface in the axial direction of 25b. Further, the detection portion of the revolution speed detection sensor 23a held at the tip end portion 34a of the sensor unit 32a inserted into the mounting hole 33a at the outer end portion in the axial direction is opposed to the outer surface in the axial direction of the encoder 25a for revolution speed detection. ing. The configuration and operation other than the formation positions of the mounting holes 33a and 33b and the installation positions of the revolution speed detection encoders 25a and 25b are the same as those in the sixth embodiment shown in FIG. And redundant description is omitted.

  FIG. 14 shows Embodiment 9 of the present invention corresponding to claims 3, 6, and 8. In the case of the present embodiment, a rotational speed detection encoder 26 a for detecting the rotational speed of the hub 2 is externally fitted and fixed to the inner end portion of the inner ring 6 constituting the hub 2. The detection portion of the rotational speed detection sensor 15a held at the tip end portion 34b 'of the sensor unit 32b' inserted into the mounting hole 33b is opposed to the outer peripheral surface of the rotational speed detection encoder 26a. Since the configuration and operation other than the installation positions of the rotational speed detection sensor 15a and the rotational speed detection encoder 26a are the same as those in the seventh embodiment shown in FIG. 12, the same reference numerals are given to the equivalent parts. The duplicated explanation is omitted.

  FIG. 15 shows a tenth embodiment of the present invention corresponding to the third, sixth, and eighth aspects. In the case of the present embodiment, a rotational speed detection encoder 26 a for detecting the rotational speed of the hub 2 is fitted and fixed to an outer portion of the intermediate portion of the hub 2. The detection portion of the rotational speed detection sensor 15a held at the tip end 34a 'of the sensor unit 32a' inserted into the mounting hole 33a is opposed to the outer peripheral surface of the rotational speed detection encoder 26a. Since the configuration and operation other than the installation positions of the rotational speed detection sensor 15a and the rotational speed detection encoder 26a are the same as those in the eighth embodiment shown in FIG. 13, the same reference numerals are given to the equivalent parts. The duplicated explanation is omitted.

  FIG. 16 shows Embodiment 11 of the present invention corresponding to claims 3, 5 and 8. In this embodiment, in addition to the structure of the third embodiment shown in FIGS. 7 to 8 described above, the rotational speed of the hub 2 can be detected. For this reason, in the case of the present embodiment, the base end portion of the substantially cylindrical cored bar 39 constituting the rotational speed detecting encoder 13a is formed on the inner ring 6 provided near the axially inner end portion of the hub 2. The left end portion in FIG. 16 is externally fixed. Then, the detection portion of the rotational speed detection sensor 15b supported by the cover 41 that covers the inner end opening of the outer ring 1 is placed around the inner peripheral surface of the tip end portion (right end portion in FIG. 16) of the core metal 39 on the entire circumference. The rotational speed of the hub 2 can be detected in close proximity to the inner peripheral surface of the permanent magnet 40 provided. Since other configurations and operations are the same as those in the third embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 17 shows Embodiment 12 of the present invention corresponding to claims 3, 5, and 8. In the case of the present embodiment, a rotational speed detection encoder 26 a for detecting the rotational speed of the hub 2 is externally fitted and fixed to the inner end portion of the inner ring 6 constituting the hub 2. The detection portion of the rotational speed detection sensor 15a held at the tip end portion 34b 'of the sensor unit 32b' inserted into the mounting hole 33b is opposed to the outer peripheral surface of the rotational speed detection encoder 26a. Since the configuration and operation other than the installation positions of the rotational speed detection sensor 15a and the rotational speed detection encoder 26a are the same as those in the above-described embodiment 11, the same parts are denoted by the same reference numerals, and redundant description is given. Omitted.

  FIG. 18 shows Embodiment 13 of the present invention corresponding to claims 3, 5, and 8. In the case of the present embodiment, a rotational speed detection encoder 26 a for detecting the rotational speed of the hub 2 is fitted and fixed to an outer portion of the intermediate portion of the hub 2. The detection portion of the rotational speed detection sensor 15a held at the tip end portion 34a 'of the sensor unit 32a' inserted into the mounting hole 33a is opposed to the outer peripheral surface of the rotational speed detection encoder 26a. Since the configuration and the operation other than the installation positions of the rotational speed detection sensor 15a and the rotational speed detection encoder 26a are the same as those in the above-described embodiment 12, the same reference numerals are given to the same parts, and overlapping explanations are given. Omitted.

  FIG. 19 shows a fourteenth embodiment of the present invention corresponding to the third, fourth, seventh and eighth aspects. In the case of the present embodiment, a pair of mounting holes 33a and 33b are formed in parallel to each other. The base end portions of the pair of sensor units 32a and 32b that are inserted into the mounting holes 33a and 33b and are parallel to each other are connected by a connecting portion 42 that is provided on the outer diameter side of the outer ring 1. Are integrally connected to each other. Also, the cables 43 for sending the detection signals of the revolution speed detection sensors 23a and 23b held at the tip portions 34a and 34b of the sensor units 32a and 32b are combined into one cable and led out from the connecting portion 42. Yes.

  In the case of the present embodiment configured as described above, the mounting workability of the sensor units 32a and 32b to the outer ring 1 is improved. Further, the cable 43 is configured by multiplexing a circuit for removing noise contained in the detection signals of the revolution speed detection sensors 23a and 23b in the connecting portion 42, and multiplexing the detection signals of both the sensors 23a and 23b. It is possible to incorporate a signal processing circuit for reducing the number of conducting wires, and a wireless transmission means for transmitting the detection signal to the vehicle body by radio. Of course, the cost can be reduced and the wiring can be simplified by using one cable 43 (multi-core cable). Since the configuration and operation of the other parts are the same as those of the fourth embodiment shown in FIG. 9, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 20 shows Embodiment 15 of the present invention corresponding to claims 3, 4, 7, and 8. In the present embodiment, the base end portions of the sensor units 32a ′ and 32b constituting the structure of the fifth embodiment shown in FIG. It is what. The operation and effect of providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other parts are the same as those of the above-described embodiment 5. And redundant description is omitted.

  FIG. 21 shows Embodiment 16 according to the third, fourth, seventh, and eighth aspects of the present invention. In the present embodiment, the base end portions of the sensor units 32a and 32b ′ constituting the structure of the sixth embodiment shown in FIG. 11 described above are connected by the connecting portion 42, and the structure satisfies the seventh aspect. It is a thing. The operation and effect of providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other parts are the same as those of the above-described embodiment 6. And redundant description is omitted.

  FIG. 22 shows Embodiment 17 of the present invention corresponding to the third, sixth, seventh and eighth aspects. In the present embodiment, the base end portions of the sensor units 32a ′ and 32b constituting the structure of the seventh embodiment shown in FIG. 12 described above are connected by the connecting portion 42, and the structure satisfies the seventh aspect. It is a thing. The operation and effect obtained by providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other parts are the same as those of the above-described embodiment 7. And redundant description is omitted.

  FIG. 23 shows Embodiment 18 according to the third, sixth, seventh and eighth aspects of the present invention. In the present embodiment, the base end portions of the sensor units 32a and 32b ′ constituting the structure of the eighth embodiment shown in FIG. 13 described above are connected by the connecting portion 42, and the structure satisfies the structure of claim 7. It is what. The operation and effect obtained by providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other parts are the same as those of the above-described embodiment 8. And redundant description is omitted.

  FIG. 24 shows Embodiment 19 of the present invention corresponding to the third, sixth, seventh and eighth aspects. In the present embodiment, the base end portions of the sensor units 32a and 32b ′ constituting the structure of the ninth embodiment shown in FIG. 14 are connected by the connecting portion 42, and the structure satisfies the structure of claim 7. It is what. The operation and effect obtained by providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other parts are the same as those of the above-described embodiment 9. And redundant description is omitted.

  FIG. 25 shows an embodiment 20 of the present invention corresponding to the third, sixth, seventh and eighth aspects. In the present embodiment, the base end portions of the sensor units 32a ′ and 32b constituting the structure of the tenth embodiment shown in FIG. 15 described above are connected by the connecting portion 42, and the structure satisfies the structure of claim 7. It is what. The operation and effect obtained by providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other parts are the same as those of the above-described embodiment 10. And redundant description is omitted.

  FIG. 26 shows Embodiment 21 of the present invention corresponding to the third, fifth, seventh and eighth aspects. In the present embodiment, the base end portions of the sensor units 32a and 32b constituting the structure of the eleventh embodiment shown in FIG. 16 described above are connected by the connecting portion 42, and the structure satisfies the seventh aspect. Is. The operation and effect obtained by providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other parts are the same as those of the embodiment 11, respectively. And redundant description is omitted.

  FIG. 27 shows a twenty-second embodiment of the present invention corresponding to the third, fifth, seventh, and eighth aspects. In the present embodiment, the base end portions of the sensor units 32a and 32b ′ constituting the structure of the twelfth embodiment shown in FIG. 17 described above are connected by the connecting portion 42, and the structure satisfies the seventh aspect. It is what. The operation and effect obtained by providing the connecting portion 42 is the same as that of the above-described embodiment 14 shown in FIG. 19 and the configuration and operation of the other portions are the same as those of the embodiment 12 described above. And redundant description is omitted.

  FIG. 28 shows Embodiment 23 of the present invention corresponding to claims 3, 5, 7, and 8. In the present embodiment, the base ends of the sensor units 32a ′ and 32b constituting the structure of the thirteenth embodiment shown in FIG. 18 are connected by the connecting portion 42, and the structure satisfies the seventh aspect. It is what. The operation and effect obtained by providing the connecting portion 42 is the same as that of the embodiment 14 shown in FIG. 19 described above, and the configuration and operation of the other parts are the same as those of the embodiment 13, respectively. And redundant description is omitted.

The present invention is not limited to the rolling bearing unit load measuring device for measuring the load applied to the rolling bearing unit that supports the wheel of the automobile as shown in each embodiment, but various rotations such as machine tools and industrial machines. It can be used to determine the load acting on the mechanical device.
In any of the embodiments, it is preferable to provide a sealing material such as an O-ring at the portion where the sensor unit is inserted into the mounting hole, and to provide waterproofing and dustproofing of this portion. It doesn't matter. Even in a structure in which compression is performed radially between the inner peripheral surface of the mounting hole and the outer peripheral surface of the sensor unit, between the outer peripheral surface of the outer ring and the flange portion (including the connecting portion) provided at the base end portion of the sensor unit. A structure that compresses in the axial direction, or a structure that is clamped from three directions between a mortar-shaped chamfered portion formed in the opening of the mounting hole and the outer peripheral surface and flange portion of the sensor unit may be employed. If the structure clamped from these three directions is adopted, the processing of each part required for installing the O-ring becomes easy, and the installation space can be saved.
In any of the embodiments, the sensor unit fixing method is not particularly limited. It can be fixed with a screw (not shown), or can be fixed with an adhesive or the like, and further can be fixed with a clip-on type using an elastic member (not shown). Further, the sensor unit may be provided obliquely with respect to the outer ring (in a state where the sensor unit is inclined with respect to a virtual plane intersecting at right angles to the central axis of the outer ring). Such a structure can be used when the sensor unit installation area is limited, such as when the sensor unit and the outer ring of the outer ring interfere with the flange for supporting the outer ring on the suspension device. It is valid.
Further, the detection surface of the rotation speed detection encoder and the detection unit of the rotation speed detection sensor can be opposed to each other in the axial direction as well as in the radial direction as shown in the figure.
In addition, each embodiment has been described for the case where it is applied to a double row angular contact type ball bearing unit in which each rolling element is a ball. However, in each double rolling cone rolling bearing unit, each rolling element is a tapered roller. It can also be applied. Even in such a double-row tapered roller bearing unit, the revolution speed of each tapered roller changes based on the applied load. Therefore, the load acting on the outer ring and the hub is determined based on the revolution speed of each tapered roller. Desired.

Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows Example 1 of this invention. The A section enlarged view of FIG. FIG. 3 is a schematic diagram showing a cage and rolling elements, a revolution speed detection encoder, and a revolution speed detection sensor taken out and viewed from above in FIG. 2. The schematic diagram of a rolling bearing unit for demonstrating the reason which can measure a load based on rotational speed. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows Example 2 of this invention. The B section enlarged view of FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows Example 3 of this invention. The C section enlarged view of FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows Example 4 of this invention. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 5. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 6. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 7. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 8. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 9. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 10. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 11. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 12. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 13. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 14. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 15. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 16. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 17. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 18. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 19. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 20. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 21. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 22. FIG. Sectional drawing of the load measuring apparatus of a rolling bearing unit which shows the same Example 23. FIG. 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a Outer ring 2, 2a, 2b, 2c Hub 3, 3a Rotation side flange 4, 4a, 4b Hub body 5 Nut 6 Inner ring 7 Outer ring raceway 8 Inner ring raceway 9a, 9b Rolling element 10, 10a Mounting hole 11 Displacement sensor 12 Sensor Ring 13, 13a Rotational speed detection encoder 14 Cover 15, 15a, 15b Rotational speed detection sensor 16 Knuckle 17 Fixed flange 18 Bolt 19 Screw hole 20 Load sensor 21 Sensor unit 22 Tip 23a, 23b Revolution speed detection sensor 24a , 24b Cage 25a, 25b Revolution speed detection encoder 26, 26a Rotational speed detection encoder 27 Holder 28 Rim part 29a, 29b Cage 30 Cable 31 Spline hole 32a, 32b, 32a ', 32b' Sensor unit 33a, 33b Installation Hole 34 a, 34b, 34a ′, 34b ′ Tip portion 35 Cylindrical portion 36 Caulking portion 37a, 37b Rim portion 38a, 38b Cage 39 Core 40 Permanent magnet 41 Cover 42 Connecting portion 43 Cable 44 Rim portion

Claims (11)

  An outer ring having a double row outer ring raceway on the inner peripheral surface, and an outer ring that does not rotate even when used, and an outer ring having a double row inner ring raceway that is arranged concentrically with the outer ring on the inner diameter side of the outer ring and rotates during use. The hub is divided into multiple rows between the inner ring raceways and the outer ring raceways, and a plurality of rows are provided for each row. The rolling elements provided, a pair of cages for holding the rolling elements of each row in a freely rollable manner, and the revolution speeds of the rolling elements in the rows are detected as the rotational speeds of the cages. A pair of revolution speed detection sensors and an arithmetic unit for calculating a load applied between the outer ring and the hub based on detection signals sent from the respective revolution speed detection sensors. Revolution speed detection sensor is held in a single sensor unit The sensor unit is formed in a single mounting hole provided in a state of passing through the outer ring in the radial direction of the outer ring at a portion between the double row outer ring raceways at an intermediate portion in the axial direction of the outer ring. Each of the cages is inserted in a state where each rim portion is positioned on the sensor unit side, and at least one rim portion of each of the cages is provided with the sensor. Extending in the axial direction toward the unit, the characteristics of the surface to be detected, which is one side surface in the axial direction facing the sensor unit, are circumferentially defined on the axial end surfaces facing each other in the rim portions of the cages. Revolution speed detection encoders that are alternately changed at equal intervals with respect to the direction are provided, and the distance between the detected surface of each revolution speed detection encoder and the detection portion of each revolution speed detection sensor is regulated to an appropriate value. Rolling Load measuring device of the bearing unit.   An outer ring having a double row outer ring raceway on the inner peripheral surface, and an outer ring that does not rotate even when used, and an outer ring having a double row inner ring raceway that is arranged concentrically with the outer ring on the inner diameter side of the outer ring and rotates during use. The hub is divided into multiple rows between the inner ring raceways and the outer ring raceways, and a plurality of rows are provided for each row. The rolling elements provided, a pair of cages for holding the rolling elements of each row in a freely rollable manner, and the revolution speeds of the rolling elements in the rows are detected as the rotational speeds of the cages. A pair of revolution speed detection sensors and an arithmetic unit for calculating a load applied between the outer ring and the hub based on detection signals sent from the respective revolution speed detection sensors. Revolution speed detection sensor is held in a single sensor unit The sensor unit is formed in a single mounting hole provided in a state of passing through the outer ring in the radial direction of the outer ring at a portion between the double row outer ring raceways at an intermediate portion in the axial direction of the outer ring. Each of the cages is inserted in a state where the respective rim portions are positioned on the sensor unit side, and among the rim portions of the respective cages, A revolution speed detection encoder is provided in which the characteristic of the detected surface that is one side surface in the axial direction facing the sensor unit is changed alternately and at equal intervals in the circumferential direction, and at least one of these revolution speed detection encoders By increasing the thickness dimension of the revolution speed detection encoder in the axial direction, the distance between the detected surface of each revolution speed detection encoder and the detection part of each revolution speed detection sensor is increased. Load measuring apparatus of the rolling bearing unit that is regulated to a proper value.   An outer ring having a double row outer ring raceway on the inner peripheral surface, and an outer ring that does not rotate even when used, and an outer ring having a double row inner ring raceway that is arranged concentrically with the outer ring on the inner diameter side of the outer ring and rotates during use. The hub is divided into multiple rows between the inner ring raceways and the outer ring raceways, and a plurality of rows are provided for each row. The rolling elements provided, a pair of cages for holding the rolling elements of each row in a freely rollable manner, and the revolution speeds of the rolling elements in the rows are detected as the rotational speeds of the cages. A pair of revolution speed detection sensors and an arithmetic unit for calculating a load applied between the outer ring and the hub based on detection signals sent from the respective revolution speed detection sensors. The revolution speed detection sensor is a pair of independent sensors. Each of these sensor units is provided in a state of passing through the outer ring in the radial direction of the outer ring at two positions separated from each other in the axial direction of the outer ring by a part of the outer ring. Inserted into a pair of mounting holes, the characteristics were changed alternately and at equal intervals in the circumferential direction on one axial side surface of the revolution speed detecting encoder provided on the axial end surface of the rim portion of each cage. A load measuring device for a rolling bearing unit in which a distance between a surface to be detected and a detection portion of each revolution speed detection sensor held by each sensor unit is regulated to an appropriate value.   A pair of mounting holes are provided in the middle part of the outer ring in the axial direction between the pair of outer ring raceways, and are covered by a pair of revolution speed detecting encoders provided in the rim part of the pair of cages. The load measuring device for a rolling bearing unit according to claim 3, wherein the detection surfaces are arranged on opposite sides.   A pair of mounting holes are provided in a portion between the pair of outer ring raceways and the both end surfaces in the axial direction of the outer ring at both ends in the axial direction of the outer ring, and 1 provided in the rim portion of the pair of cages. 4. The load measuring device for a rolling bearing unit according to claim 3, wherein the detected surfaces of the pair of revolution speed detecting encoders are arranged on opposite sides of each other.   A pair of mounting holes are formed between the pair of outer ring raceways at the axially intermediate portion of the outer ring and between the one outer ring raceway and one axial end surface of the outer ring at one axial end portion of the outer ring. The rolling according to claim 3, wherein the detected surfaces of the pair of revolution speed detecting encoders provided on the rim portions of the pair of cages are arranged on the same side with respect to the axial direction. Bearing unit load measuring device.   A pair of mounting holes are formed in parallel to each other, and base ends of a pair of sensor units provided in parallel to each other, which are respectively inserted into these mounting holes, are provided on the outer diameter side of the outer ring. The load measuring device for a rolling bearing unit according to any one of claims 3 to 6, wherein the load measuring device is integrally connected to each other by the connected portions.   Each rolling element is a ball, and a plurality of rolling elements are provided between a double-row angular outer ring raceway formed on the inner peripheral surface of the outer ring and a double-row angular inner ring raceway formed on the outer peripheral surface of the hub. The load measuring device for a rolling bearing unit according to any one of claims 1 to 7, wherein a contact angle of a back combination type is imparted to the ball.   The rotation of the hub is made possible by making the detection part of the rotation speed detection sensor supported by a part of the outer ring face the detection surface of the rotation speed detection encoder provided concentrically with the hub on a part of the hub. The speed can be detected freely, and the computing unit is based on the ratio of the revolution speed of the rolling elements in one row and the revolution speed of the rolling elements in the other row and the rotational speed of the hub, The load measuring device for a rolling bearing unit according to any one of claims 1 to 8, wherein a radial load applied between the hub and the hub is calculated.   The rotation of the hub is made possible by making the detection part of the rotation speed detection sensor supported by a part of the outer ring face the detection surface of the rotation speed detection encoder provided concentrically with the hub on a part of the hub. The speed can be detected freely, and the computing unit can determine whether the outer ring and the hub are based on the ratio between the revolution speed of the rolling elements in one row and the revolution speed of the rolling elements in the other row and the rotational speed of the hub. The load measuring device for a rolling bearing unit according to any one of claims 1 to 8, wherein an axial load applied between the first and second bearings is calculated. The computing unit calculates an axial load applied between the outer ring and the hub based on a ratio between a revolution speed of the rolling elements in one row and a revolution speed of the rolling elements in the other row. The load measuring device of the rolling bearing unit described in any one.

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