JP2009025009A - State quantity measuring device for rolling bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a structure capable of acquiring easily proper layout for each sensor module 36s<SB>1</SB>, even when a metal plate cover 8a that holds a sensor holder 10a made of a synthetic resin is installed in a narrow space, and moreover the number of sensor modules 36s<SB>1</SB>embedded in the sensor holder 10a is large, for example six or seven. <P>SOLUTION: Large apertures 35a or small apertures are formed respectively on a plurality of spots in the circumferential direction of a middle part in the axial direction of the cover 8a, and each sensor module 36s<SB>1</SB>is arranged inside each large aperture 35a and any of the apertures of the small apertures, respectively, and embedded into the sensor holder 10a in this state. By adopting such a constitution, the problem is solved. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The state quantity measuring device for a rolling bearing unit according to the present invention is used for measuring a state quantity such as an external force acting between an outer ring and a hub constituting the rolling bearing unit. Further, the obtained state quantity is used for ensuring the running stability of a vehicle such as an automobile.

  For example, a wheel of an automobile is rotatably supported by a rolling bearing unit such as a double-row angular type with respect to a suspension device. In addition, in order to ensure the running stability of automobiles, for example, anti-lock braking system (ABS), traction control system (TCS), and electronically controlled vehicle stability control system (ESC) etc. The device is in use. In order to control such various vehicle running stabilization devices, signals representing the rotational speed of the wheels, acceleration in each direction applied to the vehicle body, and the like are required. In order to perform higher-level control, it may be preferable to know the magnitude of a load (for example, one or both of a radial load and an axial load) applied to the rolling bearing unit via a wheel.

  In view of such circumstances, Patent Document 1 describes an invention in which a special encoder is used to measure the magnitude of a load applied to a rolling bearing unit. FIGS. 7 to 8 show Japanese Patent Application No. 2007-97042 as an example of the structure of the prior invention relating to the state quantity measuring device for a rolling bearing unit, which adopts the same load measurement principle as the structure described in Patent Document 1. Is shown. In the structure of this prior invention, on the inner diameter side of the outer ring 1 that does not rotate even in use, the hub 2 that is an inner ring equivalent member that rotates together with the wheel in a state where the wheel is supported and fixed in use is provided with a plurality of rolling elements 3, 3. It is rotatably supported via A preload is applied to each of the rolling elements 3 and 3 together with a contact angle of the rear combination type. In the illustrated example, balls are used as the rolling elements 3 and 3. However, in the case of an automobile bearing unit that is heavy, tapered rollers may be used instead of balls.

  Also, the inner end of the hub 2 in the axial direction ("inner" with respect to the axial direction refers to the center in the width direction of the vehicle when assembled to the automobile, and is the right side of FIGS. 1 and 7. On the contrary, in the width direction of the vehicle. The left side of FIGS. 1 and 7, which is the outer side, is referred to as “outside” in the axial direction. The same applies throughout the present specification.) The cylindrical encoder 4 is supported and fixed concentrically with the hub 2. . The encoder 4 includes an annular cored bar 5 made of magnetic metal that is externally fitted and fixed to an axially inner end of the inner ring 7 constituting the hub 2, and an axially outer end of the outer peripheral surface of the cored bar 5. Or an encoder body 6 made of a permanent magnet and fixedly attached to the entire circumference of the intermediate portion. On the outer peripheral surface of the encoder main body 6 that is the detection surface, S poles and N poles are alternately arranged at equal intervals in the circumferential direction. The boundary between these S poles and N poles has a "<" shape with the central portion in the axial direction protruding most in the circumferential direction.

  Further, an annular cover 8 made of a metal plate is supported and fixed to the inner end of the outer ring 1 in the axial direction, and a pair of sensors 9 a and 9 b are embedded inside the cover 8. The annular sensor holder 10 is held. In this state, the detection portions of both the sensors 9a and 9b are made to approach and face each other in the axial half of the detection surface of the encoder 4 one by one. In addition, magnetic detection elements such as a Hall IC, a Hall element, an MR element, and a GMR element are incorporated in the detection portions of both the sensors 9a and 9b. Each of the sensors 9a and 9b is embedded and supported in the sensor holder 10 in a sensor module formed by connecting a plurality of sensor leads (not shown) to the sensor 9a (9b). ing. Each of the plurality of sensor leads has a function of taking out an output signal of the sensor 9a (9b) and supplying electric power to the sensor 9a (9b).

  The cover 8 includes a large-diameter cylindrical portion 11, an annular portion 12 bent at a right angle from the axially inner end of the large-diameter cylindrical portion 11 toward the radially inner side, and the diameter of the annular portion 12. A small-diameter cylindrical portion 13 bent at a right angle from the inner end portion in the direction toward the outer side in the axial direction. On the other hand, a mounting flange 14 for mounting and fixing the outer ring 1 to a knuckle or the like constituting the suspension device is provided at an axially intermediate portion of the outer peripheral surface of the outer ring 1, and a mounting cylindrical surface 15 is also provided at a portion near the inner end in the axial direction. Similarly, a small diameter portion 16 for fitting whose outer diameter is smaller than that of the mounting cylindrical surface 15 is provided at the inner end portion in the axial direction. The cover 8 is supported and fixed to the outer ring 1 by fitting the outer end portion in the axial direction of the large-diameter cylindrical portion 11 to the small-diameter portion 16 for fitting with an interference fit. In this state, the outer diameter of the large-diameter cylindrical portion 11 is equal to or smaller than the outer diameter of the mounting cylindrical surface 15. The mounting cylindrical surface 15 is fitted into a mounting hole provided in the knuckle or the like when the outer ring 1 is fixed to the knuckle or the like. At this time, the cover 8 prevents the fitting operation. Must not.

  The sensor holder 10 embeds and supports the sensors 9a and 9b as it is injection-molded, and is integrally coupled to the cover 8. In this state, a harness 17 connected to a part of the sensor holder 10 and each sensor lead constituting each sensor module is formed in a through hole 18 formed in one place of the annular portion 12 of the cover 8. Through to the outside space.

  Further, between the inner peripheral surface of the small-diameter cylindrical portion 13 constituting the cover 8 and the small-diameter portion 19 formed at the inner end in the axial direction of the outer peripheral surface of the metal core 5 constituting the encoder 4, the encoder 4. A seal ring 21 that cuts off the space 20 between the space 20 and the external space is assembled. The seal ring 21 includes a cored bar 22 that is externally fixed to the small-diameter portion 19 by an interference fit, and an elastic material 23 having a tip edge thereof slidably contacted with the entire inner peripheral surface of the small-diameter cylindrical portion 13. . Further, the space 20 in which the encoder 4 is installed and the rolling elements 3 between the portion near the inner end in the axial direction of the inner peripheral surface of the outer ring 1 and the portion closer to the inner end in the axial direction of the outer peripheral surface of the inner ring 7. 3 is assembled with a combination seal ring 25 that blocks the space 24 in which the space 3 is installed. Further, since the illustrated rolling bearing unit is for supporting the driving wheel of the automobile, a spline hole 26 is provided in the center of the hub 2. The hub 2 and the constant velocity joint are tightened by tightening a bolt 29 screwed to the tip of the spline shaft 28 in a state where the spline shaft 28 of the constant velocity joint 27 is engaged with the spline hole 26. 27 is fixedly coupled.

  In the state measuring device for a rolling bearing unit configured as described above, when an axial load acts between the outer ring 1 and the hub 2, the outer ring 1 and the hub 2 are displaced relative to each other in the axial direction. Accordingly, the phase difference ratio (= phase difference / 1 period) existing between the output signals of the sensors 9a and 9b changes. This phase difference ratio takes a value commensurate with the action direction and magnitude of the axial load (the direction and magnitude of the relative displacement). Therefore, based on this phase difference ratio, the direction and magnitude of the axial load (the direction and magnitude of the relative displacement) can be determined. The processing for obtaining these is performed by an arithmetic unit (not shown). For this reason, in the memory of this computing unit, an equation or a formula representing the relationship (zero point and gain) between the phase difference ratio and the relative displacement or load in the axial direction, which has been examined in advance by theoretical calculation or experiment. Remember the map.

  In the case of the structure of the prior invention described above, the number of sensors (sensor modules) that make the detection unit face the detection surface of the encoder 4 is two. On the other hand, in Patent Documents 2-3 and Japanese Patent Application No. 2006-345849, by increasing the number of sensors (sensor modules) to 3 or more (for example, increasing to 3, 4, 6, etc.), A structure in which multi-directional displacement or external force is required is described.

  By the way, like the structure of the prior invention shown in FIGS. 7 to 8 described above, the sensor holder 10 is intended for the rolling bearing unit for supporting the driving wheel and the inner end of the outer ring 1 in the axial direction via the cover 8. In the structure for supporting and fixing the cover 8, the installation space of the cover 8 and the sensor holder 10 is surrounded by the outer ring 1, the encoder 4, the constant velocity joint 27, and a mounting hole provided in a knuckle (not shown) or the like. Moreover, it becomes an annular narrow space. For this reason, the volume of the sensor holder 10 cannot be increased too much. In particular, in the case of the structure of the prior invention shown in FIGS. 7 to 8 described above, a structure in which the cover 8 is an outer shell member of the sensor holder 10 is employed. For this reason, the plate thickness of the cover 8 is a factor for reducing the volume of the sensor holder 10. Therefore, in the case of the structure of the prior invention shown in FIGS. 7 to 8, when each of the sensor modules embedded in the sensor holder 10 is increased to 6 to 7 or the like, each of these sensor modules is used. Proper layout can be difficult if not impossible.

JP 2006-317420 A JP 2006-322928 A JP 2007-93580 A

  In view of the above-described circumstances, the rolling bearing unit state quantity measuring device of the present invention is intended for a rolling bearing unit for a drive wheel and supports a sensor holder via a cover at an axial inner end of the outer ring. Even when the number of sensor modules to be fixed and embedded in the sensor holder is increased to 6 to 7 or the like, the invention has been invented to realize a structure that makes it easy to make the layout of each sensor module appropriate. Is.

The rolling bearing unit state quantity measuring apparatus of the present invention includes a rolling bearing unit and a state quantity measuring apparatus.
Of these, the rolling bearing unit has an outer ring that has a double row outer ring raceway on the inner peripheral surface and does not rotate even when used, and an inner ring equivalent member that has a double row inner ring raceway on the outer peripheral surface and rotates when used, A plurality of rolling elements are provided between each of the inner ring raceways and the outer ring raceways so as to be capable of rolling in each row.
The state quantity measuring device includes an encoder, a plurality of sensors, and a calculator.
Of these, the encoder is supported and fixed concentrically with the inner ring equivalent member at one end in the axial direction of the inner ring equivalent member, and has a detected surface concentric with the inner ring equivalent member. The characteristics are alternately changed in the circumferential direction.
In addition, each of the sensors has a sensor holder made of a synthetic resin with respect to a metal and annular cover supported and fixed to one end portion in the axial direction of the outer ring with the detection portion facing the detection surface. The output signal is changed corresponding to the change in the characteristics of the detected surface.
Further, the computing unit is configured to determine the rotational speed of the inner ring equivalent member, the relative displacement between the outer ring and the inner ring equivalent member, based on the output signals of at least some of the sensors. It has a function of calculating one or more kinds of state quantities including at least the relative displacement or the external force out of the external force acting between the outer ring and the inner ring equivalent member.
The sensor holder is made by injection molding of a synthetic resin. In association with the injection molding, the sensors are embedded and supported and are integrally coupled to the cover.

In particular, in the case of the state quantity measuring device for a rolling bearing unit according to the present invention, through holes are respectively formed at a plurality of locations in the circumferential direction of the cover. At the same time, a plurality of sensor modules each formed by connecting a plurality of sensor leads to each of the sensors is arranged inside any one of the through holes. In this state, each of the sensor modules is embedded and supported in the sensor holder, and a part of the sensor holder is made to enter the inside of the through holes so as to block the through holes. .
In carrying out the present invention, the number, position, size, etc. of each through-hole formed in the cover are determined as appropriate so that the layout of the sensor module in the sensor holder can be made appropriate. .
When carrying out the present invention having such characteristics, preferably, as described in claim 2, the peripheral portion of each through hole formed in the cover is embedded in the sensor holder.

  In carrying out the invention described in claims 1 and 2 as described above, preferably, as described in claim 3, the cover and the inner ring equivalent member or the inner ring equivalent member are coupled and fixed. A seal ring that blocks the space in which the encoder is installed from the external space is provided over the entire circumference between the rotary member that rotates together with the inner ring equivalent member. At the same time, the cover is made of a metal plate, and has a large-diameter cylindrical portion for fitting and fixing to one end portion in the axial direction of the outer ring, and exists on the opposite side of the outer ring from the large-diameter cylindrical portion in the axial direction. A small-diameter cylindrical portion whose inner peripheral surface is a seal-sliding contact surface for sliding the entire end edge of the elastic material constituting the seal ring, and the small-diameter cylindrical portion and the large-diameter cylindrical portion And connecting portions that connect axial end portions on the sides close to each other, and the through holes are formed at a plurality of locations in the circumferential direction of the connecting portions.

  Further, when the invention described in the first to third aspects is carried out, as described in the fourth aspect, for example, the rolling bearing unit is a hub unit for supporting a wheel of an automobile. In use, the outer ring is supported by a suspension device of the automobile, and the wheel is coupled and fixed to a hub which is the inner ring equivalent member.

As described above, in the case of the rolling bearing unit state quantity measuring apparatus of the present invention, a state in which a plurality of sensor modules are respectively arranged inside any through holes formed at a plurality of positions in the circumferential direction of the cover. Then, it is embedded in the sensor holder. For this reason, according to the present invention, the rolling bearing unit for the drive wheel is a target, the sensor holder is supported and fixed to the inner end of the outer ring in the axial direction via the cover, and the number of the sensor modules is six to six. Even when the number is increased to seven, the sensor modules can be easily arranged in a suitable layout with a sufficient space regardless of the presence of the cover. If the limit design is made to eliminate this spatial margin, the sensor holder can be reduced in size accordingly.
Further, in the case of the present invention, in a state where the sensor holder is integrally coupled to the cover, the sensor holder is placed inside the through holes so as to close the through holes formed in the cover. The parts are closely entered (engaged). For this reason, the coupling strength of the sensor holder with respect to the cover can be increased, and relative displacement in any direction between the cover and the sensor holder can be effectively prevented. In particular, if the configuration described in claim 2 is adopted, the above-mentioned relative displacement can be more effectively prevented since the above-mentioned bond strength can be increased.
If the configuration described in claim 3 is adopted, the space where the encoder is installed can be blocked from the external space by the seal ring. At the same time, the cover provided with the seal sliding contact surface for sliding the tip end edge of the elastic material constituting the seal ring can be formed into a shape that can be easily processed. For this reason, the manufacturing cost of this cover can be suppressed.

1 to 6 show an example of an embodiment of the present invention corresponding to claims 1 to 4. The feature of this example is the structure of a sensor holder 10a made of synthetic resin in which _seven sensor modules 36s _{1 to} 36s ₇ are embedded, and a cover 8a made of a metal plate that holds the sensor holder 10a. Since the structure and operation of other parts are basically the same as those of the structure of the prior invention shown in FIGS. 7 to 8 described above, overlapping illustrations and explanations of equivalent parts are omitted or simplified. The description will focus on the characteristic part of the present example and the part different from the structure of the previous invention.

  In the case of this example, as shown in FIGS. 1, 2, 3, and 5, the cover 8a made of a metal plate has a crank shape in cross section and is formed in an annular shape as a whole. Such a cover 8a includes a first cylindrical portion 30, a first annular portion 31 bent at a right angle from the inner end in the axial direction of the first cylindrical portion 30 toward the inner side in the radial direction, and the first annular portion. The second cylindrical portion 32 bent at a right angle from the radially inner end portion of the portion 31 toward the axially inward direction, and the second cylindrical portion 32 bent at a right angle from the axial inner end portion of the second cylindrical portion 32 toward the radially inward direction. A two-circular ring portion 33 and a third cylindrical portion 34 bent at a right angle from the radially inner end portion of the second circular ring portion 33 toward the inner side in the axial direction are provided. Among these portions, the first cylindrical portion 30 corresponds to the “large-diameter cylindrical portion” described in claim 3 of the claims, and the third cylindrical portion 34 similarly corresponds to the “small-diameter cylindrical portion”. The first annular portion 31, the second cylindrical portion 32, and the second annular portion 33 correspond to the “connecting portion”.

  Furthermore, in the case of this example, in the axial middle portion of the cover 8a (the portion between the radial middle portion of the first annular portion 31 and the radially inner end portion of the second annular portion 33), Three large through holes 35a and 35a and six small through holes 35b and 35b are formed at equal intervals in the circumferential direction. Specifically, each of the large through holes 35a, 35a is formed at three points at equal intervals in the circumferential direction, and at the portion between the large through holes 35a, 35a in the circumferential direction. Each of the small through holes 35b and 35b is formed two by two. The shapes of the large through holes 35a and 35a and the small through holes 35b and 35b viewed from the axial direction and the radial direction are substantially rectangular. Further, the width dimension of each of the large through holes 35a and 35a in the circumferential direction is approximately twice as large as the width dimension of each of the small through holes 35b and 35b.

And in this embodiment, as shown in FIG. 1 and 6, each of the seven sensor module 36s ₁ (36s ₂ ~36s _7), compared sensors _{9s 1 (9s 2 ~9s 7)} , parallel to each other The base end portions of the two arranged sensor leads 37 and 37 are connected. An insulating member 38 for preventing contact between the two sensor leads 37, 37 is assembled at an intermediate portion between the two sensor leads 37, 37. When the present invention is carried out, the shape of each of the sensor leads 37, 37 is not particularly limited. In this example, for the sake of convenience, the shape of the sensor lead 37 (crank shape) shown in FIGS. 1 and 2 and the shape of the sensor leads 37 and 37 shown in FIG. Shape). In any case of this embodiment, the output signals of the sensors 9s ₁ ~9s ₆ that the constitute six sensor module 36s ₁ ~36s ₆ of the seven sensor module 36s ₁ ~36s ₇ is Each is used to measure the relative displacement between the outer ring 1 and the hub 2 (see FIG. 7) and the external force acting between the outer ring 1 and the hub 2. In contrast, the output signal of the sensor 9s ₇ constituting the remaining one sensor module 36 s ₇ is utilized to measure the rotational speed of the wheel to be supported by and fixed to the hub 2 (for ABS control).

Further, in this example, as shown in detail in FIG. 6, the tip portions of the sensor leads 37, 37 constituting the _seven sensor modules 36 s _{1 to} 36 s ₇ are connected to the annular bus bar 39. ing. In this state, the positional relationship between the sensors 9s _{1 to} 9s ₇ is the positional relationship in use. Further, both end portions of the bus bar 39 are respectively connected to end portions of the harness 17 (FIG. 1). Thus, when used, the arithmetic unit having a function of calculating the relative displacement and the external force from the output signals of the sensors 9s _{1 to} 9s ₇ through the sensor leads 37 and 37, the bus bar 39 and the harness 17, respectively. It can be sent to an ABS controller or the like.

In the case of this example, as shown in FIGS. 1, 3, and 4, the synthetic resin sensor holder 10a is generally cylindrical. Such sensor holder 10a is, with the possible build by injection molding, are embedded supports the end of the seven sensor module 36s ₁ ~36s ₇ and the bus bar 39 and the harness 17. At the same time, the large and small through holes 35a and 35b formed in the cover 8a are tightly closed, and almost the entire peripheral edge portion of the large and small through holes 35a and 35b (excluding the radially inner end portion) is shown in FIG. In the embedded state as shown in part A of 1, the cover 8a is integrally coupled. That is, the sensor holder 10a as described above includes a main portion 40 that occupies most of the sensor holder 10a provided outside the cover 8a in a state of being attached to the outer surface of the cover 8a. At the same time, in the state where the inside of each of the large and small through holes 35a and 35b is densely filled (closely enters inside), the blocking portions 41a and 41b provided in the inner portions of the large and small through holes 35a and 35b are provided. Prepare. Furthermore, it has sub-parts 42a and 42b provided inside the cover 8a in a state of being connected to the main part 40 through the respective blocking parts 41a and 41b. Among these portions, the outer diameter of the main portion 40 is smaller than the outer diameter of the first cylindrical portion 30 constituting the cover 8a. In addition, among the sub-parts 42a and 42b, the axially outer end surfaces of the three sub-parts 42a and 42a existing in the portions corresponding to the large through-holes 35a and 35a are connected to the small through-holes 35b and 35b. The six sub-parts 42b and 42b existing in the corresponding parts are located outward in the axial direction from the axially outer end surfaces.

In the case of this example, the seven sensor modules 36s _{1 to} 36s ₇ are arranged such that their intermediate portions are disposed inside any one of the large and small through holes 35a and 35b, respectively. The sensors 9s _{1 to} 9s ₇ are embedded and supported in the sensor holder 10a in a state of being arranged in the cover 8a. Specifically, as shown in FIGS. 2 and 5, the six sensor modules 36 s _{1 to} 36 s ₆ used for measuring the relative displacement and external force described above are placed inside the large through holes 35 a and 35 a. Two sensor modules 36s ₇ for measuring the rotational speed described above are arranged inside each one small through hole 35b of the small through holes 35b, 35b. Yes. Further, the end portions of the bus bar 39 and the harness 17 are embedded and supported in the main portion 40 constituting the sensor holder 10a.

Note that when making the cover 8a for holding the sensor holder 10a such as described above, first, the cover 8a, and the seven sensor module 36s ₁ ~36s _7, and the bus bar 39, the harness 17 Are respectively held at predetermined positions in the cavity of the injection molding apparatus. In this state, the sensor holder 10a is completed by injection molding synthetic resin into the cavity.

When the cover 8a holding the sensor holder 10a as described above is supported and fixed to the inner end of the outer ring 1 (see FIG. 7) in the axial direction, the cover 8a is provided at the inner end of the outer ring 1 in the axial direction. The first cylindrical portion 30 constituting the cover 8a is externally fixed to the fitting small diameter portion 16 by an interference fit. At the same time, by bringing the radially outer half of the axially outer side surface of the first annular portion 31 constituting the cover 8a into contact with the axially inner end surface of the outer ring 1, the cover for the outer ring 1 is provided. Positioning in the axial direction of 8a is attempted. In this state, among the _six sensors 9s _{1 to} 9s 6 used for measuring the relative displacement and the external force described above, the detection units of the _three sensors 9s ₁ , 9s ₃ and 9s ₅ are covered. The remaining three sensors 9 s ₂ , 9 s ₄ , and 9 s ₆ are connected to the outer half of the outer peripheral surface of the encoder 4 (see FIGS. 7 to 8), which is the detection surface, in the axial direction of the detected surface. The inner half is made to face each other in proximity. At the same time, the detection part of one sensor 9s ₇ for measuring the rotational speed described above is brought close to and opposed to the axially intermediate part of the detected surface. Further, in this state, the distal end portion of the elastic material 23 (see FIG. 7) constituting the seal ring 21 fitted and fixed to the inner end portion in the axial direction of the encoder 4 is used as the third cylindrical portion 34 constituting the cover 8a. Slidably contact the inner peripheral surface of the entire circumference.

As described above, in the case of the state measuring apparatus for a rolling bearing unit of the present embodiment, each seven middle portion of the sensor module 36s ₁ ~36s _7, each magnitude is formed in the circumferential direction 9 positions of the cover 8a The sensor holder 10a is embedded and supported in a state of being disposed inside any one of the through holes 35a and 35b. Therefore, in the case of this example, the rolling bearing unit for the drive wheel is the target, and the sensor holder 10a is supported and fixed to the axially inner end of the outer ring 1 (see FIG. 7) via the cover 8a. Moreover yet structure to increase the seven the number of the sensor module 36s ₁ ~36s _7, regardless of the presence of the cover 8a, the respective sensor module 36s ₁ ~36s _7, with spatial allowance, Can be easily arranged with an appropriate layout.

  In the case of this example, the large and small through holes 35a and 35b formed in the cover 8a are closed in a state where the sensor holder 10a is integrally coupled to the cover 8a. A part of the blocking portions 41a and 41b constituting the sensor holder 10a is made to enter (engage) densely inside 35a and 35b, respectively. At the same time, almost the entire peripheral portion of each of the large and small through holes 35a and 35b (the portion excluding the radially inner end portion) is embedded in the sensor holder 10a as shown in part A of FIG. . For this reason, the coupling strength of the sensor holder 10a with respect to the cover 8a can be sufficiently increased, and relative displacement in any direction between the cover 8a and the sensor holder 10a can be effectively prevented.

In the case of this example, the cross-sectional shape of the cover 8a is a crank shape. For this reason, compared to the cover 8 assembled in the structure of the prior invention shown in FIG. 7 described above, the metal plate used when the cover 8a is made as compared with the case where the cross-sectional shape of the axially inner half is U-shaped. Can be easily processed. For this reason, the manufacturing cost of this cover 8a can be suppressed.
When implementing the present invention, the specific number, position, shape, dimensions, etc. of the plurality of through holes formed in the cover are the specific number, location, shape, dimensions of the plurality of sensor modules, respectively. It is determined appropriately according to the above.

Sectional drawing of the sensor holder and the cover which embedded the some sensor module which shows an example of embodiment of this invention. The figure seen from the left of FIG. 1 which takes out and shows only a cover and several sensor modules. The perspective view of the sensor holder and the cover which embedded the some sensor module. The perspective view which takes out and shows only a sensor holder. The perspective view which takes out and shows only a cover and several sensor modules. FIG. 5 is a perspective view showing only a plurality of sensor modules and a notched annular bus bar. Sectional drawing which shows one example of the structure of the prior invention regarding the state quantity measuring apparatus of a rolling bearing unit. The figure which looked at a part of the to-be-detected surface of an encoder from radial direction.

Explanation of symbols

1 the outer ring 2 hub 3 rolling element 4 encoder 5 core metal 6 encoder main body 7 an inner ring 8,8a cover 9a, 9b, 9s ₁ ~9s ₇ sensor 10,10a sensor holder 11 large-diameter cylindrical portion 12 circular ring portion 13 small-diameter cylindrical portion 14 Mounting flange 15 Mounting cylindrical surface 16 Small diameter portion 17 for fitting 17 Harness 18 Through hole 19 Small diameter portion 20 Space 21 Seal ring 22 Core metal 23 Elastic material 24 Space 25 Combination seal ring 26 Spline hole 27 Constant velocity joint 28 Spline shaft 29 Bolt 30 First cylindrical portion 31 First annular portion 32 Second cylindrical portion 33 Second annular portion 34 Third cylindrical portion 35a Large through hole 35b Small through hole 36s _{1 to} 36s ₇ Sensor module 37 Sensor lead 38 Insulating member 39 Bus bar 40 Main part 41a, 41b Blocking part 42a, 42b Sub part

Claims (4)

A rolling bearing unit and a state quantity measuring device;
Of these, the rolling bearing unit has an outer ring that has a double row outer ring raceway on the inner peripheral surface and does not rotate even when used, and an inner ring equivalent member that has a double row inner ring raceway on the outer peripheral surface and rotates when used, Between these inner ring raceways and the both outer ring raceways, a plurality of rolling elements are provided so as to be freely rollable for each row.
The state quantity measuring device includes an encoder, a plurality of sensors, and a calculator.
Of these, the encoder is supported and fixed concentrically with the inner ring equivalent member at one end in the axial direction of the inner ring equivalent member, and has a detected surface concentric with the inner ring equivalent member. The characteristics are alternately changed in the circumferential direction.
Each of the sensors has a detection part facing the detection surface, and a metallic and annular cover supported and fixed to one end in the axial direction of the outer ring via a synthetic resin sensor holder. The output signal is changed in response to the change in the characteristics of the detected surface.
Based on the output signals of at least some of the sensors, the calculator calculates the rotational speed of the inner ring equivalent member, the relative displacement between the outer ring and the inner ring equivalent member, the outer ring, Among the external forces acting with the inner ring equivalent member, it has a function of calculating one or more kinds of state quantities including at least this relative displacement or external force,
The sensor holder is made by injection molding of synthetic resin, and along with the injection molding, the sensors are embedded and supported, and the state quantity measurement of the rolling bearing unit is integrally coupled to the cover. A device,
A plurality of sensor modules, each having a plurality of sensor leads each formed by connecting a plurality of sensor leads to each of the sensors, are formed in a plurality of circumferential positions of the cover. The sensor modules are embedded and supported in the sensor holder in a state of being placed inside any of the through holes, and a part of the sensor holder is closely inserted into the through holes to An apparatus for measuring a state quantity of a rolling bearing unit, wherein each through hole is closed.   The state quantity measuring device of the rolling bearing unit formed in Claim 1 which has embedded the peripheral part of each through-hole formed in the cover in the sensor holder. A seal ring that cuts off the space where the encoder is installed from the external space between the cover and the inner ring equivalent member or the rotating member that is coupled and fixed to the inner ring equivalent member and rotates together with the inner ring equivalent member is arranged over the entire circumference. Provided,
The cover is made of a metal plate, and has a large-diameter cylindrical portion for fitting and fixing to one end portion in the axial direction of the outer ring, and exists on the opposite side to the outer ring with respect to the large-diameter cylindrical portion in the axial direction. A small-diameter cylindrical portion whose surface is a sliding contact surface for sliding the entire end edge of the elastic material constituting the seal ring, and the small-diameter cylindrical portion and the large-diameter cylindrical portion are close to each other A connecting portion for connecting the axial end portions on the side, and through-holes are formed at a plurality of circumferential positions of the connecting portion, respectively.
The state quantity measuring device of the rolling bearing unit according to any one of claims 1 and 2.   The rolling bearing unit is a hub unit for supporting a wheel of an automobile, the outer ring is supported by a suspension of the automobile in use, and the wheel is coupled and fixed to a hub that is an inner ring equivalent member. The state quantity measuring device of the rolling bearing unit described in any one of the items.

Images