JPH1068738A - Rolling bearing unit with rotating speed detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a bearing unit by forming a recessed part recessed inside in the radial direction of an outside member toward one end face of an inside member, on a central part of a cover, and installing a connector on a part of the recessed part. SOLUTION: An inner ring 5a is externally fitted to an inner edge part of a hub 1a mainly forming an inside member. A cylindrical part formed on a part projecting to the inside in the axial direction, with respect to an inner edge face of the inner ring 5a, is fixed to the inner edge part of the hub 1a in such manner that it is calked and widened outward in the radial direction, and the inner edge face is pressed down, for preventing the dropping of the inner ring 5a. A recessed part 32 recessed inside in the radial direction, of an outside member 8 toward one edge face of the hub a1, is formed at a central part of an integrally molded cover 18a. And a connector 30 for fetching a detecting signal of an annular sensor 20a which is partially buried in the cover 18a, is installed on a part of the recessed part 32, thereby shortening a bearing unit. As a result, the bearing unit can be installed in a limited space, and the degree of freedom in design can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A rolling bearing unit with a rotation speed detecting device according to the present invention rotatably supports a wheel of an automobile on a suspension device and is used for detecting the rotation speed of the wheel.

[0002]

2. Description of the Related Art A wheel of an automobile is rotatably supported on a suspension device, and a rotational speed of the wheel is detected to control an antilock brake system (ABS) or a traction control system (TCS). Rolling bearing unit with rotation speed detection device for
Conventionally, various structures are known. Each of the rotating speed detecting devices incorporated in the rolling bearing unit with such a rotating speed detecting device includes a tone wheel that rotates together with a wheel and a sensor that outputs an output signal that changes at a frequency proportional to the rotating speed of the tone wheel. Prepare. For example, Japanese Patent Application Publication No. 94-16051 discloses a rolling bearing unit with a rotation speed detecting device as shown in FIGS.

[0003] The outer end of the hub 1, which is the main part of the inner member (the outside is the side outside the vehicle in the width direction of the vehicle when assembled to the vehicle, left in each figure), Is formed, and an inner raceway 3a and a step portion 4 are formed on the outer peripheral surface of the intermediate portion. On the outer peripheral surface of the hub 1, an inner raceway 3b is formed on the outer peripheral surface, and the inner race 5 constituting an inner member together with the hub 1 is moved outward with its outer end surface abutting against the step 4. The fitting is supported. still,
The inner raceway 3a is formed on an inner race (not shown) separate from the hub 1 instead of being formed directly on the outer peripheral surface of the hub 1, and the inner race and the inner race 5 are externally fixed to the hub 1. In some cases.

A portion of the hub 1 near the inner end is provided with a male thread portion 6.
Is formed. The inner ring 5 is fixed to a predetermined portion of the outer peripheral surface of the hub 1 by a nut 7 which is screwed to the male screw portion 6 and further tightened to form an inner member. or,
A mounting portion 9 for fixing the outer member 8 to a suspension device is provided on an outer peripheral surface of an intermediate portion of the outer member 8 disposed around the hub 1. Also, on the inner peripheral surface of the outer member 8,
Each forms an outer raceway 10a, 10b opposite to the inner raceway 3a, 3b. A plurality of rolling elements 11, 11 are provided between the inner raceways 3a, 3b and the outer raceways 10a, 10b, respectively.
The rotation of the inner member inside the outer member 8 is allowed. Although balls are used as the rolling elements 11 in the illustrated example, tapered rollers may be used as rolling elements in the case of a heavy-duty rolling bearing unit for an automobile. A seal ring 12 is attached between the inner peripheral surface of the outer end of the outer member 8 and the outer peripheral surface of the hub so that the seal ring 12 is provided between the inner peripheral surface of the outer member 8 and the outer peripheral surface of the hub. And
The outer end opening of the space in which the plurality of rolling elements 11 and 11 are provided is closed.

At the inner end of the inner race 5 (the inside is the side closer to the center in the width direction of the vehicle when assembled to the vehicle, and at the portion deviating from the inner raceway 3b at the right of each drawing), The base end (left end in FIGS. 5 and 6) of the tone wheel 13 is externally fitted and fixed. The entire tone wheel 13 is formed in an annular shape (short cylindrical shape) by a magnetic metal plate such as a steel plate. The tone wheel 13 includes a small-diameter portion 14 and a large-diameter portion 15 formed concentrically with each other by a step 16. In such a tone wheel 13, the large-diameter portion 15 is fitted to the outer peripheral surface of the end of the inner ring 5, and the step 16 is brought into contact with the edge of the inner ring 5. The support is fixed. Therefore, the small diameter portion 14 is
Supported concentrically with. Then, a plurality of through-holes 17, which are rotation-side thinned portions, are formed in the small-diameter portion 14 at equal intervals in the circumferential direction, and the magnetic characteristics in the circumferential direction are alternately and uniformly changed. ing. Each of the through holes 17 has the same shape and is a rectangle that is long in the axial direction (the left and right direction in FIGS. 5 and 6).

The inner end opening of the outer member 8 is closed by a cover 18 made into a cylindrical shape with a bottom by drawing a metal plate such as a stainless steel plate or an aluminum alloy plate. An annular synthetic resin 21 in which an annular sensor 20 is embedded is held and fixed on the inner peripheral side of the cylindrical portion 19 constituting the cover 18. This sensor 20
Comprises a permanent magnet 22, a stator 23 made of a magnetic material such as a steel plate, and a coil 24.
By embedding 2, 23, and 24 in the synthetic resin 21, the whole is formed in an annular shape.

The permanent magnet 22 of each component of the sensor 20 is formed in an annular shape (ring shape), and is magnetized in the diameter direction. Then, the inner peripheral surface of the permanent magnet 22 is connected to the small-diameter portion 14 of the tone wheel 13.
At the base end portion thereof, the outer peripheral surface of the portion where the through hole 17 is not formed is opposed via the minute gap 25. The stator 23 has a substantially J-shaped cross section and is formed in a ring shape as a whole. The inner peripheral surface of the end portion of the outer cylindrical portion 26 constituting the stator 23 and the outer peripheral surface of the permanent magnet 22 are brought close to or in contact with each other. The above stator 2
The inner peripheral surface of the inner diameter side cylindrical portion 27 constituting 3 is opposed to a portion of the tone wheel 13 where the plurality of through holes 17 are formed, also via a minute gap 25.
Further, a plurality of notches 28 as fixed-side wall-thinning portions are formed in the inner diameter side cylindrical portion 27 at the same pitch (center angle) with the through holes 17 over the circumferential direction of the inner diameter side cylindrical portion 27. pitch)
It is formed by. Accordingly, the inner cylindrical portion 27 is formed in a comb shape.

Further, the coil 24 is formed in an annular shape by winding a conductive wire around a bobbin 29 made of a non-magnetic material, and is disposed on an inner peripheral side of an outer diameter side cylindrical portion 26 constituting the stator 23. doing. The electromotive force generated by the coil 24 is extracted from a connector 30 projecting from the outer surface of the cover 18.

When the tone wheel 13 rotates together with the inner ring 5 constituting the inner member during use of the rolling bearing unit with the rotation speed detecting device constructed as described above, the magnetic flux density in the stator 23 opposed to the tone wheel 13 is increased. Is changed, and the voltage induced in the coil 24 is
It changes at a frequency proportional to the rotation speed. Stator 23
The principle that the voltage induced in the coil 24 changes in accordance with the change in the density of the magnetic flux flowing through the coil 24 is the same as that of a conventionally widely known rotational speed detecting sensor. The reason why the density of the magnetic flux flowing through the stator 23 changes in accordance with the rotation of the tone wheel 13 is as follows.

The plurality of through holes 17 provided in the tone wheel 13 and the notches 28 provided in the stator 23 have the same pitch, so that they are simultaneously opposed over the entire circumference as the tone wheel 13 rotates. There is a moment. At the moment when each of the through holes 17 and each of the notches 28 oppose each other, the column, which is a magnetic material existing between the adjacent through holes 17, and between the adjacent notches 28. The existing magnetic tongue pieces oppose each other via the minute gap 25. In the state where the pillar portions and the tongue pieces, which are each made of a magnetic material, face each other, a high-density magnetic flux flows between the tone wheel 13 and the stator 23.

On the other hand, the through hole 17 and the notch 2
8 is shifted by half, the tone wheel 1
The density of the magnetic flux flowing between the stator 3 and the stator 23 decreases. That is, in this state, the through holes 17 provided in the tone wheel 13 face the tongue pieces, and
The notch 28 provided at the side faces the column. When the pillar portion faces the notch 28 and the tongue piece faces the through hole 17 in this manner, the tone wheel 13 and the stator 2
3, there is a relatively large gap over the entire circumference. In this state, the density of the magnetic flux flowing between the two members 13 and 23 becomes low. As a result, the voltage induced in the coil 24 changes in proportion to the rotation speed of the hub. By operating as described above, the sensor 20 changes the output voltage induced in the coil 24 at a frequency proportional to the rotation speed of the inner member.

[0012]

However, in the case of the conventional structure constructed and operated as described above, the total length of the rolling bearing unit with the rotational speed detector is divided by the outer end surface of the hub 1 and the tip of the connector 30 (FIGS. 5 to 6). It is unavoidable that the dimension る extending in the axial direction up to the right end portion) becomes long. That is, according to the conventional structure, the nut 7 is used to fix the inner ring 5 to a predetermined portion on the outer peripheral surface of the hub 1. And the cover 18
The outer member 8 has a shape protruding inward from the inner end surface thereof so as not to interfere with the nut 7. Therefore, the bearing unit including the cover 18 protrudes inward of the outer member 8 beyond the axial dimension of the nut 7. In addition, in the case of the conventional structure, the connector 30 for extracting the detection signal of the sensor 20 is further protruded inward from the inner end surface of the cover 18 at the portion protruding inward from the inner end surface of the outer member 1. Since the rolling bearing unit is provided in the state, the overall length of the rolling bearing unit with the rotation speed detecting device is further increased. As a result, the rolling bearing unit with the rotation speed detecting device becomes large, and it is difficult to install the rolling bearing unit in a limited space. In view of such circumstances, the rolling bearing unit with a rotation speed detecting device of the present invention has been invented to reduce the overall length of the bearing unit.

[Means for Solving the Problems]

The rolling bearing unit with a rotational speed detecting device of the present invention has an outer raceway on its inner peripheral surface, similar to the conventional rolling bearing unit with a rotational speed detecting device shown in FIGS. An outer member that does not rotate, an inner member that has an inner raceway on the outer peripheral surface and rotates when in use, a plurality of rolling elements rotatably provided between the outer raceway and the inner raceway, and one end of the inner member An annular tone wheel fixed concentrically to the inner member and alternately and equally spaced in a circumferential direction at a diametrically inner portion of the outer member, and one end of the outer member A cover, which is fitted and fixed to the portion, and closes one end opening of the outer member; a sensor which is held by the cover and which faces the tone wheel; and a cover for taking out a detection signal of the sensor. Provided in the department It was and a connector.

In particular, in the rolling bearing unit with a rotation speed detecting device according to the present invention, the inner member includes a main part and an inner ring fitted to one end of the main part. Is fixed to the main portion by crimping a portion protruding in the axial direction from one end surface of the inner ring at one end of the main portion radially outward to suppress the one end surface.
A concave portion is provided at the center of the cover toward the one end face of the inner member and is recessed inward in the diametrical direction of the outer member. The connector is provided in a part of the concave portion.

[0015]

The rolling bearing unit with the rotation speed detecting device of the present invention configured as described above rotatably supports a wheel on a suspension device, or detects the rotation speed of the wheel itself. This is the same as the case of the conventional structure described above. In particular, in the case of the rolling bearing unit with the rotation speed detecting device of the present invention, a concave portion is provided in the center of the cover toward the one end surface of the inner member, and is recessed inward in the radial direction of the outer member. Since the connector is provided in a part of the recess, the length of the connector projecting from the end surface of the outer member can be reduced, and the rolling bearing unit with the rotation speed detecting device can be shortened.

[0016]

1 and 2 show a first embodiment of the present invention.
An example is shown. The features of the rolling bearing unit with the rotation speed detecting device of the present invention include the structure of the hub 1a, the inner ring 5a, and the fixed portion constituting the inner member of the rolling bearing unit, and the cover 18a provided with the connector 30 on a part thereof. In the structure. Since the structure and operation of the other parts are the same as those of the conventional structure shown in FIGS. 5 and 6 above, the same parts as those of the conventional structure are denoted by the same reference numerals, and redundant description is omitted, or For simplicity, the following description focuses on the features of the present invention.

A hub 1 which is a main part of the inner member
An inner ring 5a is fixed to an inner end of the inner ring 5a. This inner ring 5
a, after externally fitting to the inner end of the hub 1a, the cylindrical portion formed at the inner end of the hub 1a and protruding inward in the axial direction from the inner end surface of the inner ring 5a is diametrically outer. The hub 1a is swaged out and pressed down on the inner end face.
It is fixed to the inner end. Therefore, even if a thrust load is applied to the inner ring 5a, the inner ring 5a does not fall off. Thereby, the male screw portion 6 and the nut 7 of the conventional structure
(FIGS. 5 and 6) become unnecessary. In the illustrated example, the hub 1
The portion where the inner end portion of the inner ring 5a is swaged out shows a structure in which the inner end surface of the inner ring 5a is directly suppressed. It is also possible to do. If such a structure is adopted and the shape of the spacer is devised, the radius of curvature of the caulked portion can be increased, and even if a hub 1a made of a high carbon steel material having a small allowable elongation is used, the caulking width is increased. It is easy to perform processing so that damage such as cracks does not occur in the portion. In the present invention, since the members 6 and 7 are not required, injection molding of a synthetic resin is performed so that the connector 30 can be installed using a space vacated in a diametrically inner portion of the inner end of the outer member 8. At the center of the cover 18a integrally formed by the above, a concave portion 32 is provided which is recessed inward in the diameter direction of the outer member 8 toward one end surface of the hub 1a. By providing a connector 30 for extracting a detection signal of the annular sensor 20a, a part of which is embedded in the cover 18a, in a part of the recess 32, the rolling bearing unit with the rotation speed detecting device can be shortened. Is being planned. With such a structure, the amount of protrusion of the connector 30 from the inner end surface of the outer member 8 is reduced, and the rolling bearing unit with the rotation speed detecting device is shortened. It becomes easy to install in the space that was set.
Note that, in the illustrated example, the distal end (the right end in FIG. 1) of the connector 30 projects further inward than the inner end existing at the diametrically outer portion of the cover 18a. On the other hand, the connector 30 is provided at a portion facing the concave portion existing at the center of the inner end surface of the hub 1a, and the connector 30 is provided in the concave portion.
Of the connector 30
Can be configured so that the front end does not protrude inward from the inner end of the cover 18a.

The connector 30 and the cover 18
The sensor 20a which is opposed to the tone wheel 13a while being held at a is connected by a conductor embedded in a bobbin 29a constituting the sensor 20a. or,
In the illustrated example, the sensor 20a includes first and second stators 34 and 35 in which cutouts 28 and 28 are formed in respective outer peripheral edges and the outer peripheral edges are formed in a comb-like shape. A permanent magnet 22a in which inner peripheral ends of the stators 34 and 35 abut against both end surfaces in the magnetization direction (left and right end surfaces in FIG. 1);
And a coil 24 wound around a bobbin 29a surrounded by these members 34, 35, 22a. Notch 2 formed in first and second stators 34 and 35
8, 28 have the same pitch and the same phase. Of course, the pitch of these notches 28, 28 and the tone wheel 13
The pitches (center angle pitches) of the notches 31 formed in a are equal to each other. Therefore, in the case of this example, the rotation of the tone wheel 13a causes the permanent magnet 22a to rotate.
Causes the magnetic resistance in the magnetic circuit to change simultaneously at two locations. Accordingly, the output of the sensor 20a is increased in conjunction with the fact that the tone wheel 13a is arranged on the outer diameter side of the sensor 20a and the relative displacement speed between the stators 34 and 35 and the tone wheel 13a is increased. Thus, the reliability of the rotation speed detection can be ensured.

In the illustrated example, one O-ring 41 provided between the cover 18a and the outer member 8 prevents foreign matter such as muddy water from entering the cover 18a. . That is, on the inner side surface of the cover 18a, the sensor 20a
Is formed, and a sleeve 36 is attached along the outer peripheral surface of the convex portion 33. The sleeve 36 is formed by forming a metal plate such as a stainless steel plate or the like into an annular shape with an L-shaped cross section, and is bent outward from the inner end edge of the cylindrical portion 37 in the radial direction. A flange-shaped flange 38. The cylindrical portion 37 is disposed along the outer peripheral surface of the convex portion 33, and further projects outward from the leading edge (outer edge) of the convex portion 33. On the other hand, the flange portion 38 is embedded at the center in the thickness direction of a portion that is diametrically outward of the convex portion 33 at the outer peripheral edge of the cover 18a. still,
The outer peripheral edge of the flange portion 38 does not reach the outer peripheral edge of the cover 18a, but is embedded in the inside of the cover 18a, and muddy water or the like enters the cover 18a from the boundary between the cover 18a and the flange portion 38. Preventing entry.

Cover 1 provided with sleeve 36 as described above
A chamfered portion 39 is formed on the inner peripheral edge of the inner end opening of the outer member 8 for fitting and fixing the 8a. When the inner end opening of the outer member 8 is closed by the cover 18a, the sleeve 36 is fitted inside the inner end of the outer member 8, and the outer surface of the cover 18a is shifted toward the outer periphery. To the inner end face of In this state, a space 40 having a triangular cross section and a whole annular shape, which is surrounded on three sides by the outer peripheral portion of the outer surface of the cover 18a, the outer peripheral surface of the intermediate portion of the cylindrical portion 37, and the chamfered portion 39, is formed. It is formed. In the case of the rolling bearing unit with the rotation speed detecting device of the present embodiment, an O-ring 41 which is a kind of a seal ring is mounted in the space 40 in a state of being elastically compressed.

Since the O-ring 41 is provided in the space 40 provided at the above-mentioned position in an elastically compressed state,
The cover 18a and the outer member 8 are
It is possible to reliably prevent muddy water or the like from leaking into the inside. That is, muddy water and the like existing around the cover 18a and the outer member 8 pass through a minute gap existing between the inner end surface of the outer member 8 and the outer peripheral portion of the outer surface of the cover 18a. As shown by a, it enters into the space 40 near the outer periphery. However, the muddy water or the like that has entered the outer peripheral portion of the space 40 in this way is blocked by the O-ring 41 and does not enter the inner peripheral portion of the space 40. On the other hand, one end of a minute gap existing on the fitting surface between the outer peripheral surface of the sleeve 36 and the inner peripheral surface of the inner end portion of the outer member 8, and the contact portion between the sleeve 36 and the synthetic resin forming the cover 18a. One end of each of the existing minute gaps communicates with the inner peripheral portion of the space 40.
Therefore, muddy water or the like that has entered the portion near the outer periphery of the space 40 from the minute gap between the outer member 8 and the cover 18a,
As shown by dashed arrows B and C in FIG. 2, it does not enter the inside of the outer member.

Next, FIG. 3 shows a second embodiment of the present invention. In the case of this example, a lead wire for connecting the sensor 20a and the connector 30 is taken out from the outside of the first stator 34 to the outside surface side of the cover 18a. The terminal of the connector 30 is connected by penetrating the cover 18a. With this configuration, the cover 18a
The thickness in the vicinity of the concave portion 32 can be reduced, and the total length of the rolling bearing unit with the rotation speed detecting device can be further reduced as compared with the case of the first example described above.

FIG. 4 shows a third embodiment of the present invention. In the case of this example, the sensor 20b provided on the inner surface side of the cover 18b is provided at one central portion of the stator 42 and the outer surface of the cover 18b.
b, and a permanent magnet 22b provided inside the coil 24a in the diameter direction. The stator 42 is formed in a disk shape having a cylindrical portion 43 facing the tone wheel 13a on the outer peripheral edge, and is embedded in the cover 18b. And this stator 42
The notches 31, 31 formed in the tone wheel 13a and the notches 28, 28 having the same pitch as the notches 31, 31 formed in the tone wheel 13a are formed in the cylindrical portion 43 of the above. Therefore, the magnetic resistance between the tone wheel 13a and the stator 42 is
It changes with the rotation of a.

A cylindrical portion 44 is formed at the center of the outer surface of the cover 18b, and the bobbin 29b is embedded and supported in the cylindrical portion 44. Furthermore, this bobbin 29b
The inner end face of the permanent magnet 22b inserted inward in the diametrical direction is fixed to the center of the outer face of the stator 42 by its own magnetic force. Also, the outer surface of the permanent magnet 22b is
It is close to the bottom surface of the concave hole 45 formed at the inner end of the hub 1a constituting the inner member. Therefore, the permanent magnet 2
The magnetic flux flowing between both end surfaces in the magnetization direction of 2b flows through the hub 1a, the inner ring 5a, the tone wheel 13a, and the stator 42, all of which are made of magnetic material.

As described above, in the case of this embodiment, the magnetic flux flowing between both end surfaces in the magnetizing direction of the permanent magnet 22b passes through the stator 42, the tone wheel 13a, the inner ring 5a, and the hub 1a. Then, due to a change in the density of the magnetic flux accompanying the rotation of the tone wheel 13a, the tone wheel 1
A voltage is generated which changes at a frequency proportional to the rotation speed of 3a. In the case of this example, by configuring as described above, the sensor 20b facing the tone wheel 13a is used.
The structure of the first embodiment is simplified, and the one end of the sensor 20b is positioned inside the hub 1a in the diametrical direction. The total length of the unit can be reduced.

In the case of the present embodiment, the coil 24a is arranged near the axis of the hub 1a so that the coil 2a
The conducting wire connecting from 4a to the connector 30 can be arranged linearly and shortened. Therefore, in addition to shortening the total length of the rolling bearing unit with the rotation speed detecting device, the cost can be reduced by saving the conductive wires. In addition, in this example, since the diameter of the coil 24a is small, the average diameter of the conductive wire wound around the bobbin 29b in order to configure the coil 24a is smaller than that of the conventional structure and the first and second examples described above. Can also be greatly reduced. Therefore, the number of turns of the coil 24a can be increased without increasing the resistance of the coil 24a, and the sensor 20b caused by the coil 24a can be increased.
Output voltage can be increased. Thus, in the case of this example, in addition to shortening the total length of the rolling bearing unit with the rotation speed detecting device, it is possible to stabilize the detection of the rotation speed and reduce the cost. In practicing the present invention, the structures of the tone wheel and the sensor are not particularly limited. In addition to the magnetic type shown in the figure, a photoelectric type tone wheel and sensor can be used.

[0027]

Since the present invention is constructed and operates as described above, the overall length of the rolling bearing unit with the rotation speed detecting device can be shortened, and the rolling bearing unit with the rotation speed detecting device can be reduced in size and weight. realizable. As a result, installation in a limited space becomes possible, and the degree of freedom in vehicle design can be increased.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a partial sectional view showing a second example of the embodiment of the present invention.

FIG. 4 is a partial sectional view showing the third example.

FIG. 5 is a sectional view showing a conventional example.

FIG. 6 is an enlarged view of the right part of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Hub 2 Flange part 3, 3a, 3b Inner ring track 4 Step part 5, 5a Inner ring 6 Male thread part 7 Nut 8 Outer member 9 Mounting part 10, 10a, 10b Outer ring track 11 Rolling element 12 Seal ring 13, 13a, 13b Tone wheel 14 Small diameter part 15, 15a, 15b Large diameter part 16 Step 17 Through hole 18, 18a, 18b Cover 19 Cylindrical part 20, 20a, 20b Sensor 21 Synthetic resin 22, 22a, 22b Permanent magnet 23 Stator 24, 24a Coil Reference Signs List 25 minute gap 26 outer diameter side cylindrical part 27 inner diameter side cylindrical part 28 notch 29, 29a, 29b bobbin 30 connector 31 notch 32 concave part 33 convex part 34 first stator 35 second stator 36 sleeve 37 cylindrical part 38 flange Part 39 chamfered part 40 space 41 O-ring 42 stator 43 yen Tubular part 44 Cylindrical part 45 Concave hole

Claims (1)

[Claims] 1. An outer member having an outer raceway on an inner peripheral surface and not rotating during use, an inner member having an inner raceway on an outer peripheral surface and rotating during use, and rolling between the outer raceway and the inner raceway. A plurality of rolling elements freely provided and, at one end of the inner member, diametrically inner portions of the outer member, which are fixed concentrically with the inner member, alternately and at equal intervals in a circumferential direction. An annular tone wheel, a cover that is fitted and fixed to one end of the outer member and covers one end opening of the outer member, and faces the tone wheel while being held by the cover. In a rolling bearing unit with a rotation speed detecting device including a sensor and a connector provided on a part of the cover for extracting a detection signal of the sensor, the inner member includes a main portion, the main portion, Inside fitted to one end of The inner ring is provided on the main portion by crimping a portion protruding in the axial direction from one end surface of the inner ring at one end of the main portion to the outside in the diametrical direction to suppress the one end surface. The cover is provided with a concave portion which is recessed in the center of the cover toward the one end surface of the inner member and is diametrically inward of the outer member, and the connector is provided in a part of the concave portion. A rolling bearing unit with a rotation speed detecting device.