JP2012145129A - Bearing unit with encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost bearing unit with an encoder capable of easily positioning an encoder body with encoded information added in the circumferential direction thereof in the axial and radial directions in a short time and keeping the body in a constant positional relation in each direction for a long time.SOLUTION: The encoder 20 fixed to a rotary wheel 4 includes a hollow-disk-like encoder body 24 with encoded information added thereto and a disk-like encoder core metal 26 which holds the encoder body and can be engaged with the rotary wheel. On the rotary wheel thereof, there is formed a hollow cylindrical recessed part 12g where a side end surface of the rotary wheel in the direction of the rotary shaft Ax is concentrically recessed around the rotary shaft Ax, and on the encoder core metal, there is formed a cylindrical engaging projection 26p which projects to the side end surface of the rotary wheel and can be engaged with the recessed engaging part. A fastening member 28 penetrates the engaging projection to the engaging recessed part to fix the encoder to the rotary wheel.

Description

  The present invention relates to a bearing unit with an encoder provided with an encoder for detecting a rotation state of a bearing.

  Conventionally, a bearing unit with an encoder provided with an encoder for detecting a rotation state of a bearing while rotatably supporting a wheel (for example, a disc wheel) of an automobile or the like with respect to a vehicle body (for example, a suspension device (suspension)). Is known (see Patent Document 1). Such a bearing unit is fixed to a component on the inboard (vehicle body) side and is always provided in a non-rotating state, and is provided to face the stationary wheel, and outboard (wheel). And a rotating wheel (for example, an inner ring) that is connected to the side component and rotates together with the wheel. In this case, by incorporating a plurality of rolling elements (for example, balls, rollers) between the stationary wheel and the rotating wheel so as to roll freely, the stationary wheel and the rotating wheel are connected to each other via the rolling element. It is configured to be rotatable relative to the rotation axis.

  The bearing unit is provided with a detection device that detects the rotation state of the bearing. The detection device includes an annular encoder fixed to the rotating wheel and rotating together, and a sensor fixed to a stationary wheel or a component on the inboard (vehicle body) side and disposed opposite to the encoder. The encoder is fitted to the outer periphery of the inboard (vehicle body) side end of the rotating wheel while supporting the encoder body with a hollow disk-shaped encoder body to which predetermined encoded information is added along the circumferential direction. It has a disk-shaped encoder core. The encoder body is made of, for example, magnetic rubber, resin, metal or the like, and encoded information that can be read magnetically or optically is added to the encoder body along the circumferential direction.

  According to such a detection device, when the encoder (that is, the encoder body) rotates together with the rotating wheel during the rotation of the bearing, the encoded information added to the encoder body along the circumferential direction is magnetically or by the sensor. By optically reading, the rotation state (for example, rotation speed, rotation direction) of the bearing can be detected based on the reading result.

JP 2004-211832 A

  By the way, in order to maintain a constant rotation detection accuracy of the bearing by the above-described detection device, the encoder main body is moved in the axial direction (direction along the rotation axis of the rotating wheel) and the radial direction (of the rotating wheel) while the bearing is rotating. It is necessary to always maintain a fixed positional relationship with respect to the direction orthogonal to the rotation axis. In this case, for example, if the encoder body is displaced in the axial direction and the radial direction during the rotation of the bearing, the positional relationship between the encoder body and the sensor described above becomes unstable, and as a result, the rotation state of the bearing can be accurately determined. It may be difficult to detect.

  Further, in the conventional bearing unit including the bearing unit with an encoder disclosed in Patent Document 1 described above, the encoder is fixed to the rotating wheel by fitting the encoder core metal to the outer periphery of the inboard (vehicle body) side end of the rotating wheel. Has been. For this reason, depending on the degree of the fitting (for example, the size of the fitting tightening margin, the fitting force, etc.), for example, a creep phenomenon occurs between the encoder and the rotating wheel. There is a risk that it may be difficult to maintain a constant positional relationship with respect to the axial direction and the radial direction.

  Furthermore, in the conventional bearing unit described above, when the encoder body is positioned in the axial direction and the radial direction, the encoder core is fitted to the outer periphery of the inboard (vehicle body) side end of the rotating wheel to rotate the encoder. The process (procedure) for fixing to the wheel takes time and labor, and the manufacturing cost of the bearing unit increases.

  The present invention has been made to solve such a problem, and an object of the present invention is to easily add an encoder body to which encoded information is added along the circumferential direction in a short time in the axial direction and the radial direction. An object of the present invention is to provide a low-cost bearing unit with an encoder that can be positioned and always kept in a fixed positional relationship for a long time in each direction.

In order to achieve such an object, the present invention provides a stationary wheel that is fixed to a component on the inboard side and is maintained in a non-rotating state at all times, a stationary wheel that faces the stationary wheel, and that A bearing unit with an encoder comprising a rotating wheel connected to a component and rotating together, and an annular encoder fixed to the rotating wheel and rotating together. The encoder has predetermined encoded information in the circumferential direction. A hollow disk-shaped encoder body that is attached along the disk, and a disk-shaped encoder core that can be fitted to the rotating wheel while supporting the encoder body. A hollow cylindrical fitting recess in which a part of the side end surface in the rotation axis direction is recessed concentrically with respect to the rotation axis and along the rotation axis direction is formed. Toward the side edge of the rotating wheel The cylindrical fitting convex part which protrudes along the rotation axis direction and can be fitted into the fitting concave part is formed, and in the state where the fitting convex part is fitted to the fitting concave part, The encoder is fixed to the rotating wheel by fastening the fastening member from the fitting convex portion to the fitting concave portion along the rotation axis direction.
In the present invention, the fitting recess of the rotating wheel is composed of a cylindrical inner peripheral surface extending along the rotation axis direction and a circular bottom surface extending along a direction orthogonal to the rotation axis. And the fitting convex part of the encoder core is composed of a cylindrical outer peripheral surface extending along the rotation axis direction and a circular end surface extending along the direction orthogonal to the rotation axis. In a state where the fitting convex portion is fitted to the fitting concave portion, the cylindrical inner peripheral surface and the cylindrical outer peripheral surface are in contact with each other, thereby positioning the encoder body in the radial direction.
In the present invention, in a state where the fitting convex portion is fitted to the fitting concave portion, the circular bottom surface and the circular end surface are in contact with each other, or in the direction perpendicular to the rotation axis around the fitting concave portion. The encoder body is positioned with respect to the axial direction by contacting the portion extending along the portion and the portion extending along the direction orthogonal to the rotation axis around the fitting convex portion.

  According to the present invention, an encoder body to which encoded information is added along the circumferential direction is easily positioned in a short time in the axial direction and the radial direction, and is always constant for a long time in each direction. Thus, it is possible to realize a low-cost bearing unit with an encoder that can be held in the positional relationship.

(a) is sectional drawing which shows the whole structure of the bearing unit with an encoder which concerns on one Embodiment of this invention, (b) is an expanded sectional view which decomposes | disassembles and shows roughly the attachment state of the encoder with respect to a rotating wheel. (a) is sectional drawing which shows the whole structure of the bearing unit with an encoder which concerns on other embodiment of this invention, (b) is an expanded sectional view which decomposes | disassembles and shows roughly the attachment state of the encoder with respect to a rotating wheel.

Hereinafter, a bearing unit with an encoder according to an embodiment of the present invention will be described with reference to the accompanying drawings.
1 (a) and 1 (b) show a bearing unit with an encoder for a driven wheel. Such a bearing unit is fixed to a component on the inboard (vehicle body) side and is always provided in a non-rotating state so as to be opposed to the inside of the stationary wheel 2 and out. A rotating wheel 4 (for example, an inner ring) connected to a component on the board (wheel) side and rotating together with the wheel is provided. In this case, a plurality of rolling elements 6 and 8 (for example, balls and rollers) are rotatably incorporated in a double row (for example, two rows) between the stationary wheel 2 and the rotating wheel 4, thereby rolling the rolling element 6. , 8, the stationary wheel 2 and the rotating wheel 4 are configured to be relatively rotatable about the rotation axis Ax of the rotating wheel 4.

  The stationary wheel 2 is configured and arranged in a hollow cylindrical shape that covers the outer periphery of the rotating wheel 4, and a seal member that seals the inside of the bearing is provided between the stationary wheel 2 and the rotating wheel 4. ing. As the sealing member, a lip seal 10a is provided on the outboard (wheel) side, and a cover 10b is provided on the inboard (vehicle body) side. The cover 10b has a disk shape that can seal the inside of the bearing on the vehicle body side from the outside of the bearing, and is attached by fitting the peripheral edge thereof to the outer periphery of the stationary wheel 2. In the drawings, balls are shown as the rolling elements 6 and 8. However, depending on the type and type of the bearing unit, the purpose of use, or the environment of use, a roller may be applied.

  The stationary wheel 2 is integrally formed with a fixing flange 2a that protrudes radially outward from the outer periphery thereof, and a fixing bolt (not shown) is inserted into the fixing hole 2b of the fixing flange 2a. By fastening to the side, the stationary wheel 2 can be fixed to a suspension device (knuckle) (not shown). The rotating wheel 4 is provided with a substantially cylindrical hub 12 that rotates together with, for example, a disc wheel (not shown) of an automobile, and the hub 12 has a hub flange 12a to which the disc wheel is attached. Projected.

  The hub flange 12a extends radially outward (outward in the radial direction of the hub 12) beyond the stationary ring 2, and is arranged at predetermined intervals along the circumferential direction in the vicinity of the extended edge. A plurality of hub bolts 14 are provided. In this case, the disc wheel can be positioned and fixed with respect to the hub flange 12a by inserting a plurality of hub bolts 14 into bolt holes (not shown) formed in the disc wheel and tightening with hub nuts (not shown). it can. At this time, positioning in the radial direction of the wheel is performed by a pilot portion 12d protruding from the wheel side of the hub 12.

  The hub 12 (rotating wheel 4) is fitted with an annular rotating wheel structure 16 (a member constituting the rotating wheel 4 together with the hub 12) on a fitting surface 4f on the vehicle body side. . In this case, for example, in a state where the rolling elements 6 and 8 are held by the cage 18 between the stationary wheel 2 and the rotating wheel 4, the rotating wheel constituting body 16 is fitted to the step portion 12b formed on the fitting surface 4f. Then, the crimping region 12c at the end of the hub 12 on the vehicle body side is plastically deformed, and the crimping region 12c is crimped (adhered) along the peripheral end 16s of the rotating wheel component 16. The rotating wheel component 16 can be fixed to the rotating wheel 4 (hub 12).

  At this time, a predetermined preload is applied to the bearing unit, and in this state, the rolling elements 6 and 8 form a predetermined contact angle with each other and the raceway surfaces (stationary wheels) of the stationary wheel 2 and the rotating wheel 4 are stationary. The track surface 2s and the rotating track surface 4s) are brought into contact with each other to be freely rollable. In this case, an action line (not shown) connecting the two contact points is perpendicular to the raceway surfaces 2s and 4s, passes through the centers of the rolling elements 6 and 8, and is on one point (action) on the center line of the bearing unit. At a point). This constitutes a rear combination (DB) bearing.

  In such a bearing configuration, all of the force acting on the wheel during traveling of the vehicle is transmitted from the disk wheel to the suspension device through the bearing unit. At that time, the bearing unit has various loads (radial load, Axial load, moment load, etc.) are applied. However, since the bearing unit is a back combination (DB) bearing as described above, high rigidity is maintained against various loads.

  The bearing unit described above includes an annular encoder 20 that is fixed to the rotating wheel 4 (specifically, the hub 12) and rotates together. The encoder 20 can be fitted to the rotating wheel 4 (hub 12) while supporting the encoder body 24 and a hollow disk-shaped encoder body 24 to which predetermined encoded information is added along the circumferential direction. And a disc-shaped encoder mandrel 26. The encoder body 24 is formed of, for example, magnetic rubber, resin, metal, or the like, and encoded information that can be read magnetically or optically is added thereto along the circumferential direction.

  The rotating wheel 4 (specifically, the hub 12) has a part of a side end surface (specifically, an end surface on the vehicle body side of the hub 12) in the direction of the rotational axis Ax, with the rotational axis Ax as a center. A hollow cylindrical fitting recess 12g is formed concentrically and recessed along the direction of the rotation axis Ax. Further, the encoder cored bar 26 is a cylindrical fitting that protrudes toward the side end surface of the rotating wheel 4 (hub 12) and along the direction of the rotation axis Ax and can be fitted into the fitting recess 12g. A convex portion 26p is formed. Here, the end surface of the solid region extending inside (specifically, the inner diameter side) of the above-described caulking region 12c is assumed as the side end surface of the rotating wheel 4 (hub 12).

  In this case, the fitting recess 12g of the rotating wheel 4 (hub 12) has a cylindrical inner peripheral surface Ga extending along (in parallel with) the rotation axis Ax and a direction orthogonal to the rotation axis Ax. It is composed of a circular bottom Gb extending (in parallel). Further, the fitting convex portion 26p of the encoder metal core 26 has a cylindrical outer peripheral surface Pa extending along (in parallel with) the rotation axis Ax direction, and along a direction perpendicular to the rotation axis Ax (in parallel). It is comprised by the circular-shaped end surface Pb extended.

  Here, the inner diameter of the cylindrical inner peripheral surface Ga is preferably set to the same size as the outer diameter of the cylindrical outer peripheral surface Pa or slightly larger than the outer diameter of the cylindrical outer peripheral surface Pa. In addition, the circular bottom surface Gb and the circular end surface Pb are preferably configured to be flat surfaces that are parallel to each other. In addition, the amount of depression (gap depth) of the fitting recess 12g, the inner diameter of the cylindrical inner peripheral surface Ga associated therewith, the amount of protrusion (protrusion height) of the fitting protrusion 26p, and the cylindrical shape associated therewith Regarding the outer diameter of the outer peripheral surface Pa, it depends on the shape and size of the side end surface (the vehicle body side end surface of the hub 12) of the rotating wheel 4 (hub 12), the shape and size of the encoder core 26, and the like. Since it is set, the numerical value is not particularly limited here.

  According to this configuration, the cylindrical inner peripheral surface Ga and the cylindrical outer peripheral surface Pa are in contact with each other in the state where the fitting convex portion 26p is fitted in the fitting concave portion 12g, so that the encoder main body 24 is Positioning can be performed with high accuracy in the radial direction (direction orthogonal to the rotation axis Ax of the rotating wheel 4). Further, in the state where the fitting convex portion 26p is fitted to the fitting concave portion 12g, the above-described circular bottom surface Gb and the circular end surface Pb are in contact with each other, whereby the encoder body 24 is moved in the axial direction (of the rotating wheel 4). The direction along the rotation axis Ax can be determined with high accuracy.

  The cylindrical inner peripheral surface Ga and the circular bottom surface Gb constituting the fitting recess 12g are preferably subjected to a surface treatment such as mechanical finishing. Thereby, since both surfaces Ga and Gb can be brought into close contact with each other in a planar shape, the positioning accuracy of the encoder main body 24 in the radial direction and the axial direction can be further improved.

  Then, in the state where the fitting convex portion 26p is fitted to the fitting concave portion 12g (that is, the encoder main body 24 is positioned in the radial direction and the axial direction), the fastening member 28 is fitted along the rotation axis Ax direction. The encoder 20 (specifically, the encoder core metal 26) can be fixed to the rotating wheel 4 (hub 12) by fastening from the mating convex part 26p to the fitting concave part 12g. In this case, for example, a bolt or a tapping screw can be applied as the fastening member 28, but the bolt is shown as the fastening member 28 as an example in the drawings.

  The circular bottom surface Gb of the fitting concave portion 12g is formed with a screw hole 12h along the rotation axis Ax direction, and the circular end surface Pb of the fitting convex portion 26p is fitted to the fitting concave portion 12g. In a state where the convex portion 26p is fitted, a screw insertion hole 26h is formed at a position facing the above-described screw hole 12h. According to this, since the screw insertion hole 26h and the screw hole 12h communicate along the rotation axis Ax in the state where the fitting convex portion 26p is fitted to the fitting concave portion 12g, the fastening member 28 is fitted. It can fasten from the convex part 26p to the fitting concave part 12g.

  In this case, if the screw hole 12h of the fitting recess 12g is a female screw in the lower hole of the center hole 12t (in other words, if the center hole 12t is configured as an entrance chamfer of the female screw), the screw hole 12h The center can be made coincident with the direction of the rotation axis Ax, and the diameter of the screw insertion hole 26h of the fitting convex portion 26p can be reduced (that is, close to the nominal diameter of the screw hole 12h). Thereby, even when the diameter of the center hole 12t (opening diameter of the conical portion) and the diameter of the head portion 28a of the fastening member 28 are close to each other, the encoder 20 (encoder core metal 26) can be securely and firmly attached to the rotating wheel 4 (hub). 12).

  As described above, according to the present embodiment, the encoder main body 24 is moved in the radial direction only by fitting the fitting convex portion 26p of the encoder 20 into the fitting concave portion 12g of the rotating wheel 4 (hub 12) (so-called one-touch). It can be positioned in the axial direction. Thereby, since the encoder main body 24 can be easily positioned in a short time with respect to the radial direction and the axial direction, the manufacturing cost of the bearing unit can be greatly reduced.

  Then, in a state where the encoder main body 24 is positioned in the radial direction and the axial direction, the fastening member 28 is fastened from the fitting convex portion 26p to the fitting concave portion 12g along the rotation axis Ax direction, whereby the encoder 20 ( The encoder core metal 26) can be securely and securely fixed to the rotating wheel 4 (hub 12). Accordingly, it is possible to prevent a creep phenomenon from occurring between the encoder 20 (encoder core metal 26) and the rotating wheel 4 (hub 12) during the rotation of the bearing. And it can always be kept in a fixed positional relationship with respect to the axial direction.

  As a result, during the rotation of the bearing, the positional relationship between the encoder body 24 and the sensor 30 fixed to the stationary wheel 2 or the component on the inboard (vehicle body) side and disposed opposite to the encoder 20 is always kept constant. can do. Thereby, since the reading accuracy of the sensor 30 with respect to the encoded information added to the encoder body 24 can be stabilized, the rotation state (for example, rotation speed, rotation direction) of the bearing is determined based on the reading result. It can be detected with high accuracy.

  Further, according to the present embodiment, by reducing the size (diameter dimension) of the encoder core 26, the size (diameter dimension) of the encoder body 24 supported by the encoder core bar 26 can be similarly reduced. . Thereby, the size (diameter dimension) of the entire encoder 20 can be configured to overlap along the rotation axis Ax direction within the range of the size (diameter dimension) of the rotating wheel 4. As a result, the entire bearing unit with an encoder can be made compact and the output can be increased.

  In this case, since the degree of freedom in changing the sensing diameter can be improved by reducing the size (diameter dimension) of the encoder core 26, the sensor 30 can be shared. Further, since the distance between the encoder 20 and the stationary wheel 2 can be increased, for example, when the encoded information added to the encoder body 24 is magnetically read by the sensor 30, the magnetic flux is applied to the stationary wheel 2. Can be absorbed or the magnetic flux can be prevented from being bent toward the stationary wheel 2.

Next, a bearing unit with an encoder according to another embodiment of the present invention will be described with reference to the accompanying drawings.
In the above-described embodiment (FIG. 1), the circular bottom surface Gb and the circular end surface Pb are in contact with each other in a state where the fitting convex portion 26p is fitted to the fitting concave portion 12g, thereby the encoder main body. In the other embodiment, as shown in FIGS. 2A and 2B, the fitting convex portion 26p is fitted to the fitting concave portion 12g. In this state, a portion 12m extending around the fitting recess 12g along the direction orthogonal to the rotation axis Ax and a portion extending around the fitting projection 26p along the direction perpendicular to the rotation axis Ax. It is assumed that the encoder main body 24 is positioned in the axial direction by being in contact with each other.

Here, the part 12m around the fitting recess 12g and the part 26m around the fitting convex part 26p are preferably configured as flat surfaces parallel to each other.
According to this configuration, the cylindrical inner peripheral surface Ga and the cylindrical outer peripheral surface Pa are in contact with each other in the state where the fitting convex portion 26p is fitted in the fitting concave portion 12g, so that the encoder main body 24 is Positioning can be performed with high accuracy in the radial direction (direction orthogonal to the rotation axis Ax of the rotating wheel 4). Further, in the state where the fitting convex portion 26p is fitted to the fitting concave portion 12g, the above-described flat surfaces 12m and 26m are in contact with each other, whereby the encoder body 24 is moved in the axial direction (the rotational axis Ax of the rotating wheel 4). Can be positioned with high accuracy.

  In the above-described embodiment, both the cylindrical inner peripheral surface Ga and the circular bottom surface Gb constituting the fitting recess 12g are subjected to surface treatment (mechanical finishing). Surface treatment (mechanical finishing) may be performed only on the inner circumferential surface Ga. In this case, it is preferable to perform surface treatment (mechanical finishing) on both the flat surfaces 12m and 26m as well as the cylindrical inner peripheral surface Ga. Thereby, the positioning accuracy of the encoder body 24 in the radial direction and the axial direction can be further improved.

  Then, in the state where the fitting convex portion 26p is fitted to the fitting concave portion 12g (that is, the encoder main body 24 is positioned in the radial direction and the axial direction), the fastening member 28 is fitted along the rotation axis Ax direction. The encoder 20 (specifically, the encoder core metal 26) can be fixed to the rotating wheel 4 (hub 12) by fastening from the mating convex part 26p to the fitting concave part 12g. In this case, for example, a bolt or a tapping screw can be applied as the fastening member 28, but the tapping screw is shown as an example of the fastening member 28 in the drawing.

  In this case, in the state in which the fitting convex portion 26p is fitted to the fitting concave portion 12g and the screw insertion hole 26h and the screw hole 12h are communicated along the direction of the rotation axis Ax, the fastening member 28 is connected to the spring member 32 ( For example, it is fastened from the fitting convex part 26p to the fitting concave part 12g via a disc spring). Then, according to the fastening amount (screwing amount) of the fastening member 28, the urging force of the spring member 32 pressed by the head portion 28a of the fastening member 28 is changed to the encoder core metal 26 (specifically, the fitting convex portion 26p). Thus, the portion (flat surface) 26m around the fitting convex portion 26p is pressed against the portion (flat surface) 12m around the fitting concave portion 12g. As a result, the encoder 20 (encoder core 26) can be securely and securely fixed to the rotating wheel 4 (hub 12).

  As described above, according to the present embodiment, the portion (flat surface) 26m around the fitting convex portion 26p and the portion (flat surface) 12m around the fitting concave portion 12g are in contact with each other. Compared to the case of the embodiment (that is, the case where the circular bottom surface Gb and the circular end surface Pb are in contact with each other), the encoder core metal 26 is connected to the rotating wheel 4 (hub 12) in a region closer to the encoder body 24. ) And can be fixed.

  In other words, the receiving surface of the rotating wheel 4 (hub 12) with respect to the encoder core 26, that is, the portion (flat surface) 12m around the fitting recess 12g is made larger in diameter than the circular bottom Gb. Can do. In this case, the encoder core 26 can always be maintained in a constant posture without being affected by the centrifugal force generated during the rotation of the bearing. Thereby, since the shake of the encoder main body 24 can be suppressed, the encoder main body 24 can always be held in a fixed positional relationship with respect to the radial direction and the axial direction over a long period of time.

  Moreover, according to this embodiment, since the fastening member 28 is a tapping screw, the loosening resistance of the fastening member 28 can be improved. That is, it can be made difficult to loosen. Thereby, the encoder 20 (encoder core metal 26) can be firmly fixed to the rotating wheel 4 (hub 12) over a long period of time.

  In addition, in this embodiment, since it is the same as that of above-described one Embodiment (FIG. 1) about the structure other than the above-mentioned structure, and an effect, the description is abbreviate | omitted. In the above-described embodiment (FIG. 1) and other embodiments (FIG. 2), a bearing unit in which the stationary wheel 2 is an outer ring and the rotating wheel 4 is an inner ring is assumed. The same effect can be obtained by applying the technical idea according to each of the above embodiments to a bearing unit in which 2 is an inner ring and the rotating wheel 4 is an outer ring.

2 Static wheel 4 Rotating wheel 12 Hub 12g Fitting recess 20 Encoder 24 Encoder body 26 Encoder core 26p Fitting protrusion 28 Fastening member Ax Rotating shaft

Claims (3)

A stationary wheel that is fixed to the inboard side component and is maintained in a non-rotating state at all times, a rotating wheel that is provided opposite the stationary wheel and is connected to the outboard side component and rotates together, A bearing unit with an encoder, which is fixed to a ring and includes an annular encoder that rotates together,
The encoder includes a hollow disk-shaped encoder body to which predetermined encoding information is added along the circumferential direction, and a disk-shaped encoder core that can be fitted to a rotating wheel while supporting the encoder body. And
The rotating wheel has a hollow cylindrical fitting recess in which a part of the side end surface in the rotating shaft direction is recessed concentrically about the rotating shaft and along the rotating shaft direction. ,
The encoder core bar is formed with a cylindrical fitting convex portion that protrudes toward the side end surface of the rotating wheel and along the rotation axis direction and can be fitted into the fitting concave portion.
In a state where the fitting convex portion is fitted to the fitting concave portion, the encoder is fixed to the rotating wheel by fastening the fastening member from the fitting convex portion to the fitting concave portion along the rotation axis direction. Features bearing unit with encoder. The fitting recess of the rotating wheel is composed of a cylindrical inner peripheral surface extending along the rotation axis direction and a circular bottom surface extending along a direction orthogonal to the rotation axis,
The encoder core metal fitting convex portion is composed of a cylindrical outer peripheral surface extending along the rotation axis direction and a circular end surface extending along the direction orthogonal to the rotation axis.
The encoder main body is positioned in the radial direction by contacting the cylindrical inner peripheral surface and the cylindrical outer peripheral surface with each other in a state where the fitting convex portion is fitted to the fitting concave portion. Item 6. A bearing unit with an encoder according to Item 1.   In a state where the fitting convex portion is fitted to the fitting concave portion, the circular bottom surface and the circular end surface are in contact with each other or extend around the fitting concave portion in a direction perpendicular to the rotation axis. 3. The encoder body is positioned with respect to the axial direction by contacting the portion that has been extended and the portion that extends around the fitting convex portion along the direction orthogonal to the rotation axis. A bearing unit with an encoder described in 1.

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