JP2007016840A - Bearing device of in-wheel motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device of an in-wheel motor capable of preventing creep of a rolling bearing rotatably supporting a rotor of a hollow motor, not affected by the fixed other member, and securing desired bearing accuracy. <P>SOLUTION: In this bearing device of the in-wheel motor comprising cases 2, 3 to which the rotor and a stator are fixed, and the rolling bearing 4 mounted therebetween, the rolling bearing 4 comprises an outer ring 12 internally fitted to the outer case 2, an inner ring 13 externally fitted to the inner case 3, and a rolling element 15 rollably received between the inner and outer rings. A pulsar ring 17 of a rotating speed detecting device 16 is fastened to an end face of the outer ring 12, and a detecting portion 19 opposite to the pulsar ring 17 through a prescribed air gap is fastened to an end face of the inner ring 13 respectively through fixing bolts 20, and key grooves 21, 22 are formed on bearing fitting portions of the outer case 2 and the inner case 3, so that the pulsar ring 17 and the detecting portion 19 are engaged therewith. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bearing device for an in-wheel motor used in a vehicle having a direct drive wheel such as an automobile as a driving wheel, and more particularly to an in-wheel motor in which a rotational speed detection device for detecting the rotational speed of a wheel is incorporated in a bearing. The present invention relates to a bearing device.

  In recent years, in-wheel motor systems in which a motor is built in a wheel are being adopted in a vehicle driven by a motor such as an electric vehicle. Here, conventionally, since the spindle shaft is rotatably fixed to the knuckle that constitutes the suspension device of the vehicle, the unsprung weight is increased by the amount of the in-wheel motor. There has been a problem that the load holding property deteriorates due to an increase.

  In order to solve these problems, an in-wheel motor as shown in FIG. 7 has been proposed. In this in-wheel motor, the non-rotating side case 50a that supports the stator 50S is elastically supported with respect to the knuckle 57 via the buffer mechanism 56, and the rotating side case 50b that supports the rotor 50R and the wheel 58 include: They are coupled by a flexible coupling 64 that is coupled using linear motion guides 62 and 63. Here, the buffer mechanism 56 includes two plates 54 and 55 coupled to each other by a spring 52 and a damper 53 that operate in the vertical direction of the vehicle via a linear motion guide 51. The linear motion guides 62 and 63 are arranged such that the operation directions of the plurality of hollow disk-shaped plates 59 to 61 are orthogonal to each other.

  In such an in-wheel motor system, the motor 50 can be floating mounted on the undercarriage part of the vehicle, and the motor 50 itself can act as a weight of the dynamic damper. Since the motor shaft and the wheel shaft are coupled so as to be eccentric in any direction by the flexible coupling 64, the torque from the motor 50 to the wheel 58 can be transmitted efficiently. .

  In addition, dust boots 65 and 66 are provided in the gap formed between the motor 50 and the wheel 58 so as to be blocked from the outside, so that intrusion of stones, dust, etc. into the gap can be prevented, and the reliability of the in-wheel motor system Can be improved.

Further, a bearing 67 that rotatably supports the rotor 50R is fitted between the cases 50a and 50b. As shown in an enlarged view in FIG. 8, fixed covers 68 and 69 are attached to the outside of the bearing 67, and stepped notches 68k and 69k are provided on the surfaces facing each other, and the notches 68k and 69k are provided in the notches 68k and 69k. The hollow part 70 is formed by attaching the lid members 68p and 69p. A resin ring 71 constituting a hollow disk-shaped partition wall slidable in the motor axial direction is accommodated in the hollow portion 70. As a result, when the motor 50 is operated, the temperature inside the motor 50 rises due to the heat generated by the motor 50, and even if the motor internal pressure becomes higher than the external air pressure, the pressure difference prevents water from entering the motor 50. It is possible to realize a waterproof mechanism with a compact configuration.
Japanese Patent Laid-Open No. 2004-90696

  In such a conventional in-wheel motor, it is necessary to reduce unsprung weight from the viewpoint of improving riding comfort performance, and an ultra-thin, large-diameter bearing is adopted as the bearing 67. However, this type of ultra-thin, large-diameter bearing has the following problems. That is, the bearing is usually used by being press-fitted and fixed to the housing or the shaft in order to prevent creep during operation, but in the case of such an ultra-thin walled large diameter bearing, the bearing rigidity is extremely low. When the bearing 67 is press-fitted into the cases 50a and 50b, the accuracy at the time of bearing processing is lost due to the influence of the processing accuracy of the cases 50a and 50b, and it becomes difficult to ensure the desired bearing accuracy.

  The present invention has been made in view of such a conventional problem, and in an in-wheel motor using a hollow motor, the rolling bearing that rotatably supports the rotor of the motor is prevented from creeping and fixed to the counterpart. An object of the present invention is to provide a bearing device for an in-wheel motor that is secured by a desired bearing accuracy without being affected by the members.

  Furthermore, another object of the present invention is to provide a fixing means that incorporates a rotational speed detection device for detecting the rotational speed of the wheel into the bearing for compactness and suppresses deformation of the bearing due to the fixation of the rotational speed detection device. Is to provide.

  In order to achieve the object, the invention according to claim 1 of the present invention is a bearing device for an in-wheel motor using a hollow motor, and is a cylindrical device in which a rotor of the motor is fixed to an inner peripheral surface. An outer case, a cylindrical inner case in which a stator of the motor is fixed to the outer peripheral surface, a pair of rolling bearings mounted in an annular space formed between both ends of the two cases, and the pair of rolling bearings In a bearing device for an in-wheel motor that is incorporated in one of the rolling bearings and includes a rotational speed detecting device that detects the rotational speed of a wheel, the rolling bearing includes an outer ring fitted in the outer case, and An inner ring that is externally fitted to the inner case and a plurality of rolling elements that are rotatably accommodated between the inner ring and the outer ring, and a pulsar ring that constitutes the rotational speed detection device is fixed to the outer ring. A detecting portion facing the pulsar ring via a predetermined air gap is fixed to the inner ring, and a key groove is formed in a bearing fitting portion of the outer case and the inner case, and the pulsar ring is formed in the key groove. And the structure by which the detection part was each engaged was employ | adopted.

  As described above, a cylindrical outer case in which the rotor of the hollow motor is fixed to the inner peripheral surface, a cylindrical inner case in which the stator is fixed to the outer peripheral surface, and an annular shape formed between both ends of these two cases. In an in-wheel motor bearing device comprising: a pair of rolling bearings mounted in space; and a rotational speed detection device that detects a rotational speed of a wheel and is incorporated in one of the pair of rolling bearings. A bearing includes an outer ring fitted in the outer case, an inner ring fitted in the inner case, and a plurality of rolling elements that are rotatably accommodated between the inner ring and the outer ring. The pulsar ring is fixed to the outer ring, and a detection portion facing the pulsar ring via a predetermined air gap is fixed to the inner ring, and a keyway is formed in the bearing fitting portion of the outer case and the inner case. , Since the pulsar ring and the detection part are respectively engaged with the key groove of this, the occurrence of bearing creep can be reliably prevented with a simple structure without the inner and outer rings being press-fitted and fixed, and the mating member to be fixed The desired bearing accuracy can be ensured without being affected by the above.

  Further, as in the invention according to claim 2, the pulsar ring is configured to change the characteristics in the circumferential direction alternately and at equal intervals, and the outer ring through a predetermined radial clearance. A steel cored bar having a cylindrical fitting insertion part and a standing plate part extending radially outward from the fitting insertion part, the standing plate part of the metal core being engaged with the key groove. If they are combined, the axes of the detected portion and the outer ring can be made coincident with each other, the detection accuracy of the rotational speed detection device can be increased, and the weight and size can be reduced.

  Further, as in the invention described in claim 3, if an annular groove is formed on the inner periphery of the outer ring, and a protrusion that engages with the annular groove is formed in the insertion portion of the core metal, The pulsar ring can be positioned and fixed in the axial direction with a simple configuration with respect to the outer ring.

  Further, as in the invention described in claim 4, if a slit is formed on the end face of the outer ring, and the vertical plate portion of the core metal is engaged with the slit, the pulsar ring is rotated around the outer ring. It can be fixed in the direction by simple means.

  Further, as in the fifth aspect of the present invention, if the pulsar ring and the detection portion are fastened to the end faces of the outer ring and the inner ring via fixing bolts, the rotational speed is detected without deforming the rolling bearing. The apparatus can be securely fixed, and the bearing accuracy during processing can be ensured.

  An in-wheel motor bearing device according to the present invention is an in-wheel motor bearing device using a hollow motor, and includes a cylindrical outer case in which a rotor of the motor is fixed to an inner peripheral surface, and a stator of the motor. Built in one of the pair of rolling bearings, a cylindrical inner case fixed to the outer peripheral surface, a pair of rolling bearings mounted in an annular space formed between both ends of the two cases An in-wheel motor bearing device comprising a rotation speed detection device for detecting a rotation speed of a wheel, wherein the rolling bearing includes an outer ring fitted in the outer case, and an inner ring fitted in the inner case. And a plurality of rolling elements accommodated in a freely rotatable manner between the inner ring and the outer ring, and a pulsar ring constituting the rotational speed detecting device is fixed to the outer ring, and the pulsar A detection portion facing the ring via a predetermined air gap is fixed to the inner ring, and a key groove is formed in a bearing fitting portion of the outer case and the inner case, and the pulsar ring and the detection portion are formed in the key groove. Therefore, the bearing creep can be surely prevented with a simple structure without the inner and outer rings being press-fitted and fixed, and the desired bearing is not affected by the mating member to be fixed. Accuracy can be ensured.

  A bearing device for an in-wheel motor using a hollow motor, wherein a cylindrical outer case in which a rotor of the motor is fixed to an inner peripheral surface, and a cylindrical inner case in which a stator of the motor is fixed to an outer peripheral surface And a pair of rolling bearings mounted in an annular space formed between both ends of the two cases, and a rotational speed detection that detects the rotational speed of the wheel built in one of the pair of rolling bearings. In the in-wheel motor bearing device comprising the device, the rolling bearing includes an outer ring fitted in the outer case, an inner ring fitted in the inner case, and a rolling ring between the inner ring and the outer ring. A plurality of rolling elements housed movably, and a pulsar ring constituting the rotational speed detection device is fastened to an end face of the outer ring via a fixing bolt, and a predetermined air is supplied to the pulsar ring. A detecting portion opposed via a cap is fastened to an end surface of the inner ring via a fixing bolt, and a key groove is formed in a bearing fitting portion of the outer case and the inner case, and the pulsar ring is formed in the key groove. The detection parts are respectively engaged.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of a main part showing a first embodiment of a bearing device for an in-wheel motor according to the present invention, and FIG. 2 is an enlarged view of the main part of FIG. In this embodiment, the entire configuration is the same as the portion described in the prior art, and therefore, a duplicate description is avoided, and only the characteristic portion of the bearing device according to the present invention is described.

  The in-wheel motor bearing device includes a hollow motor 1, an outer case 2 and an inner case 3 to which the motor 1 is attached, a pair of rolling bearings 4 fixed between the cases 2 and 3, and a case. And a seal 5 for sealing the opening of the annular space formed between the two. The motor 1 includes a rotor 1a and a stator 1b disposed to face the rotor 1a via a predetermined radial clearance.

  The outer case 2 on the rotation side is formed in a cylindrical shape, and the rotor 1a is fixed to the inner peripheral surface at the center. On the other hand, the inner case 3 on the fixed side is formed in a cylindrical shape, and the stator 1b is fixed to the outer peripheral surface of the center portion thereof. A rolling bearing 4 to be described later supports the outer case 2 rotatably with respect to the inner case 3, and is fixed between the cases 2 and 3.

  The inner case 3 is formed with a small-diameter step portion 3a at an end portion, and a fixing ring 6 is press-fitted. The fixing ring 6 prevents a rolling bearing 4 described later from moving in the axial direction. The seal 5 is interposed between the fixing ring 6 and the outer case 2. The seal 5 is fitted to the inner peripheral surface of the end portion of the outer case 2, and has a substantially L-shaped cross section and is formed into an annular shape as a whole, and the first seal plate 7. It consists of a second seal plate (slinger) 8 that is opposed and fitted to the outer peripheral surface of the fixing ring 6, has a substantially L-shaped cross section, and is formed in an annular shape as a whole.

  The first seal plate 7 is made of a corrosion-resistant steel plate, such as an austenitic stainless steel plate (JIS standard SUS304 type or the like), or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). A cored bar 9 formed by pressing and a seal member 10 that is integrally vulcanized and bonded to the cored bar 9 and has a side lip 10a and a pair of radial lips 10b and 10c at the inner edge.

  The second seal plate 8 is made of a corrosion-resistant steel plate such as an austenitic stainless steel plate (JIS standard SUS304 type or the like), or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). It is formed by press working. The second seal plate 13 includes a cylindrical portion 8a that is press-fitted into the fixing ring 6, and a standing plate portion 8b that extends radially outward from the cylindrical portion 8a. The side lip 10a of the first seal plate 7 is slidably contacted with the upright plate portion 8b, and the pair of radial lips 10b and 10c are slidably contacted with the cylindrical portion 8a. And leakage of rainwater and dust from the outside is prevented. Here, the outer edges of the first seal plate 7 and the second seal plate 8 face each other through a slight radial clearance to constitute a so-called labyrinth seal 11. Since the seal 5 of the present embodiment employs such a seal configuration, the seal 5 has a strong and stable sealing property over a long period of time, and the durability of the rolling bearing 4 can be improved.

  The rolling bearing 4 is a deep groove ball bearing, and as shown in an enlarged view in FIG. 2, an outer ring 12 having an outer rolling surface 12a formed on the inner periphery, and an inner ring 13 having an inner rolling surface 13a formed on the outer periphery. A rolling element (ball) 15 accommodated between the rolling surfaces 12a and 13a via a cage 14 so as to roll freely is provided. The rolling bearing 4 incorporates a rotation speed detection device 16 that controls an antilock brake system (ABS) and detects the rotation speed of a wheel (not shown).

  The rotational speed detecting device 16 has a concavo-convex portion 17a formed on the inner periphery, and a pulsar ring 17 serving as a detected portion, and a rotational speed sensor disposed opposite to the pulsar ring 17 via a predetermined radial clearance (air gap). And an annular detector 19 having 18. In addition, the pulsar ring 17 is not limited to the one in which the unevenness 17a is formed on the inner periphery, but may be any one that changes the characteristics in the circumferential direction alternately and at equal intervals. A magnetic encoder in which the magnetic poles N and S are magnetized may be used. Further, along with the type of the pulsar ring 17, the rotational speed sensor 18 can be applied by appropriately selecting a Hall IC element, a magnetoresistive element (MR element), or the like.

  Here, in the present embodiment, the pulsar ring 17 is fastened to the end surface of the outer ring 12 via the fixing bolt 20. Further, a key groove 21 extending in the axial direction is formed in the bearing fitting portion 2 a of the outer case 2, and the outer peripheral portion of the pulsar ring 17 is engaged with the key groove 21. As a result, the pulsar ring 17 can be fixed without deforming the outer ring 12, and the outer ring 12 can be fixed to the outer case 2 without being press-fitted into the bearing fitting portion 2a of the outer case 2. Therefore, the occurrence of bearing creep can be reliably prevented with a simple configuration, and a desired bearing accuracy can be ensured without being affected by the mating member to be fixed, here, the outer case 2. Although not shown, the key groove 21 is not limited to one place in the circumferential direction, and a plurality of key grooves 21 are formed, and a plurality of convex portions are formed on the outer periphery of the pulsar ring corresponding to the number of the key grooves. May be formed into petals. Thereby, the assembly of a pulsar ring can be simplified.

  On the other hand, the detection unit 19 is fastened to the end surface of the inner ring 13 via a fixing bolt 20. Further, a key groove 22 extending in the axial direction is formed on the outer periphery of the inner case 3, and the inner peripheral portion of the detection unit 19 is engaged with the key groove 22. Thereby, the detection part 19 can be fixed without deforming the inner ring 13, and the inner ring 13 can be fixed without being press-fitted into the outer periphery (bearing fitting part) of the inner case 3. Therefore, the occurrence of bearing creep can be reliably prevented with a simple configuration, and desired bearing accuracy can be ensured without being affected by the mating member to be fixed, here, the inner case 3. Although not shown, the key groove 22 is not limited to one place in the circumferential direction, and a plurality of key grooves 22 are formed, and a plurality of convex portions are formed on the inner periphery of the detection unit corresponding to the number of key grooves. The outer shell may be formed in a petal shape. Thereby, the assembly of a detection part can be simplified.

  In the present embodiment, a deep groove ball bearing is exemplified as the rolling bearing 4, but the present invention is not limited to this, and it is sufficient that a radial load and a thrust load can be applied. For example, a pair of angular ball bearings may be used. Then, by applying a light preload to the angular ball bearing, the axial deflection of the rotor 1a during the rotation of the motor 1 can be suppressed as much as possible. Therefore, even if the weight of the motor 1 becomes a thrust load with acceleration and is applied to the rolling bearing 4, the bearing life can be reduced and the axial deflection of the rotor 1 a can be suppressed, thereby improving the riding comfort of the vehicle. be able to.

  FIG. 3A is an enlarged view of a main part showing a second embodiment of the bearing device for an in-wheel motor according to the present invention, and FIG. 3B is a side view of FIG. The second embodiment basically differs from the first embodiment (FIG. 2) described above only in the configuration of the rotational speed detection device, and the same reference numerals are given to the same parts and portions. Detailed description is omitted.

  In the present embodiment, the rotational speed detection device 23 includes a pulsar ring 24 and an annular detection unit 25 disposed opposite to the pulsar ring 24 via a predetermined radial clearance. The pulsar ring 24 includes a cored bar 26 and a magnetic encoder 27 integrally joined to the cored bar 26 by vulcanization bonding or the like. The cored bar 26 is formed by press working from a corrosion-resistant steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC or the like). Has been. The metal core 26 extends in the radially outward direction from the fitting insertion portion 26a, which is fitted into the outer ring 12 via a predetermined radial clearance, and is attached to the end surface of the outer ring 12. The cross section is substantially L-shaped and formed in an annular shape as a whole. By inserting and inserting the cored bar 26 into the outer ring 12, the axis centers of the pulsar ring 24 and the outer ring 12 can be made to coincide with each other, the detection accuracy of the rotational speed detection device 23 can be increased, and the weight and size can be reduced. Can be planned. The magnetic encoder 27 is made of a rubber magnet in which magnetic powder such as ferrite is mixed in an elastomer such as rubber and the magnetic poles N and S are alternately magnetized in the circumferential direction.

  On the other hand, the detection unit 25 includes a rotation speed sensor 28, a holding unit 29 that integrally molds the rotation speed sensor 28 with resin, and a holder 30 that protects the holding unit 29. The rotation speed sensor 28 incorporates a magnetic detection element such as a Hall element or a magnetoresistive element (MR element) that changes its characteristics in accordance with the flow direction of magnetic flux, and a waveform shaping circuit that adjusts the output waveform of the magnetic detection element. It consists of IC. Moreover, the holder 30 is formed in a disk shape by press working from a steel plate having corrosion resistance. The holder 30 is preferably formed of a non-magnetic steel plate, such as an austenitic stainless steel plate (JIS standard SUS304, etc.) so as not to adversely affect the sensing performance of the rotational speed sensor 28. .

  Here, the pulsar ring 24 is fastened to the end face of the outer ring 12 via the fixing bolt 20. Further, a key groove 21 extending in the axial direction is formed in the bearing fitting portion 2 a of the outer case 2, and a part of the standing plate portion 26 b of the core metal 26 constituting the pulsar ring 24 is engaged with the key groove 21. ing. Thus, the outer ring 12 can be fixed without deforming and the axial centers of the magnetic encoder 27 and the outer ring coincide with each other, and the outer ring 12 is press-fitted into the bearing fitting portion 2a of the outer case 2. Even if not, it can be fixed to the outer case 2. Therefore, the detection accuracy of the rotational speed detection device can be improved with a simple configuration, the occurrence of bearing creep can be reliably prevented, and the desired bearing is not affected by the fixed outer case 2. Accuracy can be ensured.

  On the other hand, the detection unit 25 is fastened to the end surface of the inner ring 13 via a fixing bolt 20. Further, a key groove 22 extending in the axial direction is formed on the outer periphery of the inner case 3, and a convex portion 30 a of the holder 30 constituting the detection unit 25 is engaged with the key groove 22. Accordingly, the detection unit 25 can be fixed without deforming the inner ring 13, and the inner ring 13 can be fixed without being press-fitted into the outer periphery of the inner case 3. Therefore, the occurrence of bearing creep can be reliably prevented with a simple configuration, and a desired bearing accuracy can be ensured without being affected by the fixed inner case 3.

  FIG. 4A is an enlarged view of a main part showing a third embodiment of a bearing device for an in-wheel motor according to the present invention, FIG. 4B is a side view of FIG. 4A, and FIG. It is a perspective view which shows the pulsar ring which concerns on. The third embodiment basically differs from the above-described embodiment (FIGS. 2 and 3) only in the configuration of the rotational speed detection device, and the same reference numerals are given to the same parts and portions. Therefore, detailed description is omitted.

  In the present embodiment, the rotational speed detection device 31 includes a pulsar ring 32 and an annular detection unit 33 disposed to face the pulsar ring 32 with a predetermined axial clearance (air gap) therebetween. The pulsar ring 32 includes a cored bar 34 and a magnetic encoder 35 integrally joined to the cored bar 34 by vulcanization adhesion or the like. The core metal 34 is formed by pressing a steel plate having corrosion resistance, such as a ferritic stainless steel plate (JIS standard SUS430, etc.) or a rust-proof cold rolled steel plate (JIS standard SPCC, etc.) by press working. It is formed in an annular shape. Further, the core metal 26 is formed by a cylindrical fitting insertion portion 34a fitted into the outer ring 12 through a predetermined radial clearance, and by cutting and raising, and a part of the core metal 26 is radially outward from the fitting insertion portion 34a. And a standing plate portion 34b extending in the direction. The magnetic encoder 35 is made of a rubber magnet in which magnetic powder such as ferrite is mixed in an elastomer such as rubber, and magnetic poles N and S are alternately magnetized in the circumferential direction.

  On the other hand, the detection unit 33 includes a rotation speed sensor 36, a holding unit 37 that integrally molds the rotation speed sensor 36 with resin, and a holder 38 that protects the holding unit 37. The rotational speed sensor 36 incorporates a magnetic detection element such as a Hall element, a magnetoresistive element (MR element), etc. that changes its characteristics according to the flow direction of the magnetic flux, and a waveform shaping circuit that adjusts the output waveform of the magnetic detection element. It consists of IC. The holder 38 is formed in a disk shape by press working from a corrosion-resistant steel plate. The holder 38 is preferably formed of a non-magnetic steel plate, such as an austenitic stainless steel plate (JIS standard SUS304, etc.) so as not to adversely affect the sensing performance of the rotational speed sensor 36. .

  Here, in the present embodiment, the cored bar 34 constituting the pulsar ring 32 is inserted into the inner peripheral surface of the outer ring 12 via a predetermined radial clearance. An annular groove 39 is formed on the inner peripheral surface of the outer ring 12 ′, and the tongue piece 40 of the metal core 34 is engaged with the annular groove 39. As shown in FIG. 5, the tongue piece 40 is formed by cutting and raising a part from the cylindrical fitting insertion portion 34 a of the core metal 34. The tongue piece 40 formed in this manner is elastically deformed in the process of inserting the cored bar 34 into the inner peripheral surface of the outer ring 12 ′, and is restored and engaged with the annular groove 39 when it coincides with the position of the annular groove 39. . Therefore, the pulsar ring 32 can be positioned and fixed in the axial direction without deforming the outer ring 12 ', and the air gap between the magnetic encoder 35 and the rotation speed sensor 36 can be set to a predetermined value by a simple means.

  Similarly to the above-described embodiment, as shown in FIG. 4, a key groove 21 extending in the axial direction is formed in the bearing fitting portion 2 a of the outer case 2, and an outer ring 12 ′ corresponding to the key groove 21. A slit 41 is formed on the end face of the. The standing plate portion 34 b of the cored bar 34 is engaged with the key groove 21 and the slit 41. Thereby, the pulsar ring 32 can be fixed to the outer ring 12 ′ in the circumferential direction by a simple means without being fastened by the fixing bolt. Further, the outer ring 12 'can be easily fixed to the outer case 2 without being press-fitted into the bearing fitting portion 2a of the outer case 2, and the deformation of the outer ring 12' can be suppressed and the bearing creep can be reduced with a simple configuration. Generation | occurrence | production can be prevented reliably, and it is not influenced by the outer case 2 fixed, but desired bearing accuracy can be ensured.

  On the other hand, the detection unit 33 is fastened to the end surface of the inner ring 13 via the fixing bolt 20. Further, a key groove 22 extending in the axial direction is formed on the outer periphery of the inner case 3, and a convex portion 30 a of a holder 38 constituting the detection unit 33 is engaged with the key groove 22. As a result, the detection unit 33 can be fixed without deforming the inner ring 13, and the inner ring 13 can be fixed without being pressed into the outer periphery of the inner case 3. Therefore, the occurrence of bearing creep can be reliably prevented with a simple configuration, and a desired bearing accuracy can be ensured without being affected by the fixed inner case 3.

FIG. 6 is a perspective view showing a modified example of the aforementioned pulsar ring (FIG. 5), and the configuration of the engaging portion with the outer ring is different. In addition, the same code | symbol is attached | subjected to the same part and site | part, and detailed description is abbreviate | omitted.
The pulsar ring 42 includes a cored bar 43 and a magnetic encoder 35 integrally joined to the cored bar 43 by vulcanization bonding or the like. The core metal 43 is formed by pressing from a steel plate having corrosion resistance, for example, a ferritic stainless steel plate (JIS standard SUS430 or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC or the like), The cross section is substantially L-shaped and formed in an annular shape as a whole.

  An annular protrusion 44 is formed by pressing from a cylindrical insertion portion 34a of the core metal 43. The protrusion 44 is engaged with an annular groove of an outer ring (not shown), and the pulsar ring 42 can be positioned and fixed in the axial direction with respect to the outer ring. If a plurality of standing plate portions 34b extending in the radial direction from the insertion portion 34a are formed in the circumferential direction, the rigidity of the insertion portion 34a can be suppressed, and deformation of the outer ring due to the insertion of the cored bar 43 can be prevented. .

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  An in-wheel motor bearing device according to the present invention is a in-wheel motor that uses a hollow motor and includes a rolling bearing that rotatably supports the motor and includes a rotation speed detection device that detects the rotation speed of a wheel. The present invention can be applied to a bearing device for an in-wheel motor provided.

It is principal part sectional drawing which shows 1st Embodiment of the bearing apparatus of the in-wheel motor which concerns on this invention. It is a principal part enlarged view same as the above. (A) is a principal part enlarged view which shows 2nd Embodiment of the bearing apparatus of the in-wheel motor which concerns on this invention. (B) is a side view of (a). (A) is a principal part enlarged view which shows 3rd Embodiment of the bearing apparatus of the in-wheel motor which concerns on this invention. (B) is a side view of (a). It is a perspective view which shows the pulsar ring of FIG. It is a perspective view which shows the modification of the pulsar ring of FIG. It is a longitudinal cross-sectional view which shows the conventional in-wheel motor. It is a principal part enlarged view which shows the bearing part of FIG.

Explanation of symbols

1 .... motor 1a ... rotor 1b ... stator 2 ... outside Case 2a ... Bearing fitting part 3 ... Inner case 3a ... Small diameter step 4 ...・ ・ ・ ・ ・ ・ Rolling bearing 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fixing ring 7 Seal plate 8 ············ Second seal plate 8a ·········· Cylindrical portions 8b, 26b, 34b ··· Standing plate portions 9, 26, 34, 43・ Core 10 ········ Sealing member 10a ········· Side lips 10b and 10c ··· Radial lip 11 ····· Labyrinth Seal 12, 12 '... Outer ring 12a ... Outer rolling surface 13 ... Inner ring 13a ... Inner rolling surface 14 ... Hold Roller 15 ... rolling elements 16, 23, 31 ... rotational speed detectors 17, 24, 32, 42 pulsar ring 17a ... uneven 18 28, 36... Rotational speed sensors 19, 25, 33... Detecting part 20 .. Fixing bolts 21, 22. .... Insertion part 30a ... ... Projections 27, 35 ... Magnetic encoders 29, 37 ... Holding parts 30, 38 ... ··· Holder 39 ················································································· ... Projection 50 ················· Motor 50R ··················································· Stator 50a ...・ ・ ・ ・ ・ ・ Rotational side cases 51, 62, 63 ・ ・ ・ ・ Linear guide 52 ・ ・ ・ ・ ・ ・ Spring 53 ・ ・ ・ ・ ・ ・ Damper 54, 55 Plate 56 ... Shock absorber 57 ... Knuckle 58 ... Wheels 59, 60, 61 ... .... Disc-shaped plate 64 ... Flexible couplings 65, 66 ... Dust boot 67 ... Bearings 68, 69 ... .... Fixed cover 68k, 69k ... Notch 68p, 69p ... Lid member 70 ... Hollow part 71 ........ resin ring

Claims (5)

An in-wheel motor bearing device using a hollow motor,
A cylindrical outer case in which the rotor of the motor is fixed to the inner peripheral surface;
A cylindrical inner case in which the stator of the motor is fixed to the outer peripheral surface;
A pair of rolling bearings mounted in an annular space formed between both ends of both cases;
In a bearing device for an in-wheel motor that is built in one of the pair of rolling bearings and includes a rotational speed detection device that detects the rotational speed of the wheel.
The rolling bearing includes an outer ring fitted into the outer case, an inner ring fitted into the inner case, and a plurality of rolling elements housed in a freely rollable manner between the inner ring and the outer ring. ,
A pulsar ring constituting the rotational speed detection device is fixed to the outer ring, and a detection portion facing the pulsar ring via a predetermined air gap is fixed to the inner ring,
A bearing device for an in-wheel motor, wherein a key groove is formed in a bearing fitting portion of the outer case and the inner case, and the pulsar ring and the detection portion are respectively engaged with the key groove.   The pulsar ring alternately detects the characteristics over the circumferential direction at equal intervals, and a cylindrical fitting insertion portion fitted into the outer ring via a predetermined radial clearance, 2. The in-wheel motor according to claim 1, further comprising a steel bar made of a steel plate having a vertical plate portion extending radially outward from the fitting insertion portion, wherein the vertical plate portion of the core metal is engaged with the key groove. Bearing device.   The bearing device for an in-wheel motor according to claim 2, wherein an annular groove is formed on an inner periphery of the outer ring, and a protrusion that engages with the annular groove is formed at the fitting insertion portion of the core metal.   4. A bearing device for an in-wheel motor according to claim 2, wherein a slit is formed in an end surface of the outer ring, and a vertical plate portion of the core metal is engaged with the slit.   3. The in-wheel motor bearing device according to claim 1, wherein the pulsar ring and the detection unit are fastened to end faces of the outer ring and the inner ring via fixing bolts, respectively.

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