JP2012202417A - Wheel drive system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent foreign matter from intruding into rolling bearings, in a wheel drive system with a speed reduction mechanism and the pair of rolling bearings lubricated with common oil.SOLUTION: A wheel 2 is rotatably supported by a pair of tapered roller bearings B, Bon the outside surface of a fixed spindle 1. A drive shaft 5 driven by a motor 4 provided at the end of the inner board-side of the fixed spindle 1 is inserted into the fixed spindle 1, the speed reduction mechanism 10 decelerating rotation of the drive shaft 5 and transmitting the decelerated rotation to the wheel 2 is arranged on the outer board-side of the fixed spindle 1, and the speed deceleration mechanism 10 and tapered roller bearings B, Bare lubricated with the common oil stored in the wheel 2. The tapered roller bearing B1 on the outer board-side, positioned on the side of the speed reduction mechanism 10, is made to function as a single sealed tapered roller bearing, and includes a seal member positioned on the outer board-side and formed with oil passage holes. The oil passage holes are covered with filters, and permanent magnets are provided around the filters.

Description

  The present invention relates to a motor and a vehicle wheel drive device that has a speed reduction mechanism that decelerates the rotation of the motor, transmits the rotation output from the speed reduction mechanism to a wheel, and rotates the wheel.

  As this type of wheel drive device, one described in Patent Document 1 has been conventionally known. This wheel drive device shows a wheel drive device for a mining dump truck, and a pair of rolling bearings are mounted on the outer diameter surface of a cylindrical axle fixed to the vehicle body, and the wheels are rotatably supported by the pair of rolling bearings. A drive shaft that is rotationally driven using a motor provided on the inboard side of the axle as a drive source is inserted into the axle, and rotation of the drive shaft is of a planetary gear type provided on the outboard side of the axle. The speed is reduced by a speed reduction mechanism and transmitted to the wheel.

  The inboard side refers to the inner side in the width direction of the vehicle body, and the outboard side refers to the outer side in the width direction.

  In the wheel drive device, the opening at both ends of the wheel is sealed, the speed reduction mechanism is lubricated with oil stored in the wheel, and at the same time, a pair of rolling bearings that rotatably support the wheel is lubricated. .

  Here, since a very large radial load is applied to the pair of rolling bearings, a tapered roller bearing is used as the rolling bearing, and the pair of tapered roller bearings are combined on the back surface, and the conical roller disposed on the outboard side is used. The inner race of the roller bearing is pressed in the axial direction by a pressure ring to apply a preload to the pair of tapered roller bearings.

JP 2009-204016 A

  By the way, in the said conventional wheel drive device, since a pair of tapered roller bearing which supports a wheel rotatably has no seal, there exist the following problems.

  That is, in the conventional wheel drive device, each of the speed reduction mechanism and the pair of conical bearings is lubricated with a common oil, and the oil contains foreign matters such as gear wear powder (iron powder, etc.). Therefore, the possibility of the foreign matter entering the pair of tapered roller bearings is very high, and the foreign matter, particularly wear powder such as gears, enters the tapered roller bearing, thereby peeling off the raceway surface and the rolling surface. As a result, damage such as scratches, indentations and the like occurs, and the durability of the tapered roller bearing is lowered.

  An object of the present invention is to prevent entry of foreign matter into a rolling bearing in a wheel drive device that lubricates a speed reduction mechanism and a pair of rolling bearings with a common oil.

  In order to solve the above problems, in the present invention, a cylindrical axle that is fixedly arranged, a pair of rolling bearings that are provided on the outer diameter surface of the axle at an axial interval, and the A wheel rotatably supported by a pair of rolling bearings, a drive shaft that is inserted into the axle and is driven to rotate using a motor as a drive source, and incorporated on the outboard side of the axle to rotate the drive shaft. A wheel drive device having a speed reduction mechanism for decelerating and transmitting to the wheel, wherein each of the pair of rolling bearings and the speed reduction mechanism is lubricated by a common oil, wherein the speed reduction mechanism of the pair of rolling bearings Single-sided seal in which the outer-board-side rolling bearing located on the side has a seal member on one side, and the seal member is located on the outer-board side Is a pneumatic bearing, to form a through oil hole to seal member of the single sealed bearing covers the oil passage hole in the filter, it was adopted a structure in which a permanent magnet in the peripheral portion of the filter.

  As described above, by adopting a bearing with a single seal as a rolling bearing on the outer board side, and assembling the rolling bearing on the outboard side, forming an oil passage hole in the sealing member, Oil for lubricating the speed reduction mechanism can flow into the bearing through the inflow hole, and the pair of rolling bearings can be lubricated with oil common to the speed reduction mechanism.

  Here, since the inflow hole is covered with a filter, foreign matter such as gear wear powder contained in the lubricating oil can be captured by the filter. For this reason, it is possible to prevent foreign matter from entering the bearing, and to suppress the deterioration of durability due to the occurrence of damage such as peeling, scratches, or indentations on the raceway surface or rolling surface of the rolling bearing.

  In addition, since a permanent magnet is provided around the filter, it is possible to attract and hold metal foreign matters such as wear powder mixed in the oil by the permanent magnet. For this reason, the amount of metallic foreign matter in the oil can be reduced, and clogging of the filter and deterioration of the lubricating performance can be suppressed.

  In the wheel drive device according to the present invention, as a seal member, a rubber seal is fixed to a core metal attached to an end of one of the outer race and the inner race of the rolling bearing, and the other race is attached to the rubber seal. A bearing seal provided with a seal lip that comes into contact with the ring can be employed.

  In the use of the bearing seal as described above, a plurality of oil passage holes are formed in the core metal at intervals in the circumferential direction, and a magnet mounting portion is provided between adjacent oil passage holes, and the plurality of oil passage holes are provided. By covering each of these with the filter and providing a permanent magnet in the magnet mounting portion, the permanent magnet can be assembled simultaneously with the assembly of the bearing seal with the filter, and the assembly of the permanent magnet is facilitated. be able to.

  In addition, in the use of the bearing seal as described above, the magnet mounting portion is a through hole, the permanent magnet is mounted on the inner surface of the cored bar to cover the magnet mounting portion, or the magnet mounting portion is a recess, and the recess is closed. By attaching a permanent magnet to the end portion, the magnet attachment portion can be made into a magnetic powder reservoir, so that a lot of magnetic wear powder can be adsorbed and held.

  The seal member is not limited to the bearing seal as described above. For example, it is a size that is attached to one end of the outer ring and the inner ring of the bearing with a single seal and forms a minute gap between the other ring and covers almost the entire bearing space. It may be composed of a ring slinger.

  In the adoption of the slinger as described above, a plurality of oil passage holes are formed in the slinger, a magnet attachment portion is provided between the adjacent oil passage holes, each of the plurality of oil passage holes is covered with a filter, and the magnet attachment portion By providing a permanent magnet in the permanent magnet, it is possible to assemble the permanent magnet at the same time as assembling the slinger, thereby facilitating the assembly of the permanent magnet.

  In addition, when a slinger is used, an annular permanent magnet is provided in the vicinity of the minute gap formed between the slinger and the other raceway ring so that a metal such as wear powder is introduced into the bearing from the minute gap. It is possible to prevent the powder from entering.

  Even when a slinger is used, the magnet mounting part can be made into a magnetic powder reservoir by using the magnet mounting part as a through-hole and mounting the permanent magnet on the inner surface of the cored bar to cover the magnet mounting part. Many magnetic wear powders can be adsorbed and held.

  Here, out of a pair of rolling bearings that rotatably support the wheel, an outer track that rotates integrally with the wheel at one end in the axial direction as a rolling bearing on the inboard side disposed at a position away from the speed reduction mechanism By adopting a rolling bearing with a rotation sensor that detects the rotation speed of the wheel and incorporating the rotation sensor located on the inboard side, it is possible to detect the rotation speed of the wheel, so a traction control system (TRC) A control signal can be output to the control unit of the anti-skid brake system (ABS).

  By providing a rotation sensor on the rolling bearing on the inboard side, the lubricating oil is filtered by the filter provided on the rolling bearing on the outboard side to trap foreign matter, and clean oil with very little foreign matter mixed in is obtained on the inboard side. Since the oil flows into the rolling bearing side and lubricates the rolling bearing, foreign matter is less likely to adhere to the rotation sensor, and the rotation speed can be detected with high accuracy.

  Here, if an annular permanent magnet is attached to the outer diameter surface of the axle or the inner diameter surface of the wheel between the pair of rolling bearings, it passes through the rolling bearing on the outboard side and flows toward the rolling bearing on the inboard side. When a small amount of metal powder is mixed in the lubricating oil, the metal powder can be adsorbed and removed by the permanent magnet, and the adhesion of the metal powder to the rotation sensor can be more effectively prevented.

  When the rolling bearing includes a rotation sensor, the encoder on the outer race ring side may be a pulsar ring, and the sensor unit on the inner race ring side may be provided with a back magnet type magnetic sensor. Since many rolling bearings used for suspensions of various construction machines such as dump trucks have relatively large diameters, the rotation sensor is made back-magnet type in this way to stabilize the performance of the rotation sensor. Can be made.

  In the present invention, as described above, a bearing with a single seal is adopted as the rolling bearing on the outer board side, and the rolling bearing is assembled as the sealing member is disposed on the outboard side. By forming, the oil for lubricating the speed reduction mechanism can flow into the bearing through the inflow hole, and the pair of rolling bearings can be lubricated with oil common to the speed reduction mechanism.

  Further, since the inflow hole is covered with the filter, the filter can capture metallic foreign matters such as gear wear powder contained in the lubricating oil. For this reason, it is possible to prevent intrusion of metallic foreign matter into the bearing, and to suppress the deterioration of durability due to the occurrence of damage such as peeling, scratches, or indentations on the raceway surface or rolling surface of the rolling bearing.

  Furthermore, by providing a permanent magnet around the filter, the permanent magnet can attract and hold foreign metal such as wear powder in the lubricating oil. For this reason, the amount of magnetic wear powder mixed in the stored oil can be reduced, and clogging of the filter and deterioration of the lubricating performance can be suppressed.

A longitudinal sectional view showing an embodiment of a wheel drive device according to the present invention Sectional drawing which expands and shows the wheel support part of FIG. The front view which shows a part of rolling bearing with a single seal shown in FIG. Sectional view along line IV-IV in FIG. Sectional drawing which expands and shows a part of FIG. Sectional view along line VI-VI in FIG. Sectional view showing another example of rolling bearing with single seal Sectional view showing still another example of a rolling bearing with a single seal Sectional view showing still another example of a rolling bearing with a single seal Sectional view showing still another example of a rolling bearing with a single seal Sectional drawing which shows the other example of a magnet attaching part Sectional drawing which expands and shows the rotation sensor part of a rolling bearing with a rotation sensor

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a wheel drive device in a dump truck as a construction machine. As shown, a fixed spindle 1 as an axle is fixed to a vehicle body not shown. A pair of rolling bearings B ₁ and B ₂ are mounted on the outer diameter surface of the fixed spindle 1 at intervals in the axial direction, and the wheel 2 having the double row tire 3 is rotated by the rolling bearings B ₁ and B ₂ . It is supported freely.

  A motor 4 is provided on the inboard side of the fixed spindle 1, and a drive shaft 5 that is rotationally driven using the motor 4 as a drive source is inserted into the fixed spindle 1, and is arranged coaxially with the fixed spindle 1. ing.

  On the outboard side of the fixed spindle 1, a speed reduction mechanism 10 that decelerates the rotation of the fixed spindle 1 and transmits it to the wheel 2 is provided. The reduction mechanism 10 includes a first planetary gear type reduction mechanism 10a and a second planetary gear type reduction mechanism 10b.

  The first planetary gear speed reduction mechanism 10a includes a sun gear 11a fixed to the shaft end of the drive shaft 5, a planetary gear 12a meshing with the sun gear 11a, and an internal gear 13a meshing with the planetary gear 12a. Thus, the rotation of the sun gear 11a is transmitted from the planetary gear 12a to the internal gear 13a, and the cylindrical gear coupling 14 connected to the internal gear 13a is rotated at a reduced speed.

  On the other hand, the second planetary gear speed reduction mechanism 10b includes a sun gear 11b fitted into the end of the gear coupling 14 and spline-coupled, a planetary gear 12b meshing with the sun gear 11b, and the planetary gear 12b. And the rotation of the sun gear 11b transmits the rotation from the planetary gear 12b to the internal gear 13b, so that the wheel 2 to which the internal gear 13b is fixed is rotated at a reduced speed. Yes.

  Here, the carrier 13c that rotatably supports the planetary gear 12b of the second planetary gear reduction mechanism 10b has a cylindrical portion 13d at an end thereof, and the cylindrical portion 13d is fitted into the outer board side end of the fixed spindle 1. Splined.

  The internal gear 13b of the second planetary gear type speed reduction mechanism 10b is connected to an end portion on the outboard side of the wheel 2, and a sealed space 16 is provided in the wheel 2 by a wheel cap 15 attached to an end surface on the outboard side of the internal gear 13b. Is formed. Oil is stored in the sealed space 16, and the speed reduction mechanism 10 is lubricated by the oil.

  Although the planetary gear type reduction mechanism is employed as the reduction mechanism 10 in the embodiment, the reduction mechanism 10 is not limited to the planetary gear type reduction mechanism, and a known reduction mechanism can be adopted.

As shown in FIG. 2, a pair of rolling bearings _B 1 described above supporting a wheel 2 rotatably, _{B 2} is an outer ring 20, an inner ring 21, the tapered rollers 22 and incorporated between the two wheels 20 and 21 It consists of a tapered roller bearing composed of a retainer 23 that holds the tapered roller 22. The pair of tapered roller bearings B ₁ and B ₂ is a rear combination and supports the wheel 2 rotatably.

The pair of tapered roller bearings B ₁ and B ₂ are lubricated by the oil stored in the sealed space 16 in the wheel 2. At this time, since the oil also lubricates the speed reduction mechanism 10, the oil contains foreign matters such as gear wear powder (iron powder or the like). When these foreign substances enter the pair of tapered roller bearings B ₁ and B ₂ , damage such as peeling, scratches, indentations and the like occur on the raceway surface and the rolling surface, thereby reducing the durability of the tapered roller bearing.

In order to solve such a problem, in the embodiment, among the pair of tapered roller bearings B ₁ and B ₂ , the tapered roller bearing B ₁ with a single seal is added to the tapered roller bearing B ₁ arranged on the outboard side. Is adopted. On the other hand, the tapered roller bearing B ₂ disposed on the inboard side employs a tapered roller bearing with a rotation sensor.

FIGS. 3 to 6 show the tapered roller bearing B ₁ with one seal, and one end opening of the bearing space formed between the outer ring 20 and the inner ring 21 is sealed with a bearing seal 24.

  As shown in FIGS. 5 and 6, the bearing seal 24 includes a cored bar 25 and a rubber seal 26 fixed to the cored bar 25. The metal core 25 has a configuration in which an inward flange 25b is provided at one end portion of the cylindrical portion 25a. The cylindrical portion 25a is fitted to a seal fitting surface 27 formed on the inner periphery of one end portion of the outer ring 20, and the seal The metal core 25 is prevented from being pulled out by the engagement of the seal mounting groove 28 formed in the fitting surface 27 and the protrusion 29 formed on the outer periphery of the other end of the cylindrical portion 25a, and the bearing seal 24 is in the mounted state. .

  Here, the cored bar 25 is a synthetic resin molded product, but may be made of metal.

  The rubber seal 26 is made of rubber having excellent wear resistance and oil resistance. A nitrile rubber can be mentioned as such rubber. The rubber seal 26 is vulcanized and bonded to the inner peripheral portion of the core metal 25, and an inner seal lip 26a and an outer seal lip 26b are provided on the inner peripheral portion. The tip of the inward seal lip 26a is in elastic contact with the inner surface 30a of the seal groove 30 formed on the outer diameter surface of the inner ring collar 21a, while the tip of the outer seal lip 26b is in contact with the inner ring collar 21a. The cylindrical seal surface 31 formed outside the seal groove 30 is in elastic contact.

  As shown in FIG. 3, a plurality of oil passage holes 32 and a plurality of magnet attachment portions 33 are alternately formed in the core metal 25 in the circumferential direction, and each of the oil passage holes 32 and the magnet attachment portions 33 is a circle. It is an arc-shaped through hole.

  The magnet mounting portion 33 is not limited to the through hole. For example, as shown in FIG. 11, it may consist of an arcuate depression. Further, in the embodiment, the plurality of oil passage holes 32 and the plurality of magnet attachment portions 33 are alternately formed in the circumferential direction.

  As shown in FIGS. 3 and 6, each of the plurality of oil passage holes 32 is covered with a filter 34. Here, the filter 34 is made of glass fiber, but may be made of a metal or synthetic resin mesh. Here, when the filter 34 is attached, it is adhered to the inner surface of the cored bar 25. However, the cored bar 25 may be molded when the cored bar 25 is molded.

  As shown in FIGS. 3 and 5, each of the plurality of magnet attachment portions 33 is covered with a plate-like permanent magnet 35. As the permanent magnet 35, a rubber magnet obtained by mixing a magnetic material such as ferrite with a rubber material made of nitrile rubber is employed here. The permanent magnet 35 is fixed to the inner surface of the cored bar 25 by bonding with an outer peripheral portion.

Piece seals tapered roller bearing B ₁ having the above structure, the bearing seal 24 is a built disposed on the outboard side. Depending Such incorporation piece seals tapered roller bearings B _1, oil to lubricate the reduction gear mechanism 10, and flows from the oil passage hole 32 in the bearing to lubricate the strip seals tapered roller bearing B _1.

  At this time, a lot of foreign matters such as gear wear powder are mixed in the oil that lubricates the speed reduction mechanism 10. When oil containing these foreign matters flows into the oil passage hole 32, the oil passage hole 32 is filtered by the filter 34. The foreign matter in the oil is captured by the filter 34.

Therefore, there is no such foreign matter enters into pieces seals tapered roller bearing B _1, can be wedged by piece seals tapered roller bearing B ₁ of the foreign matter is prevented from being damaged.

Here, the oil to lubricate the strip seals tapered roller bearing B ₁ represents a oil lubricating the reduction gear mechanism 10, foreign matter contained in the oil rich in foreign metal substance, such as gear wear powder. The metal foreign matter gradually increases as the wheel 2 is rotated by the operation of the speed reduction mechanism 10, and the filter 34 is likely to be clogged due to the increase of the metal foreign matter.

  However, since the permanent magnet 35 is provided in the bearing seal 24 and the permanent magnet 35 rotates in the stored oil, the metal foreign matter mixed in the stored oil is attracted and held by the permanent magnet 35 and removed from the stored oil. As a result, foreign metal in the stored oil is reduced.

  As a result, the filter 34 is not clogged at an early stage, and the clogging of the filter 34 and the deterioration of the lubricating performance are suppressed.

  Here, since the permanent magnet 35 is configured to cover the magnet mounting portion 33 formed of a through hole formed in the core metal 25 from the inner surface of the core metal 25, the magnet mounting portion 33 serves as a reservoir for metallic foreign matter, Metal foreign objects can be adsorbed and held.

FIG. 12 shows a tapered roller bearing B ₂ with a rotation sensor arranged on the inboard side, and the rotational speed of the wheel 2 is detected by the rotation sensor 40 incorporated in the tapered roller bearing B ₂ to perform ABS control or I will use it for traction control.

  Here, the rotation sensor 40 fixes a pulsar ring as the encoder 41 to the outer ring 20 on the rotation side. Further, a sensor case 43 having a sensor portion 42 made of a back magnet type magnetic sensor is fixed to the inner ring 21 which is a fixed side.

  The rotation sensor 40 is not limited to a back magnet type magnetic sensor.

Tapered roller bearing B ₂ with the rotation sensor, as shown in FIG. 1, the rotation sensor 40 is a built disposed on the inboard side. Thus, the provided rotation sensor 40 to the tapered roller bearing B ₂ on the inboard side, by the incorporation of the rotation sensor 40 is disposed on the inboard side, provided in the tapered roller bearing B ₁ on the outboard side lubricating oil by the filter 34 is in the foreign substance is captured filtered, very few clean oil contamination is flows into the rolling bearing B ₂ side of the inboard side, so that the lubricating the rolling bearing B _2. For this reason, there is little foreign matter adhering to the rotation sensor 40, and the rotation speed can be detected with high accuracy.

Here, as shown in FIG. 2, when an annular permanent magnet 44 is attached to the outer diameter surface of the fixed spindle 1 and the inner diameter surface of the wheel 2 between the pair of tapered roller bearings B ₁ and B ₂ , When a small amount of metallic foreign matter is mixed in the lubricating oil that passes through the tapered roller bearing B ₁ and flows toward the tapered roller bearing B ₂ on the inboard side, the metallic foreign matter is adsorbed and removed by the permanent magnet 44. It is possible to prevent the adhesion of the metallic foreign matter to the rotation sensor 40 more effectively.

  Although FIG. 3 thru | or FIG. 6 showed the tapered roller bearing as a rolling bearing, a rolling bearing is not limited to a tapered roller bearing. For example, it may be a cylindrical roller bearing or a deep groove ball bearing.

Further, in FIGS. 3 to 6, but the mounting of fitting the cylindrical portion 25a formed in the metal core 25 of the bearing seal 24 on the outer ring inner diametric surface of the outboard-side tapered roller bearing B _1, the metal core 25 You may make it attach to an outer ring | wheel outer diameter surface. A bearing seal may be attached to the inner ring.

3 to 6, the bearing seal 24 is shown as a seal member that seals the opening at one end of the bearing space of the outboard side tapered roller bearing B ₁ , but the seal member is not limited to the bearing seal 24.

  7 to 10 show other examples of the seal member. In FIG. 7, the slinger 50 attached to the inner diameter surface of the end portion of the outer ring 20 is used as a seal member. This slinger 50 is provided with an inward flange 50b at one end of a cylindrical portion 50a fitted to a seal fitting surface 27 formed on the inner diameter surface of the end portion of the outer ring 20, and the inner ring at an inner diameter portion of the inward flange 50b. 21 is provided with an inner cylindrical portion 50c that forms a minute gap 51 between the outer diameter surfaces of the end portions, the cylindrical portion 50a is press-fitted into the seal fitting surface 27, and the outer periphery of the other end portion of the cylindrical portion 50a The cylindrical portion 50a is prevented from being pulled out by the engagement of the formed protruding portion 52 and the seal mounting groove 28 formed in the seal fitting surface 27 so that the slinger 50 is mounted.

  Here, similarly to the bearing seal 24 shown in FIG. 3, the inward flange 50 b of the slinger 50 is provided with a plurality of oil passage holes and magnet attachment portions 33 including a plurality of through holes alternately in the circumferential direction. Each of the plurality of oil passage holes is covered with a filter, and each of the plurality of magnet mounting portions 33 is covered with a plate-like permanent magnet 35, but the oil passage holes and the filter are not shown. An annular permanent magnet 53 is attached to the inner peripheral portion of the outer surface of the inward flange 50 b close to the minute gap 51.

  Also in the slinger 50 shown in FIG. 7, the metallic foreign matter mixed in the oil can be attracted and held by the permanent magnet 35, and an effect can be obtained in preventing clogging of the filter. Further, since the metal foreign matter can be attracted and held by the permanent magnet 53 attached to the outer surface of the inward flange 50b, a large amount of metal foreign matter can be attracted and held by the permanent magnet 53 from the minute gap 51. It is possible to prevent metal foreign matter from entering the bearing.

  In FIG. 7, the slinger 50 is attached to the inner diameter surface of the end portion of the outer ring 20. However, as shown in FIG. 8, the slinger 50 is attached to the small-diameter seal fitting surface 60 formed on the outer diameter surface of the end portion of the outer ring 20. The cylindrical portion 50 a formed on the outer peripheral portion of the cylindrical portion 50 is fitted, and the protruding portion 61 formed on the inner periphery of the other end of the cylindrical portion 50 a is engaged with the seal mounting groove 62 formed on the seal fitting surface 60. It may be.

  Here, in FIG. 8, an annular groove 63 is formed on the outer diameter surface of the large collar 21 a of the inner ring 21, an annular permanent magnet 64 is attached to the annular groove 63, and metal foreign objects are attracted and held by the permanent magnet 64. The metallic foreign matter is prevented from entering the bearing through the minute gap 51.

  In FIG. 9, a slinger 70 provided with an inward flange 70 b at one end of a cylindrical portion 70 a fitted to a seal fitting surface 60 formed at an end of the outer ring 20 is used as a seal member. The slinger 70 has a cylindrical portion 70 a fitted to the seal fitting surface 60 of the outer ring 20, and a projecting portion 71 formed on the inner periphery of the end of the cylindrical portion 70 a and a seal mounting groove formed on the seal fitting surface 60. 62 is engaged by engagement. In the mounted state, the inward flange 70b forms a labyrinth 74 between the small diameter cylindrical surface 72 formed at the end of the inner ring 21 and the end surface 73 facing radially outward from the end of the small diameter cylindrical surface 72. is doing.

  Similarly to the bearing seal 24 shown in FIG. 3, the inward flange 70 b of the slinger 70 is provided with a plurality of oil passage holes and magnet mounting portions 33 including a plurality of through holes alternately in the circumferential direction. Each of the oil passage holes is covered with a filter, and each of the plurality of magnet mounting portions 33 is covered with a plate-like permanent magnet 35, but the oil passage holes and the filter are not shown.

  In FIG. 9, an annular groove 75 is formed in a small-diameter cylindrical surface 72 provided on the outer periphery of the large collar 21 a of the inner ring 21, and an annular permanent magnet 76 is attached to the annular groove 75. To prevent intrusion.

  Also in the slinger 70 shown in FIG. 9, the metallic foreign matter mixed in the oil can be attracted and held by the permanent magnet 35, and the effect of preventing clogging of the filter can be obtained. Further, since the metal foreign matter can be attracted and held by the permanent magnet 76 attached to the annular groove 75 of the small-diameter cylindrical surface 72, a large number of metal foreign matter can be attracted and held. Therefore, it is possible to prevent metal foreign matter from entering the bearing.

  In FIG. 9, an annular groove 75 is formed in the small-diameter cylindrical surface 72, and the permanent magnet 76 is attached to the annular groove 75. However, as shown in FIG. 10, on the inner peripheral portion of the inner surface of the inward flange 70b. An annular permanent magnet 77 may be attached to prevent foreign metal from entering the bearing from the labyrinth 74.

1 Fixed spindle (axle)
2 Wheel 4 Motor 5 Drive shaft 10 Reduction mechanism B ₁ Tapered roller bearing (rolling bearing)
B ₂ Tapered Roller Bearing (Rolling Bearing)
20 Outer ring (outer raceway)
21 Inner ring (inner race)
24 Bearing seal (seal member)
25 Core metal 26 Rubber seal 32 Oil passage hole 33 Magnet mounting portion 34 Filter 35 Permanent magnet 40 Rotation sensor 44 Permanent magnet 50 Slinger 51 Micro gap 53 Permanent magnet 64 Permanent magnet 70 Slinger 74 Labyrinth 76 Permanent magnet

Claims (10)

A cylindrical axle having a fixed arrangement, a pair of rolling bearings provided on the outer diameter surface of the axle at an axial interval, and a wheel rotatably supported by the pair of rolling bearings; A drive shaft that is inserted into the axle and is driven to rotate by using a motor as a drive source; and a speed reduction mechanism that is incorporated on the outboard side of the axle and decelerates the rotation of the drive shaft and transmits it to the wheel. In the wheel drive device in which each of the pair of rolling bearings and the speed reduction mechanism is lubricated with a common oil,
Of the pair of rolling bearings, the outer-board-side rolling bearing located on the speed reduction mechanism side has a sealing member on one side, and the sealing member is a built-in single-seal bearing located on the outer-board side, A wheel drive device characterized in that an oil passage hole is formed in a seal member of a bearing with a single seal, the oil passage hole is covered with a filter, and a permanent magnet is provided around the filter.   The seal member has a rubber seal fixed to the inner periphery of a cored bar attached to one end of the outer race and the inner race of the bearing with a single seal, and contacts the other race with the rubber seal A plurality of oil passage holes are formed in the bearing seal core metal at intervals in the circumferential direction, and a magnet mounting portion is provided between adjacent oil passage holes. The wheel driving device according to claim 1, wherein each of the plurality of oil passage holes is covered with the filter, and a permanent magnet is provided in the magnet mounting portion.   The seal member is attached to one end of the outer ring and the inner ring of the bearing with a single seal to form a minute gap between the other ring and substantially the entire bearing space. A plurality of oil passage holes are formed in the slinger at intervals in the circumferential direction, and a magnet mounting portion is provided between adjacent oil passage holes, and the plurality of oil passage holes are formed. The wheel drive device according to claim 1, wherein each of the first and second magnets is covered with the filter, and a permanent magnet is provided on the magnet mounting portion.   The wheel drive device according to claim 3, wherein an annular permanent magnet is provided in the vicinity of the minute gap formed between the slinger and the other race.   The wheel drive according to any one of claims 2 to 4, wherein the magnet attachment portion is a through hole, and the permanent magnet is an attachment that covers the magnet attachment portion including the through hole from the inner surface of the seal member. apparatus.   The wheel drive device according to any one of claims 2 to 4, wherein the magnet attachment portion is a recess, and the permanent magnet is attached to a closed end portion of the recess.   The wheel drive device according to any one of claims 1 to 6, wherein the permanent magnet is a rubber-like magnet.   A rotation sensor in which an inboard side rolling bearing arranged at a position away from the speed reduction mechanism of the pair of rolling bearings detects the rotational speed of an outer race ring that rotates integrally with the wheel at one end in the axial direction. The wheel drive device according to any one of claims 1 to 7, wherein the wheel drive device is a built-in rolling bearing, and the rotation sensor thereof is incorporated on the inboard side.   The wheel drive device according to any one of claims 1 to 8, wherein an annular permanent magnet is attached to an outer diameter surface between the pair of rolling bearings of the axle.   The wheel drive device according to any one of claims 1 to 9, wherein an annular permanent magnet is attached to an inner diameter surface between the pair of rolling bearings of the wheel.

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