JP2014172407A - Series of wheel drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a plurality of wheel drive devices in which positional relationship of a load point of a driving wheel and a counter car body side bearing is different, by sharing most of parts.SOLUTION: A series of wheel drive devices include a first wheel drive device 100, and a second wheel drive device 100' which drives a wheel 170 of which a load point is at the outer side of a car body for a counter car body side bearing than a wheel 70 which the first wheel drive device drives. The first and second wheel drive devices include common fixing members 34, 38, a rotational member 30, a car body side bearing 46, and a counter car body side bearing 47. In the first wheel drive device 100, the car body side bearing 46 and the counter car body side bearing 47 are lubricated with the same lubricant in the same space 80. In the second wheel drive device 100', a car body side space 80A in which the car body side bearing is arranged and a counter car body side space 80B in which the counter car body side bearing is arranged are partitioned by seal members 90A, 90B, and the counter car body side space 80B is sealed with a lubricant having a higher viscosity than the lubricant in the car body side space 80A.

Description

  The present invention relates to a series of wheel drive devices.

  2. Description of the Related Art A wheel drive device that drives a wheel of a work vehicle such as a forklift is known in which a speed reducer and a motor are housed inside a wheel of the wheel (for example, Patent Document 1). The wheel drive device includes a fixed member, a rotating member, and a vehicle body side bearing and an anti-vehicle body side bearing disposed between the fixed member and the rotating member, and transmits the rotation of the rotating member to the wheel. To do. Generally, in such a wheel drive device, the internal space of the speed reducer is sealed with respect to the outside, and a low-viscosity lubricant is enclosed in order to reduce stirring loss due to rotating parts in the speed reducer.

JP 2012-182917 A

  Here, depending on the vehicle, a plurality of wheel drive devices in which the positional relationship between the load point of the wheel to be driven and the non-vehicle body side bearing is different may be required. For example, a forklift may require a wheel drive device that drives a single tire and a wheel drive device that drives a double tire. In such a case, if each wheel drive device is individually designed individually, problems such as an increase in the number of parts, assembly man-hours, and complicated inventory management occur.

  The present invention has been made in view of such a situation, and an object of the present invention is to share a plurality of wheel drive devices in which the positional relationship between the load point of the wheel to be driven and the non-vehicle body side bearing is different while sharing most of the components. It is to provide a series of wheel drive devices that can be realized.

  An aspect of the present invention includes a fixing member, a rotating member, and a vehicle body side bearing and an anti-vehicle body side bearing disposed between the fixing member and the rotating member, and rotation of the rotating member is transmitted to the wheel. It is a series of wheel drive devices. This series includes a first wheel driving device, a second wheel driving device that drives a wheel whose load point is on the outside of the vehicle body with respect to the bearing on the side opposite to the vehicle body than the wheel driven by the first wheel driving device, including. The first wheel driving device and the second wheel driving device have a common fixing member, rotating member, vehicle body side bearing, and anti-vehicle body side bearing. In the first wheel drive device, the vehicle body side bearing and the anti-vehicle body side bearing are lubricated with the same lubricant in the same space. In the second wheel drive device, the vehicle body side space in which the vehicle body side bearing is arranged and the anti vehicle body side space in which the anti vehicle body side bearing is arranged are partitioned by a seal member. A lubricant having a viscosity higher than that of the lubricant is enclosed.

  According to this aspect, in the second wheel drive device, by adding a seal member, it is possible to use optimum lubricants having different viscosities in the arrangement space of the vehicle body side bearing and the anti-vehicle body side bearing. Therefore, a plurality of wheel drive devices in which the positional relationship between the load point of the wheel to be driven and the non-vehicle body side bearing is different can be realized while sharing most of the parts. In addition, the load point of a wheel means the center point of the width direction (vehicle width direction) of a wheel.

  Arbitrary combinations of the above-described constituent elements and those obtained by replacing constituent elements and expressions of the present invention with each other among methods, apparatuses, systems, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the several wheel drive device from which the positional relationship of the load point of the wheel to drive and a non-vehicle body side bearing differs can be implement | achieved, sharing most of components.

It is sectional drawing which shows the structure of the wheel drive device which concerns on one Embodiment of this invention with which the single tire was mounted | worn. It is sectional drawing which shows the structure of the wheel drive device which concerns on one Embodiment of this invention with which the double tire was mounted | worn. It is sectional drawing which shows the structure of the wheel drive device which concerns on one Embodiment of this invention with which the wide tire was mounted | worn.

  FIG. 1 and FIG. 2 are cross-sectional views when the wheel drive devices 100 and 100 ′ according to the embodiment of the present invention fastened to the wheels 70 and 170, respectively, are cut along a vertical plane including the central axis. The wheel drive device 100 is used in a work vehicle such as a forklift.

  The wheel 70 shown in FIG. 1 is a so-called single tire in which one tire 50 is attached to the wheel 48, and the wheel 170 shown in FIG. 2 is a so-called one in which two tires 150 </ b> A and 150 </ b> B are attached to the wheel 148. This is called a double tire.

  For convenience, the one that drives the single tire wheel 70 is referred to as a first wheel driving device 100, and the one that drives the double tire wheel 170 is referred to as a second wheel driving device 100 '. In the following, the first wheel drive device 100 shown in FIG. 1 will be described, but the second wheel drive device 100 ′ has the same configuration, except as otherwise noted.

  The wheel drive device 100 includes a speed reducer 10 which is a kind of planetary gear mechanism called an eccentric swing meshing type, and a motor (not shown) connected to the speed reducer 10 on the left side of FIG.

  The output shaft of the motor is connected to the input shaft 16 of the speed reducer 10 via a spline (not shown). The input shaft 16 is disposed at the center in the radial direction of external gears 24 and 26 described later. The input shaft 16 is integrally formed with two eccentric bodies 18 and 20 that are offset from the input shaft 16. The two eccentric bodies 18 and 20 are eccentric with a phase difference of 180 degrees from each other. The input shaft 16 is formed with passages 18A and 20A for supplying lubricating oil to the roller bearings 21 and 23. The eccentric bodies 18 and 20 may be configured separately from the input shaft 16 and fixed to the input shaft with a key or the like.

  Two external gears 24 and 26 are fitted on the outer circumferences of the eccentric bodies 18 and 20 via roller bearings 21 and 23 so as to be swingable. The external gears 24 and 26 are in mesh with the internal gear 28, respectively.

  The internal gear 28 passes through internal pins (also referred to as outer rollers) 28A and 28B, which are cylindrical sliding promotion members constituting the internal teeth, and the internal pins 28A and 28B, and holds them rotatably. An outer pin (also referred to as a holding pin) 28C and an internal gear main body 28D that rotatably supports the outer pin 28C and is fitted to the inner peripheral surface of the casing 30 are mainly configured. The outer pin may be supported by the casing 30 so as not to rotate.

  The number of internal teeth of the internal gear 28, that is, the number of internal pins 28A and 28B, is slightly larger (by 1 in this embodiment) than the number of external teeth of the external gears 24 and 26.

  A first carrier body 34 fixed to a vehicle body frame (not shown) is disposed on the side of the external gears 24 and 26 in the axial direction vehicle body (inside the vehicle body), and a carrier bolt is disposed on the opposite side in the axial direction (vehicle body outside). A second carrier body 38 integrated with the first carrier body 34 via 36 and carrier pins 42 is arranged. An inner pin 40 is press-fitted into the second carrier body 38. The first and carrier bodies 34 and 38 are also collectively referred to as a “fixing member”.

  The external gear 24 has twelve through holes with the same diameter formed at equal intervals at positions offset from the axis. Among them, the carrier pin 42 is inserted into three holes arranged at equal intervals of 120 degrees, and the inner pin 40 is inserted into the remaining nine holes. Therefore, the former is called the carrier pin hole 24B and the latter is called the inner pin hole 24A, but there is no difference in the shape and radial position. Corrugated teeth are formed on the outer periphery of the external gear 24, and these teeth move while in contact with the internal gear pins 28 </ b> A of the internal gear 28, so that the external teeth are externally moved in a plane whose normal is the central axis. The toothed gear 24 can swing. Although not shown, the external gear 26 has the same configuration except that there is a phase difference of 180 degrees with respect to the external gear 24.

  The inner pin 40 is inserted into the inner pin holes 24 </ b> A and 26 </ b> A penetratingly formed in the external gears 24 and 26 with a gap, and the tip thereof is press-fitted into the recess 34 </ b> A of the first carrier body 34. The inner pin 40 is in contact with a part of the inner pin holes 24A, 26A formed in the outer gears 24, 26 via the sliding promotion member 44, and restrains the rotation of the outer gears 24, 26 to Only swinging is allowed.

  The inner pin 40 is only press-fitted into the recess 34A, and is not fixed with a bolt or the like. It can be said that the inner pin 40 is a connecting member that contributes to the transmission of power between the first and second carrier bodies 34 and 38 and the external gears 24 and 26.

  The carrier pin 42 is inserted in a state where there is a gap in the carrier pin holes 24B and 26B formed through the external gears 24 and 26, and a contact portion 42C having an enlarged diameter is formed on the outer surface of the first carrier body 34 on the vehicle body. It is in contact. The carrier pin 42 and the first carrier body 34 are fastened by a carrier bolt 36. The first carrier body 34 is formed with a through hole 34C for inserting the carrier bolt 36 and a counterbore portion 34B, and a screw hole 42E for screwing the carrier bolt 36 is formed on the axial end surface of the carrier pin 42. Is formed. The second carrier body 38 is formed with a female screw hole 38 </ b> C, and is fastened to a male screw at the tip of the carrier pin 42 on the side opposite to the vehicle body to connect the carrier pin 42 and the second carrier body 38.

  The carrier pin 42 is not in contact with the carrier pin holes 24B and 26B of the external gears 24 and 26, and does not contribute to restraining the rotation of the external gears 24 and 26. It can be said that the carrier pin 42 is a connecting member that contributes only to the connection between the first carrier body 34 and the second carrier body 38.

  A casing (also referred to as “rotating member”) 30 of the speed reducer 10 has a substantially cylindrical shape, and the casing 30 is provided on the outer periphery of the first carrier body 34 via a first main bearing (also referred to as “vehicle body side bearing”) 46. Is supported rotatably. Further, a flange extending radially inward is formed on the outside of the vehicle body (ie, on the side opposite to the vehicle body) of the casing 30 (more than the external gears 24 and 26). A second main bearing (also referred to as “anti-vehicle body side bearing”) 47 is fitted into a recess 30 </ b> C formed on the inner periphery of the flange, and a casing is provided on the outer periphery of the second carrier body 38 via the second main bearing 47. 30 is rotatably supported. The first and second main bearings 46 and 47 may be press-fitted into the casing 30, or may be fixed to the casing 30 with a retaining ring (not shown) after being fitted into the gap. That is, it only needs to be fixed to the casing 30 in the axial direction.

  A wheel 48 of a wheel 70 of the work vehicle is fastened to the end surface of the casing 30 on the outer side of the vehicle body by a bolt 49, and a tire 50 is attached to the wheel 48. Similarly, in the second wheel driving device 100 ′ in FIG. 2, the wheel 148 of the wheel 170 is fastened to the end surface of the casing 30 on the outer side of the vehicle body by the bolt 49, and the tires 150 </ b> A and 150 </ b> B are attached to the wheel 148.

  A bearing nut 56 is screwed into a thread portion formed on the outer peripheral surface of the second carrier body 38. The inner ring 47C of the non-vehicle body side bearing 47 is in contact with the left end surface of the bearing nut 56, and the outer ring 47B of the anti-vehicle body side bearing 47 is in contact with the recess 30C of the casing 30. Further, the outer ring 46 </ b> B of the vehicle body side bearing 46 is in contact with the recess 30 </ b> A of the casing 30, and the inner ring 46 </ b> C of the vehicle body side bearing 46 is in contact with the shoulder portion 34 </ b> E formed in the first carrier body 34. As a result, the axial movement of the casing 30 in which the main bearings 46 and 47 are fitted is restricted by the bearing nut 56.

  A cover 60 that covers the bearing nut from the outside is attached to the end surface of the casing 30 by a bolt 62 on the outside of the vehicle body of the bearing nut 56.

  An oil seal 72 that seals between the inner periphery of the casing 30 and the outer peripheral surface of the first carrier body 34 is also provided inside the vehicle body from the vehicle body side bearing 46. The oil seal 72 is fitted (press-fitted) into a recess 30 </ b> B formed on the inner periphery of the casing 30, and is arranged so that the lip contacts the outer peripheral surface of the first carrier body 34. With this seal, the space 80 inside the casing 30 is sealed from the outside. A lubricant is enclosed in the space 80.

  The input shaft 16 as an input member of the speed reducer 10 is rotatably supported by the first carrier body 34 and the second carrier body 38 via a pair of angular ball bearings 52 and 54 that are arranged face to face. The angular ball bearings 52 and 54 have rolling elements 52A and 54A and outer rings 52B and 54B, respectively, but do not have an inner ring. Instead, rolling surfaces 52C and 54C are formed on the input shaft 16, and these function as inner rings of the angular ball bearings. In addition, it is not restricted to this structure, You may arrange | position a separate inner ring | wheel.

  Then, the effect | action of the wheel drive device 100 is demonstrated.

  The rotation of the output shaft of a motor (not shown) is transmitted to the input shaft 16 of the speed reducer 10 via a spline. When the input shaft 16 rotates, the outer circumferences of the eccentric bodies 18 and 20 perform an eccentric motion, and the external gears 24 and 26 swing through the roller bearings 21 and 23. This swinging causes a phenomenon in which the meshing positions of the external teeth of the external gears 24 and 26 and the internal tooth pins 28A and 28B of the internal gear 28 are sequentially shifted.

  The difference in the number of teeth between the external gears 24 and 26 and the internal gear 28 is set to 1, and the rotation of each external gear 24 and 26 is caused by the first carrier body 34 fixed to the body frame. It is restrained by the fixed inner pin 40. For this reason, every time the input shaft 16 makes one revolution, the internal gear 28 rotates (rotates) by an amount corresponding to the difference in the number of teeth with respect to the external gears 24 and 26 whose rotation is restricted. As a result, the casing 30 integrated with the internal gear main body 28 </ b> D rotates at a rotational speed reduced to 1 / (the number of teeth of the internal gear) by the rotation of the input shaft 16. The rotation of the casing 30 causes the forklift tire 50 to rotate via a wheel 48 fixed to the casing 30 by bolts 49.

  Subsequently, the difference between the first wheel driving device 100 and the second wheel driving device 100 ′ will be described with reference to FIGS. 1 and 2.

  The load point of the single tire wheel 70 shown in FIG. 1 is located on the line G1 between the vehicle body side bearing 46 and the non-vehicle body side bearing 47, whereas the load point of the double tire wheel 170 shown in FIG. 2 is located on the line G2 in FIG. In other words, in the second wheel drive device 100 ′, the wheel load point is located on the outer side of the vehicle body with respect to the non-vehicle body side bearing 47 as compared with the first wheel drive device 100. For this reason, when the same wheel drive device is used for single tires and for double tires, the load applied to the non-vehicle body side bearing 47 is increased when the double tires are mounted, and the durability is reduced compared to when the single tires are mounted. . In addition, the load point of a wheel means the center point of the width direction (vehicle width direction) of a wheel.

  Therefore, when the double tire is mounted, it is desirable to enclose a lubricant with a high viscosity in the space 80 inside the casing 30 to ensure an oil film on the rolling surface during operation. However, since a high-viscosity lubricant increases agitation loss, in the space where the vehicle body side bearing 46 is disposed (the space where the external gears 24 and 26, the internal gear 28 and the roller bearings 21 and 23 are disposed), it is conventional. It is desirable to use the same low viscosity lubricant.

  Therefore, the wheel drive device according to the present embodiment is designed so that a seal member that partitions the space in which the vehicle body side bearing 46 is disposed and the space in which the anti-vehicle body side bearing 47 is disposed can be additionally disposed. Specifically, an arrangement surface 88 on which the seal member is arranged is formed in advance on the inner peripheral surface of the casing 30. In the first wheel drive device 100, the contact surface 89 on the outer periphery of the second carrier body 38 that contacts the lip of the seal member disposed on the placement surface 88 is not polished.

  FIG. 2 shows a pair of seal members 90A and 90B arranged back to back. The fitting portions of the seal members 90 </ b> A and 90 </ b> B are arranged on the arrangement surface 88 </ b> A, and the lip of the seal member contacts the contact surface 89 on the outer periphery of the second carrier body 38. By these sealing members, the space inside the casing 30 is partitioned into a vehicle body side space 80A in which the vehicle body side bearing 46 is arranged and an anti vehicle body side space 80B in which the anti vehicle body side bearing 47 is arranged.

  Then, a lubricant having a viscosity higher than that of the lubricant sealed in the vehicle body side space 80A is sealed in the non-vehicle body side space 80B. This makes it possible to use different lubricants for the anti-vehicle body side bearing and the other bearings, where the load conditions become severe due to the installation of double tires. It is possible to achieve both the operation and the low stirring loss in the vehicle body side space (the space where the speed reduction mechanism such as the external gears 24 and 26 and the internal gear 28 is disposed).

  In the case of the first wheel drive device, the vehicle body side bearing 46 and the anti-vehicle body side bearing 47 may be lubricated with the same lubricant in the same space without disposing the seal member on the arrangement surface 88.

  As can be seen from FIGS. 1 and 2, the first wheel drive device 100 to which a single tire is attached and the second wheel drive device 100 ′ to which a double tire is attached are arranged with seal members 90 </ b> A and 90 </ b> B and a high viscosity. The configuration is common except that the lubricant is enclosed. That is, it is possible to adapt the same wheel drive device to tires having different load points simply by providing the wheel drive device with an arrangement surface for the seal member in advance. Therefore, we have developed and manufactured multiple types of wheel drive devices, such as adopting special bearings that can withstand high loads as anti-car body side bearings, or using different designs with different arrangements of the car body side or anti-car body side bearings. Without this, it is possible to provide a series of wheel drive devices depending on the presence or absence of a seal member.

  Instead of oil as the lubricant, grease may be enclosed in the non-vehicle body side space 80B. In this case, the seal member 90B facing away from the vehicle body is not necessary, and only one seal member 90A facing toward the vehicle body is sufficient.

  In the second wheel drive device 100 ′, the contact surface 89 on the outer periphery of the second carrier body 38 that contacts the lips of the seal members 90 </ b> A and 90 </ b> B may be polished. There is a difference in that the contact surface 89 is not polished or polished between the second carrier body 38 of the first wheel driving device 100 and the second carrier body 38 of the second wheel driving device 100 ′. However, even in such a case, the second carrier body 38 itself is shared. Alternatively, the contact surface 89 of the second carrier body 38 is polished in advance, and the second carrier in which the contact surface 89 is polished regardless of the first wheel drive device 100 or the second wheel drive device 100 ′. The body 38 may be used.

  When the second carrier body 38 is a hollow shaft having an opening 38A that opens to the vehicle body side space 80A and an opening 38B that opens to the anti-vehicle body side space 80B, as shown in FIG. It is necessary to attach the cap member 94 that closes the opening 38A or 38B to separate the vehicle body side space 80A and the anti-vehicle body side space 80B.

  Further, in the second wheel drive device 100 ′, the casing 30 may be formed with a greasing hole 92 that communicates from the outside of the wheel to the non-vehicle body side space 80 </ b> B. The lubrication hole 92 makes it possible to easily supply the lubricant to the non-vehicle body side space 80B. The greasing hole 92 can also be used as a greasing hole for removing the lubricant. In the second wheel drive device 100 ′, another greasing hole (not shown) communicating with the vehicle body side space 80 </ b> A from the outside of the wheel drive device may be formed in the casing 30. In this case, the casing 30 of the second wheel drive device 100 ′ is added with a greasing hole that does not exist in the casing 30 of the first wheel drive device 100, but the casing 30 itself is shared. become.

  Such a greasing hole may not be formed in the first wheel driving device 100. Alternatively, in common with the first wheel driving device, a greasing hole communicating with the vehicle body side space 80A and / or the non-vehicle body side space 80B is provided in advance, and unnecessary lubrication is required in the case of the first wheel driving device. A member that closes the hole may be attached separately.

  In the above, a single tire and a double tire have been described as tires to be attached to the wheel drive device, but the tires that can be attached are not limited to these. 3 shows a third wheel drive device 100 ″ equipped with a wheel 270 (so-called wide tire) composed of a wheel 248 wider than the wheel 70 shown in FIG. 1 and a tire 250. A load point of the wheel 270 is a line. It is indicated by G3.

  The load point of the wheel 270 in FIG. 3 does not extend further outward than the anti-vehicle body side bearing as in the wheel 170 in FIG. 2, but the anti-vehicle body side bearing 47 compared to the load point of the wheel 70 in FIG. In contrast to the outside of the car body. Accordingly, in the third wheel drive device 100 ″, the seal members 90A and 90B are arranged, and the anti-vehicle body side bearing 80N is sealed by sealing the anti-vehicle body side space 80B with an appropriate lubricant having a higher viscosity than the vehicle body side space 80A. 47 load increase can be dealt with.

  As described above, in the wheel drive device according to the present embodiment, by adding a seal member, an optimal lubricant having different viscosities in the arrangement space of the vehicle body side bearing and the anti-vehicle body side bearing is used, and It becomes possible to achieve both improvement in durability of the vehicle body side bearing and low stirring loss of the other bearings and the speed reduction mechanism. Therefore, a plurality of wheel drive devices in which the positional relationship between the load point of the wheel to be driven and the non-vehicle body side bearing is different can be realized while sharing most of the parts.

  The rotating member (casing 30) and the fixing members (first and second carrier bodies 34, 38) of the present embodiment share the members that serve as the base, and the first wheel driving device 100 and the second wheel driving device 100. In some cases, only one side is polished or a greasing hole is formed only on one side. As described above, even when the base member is additionally processed, when the base member is shared, the rotating member and the fixed member (or bearing) are shared. .

  Such a series of wheel drive devices can reduce the cost of development and manufacturing by making the design common, and contribute to shortening the delivery time of wheel drive devices and reducing inventory.

  The embodiment of the present invention has been described above. It is to be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective components, and such modifications are within the scope of the present invention.

  In the embodiment, the wheel driving device having a structure for transmitting the rotation of the casing to the wheel has been described. However, the present invention can also be applied to a wheel drive device having a structure in which the casing is a fixed member and the flange that takes out the rotation of the external gear is a rotating member.

  In the embodiment, an eccentric oscillating mesh type planetary gear reducer in which the input shaft (eccentric body shaft) 16 is arranged at the center of the internal gear 28 has been described as an example of the wheel drive device. However, the present invention is not limited to this type of speed reducer, for example, an eccentric oscillating planetary gear speed reducer of a type in which a plurality of eccentric body shafts are arranged at a position offset from the center of the internal gear, or a simple planetary type planetary gear. The present invention can be applied to a wheel drive device having any type of planetary gear speed reduction mechanism including a gear speed reducer. Furthermore, the present invention can be applied to a wheel drive device having a speed reduction mechanism other than the planetary gear speed reduction mechanism.

  In the embodiment, a forklift has been described as an example of a vehicle driven by a wheel drive device, but the present invention can be applied to any vehicle.

  DESCRIPTION OF SYMBOLS 10 Reduction gear, 16 Input shaft, 30 Casing (rotating member), 34 1st carrier body (fixing member), 38 2nd carrier body (fixing member), 46 1st main bearing (vehicle body side bearing), 47 2nd main Bearings (anti-car body side bearings), 48, 148, 248 wheels, 50, 150A, 150B, 250 tires, 70, 170, 270 wheels, 80A car body side space, 80B anti-car body side space, 90A, 90B sealing member, 92 Oil hole, 94 cap member, 100 first wheel drive device, 100 ′ second wheel drive device.

Claims (6)

A series of wheel drive devices comprising a fixed member, a rotating member, and a vehicle body side bearing and an anti-vehicle body side bearing disposed between the fixed member and the rotating member, and transmitting the rotation of the rotating member to a wheel. Because
A first wheel driving device, and a second wheel driving device that drives a wheel whose load point is on the outside of the vehicle body with respect to the bearing opposite to the vehicle body relative to the wheel driven by the first wheel driving device,
The first wheel driving device and the second wheel driving device have a common fixing member, a rotating member, a vehicle body side bearing and an anti-vehicle body side bearing,
In the first wheel drive device, the vehicle body side bearing and the anti-vehicle body side bearing are lubricated with the same lubricant in the same space,
In the second wheel drive device, a vehicle body side space where the vehicle body side bearing is arranged and an anti vehicle body side space where the anti vehicle body side bearing is arranged are partitioned by a seal member, A series of wheel drive devices, wherein a lubricant having a viscosity higher than that of the lubricant in the vehicle body side space is enclosed. The first and second wheel drive devices have a hollow shaft, one end of the hollow shaft opens into the vehicle body side space, the other end opens into the anti-vehicle body side space,
The series of wheel drive devices according to claim 1, wherein a cap member that closes an opening of the hollow shaft is disposed in the second wheel drive device.   3. The wheel drive device series according to claim 1, wherein an arrangement surface on which the fitting portion of the seal member is arranged is provided in common to the first and second wheel drive devices. 4.   4. The wheel drive device series according to claim 1, wherein in the second wheel drive device, a contact surface with which a lip of the seal member contacts is polished.   The wheel drive device series according to any one of claims 1 to 4, wherein the second wheel drive device is provided with a greasing hole for lubricating the anti-vehicle body side space.   The series of wheel drive devices according to claim 5, wherein the greasing hole is provided in the rotating member, and the greasing hole also serves as a greasing hole.

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