JP6886315B2 - Wheel drive - Google Patents

Description

The present invention relates to a wheel drive device.

Conventionally, as a wheel drive device for driving wheels of a transport carriage or the like, one having a reduction mechanism incorporated therein has been known. This type of wheel drive may be used in places where cleanliness is required, such as in clean rooms. In this case, it may be required to take measures against leakage of the lubricant sealed inside the wheel drive device. As a wheel drive device taking this measure, Patent Document 1 discloses a bearing in which a bearing that rotatably supports a rotating body is a bearing with a seal, and a seal member is arranged on the external space side of the bearing with the seal. There is.

Japanese Unexamined Patent Publication No. 2012-71810

As a result of examination by the present inventor, it has been recognized that the technique of Patent Document 1 is insufficient in measures against lubricant leakage and there is room for improvement.

A certain aspect of the present invention is made in view of such a situation, and one of the objects thereof is to provide a wheel drive device capable of effectively taking measures against leakage of a lubricant.

One aspect of the present invention relates to a wheel drive device, which comprises a deceleration mechanism for decelerating rotation transmitted from a drive source, a rotating body to which rotation decelerated by the deceleration mechanism is transmitted and a tire is integrated, and the rotation. A fixing member that rotatably supports the body, an oil seal that is arranged between the rotating body and the fixing member and seals a space in which the deceleration mechanism is housed, and a sealing space sealed by the oil seal. A wheel drive device comprising a lubricant sealed in, wherein the lubricant contains at least two types of lubricants having different mixing densities, and the amount of the lubricant sealed is the volume of the sealed space. It is 35% or less.

Another aspect of the present invention relates to a wheel drive device, which comprises a deceleration mechanism for decelerating rotation transmitted from a drive source, a rotating body for which rotation decelerated by the deceleration mechanism is transmitted and a tire is integrated, A fixing member that rotatably supports the rotating body, an oil seal that is arranged between the rotating body and the fixing member and seals a space in which the deceleration mechanism is housed, and a sealing that is sealed by the oil seal. It is a wheel drive device including a lubricant sealed in a space, and includes a shake-off plate that rotates integrally with the rotating body and shakes off the lubricant leaked from the location where the oil seal is arranged.

Another aspect of the present invention relates to a wheel drive device, which comprises a deceleration mechanism for decelerating rotation transmitted from a drive source, a rotating body to which rotation decelerated by the deceleration mechanism is transmitted, and a tire integrated therein. A fixing member that rotatably supports the rotating body, an oil seal that is arranged between the rotating body and the fixing member and seals a space in which the deceleration mechanism is housed, and a sealing that is sealed by the oil seal. It is a wheel drive device including a lubricant sealed in a space, and includes an oil pan that receives the lubricant leaked from the location where the oil seal is arranged.

According to the present invention, it is possible to provide a wheel drive device capable of effectively taking measures against leakage of a lubricant.

It is a front sectional view which shows the wheel drive device of 1st Embodiment. It is an enlarged view which shows the deceleration mechanism of 1st Embodiment together with the peripheral structure. It is a figure for demonstrating the distribution of the lubricant in the enclosed space of 1st Embodiment. It is a figure for demonstrating the path that a lubricant follows from the place where the 1st oil seal is arranged. It is an enlarged view of a part of FIG. It is a partial cross-sectional view of a part of the wheel drive device of FIG. 1 as seen from the anti-vehicle body side. FIG. 5 is an external view of a part of the wheel drive device of FIG. 1 as viewed from the anti-vehicle body side. It is a top view which shows the 1st oil pan and the 2nd oil pan of 1st Embodiment. FIG. 8 is a cross-sectional view taken along the line AA of FIG. 10 (a) to 10 (c) are views of the pan support member viewed from the anti-rotating body side, a view seen from the rotating body side, and a view seen from one side in the traveling direction Y. It is a figure which shows a part of the 1st oil pan and a pan support member of 1st Embodiment. It is a front sectional view of a part of the wheel drive device of 2nd Embodiment. It is a side sectional view which shows the peripheral end portion of the wheel cover of 2nd Embodiment.

Hereinafter, in the embodiments and modifications, the same components will be designated by the same reference numerals, and duplicate description will be omitted. Further, in each drawing, for convenience of explanation, some of the constituent elements are appropriately omitted, and the dimensions of the constituent elements are appropriately enlarged or reduced. In addition, different components that have something in common are distinguished by adding "1st, 2nd", etc. at the beginning of the name and "-A, -B", etc. at the end of the code, and collectively refer to them. When, these are omitted.

(First Embodiment)
FIG. 1 is a front sectional view showing the wheel driving device 10 of the first embodiment. The wheel drive device 10 of the present embodiment is assembled to the vehicle body 12 of the transport carriage and is used for driving the tires 14 of the transport carriage. The transport carriage of this embodiment is a tracked carriage, and the tire 14 of this embodiment travels on a traveling surface 16a provided on a rail 16 laid on a floor surface. Hereinafter, the direction along the rotation center line La of the tire 14 is defined as the axial direction X of the tire 14, and the circumferential direction and the radial direction around the rotation center line a will be described simply as “circumferential direction” and “diameter direction”. The traveling direction of the tire 14 is a horizontal direction orthogonal to the axial direction X.

The wheel drive device 10 mainly includes an input shaft 18, a reduction mechanism 20, a rotating body 22, carriers 24-A, 24-B, and a first oil seal 26. The wheel drive device 10 of the present embodiment is roughly divided into a lubricant (not shown) sealed in the sealed space 28 (described later) on the inner peripheral side of the rotating body 22, and an external structure of the sealed space 28. And has the main features. The former will be explained first.

The input shaft 18 is for receiving the rotation transmitted from the output shaft 30 of the drive source. The drive source in this embodiment is a motor, but a gear motor or the like in which the motor and the reduction gear are integrated may also be used. An output shaft 30 of a drive source protruding outward in the vehicle width direction from the vehicle body 12 is connected to the input shaft 18. The input shaft 18 is provided so as to be rotatable integrally with the output shaft 30, and the rotation of the drive source is transmitted from the output shaft 30. The rotation center line of the input shaft 18 is provided coaxially with the rotation center line La of the tire 14.

FIG. 2 is an enlarged view showing the deceleration mechanism 20 together with the peripheral structure. The speed reduction mechanism 20 is for decelerating the rotation transmitted from the drive source. The deceleration mechanism 20 of the present embodiment is an eccentric swing type deceleration mechanism. The speed reduction mechanism 20 mainly has eccentric bodies 32-A and 32-B, an external gear 34, an eccentric bearing 36, and an internal gear 38.

The eccentric body 32 is integrally formed with the input shaft 18 and is rotatably provided integrally with the input shaft 18. The eccentric bodies 32-A and 32-B include a first eccentric body 32-A and a second eccentric body 32-B adjacent to each other in the axial direction X. The axes of the first eccentric body 32-A and the second eccentric body 32-B are eccentric in opposite directions with the rotation center line La of the tire 14 in between.

The external tooth gear 34 is individually provided corresponding to each of the first eccentric body 32-A and the second eccentric body 32-B. The external gear 34 is supported by the corresponding eccentric bodies 32-A and 32-B via the eccentric body bearing 36, and is swung by the eccentric bodies 32-A and 32-B. Specifically, the external gear 34 rotates its own axis around the rotation center line La of the tire 14 when the corresponding eccentric bodies 32-A and 32-B rotate around the rotation center line La of the tire 14. It is rocked like this.

The external gear 34 is formed with a central hole 34a that penetrates the axial core of the external gear 34 in the axial direction X. Corresponding eccentric bodies 32-A and 32-B and eccentric bearings 36 are arranged inside the central hole 34a of the external gear 34.

A plurality of pin holes 34b penetrating in the axial direction X are formed in the external gear 34. The pin holes 34b are provided at positions offset from the axis of the external gear 34 with a gap in the circumferential direction. The inner pin 40 is inserted into the pin hole 34b with play. An inner roller 42 rotatably supported by the inner pin 40 is provided on the outer peripheral side of the inner pin 40. Both ends of the inner pin 40 are fixed to a pair of carriers 24 and are supported by the pair of carriers 24.

The eccentric body bearing 36 is individually provided corresponding to each of the first eccentric body 32-A and the second eccentric body 32-B. The eccentric bearing 36 is provided between the corresponding eccentric bodies 32-A and 32-B and the external gear 34.

The eccentric body bearing 36 of this embodiment is a roller bearing. The eccentric bearing 36 has a plurality of first rolling elements 36a, a retainer 36b, a first inner ring 36c, and a first outer ring 36d. The first rolling element 36a is provided at intervals around the rotation center line La of the tire 14. The retainer 36b holds the relative positions of the plurality of first rolling elements 36a and rotatably supports the plurality of first rolling elements 36a.

The first inner ring 36c of the present embodiment is composed of a member different from the eccentric body 32, and is integrated with the outer peripheral surface of the eccentric body 32 by tightening and fitting. The outer peripheral surface of the first inner ring 36c constitutes a first inner rolling surface 36e on which the first rolling element 36a rolls in the circumferential direction.

The first outer ring 36d of the present embodiment is formed by the inner peripheral surface of the central hole 34a of the external gear 34. The first outer ring 36d is composed of a part of the same member as the external gear 34. The inner peripheral surface of the first outer ring 36d constitutes the first outer rolling surface 36f in which the first rolling element 36a rolls in the circumferential direction.

An external gear 34 is inscribed in the internal gear 38. The internal gear 38 of the present embodiment has a plurality of outer pins 38a supported on the inner peripheral portion of the casing 46 (described later) and a plurality of outer rollers 38b rotatably supported by each of the plurality of outer pins 38a. And have. Each of the plurality of outer rollers 38b constitutes the internal teeth of the internal gear 38. The number of internal teeth of the internal gear 38 (the number of external rollers 38b) is one more than the number of external teeth of the external gear 34 in the present embodiment.

See FIG. The rotation decelerated by the deceleration mechanism 20 is transmitted to the rotating body 22. The tire 14 is integrated with the rotating body 22. The rotating body 22 has an annular shape as a whole, and a reduction mechanism 20 and a carrier 24 are arranged on the inner peripheral side thereof.

The rotating body 22 has, in addition to the tire 14 in contact with the traveling surface 16a, a wheel 44 on which the tire 14 is mounted, and a casing 46 in which the internal gear 38 of the speed reduction mechanism 20 is provided on the inner peripheral portion.

The tire 14 is attached to the outer peripheral portion of the wheel 44 by adhesion or the like. The tire 14 is made of a soft material, and the wheel 44 is made of a hard material that is harder than the soft material of the tire 14. To give an example of this, the soft material is an elastic body such as urethane rubber, and the hard material is a metal such as steel.

The casing 46 is the casing of the speed reduction mechanism 20, and also serves as an output member for taking out the rotation decelerated by the speed reduction mechanism 20. The casing 46 is arranged on the inner peripheral side of the wheel 44 and is integrated with the wheel 44 by the bolt B1.

The carriers 24-A and 24-B include an inner carrier 24-A arranged on the vehicle body side of the external gear 34 and an outer carrier 24-B arranged on the vehicle body side of the external gear 34. .. In this specification, the vehicle body side refers to the vehicle body 12 side in the axial direction X with reference to the referenced component (external gear 34 in this case), and the anti-vehicle body side refers to the vehicle body 12 in the axial direction. The opposite side of X. The inner carrier 24-A is fixed to the wheel cover 48, which will be described later, by the carrier bolt B2. The outer carrier 24-B is fixed to a part of the wheel cover 48 by fitting.

See FIG. A main bearing 50 that rotatably supports the rotating body 22 is provided between the casing 46 of the rotating body 22 and the inner carrier 24-A and between the casing 46 of the rotating body 22 and the outer carrier 24-B. .. The inner carrier 24-A and the outer carrier 24-B function as fixing members that rotatably support the rotating body 22 via the main bearing 50.

The main bearing 50 of this embodiment is a roller bearing. The main bearing 50 has a plurality of second rolling elements 50a, a second inner ring 50b, and a second outer ring 50c. The second rolling element 50a is provided at intervals around the rotation center line La of the tire 14. The second inner ring 50b of the present embodiment is made of a member different from the carrier 24, and is integrated with the outer peripheral surface of the carrier 24 by tightening and fitting. The outer peripheral surface of the second inner ring 50b constitutes a second inner rolling surface 50d on which the second rolling element 50a rolls in the circumferential direction. The second outer ring 50c of the present embodiment is composed of a member different from the casing 46 of the rotating body 22, and is integrated with the inner peripheral surface of the casing 46 by tightening and fitting. The inner peripheral surface of the second outer ring 50c constitutes a second outer rolling surface 50e on which the second rolling element 50a rolls in the circumferential direction. The space formed between the second inner ring 50b and the second outer ring 50c is open toward both sides in the axial direction X.

The inner carrier 24-A is formed with a first through hole 24a that penetrates the central portion in the radial direction. A first input shaft bearing 52-A is provided inside the first through hole 24a, and the inner carrier 24-A rotatably supports the input shaft 18 via the first input shaft bearing 52-A. The first through hole 24a is covered with a shaft cover 54 arranged on the vehicle body side of the first input shaft bearing 52-A, and the input shaft 18 penetrates the shaft cover 54 in the axial direction X. A second oil seal 56 is provided between the shaft cover 54 and the input shaft 18, and the first through hole 24a is sealed by the shaft cover 54 and the second oil seal 56.

A second through hole 24b is formed in the outer carrier 24-B so as to penetrate the central portion in the radial direction. A second input shaft bearing 52-B is provided inside the second through hole 24b, and the outer carrier 24-B rotatably supports the input shaft 18 via the second input shaft bearing 52-B. The second through hole 24b is sealed by the second input shaft bearing 52-B and the seal cap 58 arranged on the side opposite to the vehicle body from the input shaft 18.

The first oil seal 26 is arranged between the casing 46 of the rotating body 22 and the inner carrier 24-A, or between the casing 46 of the rotating body 22 and the outer carrier 24-B. The first oil seal 26 forms a sealed space 28 in which a lubricant (not shown in this figure) is sealed by sealing the space in which the speed reduction mechanism 20 is housed. A plurality of the first oil seals 26 of the present embodiment are arranged side by side in the axial direction X, but the number thereof is not particularly limited. The first oil seal 26 is formed of a ring-shaped elastic body. The cross-sectional shape of the tire 14 of the first oil seal 26 along the rotation center line La forms a groove shape that opens toward the enclosed space 28 side sealed by the first oil seal 26.

The operation of the wheel drive device 10 described above will be described.
When the rotation of the drive source is transmitted from the output shaft 30 to the input shaft 18, the input shaft 18 rotates. When the input shaft 18 rotates, the rotation of the input shaft 18 is decelerated by the speed reduction mechanism 20 and transmitted to the casing 46 of the rotating body 22. When the rotation is transmitted from the speed reduction mechanism 20 to the rotating body 22, the tire 14 integrated with the rotating body 22 rotates, so that the tire 14 travels on the traveling surface 16a.

Here, when the input shaft 18 rotates, the deceleration mechanism 20 rotates the eccentric body 32 together with the input shaft 18 around the rotation center line La. When the eccentric body 32 rotates around its rotation center line La, the external gear 34 swings so that the axis of the external gear 34 rotates around its rotation center line La. When the external gear 34 swings, the meshing positions of the external gear 34 and the internal gear 38 are sequentially displaced. As a result, each time the input shaft 18 makes one rotation, the internal gear 38 rotates relative to the external gear 34 by the amount corresponding to the difference in the number of teeth from the external gear 34, and the rotation component thereof. Is transmitted to the casing 46 of the rotating body 22. At this time, the rotation of the input shaft 18, that is, the rotation transmitted from the drive source, is decelerated at a reduction ratio corresponding to the difference in the number of teeth between the external gear 34 and the internal gear 38, and the rotating body is reduced from the internal gear 38. It is transmitted to 22.

FIG. 3 is a diagram for explaining the distribution of the lubricants 60-A and 60-B in the enclosed space 28. The sealing space 28 is a space defined by being surrounded by the rotating body 22 and the carrier 24, and is sealed by a shaft cover 54, a second oil seal 56, a seal cap 58, and the like in addition to the first oil seal 26. It is a closed space. The enclosed space 28 can also be regarded as a closed space defined by an object other than the lubricants 60-A and 60-B. The objects other than the lubricants 60-A and 60-B here are the input shaft 18, the reduction mechanism 20, the rotating body 22, the carrier 24, the first oil seal 26, the main bearing 50, the input shaft bearing 52, and the shaft cover. 54, a second oil seal 56, a seal cap 58, and the like.

The enclosed space 28 includes a storage space 28a in which the speed reduction mechanism 20 is housed, and a gap space 28b provided between the rotating body 22 and the carrier 24. The storage space 28a of the present embodiment is formed between the pair of carriers 24 on the inner peripheral side of the rotating body 22. The gap space 28b is provided so as to extend radially outward from the eccentric body 32 and the eccentric bearing 36 of the storage space 28a in the axial direction X from the storage space 28a, and a first oil seal is provided at the terminal position of the axial direction X. 26 is provided. The main bearing 50 is provided in the gap space 28b at a position closer to the storage space 28a than the first oil seal 26. The main bearing 50 is arranged between the rotating body 22 and the carrier 24 at a position closer to the enclosed space 28 than the first oil seal 26.

The lubricants 60-A and 60-B of this embodiment are greases. The lubricants 60-A and 60-B include a hard lubricant 60-A having a different mixing consistency and a soft lubricant 60-B. In this figure, the portion with double hatching indicates the hard lubricant 60-A, and the portion with the dot pattern indicates the soft lubricant 60-B. The "mixture consistency" here is a characteristic value indicating the hardness and fluidity of the grease. This mixing consistency is expressed in millimeters by allowing the tip of a specified cone to penetrate onto the grease by a specified method and multiplying the penetration depth by 10. The "miscibility" is a measured value immediately after the grease is mixed 60 times under the specified conditions. The American Lubricating Grease Association (NLGI) classifies greases using the mixing consistency number based on the numerical range of the mixing consistency, and the Japanese Industrial Standards (JIS) also follow this. In the present embodiment, the lubricant 60 is specified by using the mixing consistency measured according to the conditions specified in JIS K2220 and the mixing consistency number specified in JIS K2220.

As the hard lubricant 60-A, one having a low mixing consistency is used, and as the soft lubricant 60-B, one having a higher mixing consistency than the hard lubricant 60-A is used. That is, the hard lubricant 60-A has a higher viscosity and less fluidity than the soft lubricant 60-B, and is a hard lubricant, and the soft lubricant 60-B has a lower viscosity and flows than the hard lubricant 60-A. It is a highly viscous and soft lubricant. For the hard lubricant 60-A, a lubricant having an mixing consistency number in a small mixing consistency range is used. As the soft lubricant 60-B, a lubricant having an mixing consistency number in the mixing consistency range larger than the mixing consistency number corresponding to the mixing consistency number used in the hard lubricant 60-A is used. Specifically, in the present embodiment, the hard lubricant 60-A is a lubricant having a mixing consistency No. 2, and the mixing consistency range is 265 to 295 [1/10 mm]. In the present embodiment, the soft lubricant 60-B is a lubricant having a mixing consistency No. 00, and the mixing consistency range is 400 to 430 [1/10 mm].

In the wheel drive device 10 of the present embodiment, the encapsulation amount of the lubricants 60-A and 60-B and the volume of the encapsulation space 28 in which the lubricants 60-A and 60-B are enclosed (hereinafter referred to as the encapsulation space volume). There is one characteristic in the relationship with. The "encapsulation amount of the lubricants 60-A and 60-B" means the total encapsulation amount of the hard lubricant 60-A and the soft lubricant 60-B. This "enclosed space volume" does not include the portion occupied by the above-mentioned "objects other than the lubricants 60-A and 60-B" (input shaft 18, deceleration mechanism 20, etc.) forming the enclosed space 28.

The encapsulation amount of the lubricants 60-A and 60-B is set to 35% or less of the encapsulation space volume. More preferably, it is set to 30% or less of the enclosed space volume. This is set based on the experimental study results of the present inventor. In this experiment, the first oil seal 26 was used under the condition that the encapsulation amounts of the lubricants 60-A and 60-B with respect to the encapsulation space volume were variously changed by using the wheel drive device 10 incorporating various deceleration mechanisms. It was confirmed whether or not the lubricant leaked from the place where the wheel was placed. In this experiment, under the condition that the forward rotation of the input shaft 18 for 30 seconds at the rotation speed of 2680 [rpm] and the reverse rotation of the input shaft 18 for 30 seconds at the same rotation speed are repeated for two days, the lubricant was used. Checked for leaks. In addition to the eccentric swing type deceleration mechanism of the present embodiment, the various deceleration mechanisms include a parallel shaft gear deceleration mechanism, an orthogonal shaft gear deceleration mechanism, a planetary gear deceleration mechanism, and the like. As a result, when the encapsulation amount of the lubricant 60 was 40% of the encapsulation space volume, leakage of the lubricant was confirmed. On the other hand, when the encapsulation amount of the lubricant 60 was 35% or less of the encapsulation space volume, no leakage of the lubricant was observed. Based on the experimental results, the amount of the lubricant 60 to be sealed is set.

Here, in the above-mentioned experimental study, when only one type of lubricant is sealed in the sealing space 28, the present inventor determines the filling amount of the lubricants 60-A and 60-B in the sealed space volume. It was found that when the content is 35% or less, the required lubricity cannot be stably obtained at a plurality of required lubrication points in the enclosed space 28. It is considered that this is because when the encapsulation amount of the lubricant 60 is 35% or less of the encapsulation space volume by using only one kind of lubricant, it becomes difficult to spread the lubricant over the entire lubrication required portion. In addition, the lubrication-required portion here means a predetermined portion in the enclosed space 28 as a portion requiring lubrication in particular. In this embodiment, the eccentric bearing 36 and the main bearing 50 are defined as points requiring lubrication.

Therefore, in the present embodiment, as described above, the hard lubricant 60-A having low fluidity and the soft lubricant 60-B having high fluidity are used in combination. As a result, the soft lubricant 60-B is allowed to flow to spread the soft lubricant 60-B to some parts requiring lubrication, while the soft lubricant 60-B is difficult to spread to the other parts requiring hard lubrication. By applying the agent 60-A, lubricity can be ensured regardless of the flow state of the soft lubricant 60-B. As a result, the design is such that the encapsulation amount of the lubricants 60-A and 60-B is set to 35% or less of the encapsulation space volume while stably obtaining the required lubricity at a plurality of lubrication-requiring points in the encapsulation space 28. Is now acceptable. Further, as a result, it has become possible to design that the encapsulation amount of the lubricants 60-A and 60-B is set to 30% or less of the encapsulation space volume while stably obtaining the same required lubricity. ..

Here, since a large load acts on the eccentric body bearing 36 as the eccentric body 32 rotates, it is necessary to ensure lubricity. Further, since the eccentric bearing 36 has a higher peripheral speed than other parts in the enclosed space 28, the lubricant is shaken off by the centrifugal force or the like, so that the lubrication is likely to run out. Therefore, in the present embodiment, the eccentric bearing 36 is defined as one of the lubrication-requiring points in the enclosed space 28 that requires special lubrication. The eccentric body bearing 36 in the present embodiment corresponds to the above-mentioned location requiring lubrication in which the soft lubricant 60-B is difficult to spread even when the soft lubricant 60-B is flowed.

The hard lubricant 60-A is applied to the eccentric bearing 36 defined as the lubrication required portion. Specifically, the hard lubricant 60-A is applied to a portion of the eccentric bearing 36 where the first rolling element 36a rolls and contacts. More specifically, with respect to all of the plurality of first rolling elements 36a, the hard lubricant 60-A is applied to the outer peripheral surface of the first rolling elements 36a. Further, the hard lubricant 60-A is continuously applied to the first inner rolling surface 36e and the first outer rolling surface 36f on which the first rolling element 36a rolls over the entire circumference in the circumferential direction. .. As a result, the required lubricity can be stably obtained in the eccentric bearing 36, which is prone to run out of lubrication. In addition to this, with respect to each of the plurality of first rolling elements 36a and the retainer 36b, the hard lubricant 60-A is also applied to the contact points between the plurality of first rolling elements 36a and the retainer 36b.

Further, since a large load is likely to be applied to the main bearing 50 when the tire 14 is running, it is necessary to ensure lubricity. Therefore, in the present embodiment, the main bearing 50 is defined as one of the lubrication-required points in the enclosed space 28, and the hard lubricant 60-A is also applied to the main bearing 50. Specifically, the hard lubricant 60-A is applied to a portion of the main bearing 50 where the second rolling element 50a rolls into contact. More specifically, with respect to all of the plurality of second rolling elements 50a, the hard lubricant 60-A is applied to the outer peripheral surface of the second rolling elements 50a. Further, the hard lubricant 60-A is continuously applied to the second inner rolling surface 50d and the second outer rolling surface 50e on which the second rolling element 50a rolls over the entire circumference in the circumferential direction. .. When the hard lubricant 60-A is applied to the main bearing 50 in this way, the following effects can be obtained in addition to ensuring the lubricity of the main bearing 50, which is a required lubrication point.

When the rotating body 22 is in a stationary state, the soft lubricant 60-B is present in the lower portion of the gap space 28b of the enclosed space 28, as shown in FIG. 3, and the other portion of the gap space 28b. Will not exist in. When the rotating body 22 rotates under this state, the soft lubricant 60-B receives centrifugal force or the like so as to fill the other portion of the gap space 28b in which the soft lubricant 60-B does not exist. Try to flow to. At this time, a part of the soft lubricant 60-B tends to flow toward the first oil seal 26 side in the gap space 28b. Under this influence, the first oil seal 26 is given a dynamic pressure from the soft lubricant 60-B toward the side opposite to the encapsulation space 28 in the axial direction X, that is, toward the external space side.

Here, when the hard lubricant 60-A is applied to the main bearing 50, the passage area where the soft lubricant 60-B can flow inside the main bearing 50 by the volume of the hard lubricant 60-A. Will decrease. As a result, as compared with the case where the hard lubricant 60-A is not applied, the soft lubricant 60-B is less likely to flow toward the inside of the main bearing 50 toward the first oil seal 26, and the main bearing 50 is more difficult to flow. It is possible to delay the filling of the space 28c on the side of the first oil seal 26 with the soft lubricant 60-B. As a result, at the initial stage when the rotating body 22 starts to rotate, the dynamic pressure applied to the first oil seal 26 from the soft lubricant 60-B can be reduced, and the lubricant from the location where the first oil seal 26 is arranged can be reduced. Leakage can be suppressed.

The lower limit of the encapsulation amount of the lubricants 60-A and 60-B is not particularly limited in relation to the leakage countermeasures of the lubricants 60-A and 60-B, but is 25% or more of the encapsulation space volume. It may be set. If this condition is satisfied, the lubricants 60-A and 60-B can be easily distributed to all the parts requiring lubrication in the enclosed space 28, and the required lubrication is required in all the parts requiring lubrication. It becomes easier to secure the sex. In the present embodiment, the locations where lubrication is required include the eccentric bearing 36, the main bearing 50, the gear meshing portion of the reduction mechanism 20, the input shaft bearing 52, and the like.

According to the wheel drive device 10 of the present embodiment, since the encapsulation amount of the lubricants 60-A and 60-B is set to 35% or less of the encapsulation space volume, lubrication from the arrangement location of the first oil seal 26 Effective measures against leakage of agents.

Next, the description of the external structure of the enclosed space 28 of the wheel drive device 10 will be given.
Consider an example of the path that the lubricant 60 follows when the lubricant 60 leaks to the outside from the location where the first oil seal 26 is arranged. FIG. 4 is a diagram for explaining a path followed by the lubricant 60 from the location where the first oil seal 26 is arranged. The lubricant 60 leaking to the outside propagates along the inner peripheral portion of the rotating body 22 toward the outside in the axial direction, and also propagates to the side surface portion 22a of the rotating body 22 (see arrow Pa1). When the rotating body 22 is stationary, the lubricant 60 transmitted to the side surface portion 22a of the rotating body 22 is transmitted to the outer peripheral end portion thereof due to its own weight, and from there to the traveling surface 16a of the rotating body 22. It tries to travel toward the contact surface 22b (see arrow Pa2). If the lubricant 60 is transmitted to the contact surface 22b of the rotating body 22, there is a concern that it may have an adverse effect, and countermeasures are required.

FIG. 5 is an enlarged view of a part of FIG. Therefore, as shown in FIGS. 1 and 5, the wheel drive device 10 of the present embodiment includes a swing plate 62 that is fixed to the rotating body 22 and can rotate integrally with the rotating body 22. The swing plate 62 of the present embodiment is individually fixed to the side surface portions 22a of the rotating body 22 on both sides in the axial direction X. The shake-off plate 62 is for shaking off the lubricant 60 leaking from the arrangement portion of the first oil seal 26.

The swing-off plate 62 is a ring-shaped plate body extending outward in the radial direction as a whole. The swing plate 62 of the present embodiment has a flat ring-shaped ring portion 62a and a bent portion 62b bent from the outer peripheral end portion of the ring portion 62a toward the counter-rotating body side in the axial direction X. The anti-rotating body side in the present specification means the side opposite to the side where the rotating body 22 in the axial direction X is located, with reference to the referred component (ring portion 62a in this case).

The ring portion 62a is superposed on the side surface portion 22a of the rotating body 22, and is detachably fixed to the side surface portion 22a of the rotating body 22 by the bolt B1 penetrating the ring portion 62a. In the present embodiment, the inner peripheral surface of the ring portion 62a is provided at a position aligned with the inner peripheral surface 22c of a part of the rotating body 22 adjacent to the swing plate 62 in the axial direction X. The bent portion 62b has a tapered shape so that the diameter increases toward the counter-rotating body side. The bent portion 62b of the present embodiment has a cone shape that is continuous over the entire circumference around the rotation center line La of the tire 14.

In the present embodiment, the outer peripheral end portion 62c of the swing-off plate 62 is provided at a position offset radially inward from the boundary surface 64 between the tire 14 and the wheel 44. It is also considered that the outer peripheral end portion 62c of the swing plate 62 is provided at a position offset radially inward from the contact surface 22b of the rotating body 22. The outer peripheral end portion 62c of the swing-off plate 62 in the present embodiment is the outer peripheral end portion of the bent portion 62b.

The lubricant 60 leaking to the outside from the location where the first oil seal 26 is arranged is transmitted to the outer surface of the swing plate 62 on the way along the outer surface of the rotating body 22. When the rotating body 22 rotates, the lubricant 60 transmitted to the outer surface of the swing-off plate 62 rotates the swing-off plate 62 integrally with the rotating body 22, so that the lubricant 60 is radially outward from the outer peripheral end portion 62c of the swing-off plate 62. It is shaken off in the direction Pb. As a result, the lubricant 60 is separated from the rotating body 22 before being transmitted to the contact surface 22b of the rotating body 22. Therefore, according to the present embodiment, even if the lubricant 60 leaks out, it is possible to prevent the occurrence of an adverse effect due to the lubricant 60 being transmitted to the contact surface 22b of the rotating body 22, and it is effective to take measures against the leakage of the lubricant 60. It can be planned.

Further, the swing plate 62 has a bent portion 62b bent from the ring portion 62a to the counter-rotating body side. Consider the case where the swing plate 62 does not have the bent portion 62b. In order to separate the lubricant 60 from the rotating body 22, it is necessary to arrange the outer peripheral end portion 62c of the swing plate 62 at a position away from the side surface portion 22a of the rotating body 22. When the swing plate 62 does not have the bent portion 62b, in order to satisfy this condition, in the example of this figure, the swing plate 62 is offset at least radially outward from the boundary surface 64 between the tire 14 and the wheel 44. It is necessary to arrange the outer peripheral end portion 62c (the outer peripheral end portion of the ring portion 62a) of the plate 62. Therefore, the outer diameter dimension of the swing plate 62 is further increased.

In this respect, when the swing plate 62 has the bent portion 62b, the outer peripheral end portion 62c of the swing plate 62 is located at a position away from the side surface portion 22a of the rotating body 22 regardless of the shape of the side surface portion 22a of the rotating body 22. Can be placed. Therefore, in separating the lubricant 60 from the rotating body 22, the outer diameter dimension of the swing plate 62 can be reduced, and the swing plate 62 can be miniaturized. Further, by reducing the outer diameter dimension of the shake-off plate 62, the peripheral speed at the outer peripheral end portion 62c of the shake-off plate 62, which is the shake-off point of the lubricant 60, can be reduced. As a result, the speed of the lubricant 60 shaken off from the shake-off plate 62 can be suppressed, and the scattering of the lubricant 60 around the portion receiving the lubricant 60 can be suppressed.

Next, other features of the wheel drive device 10 will be described.
As shown in FIG. 1, the wheel drive device 10 includes a wheel cover 48 that covers the rotating body 22. FIG. 6 is a partial cross-sectional view of a part of the wheel drive device 10 of FIG. 1 as viewed from the anti-vehicle body side. As shown in FIGS. 1 and 6, the wheel cover 48 includes an outer peripheral cover portion 48a that covers the rotating body 22 from the outer peripheral side, side cover portions 48b and 48c that cover the rotating body 22 from the axial direction X, and the rotating body 22. It has an opening 48d that protrudes downward.

The cross-sectional shape of the outer peripheral cover portion 48a orthogonal to the axial direction X is an arc shape that opens downward. The peripheral end portions 48e of the outer peripheral cover portion 48a are provided with inner flange portions 48f that project from one circumferential end portion 48e toward the other circumferential end portion 48e.

The side cover portions 48b and 48c include an inner side cover portion 48b arranged on the vehicle body 12 side in the axial direction X from the rotating body 22, and an outer side cover portion arranged on the opposite side of the vehicle body in the axial direction X from the rotating body 22. 48c and are included. The inner carrier 24-A is fixed to the inner side cover portion 48b by the carrier bolt B2, and a part of the outer carrier 24-B is fixed to the outer side cover portion 48c by fitting. In this way, the wheel cover 48 functions as a member integrated with the carrier 24 (fixing member).

A tubular portion 48g extending in the axial direction X is provided inside the inner side cover portion 48b in the radial direction. The input shaft 18 is inserted inside the tubular portion 48 g. The vehicle body side end of the tubular portion 48 g is abutted against the vehicle body 12 and connected by bolts. As a result, the wheel cover 48 is assembled to the vehicle body 12.

As shown in FIGS. 5 and 6, the opening 48d is formed at the lower end of the wheel cover 48 and opens downward. The opening 48d is formed by both end portions 48e of the outer peripheral cover portion 48a in the circumferential direction and lower edge portions 48h of each side cover portion 48b. A first gap 66 is formed between the lower edge portion 48h forming the opening 48d of the side cover portion 48b and the rotating body 22. A second gap 68 is formed between the circumferential end 48e forming the opening 48d of the outer peripheral cover 48a and the rotating body 22. The first gap 66 is formed on both sides of the rotating body 22 in the axial direction, and the second gap 68 is formed on both sides of the rotating body 22 in the traveling direction.

Consider the path followed by the lubricant 60 leaking to the outside from the location where the first oil seal 26 is arranged. The path followed by the lubricant 60 leaking to the outside is a first path passing through a first gap 66 between the wheel cover 48 and the rotating body 22, and between the wheel cover 48 and the rotating body 22. There is a second path that passes through the second gap 68. In the first path, in addition to the lubricant 60 that propagates through the side surface portion 22a of the rotating body 22, the lubricant 60 that travels down the inner surface of the side cover portion 48b of the wheel cover 48 tries to pass through. In the second path, the lubricant 60 that runs down the inner peripheral surface of the outer peripheral cover portion 48a of the wheel cover 48 tries to pass through. The lubricant 60 adhering to the inner surface of the side cover portion 48b of the wheel cover 48 and the inner peripheral surface of the outer peripheral cover portion 48a is shaken off by the swing-off plate 62 and leaks from the location where the first oil seal 26 is arranged. It becomes a part of the lubricant 60. That is, the lubricant 60 passing through either the first path or the second path leaks from the location where the first oil seal 26 is arranged.

The wheel drive device 10 includes oil pans 70 and 72 for receiving the lubricant 60 leaked from the location where the first oil seal 26 is arranged. The oil pans 70 and 72 include a first oil pan 70 that receives the lubricant 60 that passes through the first gap 66 described above, and a second oil pan 72 that receives the lubricant 60 that passes through the second gap 68 described above. .. Further, the wheel drive device 10 includes a pan support member 74 that supports the first oil pan 70.

As shown in FIG. 5, the first oil pan 70 of the present embodiment is arranged on one side of the rotating body 22 in the axial direction below the first gap 66 described above. The first oil pan 70 of the present embodiment is arranged at a position offset radially inward from the boundary surface 64 of the tire 14 and the wheel 44. The first oil pan 70 of the present embodiment is individually provided corresponding to each of the first gaps 66 on both sides of the rotating body 22 in the axial direction (see FIG. 1).

FIG. 7 is an external view of a part of the wheel drive device 10 of FIG. 1 as viewed from the anti-vehicle body side. The first oil pan 70 is a long member long in the traveling direction Y of the tire 14. In other words, the first oil pan 70 extends in the traveling direction Y of the tire 14. As shown in FIGS. 5, 7, and 8, the first oil pan 70 has a first pan portion 70a that receives the lubricant 60. The first pan portion 70a has a box shape that opens upward, and can store the lubricant received inside the first pan portion 70a. The first pan portion 70a is arranged vertically below the outer peripheral end portion 62c of the swing plate 62. As a result, the lubricant 60 that has been shaken off in the radial direction Pb from the outer peripheral end portion 62c of the shake-off plate 62 is received by the first pan portion 70a. Further, both end portions 70b of the first pan portion 70a in the longitudinal direction are arranged below the outer peripheral surface of the outer peripheral cover portion 48a of the wheel cover 48.

FIG. 8 is a plan view showing the first oil pan 70 and the second oil pan 72. As shown in FIGS. 6 and 8, the second oil pan 72 of the present embodiment is arranged below the second gap 68 on one side of the rotating body 22 in the traveling direction Y. The second oil pan 72 of the present embodiment is individually provided corresponding to each of the second gaps 68 on both sides of the rotating body 22 in the traveling direction Y.

The second oil pan 72 extends in the axial direction X of the tire 14. The second oil pan 72 has a second pan portion 72a that receives the lubricant 60 and a second fixing portion 72b that is fixed to the wheel cover 48. The second pan portion 72a has a long elongated shape along the axial direction X, and has a groove shape that opens upward. Both end portions 72c in the longitudinal direction of the second pan portion 72a of the present embodiment have a shape that is open toward both outer sides in the longitudinal direction thereof.

FIG. 9 is a cross-sectional view taken along the line AA of FIG. The second pan portion 72a of the present embodiment is arranged above the first pan portion 70a of the first oil pan 70. As a result, the lubricant 60 in the second pan portion 72a is transmitted from the end portion 72c in the longitudinal direction into the first pan portion 70a in the direction Pc. In this way, the second oil pan 72 is provided so that the lubricant in the second oil pan 72 can be guided into the first oil pan 70.

As shown in FIG. 6, the second fixing portion 72b has a plate shape that is overlapped with the inner flange portion 48f of the wheel cover 48 from the lower side, and is detachably fixed by the bolt B3. The second oil pan 72 is fixed to the circumferential end 48e of the outer peripheral cover 48a of the wheel cover 48.

10 (a) to 10 (c) are views of the pan support member 74 viewed from the anti-rotating body side, a view seen from the rotating body side, and a view seen from one side in the traveling direction Y. The pan support member 74 is a long member that is long along the traveling direction Y of the tire 14. As shown in FIGS. 5 and 10, the pan support member 74 has a pan storage portion 74a in which the first oil pan 70 is housed. The pan storage portion 74a has a groove shape that extends along the longitudinal direction of the pan support member 74 and opens upward. The bread storage portion 74a is arranged below the first gap 66 described above. Further, the pan storage portion 74a is arranged at a position offset radially inward from the boundary surface 64 between the tire 14 and the wheel 44.

The pan storage portion 74a includes a bottom wall portion 74b that supports the first oil pan 70, an inner side wall portion 74c that rises from the rotating body side of the bottom wall portion 74b, and an outer wall portion 74d that rises from the anti-rotating body side of the bottom wall portion 74b. Has. The outer side wall portion 74d extends upward from the inner side wall portion 74c, and is arranged on the counter-rotating body side of the side cover portion 48b of the wheel cover 48. The outer side wall portion 74d is overlapped with the side cover portion 48b of the wheel cover 48 in the axial direction X, and is detachably fixed to the wheel cover 48 by the bolt B4. The pan support member 74 will be integrated with the carrier 24 together with the wheel cover 48. The first oil pan 70 is supported by a pan support member 74 integrated with the carrier 24.

The first oil pan 70 and the pan support member 74 of the present embodiment are made of a soft magnetic material such as a steel material. As shown in FIGS. 5 and 7, a magnet 76 is attached to the lower surface of the first pan portion 70a of the first oil pan 70 by adhesion or the like. The magnet 76 of the present embodiment is a plate-shaped elongated body that is long along the longitudinal direction of the first pan portion 70a. The magnet 76 of the present embodiment is attached to the first pan portion 70a in the range from one end to the other end in the longitudinal direction of the first pan 70a. The magnet 76 attracts the pan support member 74 by magnetic force. As a result, the first oil pan 70 is held by the magnetic force of the magnet 76 with respect to the pan support member 74.

The bread storage portion 74a has inclined portions 74e rising from both ends in the longitudinal direction of the bottom wall portion 74b. The inclined portion 74e has a plate shape having a smaller dimension in the width direction orthogonal to the longitudinal direction than the bottom wall portion 74b.

FIG. 11 is a diagram showing a part of the first oil pan 70 and the pan support member 74. The inclined portion 74e of the pan support member 74 is inclined upward toward the outside in the longitudinal direction of the pan support member 74. Here, the outside in the longitudinal direction means the outside in the longitudinal direction of the pan support member 74 from the space in the pan storage portion 74a.

Consider a case where one end of the first oil pan 70 is pulled in the pulling direction Pd toward one side in the longitudinal direction of the pan support member 74. As shown in FIG. 11A, when one end of the first oil pan 70 is pulled until it comes into contact with the inclined portion 74e of the pan support member 74, and then the first oil pan 70 is strongly pulled in the same direction, the first oil pan 70 is pulled. The oil pan 70 is guided by the inclined portion 74e to move upward. At this time, since the first oil pan 70 is separated from the bottom wall portion 74b of the pan support member 74, the holding force by the magnet 76 is weakened, and the first oil pan 70 can be easily pulled out. By continuing to pull the first oil pan 70 in the pulling direction Pd as it is, the first oil pan 70 is pulled out from the pan support member 74. When the first oil pan 70 is pulled out, the first oil pan 70 is pulled out from the pan support member 74 with a slide of the pan support member 74 with respect to the pan storage portion 74a.

As described above, the first oil pan 70 can be pulled out in the pulling direction Pd toward one side in the longitudinal direction of the pan support member 74. The first oil pan 70 of the present embodiment is not fixed to the pan support member 74 by bolts, pins, or the like, and can be pulled out from the pan support member 74 only by pulling out. Here, "pullable" includes the case where the first oil pan 70 is fixed to the pan support member 74 with bolts, pins, etc., and the bolts, pins, etc. are removed and then pulled out. Of course, it is preferable that the first oil pan 70 can be pulled out from the pan support member 74 only by the pulling operation as in the present embodiment.

The first oil pan 70 pulled out from the pan support member 74 can be pushed into the pan support member 74 by moving it in the direction opposite to the pulling direction Pd. As described above, it can be said that the first oil pan 70 can be inserted and removed from the pan storage portion 74a of the pan support member 74 in the longitudinal direction of the pan support member 74.

As shown in FIGS. 8 and 11, the first oil pan 70 is provided at a position different from the inner wall surface of the first pan portion 70a, and when the first oil pan 70 is pulled out from the pan support member 74, an object is pulled out. It has a hooking portion 70c that can be hooked. The object here is a worker's finger, a tool, or the like. The hanging portion 70c is provided at the end portion of the first oil pan 70 on the Pd side in the pulling direction. Specifically, the first pan portion 70a has a standing wall portion 70d that forms a lubricant storage chamber and rises from the bottom wall portion at an end portion on the Pd side in the pulling direction. The hanging portion 70c has a plate shape extending from the upper end portion of the standing wall portion 70d of the first pan portion 70a in the pulling direction Pd. A hanging hole 70e for inserting an object is formed in the hanging portion 70c, and the object is hooked by inserting the object through the hanging hole 70e.

The effects of the wheel drive device 10 described above will be described.
The wheel drive device 10 includes oil pans 70 and 72 that receive the lubricant 60 leaked from the first oil seal 26. Therefore, the oil pans 70 and 72 can prevent the lubricant leaking from the first oil seal 26 from falling onto the floor surface, and the leakage countermeasure of the lubricant 60 can be effectively taken.

When attaching / detaching the first oil pan 70, it is often difficult to secure a work space on both sides of the wheel drive device 10 in the axial direction X. For example, there is often a vehicle body 12 on the vehicle body side of the wheel drive device 10 and a structure on the opposite vehicle body side. In this example, the structure here is a storage shelf to which luggage is delivered to and from the transport trolley. On the other hand, if the space is on any side of the traveling direction Y with respect to the wheel drive device 10, it is easy to secure a work space used for attaching / detaching the first oil pan 70. In the present embodiment, the first oil pan 70 can be pulled out in the longitudinal direction of the pan support member 74, which is the traveling direction Y of the tire 14. Therefore, it becomes easy to pull out the first oil pan 70 while avoiding interference with the structures around the wheel drive device 10. Further, there is an advantage that the first oil pan 70 can be attached and detached without disassembling the wheel drive device 10.

The first oil pan 70 is held by the pan support member 74 by the magnetic force of the magnet 76. Therefore, the first oil pan 70 can be easily attached and detached from the pan support member 74, and the first oil pan 70 can be prevented from coming off from the pan support member 74 due to vibration of the wheel drive device 10 during traveling.

The inclined portion 74e of the pan support member 74 is inclined upward toward the outside in the longitudinal direction of the pan support member 74. Therefore, by strongly pulling the first oil pan 70, the first oil pan can be pulled out from the pan support member 74 while being guided by the inclined portion 74e of the pan support member 74.

The first oil pan 70 has a hooking portion 70c on which an object is hooked when the first oil pan 70 is pulled out from the pan support member 74. Therefore, by hooking an object such as a finger on the hooking portion 70c of the first oil pan 70, it becomes easier to apply a pulling force to the first oil pan 70, and workability when pulling out the first oil pan 70 is improved. ..

The oil pans 70 and 72 include a first oil pan 70 and a second oil pan 72. Therefore, the lubricant passing through either the first gap 66 or the second gap 68 can be received by the oil pans 70 and 72, and the oil pans 70 and 72 can be used to prevent leakage of the lubricant 60 in a wide range.

Further, the second oil pan 72 is provided so as to be able to induce the lubricant 60 in the first oil pan 70. Therefore, the lubricant 60 received in the second oil pan 72 is also collected in the first oil pan 70. Therefore, at the time of the recovery work of the lubricant 60, it is only necessary to recover the lubricant of the first oil pan 70, and the work man-hours required for the recovery work can be reduced.

The first oil pan 70 is arranged vertically below the outer peripheral end portion 62c of the swing-off plate 62. Therefore, the lubricant shaken off by the shake-off plate 62 is received by the first oil pan 70 and collected in the first oil pan 70.

A part (both ends) of the first oil pan 70 is arranged below the outer peripheral surface of the outer peripheral cover portion 48a of the wheel cover 48. Therefore, as compared with the case where the first oil pan 70 is arranged only inside the wheel cover 48 or below the opening 48d, it becomes easier to visually recognize the stored state of the lubricant in the first oil pan 70 from the outside. As a result, it is possible to easily determine whether or not the lubricant in the first oil pan 70 needs to be recovered without removing the first oil pan 70 from the wheel drive device 10.

As shown in FIG. 10, a bread recess 74f that is recessed downward is formed in the upper portion of the inner side wall portion 74c of the bread support member 74. The second pan portion 72a of the second oil pan 72 is arranged inside the pan recess 74f of the first pan portion 70a to avoid interference with the second oil pan 72. Further, a downwardly recessed recess 74g for the swing plate is formed on the upper portion of the inner side wall portion 74c of the first pan portion 70a. A part of the bent portion 62b of the swing plate 62 is arranged inside the recess 74g for the swing plate of the first pan portion 70a, and interference with the bent portion 62b of the swing plate 62 is avoided.

(Second Embodiment)
FIG. 12 is a front sectional view of a part of the wheel drive device 10 of the second embodiment. The wheel drive device 10 of the second embodiment does not include the oil pans 70 and 72 of the first embodiment. Further, the wheel drive device 10 of the second embodiment is different from the first embodiment mainly in that the swing-off plate 62 and the lubricant absorbent 78 described later are provided.

The swing plate 62 of the second embodiment does not have the bent portion 62b of the first embodiment, and the outer peripheral end portion of the ring portion 62a becomes the outer peripheral end portion 62c of the swing plate 62. The outer peripheral end portion 62c of the swing plate 62 is provided at a position offset radially outward from the boundary surface 64 between the tire 14 and the wheel 44. The outer peripheral end portion 62c of the swing-off plate 62 of the present embodiment is provided at a position offset radially inward from the contact surface 22b in contact with the traveling surface 16a of the tire 14. As a result, the lubricant 60 is shaken off in the direction Pb from the outer peripheral end portion 62c of the swing-off plate 62 at a position away from the side surface portion 22a of the tire 14 of the rotating body 22. That is, also in the present embodiment, the lubricant 60 can be separated from the rotating body 22 before being transmitted to the contact surface 22b of the rotating body 22. Therefore, also in this embodiment, even if the lubricant 60 leaks out, it is possible to prevent the occurrence of an adverse effect due to the lubricant 60 being transmitted to the contact surface 22b of the rotating body 22, and it is possible to effectively take measures against the leakage of the lubricant 60. It can be planned.

FIG. 13 is a side sectional view showing a circumferential end portion 48e of the wheel cover 48. See FIGS. 12 and 13. The lubricant absorbent 78 is for absorbing the lubricant 60 leaked from the location where the first oil seal 26 is arranged. The lubricant absorbent 78 includes a first lubricant absorbent 78-A attached to the rotating body 22 and a second lubricant absorber 78-B attached to the wheel cover 48. The lubricant absorbent 78 is made of a material having a property of absorbing a liquid. This material is, for example, a woven fabric, a non-woven fabric, or the like.

The first lubricant absorbent 78 is provided in a path through which the lubricant leaking from the arrangement of the first oil seal 26 propagates on the outer surface of the rotating body 22. As this path, there is a seam 80 between the first oil seal 26 and the rotating body 22, and the first lubricant absorbent 78 of the present embodiment is provided so as to close the seam 80. Although not shown, the first lubricant absorbent 78 is individually provided on both sides of the rotating body 22 in the axial direction X.

The position of the first lubricant absorbent 78 with respect to the rotating body 22 is held by the swing-off plate 62. Specifically, the swing plate 62 has, in addition to the ring portion 62a, a pressing portion 62d bent from the inner peripheral end portion of the ring portion 62a toward the rotating body side. The pressing portion 62d sandwiches the first lubricant absorbent 78 with the inner peripheral portion of the rotating body 22, and holds the position of the first lubricant absorbing material 78 with respect to the rotating body 22. In this way, the swing plate 62 is detachably fixed to the rotating body 22 and functions as a holding member for holding the position of the first lubricant absorbent 78. Since the swing-off plate 62 also functions as the holding member, the first lubricant absorbent 78-A can also be attached / detached from the rotating body 22 when the swing-off plate 62 is attached / detached from the rotating body 22. The holding member may be provided separately from the swing plate 62.

The second lubricant absorbent 78-B is provided on the path through which the lubricant 60 adhering to the inner peripheral surface of the outer peripheral cover portion 48a of the wheel cover 48 is transmitted. As this path, there is an upper surface of the inner flange portion 48f of the wheel cover 48, and the second lubricant absorbent 78-B of the present embodiment is provided on the upper surface of the inner flange portion 48f. The second lubricant absorbent 78-B is arranged on the inner flange portion 48f of the wheel cover 48 and is sandwiched between the second lubricant absorbent material 78-B and the head portion of the bolt B5 to maintain the position with respect to the wheel cover 48. The lubricant 60 adhering to the inner peripheral surface of the wheel cover 48 is shaken off by the shake-off plate 62, and becomes a part of the lubricant 60 leaking from the arrangement portion of the first oil seal 26. That is, both the first lubricant absorber 78 and the second lubricant absorber 78-B absorb the lubricant 60 leaked from the arrangement location of the first oil seal 26.

According to the wheel drive device 10 described above, even if the lubricant 60 leaks from the location where the first oil seal 26 is arranged, the lubricant 60 is absorbed by the lubricant absorbent 78 to surround the lubricant 60. Can be prevented from spreading to.

The examples of the embodiments of the present invention have been described in detail above. All of the above-described embodiments are merely specific examples for carrying out the present invention. The content of the embodiment does not limit the technical scope of the present invention, and many design changes such as changes, additions, and deletions of components are made without departing from the idea of the invention defined in the claims. It is possible. In the above-described embodiment, the contents that can be changed in such a design are described with the notations such as "in the embodiment" and "in the embodiment", but the contents are designed without such notations. It's not that changes aren't tolerated. Further, the hatching attached to the cross section of the drawing does not limit the material of the object to which the hatching is attached.

Although the example in which the wheel drive device 10 is incorporated in the transport carriage has been described, the incorporation partner thereof is not particularly limited. Further, although this transport trolley has been described by taking a tracked trolley as an example, a trackless trolley may be used.

The speed reduction mechanism 20 has been described by taking an eccentric swing type speed reduction mechanism as an example, but the type thereof is not particularly limited. For example, any of a planetary gear mechanism, a parallel shaft gear mechanism, an orthogonal shaft gear reduction mechanism, a flexure meshing type reduction mechanism, and the like may be included.

Although the example in which the eccentric body 32 is separate from the input shaft 18 has been described, the eccentric body 32 may be provided as a part of the same single member as the input shaft 18. Although the example in which the first inner ring 36c of the eccentric body bearing 36 is formed of a member different from the eccentric body 32 has been described, the first inner ring 36c may be made of a part of the same member as the eccentric body 32. Although the example in which the first outer ring 36d of the eccentric bearing 36 is composed of a part of the same member as the external gear 34 has been described, it may be composed of a member different from the external gear 34.

An example has been described in which a lubricant having a consistency number 2 is used for the hard lubricant 60-A and a lubricant having a consistency number 00 is used for the soft lubricant 60-B, but the present invention is not limited to this. .. For example, the hard lubricant 60-A and the soft lubricant 60-B use the same consistency number lubricant, and the soft lubricant 60-B uses a lubricant having a consistency greater than that of the hard lubricant 60-A. You may use it. In addition to this, the consistency numbers of the lubricants used by the hard lubricant 60-A and the soft lubricant 60-B are not particularly limited. Even in this case, as the soft lubricant 60-B, a lubricant having a consistency number in the mixing consistency range larger than the mixing consistency range corresponding to the consistency number used in the hard lubricant 60-A is used. You may be.

Further, although the example in which the lubricant 60 includes two types of lubricants having different mixing consistency has been described, three or more types of lubricants may be contained. That is, the lubricant 60 may contain at least two types of lubricants having different mixing consistency. Further, although the example of grease has been described for the lubricant 60, the type thereof is not limited to this, and for example, the soft lubricant 60-B may be used as a lubricating oil.

When the encapsulation amount of the lubricant 60 is set to 35% or less of the encapsulation space volume, an example of applying the hard lubricant 60-A to both the eccentric bearing 36 and the main bearing 50 has been described, but only one of them has been described. It may be applied, or it may be applied to other places requiring lubrication.

Further, when combined with any one or both of the swing plate 62 and the oil pans 70 and 72, the amount of the lubricant 60 enclosed may be set to more than 35% of the enclosed space volume. Further, although the oil pans 70 and 72 have been described as an example in combination with the shake-off plate 62, they may be used without being combined with the shake-off plate 62.

Although the example in which the swing plate 62 is fixed to the side surface portion 22a of the rotating body 22 has been described, the lubricant 60 leaking from the arrangement location of the first oil seal 26 is fixed on the path along the outer surface of the rotating body 22. If so, the position is not particularly limited. For example, the swing plate 62 may be fixed to the outer peripheral portion of the rotating body 22 in addition to the side surface portion 22a of the rotating body 22.

An example has been described in which the first oil pan 70 can be pulled out from the pan support member 74 only by pulling out the oil pan 70. The example in which the pull-out direction Pd of the pan support member 74 is the longitudinal direction of the pan support member 74 has been described, but the present invention is not limited to this, and may be, for example, a vertical direction intersecting the longitudinal direction of the pan support member 74. Further, the first oil pan 70 may be fixed to a pan support member 74, a fixing member such as a carrier 24, or the like by using bolts or the like.

Although the pan support member 74 has been described by taking an example of a configuration having an inclined portion 74e, a configuration having no inclined portion 74e may be used. When the first oil pan 70 is not fixed to the pan support member 74, the inclined portion 74e of the pan support member 74 hits the first oil pan 70 in addition to the function of guiding the first oil pan 70. The contact exerts a function of regulating the relative displacement of the first oil pan 70 in the longitudinal direction.

Although the example in which the magnet 76 is attached to the lower surface of the first oil pan 70 has been described, the attachment position thereof is not particularly limited. For example, it may be attached to another part of the first oil pan 70, or may be attached to the pan support member 74.

The specific shape of the hooking portion 70c of the first oil pan 70 is not particularly limited as long as it has a shape in which an object can be hooked. For example, a convex portion serving as a handle protruding from the first pan portion 70a, a recess provided on the outer wall surface of the first pan portion 70a, or the like on which an object can be hooked may be used.

Although the example in which the pan support member 74 is fixed to the wheel cover 48 has been described, it may be fixed to the carrier 24. Further, the pan support member 74 may be fixed to the integrated member if there is another member integrated with the carrier 24.

In the second oil pan 72, in order to guide the lubricant in the second oil pan 72 into the first oil pan 70, the longitudinal end 72c of the second pan 72a is directed outward in the longitudinal direction. An example of forming an open shape has been described, but the specific structure thereof is not particularly limited. For example, a through hole may be provided in the bottom wall portion of the end portion 72c of the second pan portion 72a so that the through hole can be guided into the first oil pan 70.

Further, the example in which the second oil pan 72 is provided so that the lubricant received by the second oil pan 72 can be guided to the first oil pan 70 has been described. In addition to this, the first oil pan 70 may be provided so that the lubricant received by the first oil pan 70 can be guided by the second oil pan 72. In this case, in order to facilitate recovery of the lubricant 60 collected in the second oil pan 72, the second oil pan 72 is supported by the pan support member 74, and the second oil pan 72 is pulled out with respect to the pan support member 74. It may be possible.

The shape of the first oil pan 70 and the second oil pan 72 is not particularly limited as long as they can receive the lubricant 60. Further, although the case where both the first oil pan 70 and the second oil pan 72 are used in combination has been described as an example, only one of them may be used.

10 ... Wheel drive device, 14 ... Tire, 20 ... Reduction mechanism, 22 ... Rotating body, 28 ... Encapsulation space, 32-A, 32-B ... Eccentric body, 34 ... External gear, 36 ... Eccentric body bearing, 44 ... Wheel, 46 ... Casing, 48 ... Wheel cover, 48a ... Outer cover, 48b ... Side cover, 48d ... Opening, 50 ... Main bearing, 60-A ... Hard lubricant, 60-B ... Soft lubricant, 62 ... Shake plate, 62a ... Ring part, 62b ... Bending part, 64 ... Boundary surface, 66 ... First gap, 68 ... Second gap, 70 ... First oil pan, 70c ... Hanging part, 72 ... Second oil pan, 74 ... Pan support member, 74e ... Inclined portion, 76 ... Magnet, 78 ... Lubricant absorber.

Claims (9)

A deceleration mechanism that slows down the rotation transmitted from the drive source,
The rotating body whose tires are integrated by transmitting the rotation decelerated by the deceleration mechanism and
A fixing member that rotatably supports the rotating body and
An oil seal arranged between the rotating body and the fixing member and sealing a space in which the deceleration mechanism is housed,
A wheel drive device including a lubricant sealed in a sealing space sealed by the oil seal.
The lubricant contains at least two types of lubricants having different mixing consistency.
The amount of the lubricant enclosed is 35% or less of the volume of the enclosed space.
The deceleration mechanism
Eccentric body and
An external gear that is swung by the eccentric body,
It has an eccentric bearing arranged between the eccentric body and the external gear.
The lubricant is
The hard lubricant applied to the eccentric bearing and
A wheel drive device containing a soft lubricant having a higher mixing consistency than the hard lubricant. A main bearing is provided between the rotating body and the fixing member at a position closer to the enclosed space than the oil seal.
The lubricant is
The hard lubricant applied to the main bearing and
The wheel drive device according to claim 1, further comprising a soft lubricant having a higher mixing consistency than the hard lubricant. A deceleration mechanism that slows down the rotation transmitted from the drive source,
The rotating body whose tires are integrated by transmitting the rotation decelerated by the deceleration mechanism and
A fixing member that rotatably supports the rotating body and
An oil seal arranged between the rotating body and the fixing member and sealing a space in which the deceleration mechanism is housed,
A wheel drive device including a lubricant sealed in a sealing space sealed by the oil seal.
A shake-off plate that rotates integrally with the rotating body and shakes off the lubricant leaked from the location where the oil seal is arranged is provided.
The rotating body has a wheel on which the tire is mounted on the outer circumference.
The outer peripheral end of the swing plate is a wheel drive device provided at a position offset radially outward from the interface between the tire and the wheel. A deceleration mechanism that slows down the rotation transmitted from the drive source,
The rotating body whose tires are integrated by transmitting the rotation decelerated by the deceleration mechanism and
A fixing member that rotatably supports the rotating body and
An oil seal arranged between the rotating body and the fixing member and sealing a space in which the deceleration mechanism is housed,
A wheel drive device including a lubricant sealed in a sealing space sealed by the oil seal.
A shake-off plate that rotates integrally with the rotating body and shakes off the lubricant leaked from the location where the oil seal is arranged is provided.
A lubricant absorber that absorbs the lubricant leaked from the location where the oil seal is placed is provided.
A wheel drive device in which the swing plate is detachably fixed to the rotating body and holds the position of the lubricant absorbent with respect to the rotating body. A deceleration mechanism that slows down the rotation transmitted from the drive source,
The rotating body whose tires are integrated by transmitting the rotation decelerated by the deceleration mechanism and
A fixing member that rotatably supports the rotating body and
An oil seal arranged between the rotating body and the fixing member and sealing a space in which the deceleration mechanism is housed,
A wheel drive device including a lubricant sealed in a sealing space sealed by the oil seal.
Equipped with an oil pan that receives the lubricant leaked from the location of the oil seal.
A pan support member integrated with the fixing member and supporting the oil pan is provided.
The oil pan and the pan support member are long members that are long in the traveling direction of the tire.
The oil pan is a wheel drive device that can be pulled out in the longitudinal direction of the pan support member. The wheel drive device according to claim 5 , wherein the oil pan is held by the magnetic force of a magnet with respect to the pan support member. The wheel drive device according to claim 5 or 6 , further comprising an inclined portion inclined upward toward the outside in the longitudinal direction of the pan support member at an end portion in the longitudinal direction of the pan support member. A deceleration mechanism that slows down the rotation transmitted from the drive source,
The rotating body whose tires are integrated by transmitting the rotation decelerated by the deceleration mechanism and
A fixing member that rotatably supports the rotating body and
An oil seal arranged between the rotating body and the fixing member and sealing a space in which the deceleration mechanism is housed,
A wheel drive device including a lubricant sealed in a sealing space sealed by the oil seal.
Equipped with an oil pan that receives the lubricant leaked from the location of the oil seal.
In the oil pan
The first oil pan extending in the traveling direction of the tire and
A second oil pan extending in the axial direction of the tire is included.
One of the first oil pan and the second oil pan is a wheel drive device provided so as to be able to guide the received lubricant to the other oil pan. A deceleration mechanism that slows down the rotation transmitted from the drive source,
The rotating body whose tires are integrated by transmitting the rotation decelerated by the deceleration mechanism and
A fixing member that rotatably supports the rotating body and
An oil seal arranged between the rotating body and the fixing member and sealing a space in which the deceleration mechanism is housed,
A wheel drive device including a lubricant sealed in a sealing space sealed by the oil seal.
Equipped with an oil pan that receives the lubricant leaked from the location of the oil seal.
A shake-off plate that rotates integrally with the rotating body and shakes off the lubricant leaked from the location where the oil seal is arranged is provided.
The oil pan is a wheel drive device arranged vertically below the outer peripheral end of the swing plate.

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