WO2020184623A1

WO2020184623A1 - Wheel module

Info

Publication number: WO2020184623A1
Application number: PCT/JP2020/010596
Authority: WO
Inventors: 浩幸古崎
Original assignee: ミネベアミツミ株式会社
Priority date: 2019-03-13
Filing date: 2020-03-11
Publication date: 2020-09-17
Also published as: CN113557653A; JP2020150652A; JP7263062B2

Abstract

This wheel module is provided with: a wheel part which has a tire fitted thereon; a drive part at least partially embedded in the wheel part; and a grounding member which is electrically connected to the drive part. The wheel part and the drive part are each formed from a combination of a plurality of members including a first metal member and a second metal member which is obtained by forming an insulation layer through an alumite treatment performed on the surface of a metal substrate. In addition, the first metal member and the second metal member, both of which can be made electrically nonconductive, are respectively installed in such a manner as to be in contact with each other at exposed parts which are conductive parts formed apart from the insulation layer.

Description

Wheel module

The present invention relates to a wheel module.

Conventionally, a wheel module having a wheel portion to which a tire is attached and a drive portion having a motor is known. The wheel portion and the driving portion in such a wheel module are each composed of a combination of a plurality of members including a metal material (see, for example, Patent Document 1).

Further, in such a wheel module, in order to reduce the weight, at least a part of the metal material is alumite-treated aluminum from the viewpoint of rust prevention and corrosion resistance.

Japanese Unexamined Patent Publication No. 2014-07675

However, since the film on the aluminum surface formed by the alumite treatment serves as an insulating layer, even if the alumite-treated members are assembled together, the members do not conduct with each other, and the combined parts always have the same potential. Can't be.

Therefore, for example, when a rubber tire, which is an insulator provided in a wheel portion, touches the road surface and rotates, the tire and the road surface rub against each other, and static electricity due to friction is generated to charge the tire. Then, as charging progresses, electrostatic discharge suddenly occurs, which may destroy electronic components and the like in the vicinity of the discharge portion provided in the drive unit.

The present invention has been made in view of the above, and an object of the present invention is to provide a wheel module capable of preventing electronic components and the like from being destroyed by electrostatic discharge generated by the progress of electrostatic charging. And.

In order to solve the above-mentioned problems and achieve the object, the wheel module according to one aspect of the present invention includes a wheel portion to which a tire is attached, a drive portion in which at least a part thereof is built in the wheel portion, and the above. It includes a grounding member electrically connected to the drive unit. The wheel portion and the driving portion are each composed of a combination of a plurality of members including a first metal member and a second metal member having an insulating layer formed on the surface of a metal base material. Then, the first metal member and the second metal member, which can be non-conducting, are assembled in contact with each other in an exposed portion which is a conductive portion formed so as to avoid the insulating layer.

According to one aspect of the present invention, it is possible to prevent the electronic components and the like in the vicinity of the discharge portion from being destroyed by the electrostatic discharge caused by the electrostatic charge.

FIG. 1 is a perspective view showing a dolly including a wheel module according to the embodiment. FIG. 2A is an explanatory diagram showing an example for realizing a contact state having continuity when the first metal member and the second metal member having an insulating layer formed on the surface are combined. FIG. 2B is an explanatory diagram showing another example for realizing a contact state having continuity when the first metal member and the second metal member having an insulating layer formed on the surface thereof are combined. FIG. 3A is a first perspective view showing the appearance of the wheel module according to the embodiment. FIG. 3B is a second perspective view showing the appearance of the wheel module according to the embodiment. FIG. 4 is an exploded perspective view showing the configuration of the wheel module according to the embodiment. FIG. 5 is an exploded perspective view showing the configuration of the drive unit of the wheel module according to the embodiment. FIG. 6 is an exploded perspective view showing a configuration of an electric unit in the drive unit of the wheel module according to the embodiment. FIG. 7 is a perspective view showing a motor case of the wheel module according to the embodiment and a stator core housed in the motor case. FIG. 8A is a front view of a part of the wheel module according to the embodiment. FIG. 8B is an enlarged view of part A in FIG. 8A.

Hereinafter, the wheel module according to the embodiment will be described with reference to the drawings. In each drawing referred to in the following description, the relationship and ratio of the dimensions of each element may differ from the actual one. In addition, there are cases where parts having different dimensional relationships and ratios are included between the drawings. Further, in each drawing, components having the same role are designated by the same reference numerals.

FIG. 1 is a perspective view showing the appearance of the carriage 100 provided with the wheel module 200 according to the embodiment. As shown in FIG. 1, the wheel module 200 is used as a moving mechanism of the carriage 100. That is, as shown in the figure, the trolley 100 has a loading platform 110, a handle 120, and a wheel module 200 according to the embodiment.

The loading platform 110 is a member formed in a thick plate shape, and luggage is placed on the upper surface thereof. The handle 120 is a U-shaped curved rod-shaped member for the user to grip when moving the carriage 100, and is attached to the upper surface of the loading platform 110.

The wheel module 200 is a wheel that rotates by a drive current supplied from a power source (not shown), and is attached to the lower surface of the loading platform 110. The wheel module 200 according to the embodiment is provided on the carriage 100 as a middle wheel. However, the wheel module 200 may be provided on the carriage 100 as a front wheel or as a rear wheel. Alternatively, it may be provided as a combination of any two or more of the front wheels, the middle wheels, and the rear wheels.

The wheel module 200 is driven, for example, as an aid when a user loads and transports a load on the loading platform 110 of the trolley 100, or when the trolley 100 has a function of following another trolley and self-propelling. Is driven according to the distance to other trolleys.

Each component of the wheel module 200 according to the embodiment is composed of a combination of an insulating member and a metal member or a combination of metal members. Here, a schematic configuration of a state in which the metal members including the first metal member 1 and the second metal member 2 are combined will be described with reference to FIGS. 2A and 2B.

FIG. 2A is an explanatory view and a view showing an example for realizing a contact state having continuity when the first metal member 1 and the second metal member 2 having the insulating layer 2b formed on the surface thereof are combined. 2B is an explanatory diagram showing another example for realizing a contact state having continuity when the first metal member and the second metal member having an insulating layer formed on the surface are combined.

Each component of the wheel module 200 according to the embodiment is composed of a combination of a first metal member 1 and a second metal member 2. For example, the wheel module 200 according to the present embodiment includes a wheel unit 210 and a drive unit 220, which will be described later (see FIGS. 3A and 3B).

Most of the metal parts of the wheel unit 210 and the drive unit 220 are made of aluminum alloy in order to reduce the weight. Then, the aluminum at the portion where the outer surface comes into contact with the outside air is subjected to anodizing treatment to protect the surface so as to form a film (insulating layer) on the surface.

Since the film formed by the alumite treatment is the insulating layer 2b, the first metal member 1 which is still an aluminum product and the second metal member 2 which is an alumite-treated aluminum product are brought into contact with each other. Even if they are combined, they do not conduct with each other. Further, even if the second metal members 2 which are alumite-treated aluminum products are brought into contact with each other and combined, they do not conduct with each other in the same manner. On the other hand, in the case of a combination of the first metal members 1 which are aluminum products that have not been anodized, they become conductive when they come into contact with each other, and both are always at the same potential.

Therefore, in the present embodiment, the first metal member 1 and the second metal member 2 are assembled in a state of being in contact with each other in the exposed portion 4 formed so as to avoid the insulating layer 2b. That is, the exposed portion formed by peeling the insulating layer 2b from the first metal member 1 and the second metal member 2 which is alumite-treated to form the insulating layer 2b and may accumulate and be charged. In No. 4, they are assembled in a state where they are in contact with each other.

The wheel module 200 in the present embodiment includes a first metal member 1 made of aluminum and a second metal member 2 made of aluminum having a coating film (insulating layer) formed on the surface thereof to be an insulating layer 2b. Each is composed of a combination of members.

Here, both the first metal member 1 and the metal base material 2a of the second metal member 2 are made of aluminum alloy, but the type of metal as a material is not particularly limited. Further, the insulating layer 2b is not limited to the one obtained by alumite treatment as long as it has an insulating property, and is not limited to the one obtained by including a paint or the like.

Here, the outline of the assembly structure of the first metal member 1 which is an aluminum product and the second metal member 2 which is an alumite-treated aluminum product in the wheel module 200 according to the embodiment will be described.

As shown in FIGS. 2A and 2B, the first metal member 1 and the second metal member 2 are assembled in a state of being in contact with each other in the exposed portion 4 formed so as to avoid the insulating layer 2b. That is, the exposed portion 4 is an exposed region formed by avoiding a part of the insulating layer 2b, in other words, it is also a peeled region where a part of the insulating layer 2b is peeled off. The first metal member 1 comes into contact with the metal base material 2a of the second metal member 2 through such an exposed region. In FIGS. 2A and 2B, reference numeral 5 indicates a contact portion between the first metal member 1 and the metal base material 2a of the second metal member 2.

In FIG. 2A, the exposed portion 4 forms a part of the screw hole 3, and the first metal member 1 and the second metal member 2 are in contact with each other via the conductive screw member 6. They are in contact with each other at 5 and are conducting with each other. The contact portion 5 in this case is a meshing portion between the male screw portion of the screw member 6 and the female screw portion formed in the screw hole 3.

In FIG. 2B, the first metal member 1 and the metal base material 2a of the second metal member 2 come into contact with each other at the contact portion 5 via the exposed portion 4, which is an exposed region where a part of the insulating layer 2b is exposed. , Conducting with each other. Here, the insulating layer 2b is formed of a coating film of several μs to several tens of μs, and if the first metal member 1 and the second metal member 2 are crimped with a predetermined force, both are exposed portions 4. Contact through. The contact portion 5 in this case is a portion where the first metal member 1 and the metal base material 2a of the second metal member 2 are in direct contact with each other.

Further, when the first metal member 1 and the second metal member 2 are assembled by abutting the end faces of each other, for example, the end faces of the second metal member 2 are masked by post-processing or during alumite treatment. It is preferable to form a portion where the metal base material 2a is exposed (exposed state).

Further, in addition to the above-described configuration, for example, a convex portion is formed on either one of the metal base material 2a of the first metal member 1 and the second metal member 2, and a concave portion that can be fitted with the convex portion is formed. It may be formed on either one of the metal member 1 of 1 and the metal base material 2a of the second metal member 2. With such a configuration, the convex portion and the concave portion can be fitted to each other via the exposed portion 4, so that the first metal member 1 and the metal base material 2a of the second metal member 2 can be brought into contact with each other.

In this way, even if the first metal member 1 and the second metal member 2 having the insulating layer 2b formed on the surface thereof are combined, both can be made conductive through the exposed portion. Therefore, for example, Even if the insulating layer 2b of the second metal member 2 is charged, it is electrically connected to the first metal member 1, so that the first metal member 1 and the second metal member having the insulating layer 2b formed on the surface thereof. 2 has the same potential. Therefore, for example, even if the wheel portion 210 is grounded on the road surface and is charged by rotating, the connection point between the first metal member 1 and the second metal member 2 having the insulating layer 2b formed on the surface thereof is promptly connected. It is connected to a grounding lead wire 7 (see FIG. 3B) which is a grounding member (grounding wire) provided in the wheel module 200. Since the grounding lead wire 7 is electrically connected to the drive unit 220 and is grounded, electrostatic discharge does not occur due to the passage of static electricity. For example, an electronic component provided in the drive unit 220 or the like. It is possible to prevent the risk of destroying the battery. Further, when the wheel module 200 according to the embodiment is used for a transport device such as a trolley, it is possible to prevent the possibility of destroying an electrically fragile transported item or the like.

Here, the wheel module 200 according to the present embodiment will be described more specifically with reference to FIGS. 3A to 8B. FIG. 3A is a first perspective view showing the appearance of the wheel module 200 according to the embodiment, and FIG. 3B is a second perspective view of the same. Further, FIG. 4 is an exploded perspective view showing the configuration of the wheel module 200 of the above, FIG. 5 is an exploded perspective view showing the configuration of the drive unit of the wheel module 200 of the same, and FIG. 6 is a drive of the wheel module 200 of the same. It is an exploded perspective view which shows the structure of the electric part in a part. 7A and 7B are perspective views showing a motor case of the wheel module 200 of the same as above and a stator core housed in the motor case, FIG. 8A is a front view of a part of the wheel module 200 of the same as above, and FIG. 8B is a front view. It is an enlarged view of the part A in FIG. 8A.

As shown in FIGS. 3A, 3B and 4, the wheel module 200 includes a tire 211, a wheel portion 210, a drive portion 220, and a brake portion 230.

The wheel portion 210 includes a wheel 215 on which the tire 211 is mounted, and a front frame 212 and a rear frame 213 that form a frame portion arranged inside the wheel 215.

The drive unit 220 is driven by a drive current supplied from a power source (not shown), rotates about a rotation axis, and rotates the wheel unit 210. The brake unit 230 stops the rotation of the wheel unit 210 in response to control by a control mechanism (not shown), a user, or the like.

The tire 211 provided on the wheel portion 210 has a ground contact surface having a predetermined width and a circle having a diameter of, for example, 100 to 300 mm, which is made of a synthetic resin such as rubber which is an insulating material or a material having high electric resistance. It is formed in a ring shape. The tire 211 rotates and the friction with the road surface causes the tire 211 to accumulate an electric charge. When the electric charge accumulates, for example, when a metal that is a conductor is brought close to or brought into contact with the tire 211, if there is a potential difference, the accumulated electric charge causes an electrostatic discharge toward the conductor. There is. Even if a tire having a certain degree of conductivity is selected, by using this configuration, it is possible to further reduce the possibility of electrostatic discharge, not limited to the conductivity of the tire, so that the degree of freedom in selecting members is increased. Can be improved.

The wheel 215 is an annular member having a flange portion capable of locking the tire 211 formed on the outer peripheral surface, and the frame portion is screwed so as to surround the circular hole portion where the end portion of the stored frame portion is exposed. A plurality of screw holes 3 are formed for this purpose.

The wheel 215 is formed by the above-mentioned second metal member 2. That is, the wheel 215 is an alumite-treated aluminum product. However, after the alumite treatment, the contact portion 5 that comes into contact with the screw 216a is provided by forming the exposed portion 4 in which the aluminum portion that is the conductor is exposed.

As shown in FIG. 4, the frame portion is configured such that the front frame 212 and the rear frame 213 are butted in the axial direction. The front frame 212 has a substantially cylindrical shape with one side surface as an open surface, one side surface opposite to the open surface is fastened to the wheel 215 by a screw 216a, and the other side surface as an open surface is a rear frame 213 and a screw 216b. Is concluded by. The rear frame 213 is an annular member formed flatter than the front frame 212, and screw holes 3 for inserting screws 216b for fastening to the front frame 212 are provided in the flange portion at predetermined intervals in the circumferential direction. It is formed by opening.

Here, the front frame 212 and the rear frame 213 constituting the frame portion are each formed of the above-mentioned second metal member 2 in the same manner as the wheel 215. That is, it is an alumite-treated aluminum product. However, after the alumite treatment, the screw hole 3 is further post-processed to form an exposed portion 4 in which the aluminum portion which is the conductor is exposed, and the contact portion 5 with the

screws

216a and 216b is provided.

As described above, the wheel 215, the front frame 212, and the rear frame 213 constituting the wheel portion 210 are each formed of an alumite-treated aluminum product (second metal member 2). However, since the screw hole 3 having the exposed portion 4 which is a conductive portion is formed after the alumite treatment, the aluminum portion (metal base material 2a) which is a conductor is formed in the insulating layer 2b formed by the alumite treatment. The exposed portion 4 is formed so as to be exposed. Therefore, when the

screws

216a and 216b, which are conductors, are inserted into the screw holes 3 and the wheel 215, the front frame 212, and the rear frame 213 are integrally assembled, they become conductive via the

screws

216a and 216b, respectively. Therefore, the electric charge that the wheel portion 210 touches the road surface and rotates and is charged flows from the wheel 215 toward the front frame 212, and the wheel portion 210 and the front frame 212 are electrically conducted with each other to have the same potential.

A part of the drive unit 220 is arranged inside the wheel unit 210, and as shown in FIG. 3B, the drive unit 220 is driven by a drive current from a power source (not shown) supplied via the feeder line 223. The wheel portion 210 and the tire 211 are rotated around the rotation axis.

Specifically, the drive unit 220 includes a motor unit 250 and a transmission unit 260, as shown in FIGS. 4 and 5. As shown in FIG. 6, the motor unit 250 includes a motor case 221, a stator 225 built in the motor case 221, a rotor 226, a rotating shaft 227, and a gear base plate 229. The transmission unit 260 is substantially configured by a planetary gear mechanism, and as shown in FIG. 5, includes

planetary gears

261a, 261b, 261c and a gear plate 263 that holds these

planetary gears

261a, 261b, 261c. ..

The stator 225 and the rotor 226 form an inner rotor type motor, and the rotor 226 rotates about the rotary shaft 227 by the drive current supplied via the feeder line 223 (see FIG. 3B). The rotational force generated by the rotation of the rotor 226 is transmitted to the wheel portion 210 via the transmission portion 260 having the

planetary gears

261a, 261b, and 261c.

As shown in FIGS. 6 and 7, the stator 225 has a configuration in which a plurality of salient poles are arranged side by side in the circumferential direction on the inner peripheral surface of the stator core 225a formed in a hollow cylindrical shape, and each protrusion is arranged. A coil 225b is wound around the pole. A feeder line 223 (see FIG. 3B) for supplying a drive current from a power source (not shown) is connected to the coil 225b. Further, an insulator 225c serving as an insulator is arranged between the stator core 225a and the coil 225b.

On the other hand, as shown in FIG. 6, the rotor 226 is arranged inside the stator 225, and the wheel portion 210 is rotated by rotating the rotor 226 about the rotating shaft 227 with respect to the stator 225. Specifically, the rotor 226 has a configuration in which a plurality of magnets 226b are arranged side by side in the circumferential direction along the inner peripheral surface of the annular rotor core 226a formed in a columnar shape, and each magnet 226b is arranged. It is arranged so as to face each coil 225b of the stator 225. As a result, the rotor 226 rotates about the rotating shaft 227 by the electromagnetic force generated in the coil 225b when the driving current flows through the coil 225b of the stator 225.

Further, the rotary shaft 227 fixed to the rotor 226 while penetrating the center of the rotor 226 is rotatably supported by the motor case 221 via two ball bearings 228a provided with the rotor core 226a interposed therebetween. .. Further, a plurality of washers 228b are interposed between the rotor 226 and the gear base plate 229 in a stacked state.

By the way, the motor case 221 incorporating the stator 225 has a large-diameter cylindrical portion 221a incorporating the stator 225 and a small-diameter cylindrical portion 221b accommodating the brake portion 230 described later. The large-diameter cylindrical portion 221a is housed in the frame portion composed of the front frame 212 and the rear frame 213, and the small-diameter cylindrical portion 221b projects outward from the rear frame 213. The motor case 221 and the rear frame 213 are attached via ball bearings 214b as shown in FIG. An O-ring 224b is interposed between the motor case 221 and the ball bearing 214b.

Further, as shown in FIG. 3B, a grounding lead wire 7 which is a grounding member is attached to the small diameter cylindrical portion 221b of the motor case 221. The grounding lead wire 7 is electrically connected to the drive unit 220 and is grounded. The motor case 221 is an alumite-treated aluminum product (second metal member 2) like the wheel 215, front frame 212, and rear frame 213 described above, and an insulating layer 2b is formed on the surface thereof. .. Therefore, an exposed portion 4 for exposing the aluminum portion, which is the metal base material 2a, is formed on the small-diameter cylindrical portion 221b, and the base end of the grounding lead wire 7 is attached to the exposed portion 4. Then, the tip of the grounding lead wire 7 is brought into contact with the back surface of the loading platform 110 of the carriage 100 shown in FIG.

Further, as shown in FIG. 6, a gear base plate 229 that rotatably supports the

planetary gears

261a, 261b, and 261c of the transmission unit 260 is attached to the motor case 221 by a bolt with a washer 216d.

Further, in the present embodiment, a temperature sensor (not shown) is arranged between the stator 225 and the large-diameter cylindrical portion 221a of the motor case 221. That is, the motor case 221 according to the present embodiment is configured to accommodate electronic components such as a temperature sensor. The temperature sensor housed in the motor case 221 can communicate with the outside via the signal line 222 (see FIG. 3B). The signal line 222, together with the feeder line 223, extends to the outside from the outlet 221c formed in the small-diameter cylindrical portion 221b of the motor case 221.

The motor case 221 is an alumite-treated aluminum product (second metal member 2) as described above. However, as shown in FIGS. 7, 8A and 8B, the exposed portion where the aluminum portion, which is the conductor, is exposed by post-processing the screw hole 3a through which the set screw 8 for fixing the stator core 225a is inserted. 4 is formed, and a contact portion 5 that comes into contact with the set screw 8 is formed. Therefore, when the set screw 8 having conductivity is inserted into the screw hole 3a and the stator core 225a is fixed to the motor case 221, the stator core 225a and the motor case 221 are formed with the screw hole 3a and the set screw 8 in which the exposed portion 4 is formed. Conducts to each other through. Here, the meshing portion between the male screw portion of the set screw 8 and the female screw portion formed in the screw hole 3a is the contact portion 5.

Further, as shown in FIG. 8B, the metal base material 2a is also exposed at the position where the large-diameter cylindrical portion 221a of the motor case 221 and the gear base plate 229 come into contact with each other, and the exposed portion becomes the contact portion 5 and both They are conducting with each other.

Further, although not shown, the metal base material 2a is also exposed on the surface where the front frame 212 and the rear frame 213 are in contact with each other, and both are electrically connected to each other at the exposed portion.

In this way, the motor case 221 having the insulating layer 2b (see FIG. 2A) formed on the surface by alumite treatment is housed in the motor case 221 without being charged by the insulator which is the insulator on the stator core 225a side. It does not adversely affect electronic components such as temperature sensors.

As shown in FIG. 5, the planetary gear mechanism constituting the transmission unit 260 includes three

planetary gears

261a, 261b, 261c and a gear plate 263 arranged so as to surround the three

planetary gears

261a, 261b, 261c. To be equipped.

The

planetary gears

261a, 261b, and 261c are attached to gear

bearings

262a, 262b, and 262c provided on the gear base plate 229, and each meshes with the sun gear 227a provided on the tip side of the rotary shaft 227. Further, the gear plate 263 is fixed to the front frame 212, and an internal gear (not shown) is formed on the inner peripheral surface. The

planetary gears

261a, 261b, and 261c are meshed with the internal gears, respectively. The gear plate 263 and the front frame 212 are attached via ball bearings 214a as shown in FIG. An O-ring 224a is interposed between the gear plate 263 and the ball bearing 214a.

With this configuration, when the rotating shaft 227 rotates in response to the rotation of the rotor 226, the three

planetary gears

261a, 261b, and 261c that mesh with the sun gear 227a formed on the rotating shaft 227 rotate, respectively. Then, as shown in FIG. 5, the gear plate 263 on which the internal gear is formed is fixed to the gear base plate 229 attached to the motor case 221 by a bolt with a washer 216c. Therefore, the rotation of the three

planetary gears

261a, 261b, and 261c causes the gear plate 263 on which the internal gear is formed to rotate, and the wheel portion 210 rotates with the rotation of the gear plate 263. That is, the rotational force generated by the rotation of the rotor 226 is transmitted to the wheel portion 210 while the rotational speed is reduced by the transmission portion 260.

As shown in FIG. 4, the brake portion 230 housed in the small-diameter cylindrical portion 221b of the motor case 221 and stops the rotation of the wheel portion 210 has a built-in brake mechanism having a brake shoe or the like (not shown) in the cylindrical casing 233. ing. An end cap 240 is attached to the opening at the end of the small-diameter cylindrical portion 221b of the motor case 221 that houses the brake portion 230 (see FIG. 3B).

The brake unit 230 can stop the rotation of the wheel module 200 via a signal line 231 (see FIG. 3A) connected to a control mechanism (not shown). The signal line 231 extends to the outside from the outlet 241 provided on the end cap 240. Further, the electric power for operating the brake mechanism is supplied from the feeder line 232 (see FIG. 3A) connected to a power source (not shown). The brake shoe of the brake mechanism acts on the end side of the rotating shaft 227 to stop the rotation of the wheel portion 210.

The drive unit 220 and the brake unit 230 described above are composed of a combination of a plurality of metal members. Most of them are a combination of conductors, but as described above, an alumite-treated aluminum product on which the insulating layer 2b is formed may be combined with a conductor.

In that case, in the present embodiment, the alumite-treated aluminum product is post-processed to form an exposed portion 4 in which the metal base material 2a is exposed, and the member serving as another conductor is formed through the exposed portion 4. Combined to make contact. Therefore, the combined metal members become conductive with each other.

Further, in the wheel module 200 according to the present embodiment, the motor case 221 and the frame portion are connected to each other via

metal ball bearings

214a and 214b. That is, as shown in FIG. 8A, the ball bearing 214a is interposed between the large-diameter cylindrical portion 221a side of the motor case 221 and the front frame 212, and the small-diameter cylindrical portion 221b side of the motor case 221 and the rear frame 213. A ball bearing 214b is interposed between them.

Therefore, the wheel module 200 according to the present embodiment conducts from the wheel portion 210 on which the tire 211 is mounted to the grounding lead wire 7.

By the way, the wheel module 200 is attached to the back surface of the loading platform 110 in the carriage 100 via the support member 9 shown in FIG. 8A (see FIG. 1). As shown in FIG. 8A, the support member 9 has a support base 91 and a bracket 92.

The support base 91 is a member of a thick plate formed in an L shape in cross section, and its upper side surface is attached to the back surface of the loading platform 110 of the carriage 100. Further, the bracket 92 is connected to the inner surface of the bent portion of the support base 91. The bracket 92 is also made of a thick plate member, the upper end portion is fixed to the inner side surface of the bent portion of the support base 91, and the lower end portion is arranged so as to be substantially orthogonal to the rotating shaft 227 of the drive unit 220. Has been done. The shape and configuration of the support member 9 are not limited to those shown in the figure, and can be appropriately designed.

The wheel module 200 described above includes a first metal member 1 and a second metal member 2 having an insulating layer 2b formed on the surface of the metal base material 2a for both the wheel unit 210 and the drive unit 220. It was assumed that it was composed of a combination of the members of. Further, in both the wheel portion 210 and the drive portion 220, the first metal member 1 and the second metal member 2 are assembled in a state of being in contact with each other in the exposed portion 4 formed in the insulating layer 2b. ..

However, of the wheel portion 210 and the drive portion 220, at least the first metal member 1 and the second metal member 2 in the drive portion 220 are assembled in a state of being in contact with each other in the exposed portion 4 formed in the insulating layer 2b. It may be a configured configuration.

With such a configuration, it is possible to suppress an increase in cost, which is beneficial in terms of cost effectiveness.

Further, in the wheel module 200 described above, since the drive unit 220 performs PWM control, the drive unit 220 may be a source of noise. In particular, if the potential difference between the ground and the housing composed of the aluminum front frame 212, rear frame 213, motor case 221 and the like is different, the potential difference will be different when noise is conducted through the aluminum housing. Noise may be reflected at continuous points or surfaces, and noise may be emitted to the outside of the wheel module 200 from discontinuous points or surfaces having different potential differences, which may adversely affect peripheral devices. However, with this configuration, it is covered with an aluminum housing, and by connecting the housing to the ground, the potential from the housing to the ground is made the same potential, thereby suppressing noise emission to the outside. Is possible.

From the above-described embodiment, the following wheel module 200 is realized.

(1) A wheel portion 210 to which the tire 211 is attached, a drive portion 220 having at least a part built in the wheel portion 210, and a grounding lead wire 7 electrically connected to the drive portion 220 are provided. The wheel portion 210 and the drive portion 220 are each formed by a combination of a plurality of members including a first metal member 1 and a second metal member 2 having an insulating layer 2b formed on the surface of the metal base material 2a by alumite treatment. The first metal member 1 and the second metal member 2, which are configured and can be non-conducting, are assembled in contact with each other in the exposed portion 4, which is a conductive portion formed so as to avoid the insulating layer 2b. Wheel module 200.

According to such a configuration, charging due to static electricity does not proceed in any of the first metal member 1 and the second metal member 2 that come into contact with each other. Therefore, it is possible to prevent, for example, electronic components arranged in the vicinity of the discharge portion from being destroyed by the electrostatic discharge generated by the progress of charging.

(2) In the above (1), the metal base material 2a of the second metal member 2 is an aluminum alloy, and the insulating layer 2b is a wheel module 200 formed by alumite treatment.

According to such a configuration, the weight can be reduced and the wheel module 200 having good corrosion resistance can be obtained.

(3) In the above (1) or (2), the exposed portion 4 is an exposed region in which a part of the insulating layer 2b is exposed, and the first metal member 1 is a second metal member via the exposed region. Wheel module 200 in contact with the metal base material 2a of 2.

According to such a configuration, the above configuration (1) or (2) can be realized by simple post-processing.

(4) In the above (1) or (2), the exposed portion 4 forms a part of the screw holes 3 and 3a, and the first metal member 1 and the second metal member 2 are conductive. A wheel module 200 that comes into contact with a screw member 6 (set screw 8,

screws

216a, 216b, bolts with

washers

216c, 216d).

According to such a configuration, the above configuration (1) or (2) can be realized by post-processing the screw holes 3 and 3a required for assembling the parts.

(5) In the above (4), the drive unit 220 includes a motor (stator 225 and rotor 226), a motor case 221 for accommodating the motor, and a grounding lead wire 7, and is a first metal member 1 included in the motor. A wheel module 200 in which a certain stator core 225a and a motor case 221 which is a second metal member 2 are in contact with each other via a set screw 8.

According to this configuration, at least from the motor case 221 to the grounding lead wire 7 becomes conductive, so that the electric charge does not proceed in the motor case 221. Therefore, it is possible to prevent electronic components such as sensors provided in the motor case 221 from being destroyed by electrostatic discharge caused by charging.

(6) In (5) above, the second metal member 2 is a wheel module 200 including at least a wheel portion 210 in addition to the motor case 221.

According to such a configuration, the wheel portion 210 or the like having the tire 211 rotates while being in contact with the ground and is easily charged, but the wheel portion 210 to the grounding lead wire 7 is totally conductive. become. Therefore, in this case, it is possible to prevent, for example, electronic components from being destroyed by electrostatic discharge caused by charging.

(7) In the above (5) or (6), the motor case 221 is a wheel module 200 capable of storing electronic components (for example, a temperature sensor) in addition to the motor.

According to such a configuration, it becomes possible to provide a more excellent wheel module 200 by using various electronic parts such as a temperature sensor by using the motor case 221 and using the electronic parts. There is no risk of damage due to electrostatic discharge from metal materials.

(8) In any of the above (1) to (7), the wheel module 200 can be attached to the back surface of the carriage 100 via the support member 9, and the tip of the grounding lead wire 7 is in contact with the carriage 100.

According to such a configuration, it is possible to provide a carriage 100 using the wheel module 200 having the features (1) to (7) above.

The present invention is not limited to the above-described embodiments. For example, in the present embodiment, an example of having a so-called inner rotor type motor configuration in which the rotor 226 is arranged inside the stator 225 has been described. For example, an outer rotor in which the stator is arranged inside the rotor has been described. The wheel module 200 may have a motor configuration of the type.

Further, in the above-described embodiment, the rotational force of the motor is transmitted to the wheel unit 210 via the planetary gear mechanism, but the motor directly transmits the rotational force to the wheel unit 210 without using the planetary gear mechanism. The wheel module 200 may have a so-called direct drive configuration.

Further, in the above-described embodiment, as shown in FIG. 1, an example in which the wheel module 200 is applied to a six-wheel trolley has been described, but for example, two wheels, four wheels, or a larger number of wheels than six wheels are used. It can also be applied to a dolly that has it.

Further, in the above-described embodiment, an example in which the wheel module 200 is used as a wheel of the carriage 100 has been described, but the embodiment is not limited to this. For example, the wheel module 200 described above can be used as a wheel for a stroller, a wheelchair, various carts, or a moving device for riding or transporting. Further, for example, it can be used for various robots that move by wheels.

Also, although this is not shown, the protective layer is exposed at the point where the large-diameter cylindrical portion 221a of the motor case 221 comes into contact with the gear base plate 229, and is conducting there.

Further, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

1 1st metal member, 2 2nd metal member, 2a metal base material, 2b insulating layer, 3, 3a screw hole, 4 exposed part, 5 contact part, 6 screw member, 8 set screw, 100 trolley, 200 wheels Module, 210 wheel part, 211 tire, 216a, 216b screw, 216c, 216d bolt with washer, 220 drive part, 221 motor case, 225 stator, 225a stator core, 226 rotor

Claims

The wheel part where the tire is attached and
A drive unit with at least a part built into the wheel unit,
A grounding member electrically connected to the drive unit,
With
The wheel portion and the driving portion are each composed of a combination of a plurality of members including a first metal member and a second metal member having an insulating layer formed on the surface of a metal base material, and each of them is not. A wheel module in which the first metal member and the second metal member, which can be conductive, are assembled in contact with each other in an exposed portion which is a conductive portion formed so as to avoid the insulating layer.
The wheel module according to claim 1, wherein the metal base material of the second metal member is an aluminum alloy, and the insulating layer is a film formed by an alumite treatment.
The exposed portion is an exposed region in which a part of the insulating layer is exposed, and the first metal member comes into contact with the metal base material of the second metal member through the exposed region. The wheel module according to 1 or 2.
The exposed portion forms a part of a screw hole, and the first metal member and the second metal member come into contact with each other via a conductive screw member, according to claim 1 or 2. Described wheel module.
The drive unit includes a motor, a motor case for accommodating the motor, and the grounding member.
The wheel module according to claim 4, wherein the stator core, which is the first metal member of the motor, and the motor case, which is the second metal member, are in contact with each other via the screw member.
The wheel module according to claim 5, wherein the second metal member includes at least the wheel portion in addition to the motor case.
The wheel module according to claim 5 or 6, wherein the motor case can store electronic components in addition to the motor.
The wheel module according to any one of claims 1 to 7, which can be attached to the back surface of the carriage via a support member, and the tip of the ground contact member contacts the carriage.