JP2020072777A - Autonomous travel type cleaner - Google Patents

Abstract

To provide an autonomous travel type cleaner capable of miniaturizing a wheel unit.SOLUTION: In an autonomous travel type cleaner, wheels 2, 3 rotate by an input of a driving source, and includes a shaft 34 for supporting a load of a vehicle body, and speed reduction mechanisms 33, 35, 36, 37, 38 provided between the shaft 34 and the wheels 2, 3. The speed reduction mechanisms are constituted by a plurality of stages of speed reduction gears 33, 35, 36, 37, 38, they are arranged in a region equal to or less than an outer diameter dimension s3 of the wheels 2, 3 when viewed in a rotary shaft direction of the driving wheels 2, 3 rotated respectively by the drive of each travel motor. When viewed in the frontward/backward direction, part of or all of each of the speed reduction gears 33, 35, 36, 37, 38 constituting the speed reduction mechanism is positioned in a region of a width dimension s4 of the driving wheels 2, 3. The last speed reduction gear 38 reduces speed by the speed reduction gears 35, 36 using an inscribed trochoidal curve.SELECTED DRAWING: Figure 15

Description

  The present invention relates to an autonomous traveling vacuum cleaner.

2. Description of the Related Art Conventionally, there is known an autonomous traveling vacuum cleaner that cleans an indoor space while moving autonomously. The autonomous traveling type vacuum cleaner is equipped with a rechargeable battery as a power source, and a controller controls a traveling motor that drives a wheel unit to perform autonomous traveling while scraping dust using a motor-driven rotating brush. Suction with a suction fan to clean.
The autonomous traveling type vacuum cleaner is automatically traveling by a pair of left and right driving wheels.

  Here, in order to automatically drive the autonomous cleaner, it is necessary to adjust the reduction ratio within a certain value range, for example, 40 to 80, according to the torque of the motor that drives the wheels. That is, the torque for driving the wheels is 40 to 80 times the torque of the motor.

JP, 2010-221964, A

By the way, there are the following two types of wheel deceleration mechanisms for conventional autonomous cleaners.
For example, in one type, the wheel deceleration structure is a structure in which the motor is decelerated via a gear to operate the wheel. At this time, since the gears are arranged in series in order to increase the reduction ratio, the gears become longer in the front-rear direction than the wheels. As described above, with the structure in which the ordinary spur gears are arranged in series, it is necessary to use multiple gears even when a motor having a large torque is used and a reduction ratio is small, and the wheel unit becomes large. An increase in the size of the wheel unit leads to an increase in the size of the main body, which makes it difficult to clean a narrow space, which is not desirable and needs to be reduced in size.

  In the front-rear direction of the autonomous vacuum cleaner, a storage battery that supplies power, a dust suction port, and a scraping brush that scrapes off dust are arranged, and interfere with these components. Extending in the front-rear direction leads to an increase in the size of the autonomous traveling type vacuum cleaner, which is inconvenient.

On the other hand, as for the motor, a commutator motor that is long enough to generate a torque for moving the autonomous cleaner is used.
Therefore, there has been proposed a configuration described in Patent Document 1 using a gear arrangement and an outer rotor brushless motor that has the same diameter as the commutator motor and that can obtain a larger torque than the commutator motor.

As another type, the structure of the wheel deceleration mechanism described in Patent Document 1 is arranged such that the diametrical direction of the deceleration mechanism fits inside the wheel.
In the case of this structure, since the outer diameter of the gear cannot be made large, the reduction ratio per one stage cannot be made large. Therefore, in order to obtain a large required reduction ratio, it is necessary to stack the gears vertically and to arrange the gears in a plurality of stages, which increases the size of the wheel in the thrust direction.
Further, if the length of the reduction mechanism in the thrust direction is suppressed, the reduction ratio becomes smaller, so it is necessary to increase the torque of the motor, which leads to an increase in cost such as upgrading the grade of the magnet.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an autonomous traveling vacuum cleaner capable of downsizing a wheel unit.

In order to solve the above problems, an autonomous traveling cleaner of the present invention includes a suction fan for generating a negative pressure, a suction port for sucking dust on a surface to be cleaned by the negative pressure of the suction fan, and the suction fan. In a dust collecting case for collecting dust disposed between the flow paths of the suction port, and an autonomous traveling vacuum cleaner having at least two wheels for autonomous traveling, the wheels are rotated by input of a drive source, A shaft for supporting the load of the vehicle body and a reduction mechanism provided between the shaft and the wheels are provided, and the reduction mechanism is composed of a plurality of reduction gears, and is rotated by the drive of each traveling motor. Each of the reduction gears, which is arranged in a region equal to or smaller than the outer diameter dimension of the drive wheel when viewed in the rotational axis direction of the drive wheel, and which constitutes the reduction mechanism within the region of the width dimension of the drive wheel when viewed in the front-rear direction. Part or all of Is positioned, and the final reduction gear is decelerated by the reduction gear using an inscribed trochoid curve.

  According to the present invention, it is possible to provide an autonomous traveling type vacuum cleaner capable of downsizing a wheel unit.

The perspective view which looked at the autonomous traveling type vacuum cleaner concerning the embodiment of the present invention from the left front. The bottom view of an autonomous traveling type vacuum cleaner. AA sectional drawing of FIG. The perspective view which shows the internal structure which removed the case of the autonomous traveling type vacuum cleaner. Perspective view taken along line BB in FIG. FIG. 3 is a perspective view of the wheel assembly of the first embodiment as seen obliquely from above and rear. 1 is a side sectional view of a wheel assembly according to a first embodiment. CC sectional drawing of FIG. 7A. The disassembled perspective view of a wheel assembly. FIG. 9 is an exploded perspective view of the wheel assembly viewed from the opposite direction of FIG. 8. FIG. 3 is an exploded perspective view of the planetary gear assembly. FIG. 3 is a schematic vertical cross-sectional view showing a meshed state of a reduction gear mechanism between a drive wheel and a motor. The perspective view which looked at the wheel assembly of Embodiment 2 from the slanting upper back. FIG. 6 is an exploded perspective view of the wheel assembly of the second embodiment. FIG. 14 is an exploded perspective view of the wheel assembly viewed from the opposite direction of FIG. 13. FIG. 13 is a sectional view taken along line DD of FIG. 12. Sectional drawing which cut | disconnected by the cross section which can see a pinion gear and a gearwheel. FIG. 16 is a sectional view taken along line EE in FIG. 15. FIG. 16 is a sectional view taken along line FF of FIG. 15. (A) is a schematic vertical cross-sectional view showing a meshing state of a reduction gear mechanism between a drive wheel and a motor, and (b) is a principle view showing bearings on both sides of the reduction gear mechanism and a camshaft and how a load is applied. The perspective view which looked at the wheel assembly of Embodiment 3 from the slanting upper back. FIG. 21 is a perspective view of the interior of the wheel assembly with the drive wheels of the third embodiment removed, as seen from the upper rear side in the direction opposite to FIG. FIG. 3 is a schematic vertical cross-sectional view showing a meshed state of a reduction gear mechanism between a drive wheel and a motor. FIG. 6 is a vertical cross-sectional view showing an in-wheel motor drive device including the motor drive device of Patent Document 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a perspective view of an autonomous traveling type vacuum cleaner according to an embodiment of the present invention as seen from the front left. In the traveling direction of the autonomous traveling cleaner S, the side on which the side brush 7 is provided is the front, the vertically upward direction is the upper side, the drive wheels 2 and 3 face each other, and the drive wheel 2 side is the left side. The drive wheel 3 side is the right side. That is, as shown in FIG. 1 and the like, front-back, up-down, and left-right directions are defined.
FIG. 2 is a bottom view of the autonomous traveling type vacuum cleaner.

The autonomous traveling cleaner S is an electric device that automatically cleans a predetermined cleaning area (for example, a floor surface Y of a room) while autonomously moving.
The autonomous traveling vacuum cleaner S includes a case 1 (1u, 1s) forming an outer shell, a pair of lower drive wheels 2 and 3 (see FIG. 2), and an auxiliary wheel 4. The autonomous cleaner S includes a rotating brush 5, a guide brush 6 and a side brush 7 at the bottom, and sensors 8 (8a, 8b, 8c) (see FIGS. 2, 3 and 4) around the periphery. ing.

The drive wheels 2 and 3 are rotationally driven by traveling motors 21 and 21A (see FIG. 6), respectively. The auxiliary wheel 4 is a driven wheel and is a caster that freely rotates. The drive wheels 2 and 3 are provided on the center side in the front-rear direction and the outer side in the left-right direction of the autonomous traveling vacuum cleaner S, and the auxiliary wheels 4 are provided on the front side in the front-rear direction and the center side in the left-right direction. ..
The side brush 7 is provided on the front side of the autonomous traveling cleaner S and on the outer side in the left-right direction. As shown by an arrow α1 in FIG. The dust on the floor is collected on the side of the rotating brush 5 (see FIG. 2) in the center by rotating so as to sweep from the inside toward the inside. The two guide brushes 6 are provided on the inner side in the left-right direction with respect to the drive wheels 2 and 3, respectively, and fixed so as to guide dust collected by the side brushes 7 so as not to escape from the width of the rotary brush 5 to the outside. It is a brush.
The rotating brush 5 is provided behind the drive wheels 2 and 3 of the autonomous traveling cleaner S. The left and right ends of the rotary brush 5 in the left-right direction can be located inside the drive wheels 2 and 3 or inside the guide brush 6, respectively.

FIG. 3 is a sectional view taken along line AA of FIG.
FIG. 4 is a perspective view showing the internal configuration of the autonomous traveling type vacuum cleaner with the case removed. Note that FIG. 4 shows a state in which the dust collection case 12 is removed.
FIG. 5 is a perspective view showing a BB cross section of FIG. 4.

  As shown in FIG. 3, the autonomous traveling cleaner S includes a rechargeable battery 9, a control device 10, a suction fan 11, and a dust collection case 12 inside. A suction port 12i is formed above the rotating brush 5 as an inlet of the dust collection case 12. A dust collecting filter 13 is attached to the outlet of the dust collecting case 12.

The rechargeable battery 9 is, for example, a secondary battery that can be reused by charging, and is housed in the battery housing unit 1s6 (see FIG. 2). The rechargeable battery 9 is arranged across the left and right ends of the autonomous traveling cleaner S (see FIGS. 3 and 5).
Electric power from the rechargeable battery 9 is supplied to the sensor 8, each motor (21, 21A, 5m) such as a driving device, the control device 10, the suction fan 11 and the like.
The autonomous traveling cleaner S is centrally controlled by the control device 10.

(Suction fan 11)
As shown in FIG. 4, the suction fan 11 is arranged near the center of the lower case 1s.
In the air flow path of the suction fan 11, the dust collection case 12, the dust collection filter 13, the suction fan 11, and the exhaust port 1s5 (see FIG. 2) are sequentially arranged from the suction port 14i (see FIG. 3) toward the downstream side. Is provided. The exhaust port 1s5 is provided in front of the rotating brush 5 and inside the drive wheels 2 and 3 in the left-right direction. By driving the suction fan 11 (see FIGS. 3 and 5), the air in the dust collection case 12 is discharged to the outside from the exhaust port 1s5 to generate a negative pressure, and the dust is removed from the floor surface Y through the suction port 14i. Suction into the dust collection case 12.

A rotary brush 5 (see FIG. 2) for scraping dust on the floor is provided near the suction port 14i.
The suction fan 11 is installed between the lower case 1s and an elastic body (not shown). By interposing the elastic body, the vibration of the suction fan 11 is attenuated and hardly transmitted to the lower case 1s, and the vibration and noise can be reduced.

  When the suction fan 11 and the rotary brush motor 5m (see FIG. 4) are driven, the rotary brush 5 (see FIG. 3) scrapes dust such as the floor surface. The dust that has been scratched is guided into the dust collection case 12 through the suction port 14i and the suction port 12i. The air from which dust has been removed by the dust collecting filter 13 is exhausted through the exhaust port 1s5 (see FIG. 2). The dust collection case 12 can be attached and detached by opening the lid 1u1 (see FIG. 1) provided on the upper case 1u, and the dust collection filter 13 is removed to discard the dust.

(Outline of operation of autonomous traveling vacuum cleaner S)
Here, the rough operation of the autonomous traveling type cleaner S will be described.
The autonomous traveling vacuum cleaner S is autonomously moved by the drive wheels 2 and 3 and the auxiliary wheel 4 (see FIG. 2), and is capable of forward movement, reverse movement, left / right turning, super-complex turning, and the like. Then, the autonomous traveling cleaner S collects dust collected by the side brush 7 and the guide brush 6 and attached to the periphery of the rotating brush 5 by the suction force of the suction fan 11 via the suction port 14i. 12 is sucked into the dust collection case 12 through the suction port 12i, and is retained in the dust collection case 12 by the dust collection filter 13 at the outlet.
When dust is collected in the dust collection case 12, the user appropriately takes out the dust collection case 12 from the main body Sh, removes the dust collection filter 13, and discards the dust.

Hereinafter, other configurations of the autonomous traveling cleaner S will be described in detail.
(Case 1)
The case 1 is a housing that forms an outer shell and houses the traveling motors 21 and 21A, the rotary brush motor 5m, the suction fan 11, the dust collection case 12, the control device 10, and the like.
The case 1 includes an upper case 1u that forms an upper wall, a lower case 1s (see FIG. 2) that forms a bottom wall (and a part of side walls), and a bumper 1b installed in the lower front part of the case 1. ..

The upper case 1u is provided with a lid 1u1 (see FIG. 1) for inserting and removing the dust collection case 12 (see FIG. 3).
As shown in FIG. 2, the lower case 1s is formed with a wheel unit housing portion 1s1, a side brush mounting portion 1s3, a hole portion 1s4, an exhaust port 1s5, and a battery housing portion 1s6.

The wheel unit accommodating portions 1s1 are formed on the left and right sides of the center of the lower case 1s, which has a substantially circular shape in plan view in FIG.
The wheel unit accommodating portion 1s1 accommodates wheel units 20 and 30 on which the drive wheels 2 and 3 are supported and driven.
A suction portion 14 is provided in the hole portion 1s4. A plurality of exhaust ports 1s5 are formed in the vicinity of the center of the lower case 1s and at a position sandwiched between the left and right wheel unit accommodating portions 1s1.

The battery housing portion 1s6 is formed in front of the center of the lower case 1s.
The rechargeable battery 9 is housed in the battery housing portion 1s6. Side brush attachment portions 1s3 for attaching the side brushes 7 are formed on the left and right of the battery housing portion 1s6.
On the rear side of the lower case 1s, that is, on the exhaust port 1s5 and on the rear side of the wheel unit accommodating portion 1s1, there is formed a hole portion 1s4 in which the suction portion 14 (see FIG. 2) is provided.

  The bumper 1b (see FIGS. 1 and 2) is installed so as to be movable in the front-rear direction according to a force applied from the outside when the bumper 1b collides with an obstacle such as a wall. The bumper 1b is biased outward by a pair of left and right bumper springs (not shown).

  When the acting force at the time of colliding with an obstacle through the bumper 1b acts on the bumper spring, the bumper spring is deformed so as to fall inward in plan view, and the bumper 1b is retracted while biasing the bumper 1b outward. Tolerate. When the bumper 1b moves away from the obstacle and loses the acting force, the bumper 1b returns to its original position by the urging force of the bumper spring. Incidentally, the backward movement of the bumper 1b (that is, contact with an obstacle) is detected by a bumper sensor 8a (see FIG. 4) described later, and the detection result is input to the control device 10.

(Suction part 14)
The suction unit 14 shown in FIG. 3 forms a part of a flow path of air containing dust that is sucked by the suction fan 11. The flow path downstream from the suction section 14 communicates with the dust collection case 12, the dust collection filter 13, the suction fan 11, and the exhaust port 1s5 (see FIG. 2) in order.
A rotary brush 5 for scraping dust is arranged in the suction unit 14, and a rotary brush motor 5m (see FIG. 4) for driving the rotary brush 5 is fixed. The suction portion 14 has a suction port 14i for sucking the dust scraped by the rotating brush 5 into the dust collection case 12. The suction port 14i is formed to have substantially the same length as the rotary brush 5 (see FIG. 2).
As shown in FIG. 3, the suction port 14i communicates with the suction port 12i of the opening of the dust collection case 12, and dust is collected in the dust collection case 12 through the suction port 14i and the suction port 12i.

  In the suction portion 14, a rotary brush housing portion 14b for housing the rotary brush 5 is formed in the lower case 1s, and the above-mentioned rotary brush 5 is arranged in the rotary brush housing portion 14b. The rotating brush 5 is rotatably attached to the suction unit 14. The rotating brush 5 is detachably attached to the suction portion 14.

(Dust collection case 12)
The dust collection case 12 shown in FIG. 3 is a container for collecting the dust sucked from the floor surface Y through the suction port 14i formed in the suction portion 14. The dust collection case 12 has substantially the same horizontal dimension as the rotating brush 5.
The dust collection case 12 includes a main body that stores the collected dust, a lid that allows the collected dust to be taken out, and a foldable handle on the top of the main body. The main body of the dust collection case 12 has a lower surface corresponding to the shape of the upper portion of the suction portion 14, and is provided with a suction opening 12i having a substantially same opening shape facing the suction opening 14i. The lid faces the suction port of the suction fan 11 and includes the dust collecting filter 13 described above.

(Sensor 8)
The bumper sensor 8a shown in FIG. 4 is a sensor, such as a photocoupler, that detects that the bumper 1b (see FIG. 1) has come into contact with an obstacle by retracting the bumper 1b. When an obstacle comes into contact with the bumper 1b, the sensor light is blocked by the backward movement of the bumper 1b. A detection signal corresponding to this change is output to the control device 10.

The distance measuring sensor 8b shown in FIG. 4 is an infrared sensor that detects the distance to an obstacle. In this embodiment, the distance measuring sensors 8b are provided at a total of three positions on the front surface and both side surfaces.
The distance measuring sensor 8b has a light emitting portion (not shown) that emits infrared light, and a light receiving portion (not shown) that receives reflected light that is reflected by infrared light reflected by an obstacle. The distance to the obstacle is calculated based on the intensity of the reflected light detected by the light receiving unit. At least the vicinity of the distance measuring sensor 8b of the bumper 1b is made of resin or glass that transmits infrared rays.
Incidentally, another type of sensor (for example, an ultrasonic sensor or a visible light sensor) may be used as the distance measuring sensor 8b.

  The floor distance measuring sensor 8c shown in FIG. 2 is an infrared sensor that measures the distance to the floor, and is installed at four locations on the lower surface front, rear, left, and right of the lower case 1s. By detecting a large step such as stairs by the floor distance measuring sensor 8c, the autonomous traveling cleaner S can be prevented from falling. For example, when the floor distance measuring sensor 8c detects a step difference of about 30 mm or more in the front, the control device 10 (see FIG. 3) controls the traveling motors 21 and 21A to move the main body unit Sh backward, and autonomously travels. The traveling direction of the mold cleaner S is changed.

(Control device 10)
The control device 10 shown in FIG. 3 is configured by mounting, for example, a microcomputer and peripheral circuits on a substrate. The microcomputer implements various processes by reading a control program stored in a ROM (Read Only Memory), expanding the control program in a RAM (Random Access Memory), and executing it by a CPU (Central Processing Unit). The peripheral circuit has an A / D / D / A converter, a drive circuit for various motors, a sensor circuit, a charging circuit for the rechargeable battery 9, and the like.

  The control device 10 executes arithmetic processing according to the operation of the operation button bu by the user and the signal input from the sensor 8, and the motors (21, 21A, 5m), the sensor 8, the suction fan 11 and the like. Input and output signals.

(Auxiliary wheel 4)
The auxiliary wheel 4 shown in FIG. 2 is provided at the center in the left-right direction in front of the lower case 1s. The auxiliary wheel 4 is a wheel for keeping the main body Sh at a predetermined height together with the drive wheels 2 and 3 to smoothly move the autonomous traveling cleaner S. The auxiliary wheel 4 is axially supported by the lower case 1s so that the auxiliary wheel 4 is driven to rotate by a frictional force generated between the auxiliary wheel 4 and the floor surface Y along with the movement of the main body Sh, and further rotates 360 degrees in the horizontal direction.

<< Embodiment 1 >>
Next, the wheel assemblies 20 and 30 including the drive wheels 2 and 3 of the autonomous traveling cleaner S of the first embodiment will be described.
The wheel assembly 20 including the drive wheels 2 and the wheel assembly 30 including the drive wheels 3 can be configured to be similar to each other in plane symmetry with respect to the left and right center planes of the autonomous traveling cleaner S. The description of the structure can be made in the same manner as the wheel assembly 30, and therefore will not be repeated as the description of the wheel assembly 30.

FIG. 6 is a perspective view of the wheel assembly of the first embodiment as seen obliquely from above and rear, FIG. 7A is a side sectional view of the wheel assembly of the first embodiment, and FIG. 7B is a CC cross section of FIG. 7A. It is a figure.
8 is an exploded perspective view of the wheel assembly, and FIG. 9 is an exploded perspective view of the wheel assembly viewed from the opposite direction of FIG. FIG. 10 is an exploded perspective view of the planetary gear assembly.

The speed reduction mechanism between the drive wheel 2 and the motor 21 that drives the drive wheel 2 in the wheel assembly 20 of the first embodiment will be described.
Specifically, as shown in FIG. 7A, the motor 21 is arranged coaxially with the drive wheel 2, and as shown in FIG. 7B, the sun gear 22 is press-fitted onto the drive shaft (input shaft) of the motor 21. It is fixed. The motor 21 is fixed to the motor bracket 21b.

As shown in FIG. 7B, three planet gears 23 are provided so as to mesh with the teeth on the outer periphery of the sun gear 22.
A first outer gear 24 of an internal gear having internal teeth 24h meshing with teeth 23h on the outer periphery of the three planetary gears 23 is fixed to a non-rotating portion such as the main body Sh illustrated in FIG.
Further, as shown in FIGS. 7A and 8, a second outer gear 25, which is an internal gear having internal teeth 25h, is rotatably provided so as to mesh with the outer teeth of the three planet gears 23. The drive wheel 2 (see FIG. 6) is fixed to the second outer gear 25 and constitutes an output shaft.

The rotatable second outer gear 25 has the same reference circle diameter as the fixed first outer gear 24 by changing the transition angle by changing the number of teeth different from the fixed first outer gear 24. .. Thus, the inner teeth 25h of the second outer gear 25 are arranged so as to mesh with the teeth 23h of the three planetary gears 23.
From the above, the reduction mechanism between the motor 21 and the drive wheel 2 is configured to include the sun gear 22, the three planetary gears 23, the first outer gear 24, and the second outer gear 25.

  As shown in FIGS. 8 and 9, the second outer gear 25 is a bottomed cylindrical resin component having a short depth. The second outer gear 25 has a disc-shaped bottom plate 25a and a cylindrical plate 25b having a shape rising from the edge of the bottom plate 25a. Inner teeth 25h are formed on the inner peripheral surface side of the cylindrical plate 25b.

  In the bottom plate 25a of the second outer gear 25, a circular hole 25a0 is formed in the center for escaping the motor shaft 21j. Further, on the inner surface side of the bottom plate 25a of the second outer gear 25, three bosses 25a1 (see FIG. 8) extending toward the motor 21 side are formed. Female screws 25a2 may be formed on each boss 25a1 from the outer surface side of the bottom plate 25a to the inner surface side (from the left side to the right side of FIG. 8). For example, by using a tapping screw, the boss 25a1 can be fixed without being threaded.

  The drive wheel 2 has a disc-shaped bottom plate 2s and a cylindrical wheel portion 2w rising from the edge of the bottom plate 2s. The drive wheel 2 is formed of, for example, an elastomer. The drive wheel 2 may be made of a material other than the elastomer. The outer diameter dimension s1 (see FIG. 7A) of the wheel portion 2w of the drive wheel 2 is about 50 mm to about 80 mm. The outer diameter dimension s1 of the wheel portion 2w may be about 80 mm at the maximum, and the minimum outer diameter dimension s1 may be about 50 mm.

The wheel portion 2w is a portion that comes into contact with the floor surface Y during traveling, and when mounted on the autonomous traveling cleaner S, the wheel portion 2w has a cylindrical surface 2w1 on the inner side in the left-right direction. On the other hand, on the outer side of the wheel portion 2w in the left-right direction, a cylindrical uneven cylindrical surface 2w2 having a concave shape 2wo and a convex shape 2wt is formed.
As shown in FIG. 8, the disc-shaped bottom plate 2s is formed with three bosses 2s1 for fixing the second outer gear 25 inside. A hole 2s2 through which a screw n1 for fixing the second outer gear 25 is inserted is formed through each boss 2s1.

  The drive wheel 2 and the second outer gear 25 are assembled in the following manner. The screw n1 is inserted into the hole 2s2 formed in the disc-shaped bottom plate 2s of the drive wheel 2 and screwed into the female screw 25a2 of the second outer gear 25, whereby the drive wheel 2 outputs the second outer It is fixed to the gear 25.

  With the above configuration, the three planetary gears 23 rotate by meshing with the inner teeth 24h of the fixed first outer gear 24 and the inner teeth 25h of the rotatable second outer gear 25, respectively. While the three planet gears 23 move the inner teeth 24h of the fixed first outer gear 24 one revolution, the rotatable second outer gear 25 should rotate by the number of teeth different from that of the first outer gear 24. Becomes

FIG. 11 shows the meshing state of the reduction mechanism between the drive wheel 2 and the motor 21 that drives the drive wheel 2. FIG. 11 is a schematic vertical cross-sectional view showing the meshing state of the reduction gear mechanism between the drive wheel and the motor.
When the number of teeth z1 of the sun gear 22, the number of teeth z2 of the planetary gear 23, the number of teeth z3 of the fixed first outer gear 24, and the number of teeth z4 of the rotatable second outer gear 25 are set, the drive from the input motor 21 is performed. The reduction ratio N to the output of the second outer gear 25 where the wheel 2 is fixed is calculated as follows.
Here, when the number of planet gears 23 is n and m is a natural number of 1, 2, 3, ..., The number of teeth z1 of the sun gear 22 has the number of teeth of the number of planet gears 23, It is expressed by the following equation (1).
z1 = n × m (1)

Further, the number z3 of teeth of the fixed first outer gear 24 has a number of teeth corresponding to the number of the planetary gears 23, where m is a natural number of 1, 2, 3, ... Therefore, when m is a natural number of 1, 2, 3, ..., It is expressed by the following equation (2).
z3 = n × m (2)
The number of teeth z4 of the rotatable second outer gear 25 is expressed by the following equation (3).
z4 = z3 + (n × m) (3)

The planet gear 23 only mediates between the sun gear 22, the first outer gear 24, and the second outer gear 25,
The reduction ratio N1 is expressed by the following equation (4).
N1 = z4 × (z3 + z1) ÷ (z1 × (z4-z3)) (4)

For example, if z1 = 57, z2 = 15, z3 = 84, and z4 = 87, the reduction ratio N1 becomes 71.7.
In this way, with the configuration of the wheel assembly 20, the reduction ratio N1 = about 40 to about 80 can be realized.

As shown in FIG. 7A, the wheel 2 is arranged outside the outer circumference of the fixed first outer gear 24 and the rotatable second outer gear 25. Thereby, the mysterious planetary gear reduction mechanism can be arranged inside the wheel 2. Similarly, the mysterious planetary gear reduction mechanism can be arranged inside the wheel 3.
Therefore, the reduction mechanism of the drive wheels 2 and 3 can be downsized both in the thrust direction (axial direction) and the diametrical direction of the drive wheels 2 and 3.

<Buffer mechanism K>
When an external force received by the drive wheels 2 and 3 from the ground is applied to the gear parts (22, 23, 24, 25), backlash or the like changes, which may cause a problem that noise and energy transmission loss increase. is there.
Therefore, as shown in FIGS. 7A and 7B, a buffer mechanism K is provided between the drive wheel 2 and the housing 26.

The housing 26 is provided between the drive wheel 2 and the rotatable second outer gear 25 to which the drive wheel is fixed.
The buffer mechanism K includes a pin 26p supported by the housing 26 and a cylindrical roller 26r rotatably inserted in the pin 26p.
As shown in FIGS. 8 and 9, the housing 26 is a bottomed cylindrical resin component having a shallow depth. The housing 26 has a disk-shaped bottom plate 26a, a cylindrical side plate 26b, and a flange plate 26c.

A central hole 26a1 into which the three bosses 25a1 of the drive wheel 2 are inserted is formed in the center of the bottom plate 26a.
A pin 26p of stainless steel or the like is fixed to the flange plate 26c in the axial direction of the drive wheel 2. A roller 26r is rotatably inserted in the pin 26p. The roller 27r is made of resin such as POM (Polyoxymethylene, Polyacetal). The roller 26r is arranged at the position shown in FIG. 7A, the pin 26p is passed through the roller 26r, and then the pin 26p is fixed to the flange plate 26c and the cylindrical side plate 26b by press fitting or the like. As a result, the roller 26r is rotatably provided on the pin 26p.

  With the above configuration, the clearance between the inner peripheral surface 2n (see FIG. 7A) of the drive wheel 2 and the roller 27r is narrowed, so that the impact or external force that the drive wheel 2 receives from the floor surface Y is transferred to the housing 26 via the roller 26r. Can be received at. As a result, it is possible to suppress the impact or external force applied to the drive wheel 2 from the floor surface Y from being transmitted to gears such as the planetary gear 23 and the sun gear 22.

According to the configuration of the first embodiment, the following operational effects are exhibited.
1. The reduction mechanism of the drive wheels 2 and 3 including the motor 21 is set to approximately the outer diameter dimension s1 and the width dimension s2 of the drive wheels 2 and 3, respectively, but the reduction ratio N1 required for the autonomous traveling cleaner S is about 40. ˜80, preferably 70-80 can be achieved.

2. As shown in FIGS. 6, 7A, and 7B, when viewed in the axle directions of the drive wheels 2 and 3, the reduction mechanism (22, 23, 24, 25) of the drive wheels 2 and 3 including the motor 21 is used. The drive wheels 2 and 3 can be accommodated within the area of the outer diameter dimension s1. Therefore, the rechargeable battery 9, the dust collection case 12, the suction port 14i, and the rotating brush 5 can be arranged at any position in the front-rear direction area excluding the drive wheels 2 and 3. Therefore, the autonomous traveling vacuum cleaner S can be downsized. Moreover, since the rechargeable battery 9, the dust collection case 12, the suction port 14i, and the rotary brush 5 can be arranged by sufficiently using the left and right directions excluding the regions of the drive wheels 2 and 3, the basic function of the autonomous traveling cleaner S can be improved. ..

3. When the autonomous traveling cleaner S is viewed in the front-rear direction (see FIGS. 1 and 4), as shown in FIG. 7A, the motor 21 and the gears of the reduction mechanism (in each width dimension s2 of the drive wheels 2 and 3) 22, 23, 24, 25) can be partly or wholly accommodated.
From the above, the reduction mechanism of the drive wheels 2 and 3 can be downsized. That is, it is possible to reduce the size of the reduction mechanism of the drive wheels 2 and 3 while increasing the reduction ratio N1.

4. In this reduction mechanism, a large external force resulting from the torque is applied to the planetary gear 23, the first outer gear 24, and the second outer gear 25, and a large stress is generated. However, in this reduction mechanism, since three planetary gears 23 are used, the external force becomes 1/3 and the generated stress also becomes 1/3. In addition, the external force applied to the first outer gear 24 and the second outer gear 25 is also transmitted through the three planetary gears 23, and thus becomes 1/3 each. Therefore, the stress generated in each of the first outer gear 24 and the second outer gear 25 becomes 1/3.
Therefore, in this speed reduction mechanism, the generated stress is reduced and the mechanical reliability is high.

5. Between each of the drive wheels 2 and 3 and the housing 26, a cushioning mechanism K that narrows the clearance between the drive wheel 2 and the roller 26r supported by the housing 26 is provided. Therefore, the housing 26 can receive an impact and an external force applied to the drive wheels 2 and 3. Therefore, the impact and the external force applied to the drive wheels 2 and 3 are suppressed from being transmitted to the gears (22, 23, 24, 25) of the reduction mechanism.
Therefore, the speed reducing mechanism (22, 23, 24, 25) is highly reliable and can have a long life.

6. From the above, it is possible to realize the autonomous traveling type cleaner S having a reduction mechanism that is small in size, capable of high output torque, and has reduced mechanical stress and high mechanical reliability.
In addition, in the said 1st Embodiment, although the case where three planetary gears 23 were used was illustrated, if the number of planetary gears 23 is plural, the number can be suitably selected.

<< Embodiment 2 >>
Next, the wheel assemblies 20A and 30A including the drive wheels 2 and 3 of the autonomous traveling cleaner S according to the second embodiment will be described.
Since the wheel assembly 20A including the drive wheels 2 and the wheel assembly 30A including the drive wheels 3 can be configured to be similar to each other in plane symmetry with respect to the left and right center planes of the autonomous traveling cleaner S, the wheel assembly 20A of the wheel assembly 20A. The description of the configuration can be made in the same manner as the description of the wheel assembly 30A, and thus the description of the wheel assembly 30A will not be repeated.

FIG. 12 is a perspective view of the wheel assembly of the second embodiment as seen obliquely from above and rear.
13 is an exploded perspective view of the wheel assembly of the second embodiment, and FIG. 14 is an exploded perspective view of the wheel assembly as seen from the opposite direction of FIG.
15 is a cross-sectional view taken along the line D-D of FIG. 12, and FIG. 16 is a cross-sectional view taken along a cross section where the pinion gear and the gear can be seen.

As a reduction gear mechanism between the drive wheel 2 and the motor 31 in the wheel assembly 20A, a reduction gear mechanism of a planetary gear using a trochoid curve is adopted.
As shown in FIG. 16, a motor 31 (rotating shaft 31j) is provided eccentrically to the rotating shaft of the drive wheel 2 (position of the cam shaft 34).

A pinion gear 32 is fixed to a rotating shaft 31j of the motor 31.
As shown in FIG. 12, the motor 31 is fixed to the first housing ha. The first housing ha is fixed to a second housing hb that is a structural member of the drive wheel 2.
Specifically, as shown in FIG. 13, a screw insertion hole ha1 is formed in the first housing ha, while a female screw hb1 is threaded in the second housing hb. The first housing ha is fixed to the second housing hb by inserting a screw (not shown) through the screw insertion hole ha1 of the first housing ha and screwing the screw into the female screw hb1 of the second housing hb.
Further, a gear 33 meshing with the pinion gear 32 is provided with more teeth than the pinion gear 32 (see FIG. 16).

Here, helical gears are adopted as the pinion gear 32 and the gear 33 of the first gear for the purpose of noise reduction.
A cam shaft 34 (see FIG. 13, FIG. 14, etc.) is fixed to the rotating shaft of the gear 33.
As a result, the output of the motor 31 is decelerated and transmitted to the camshaft 34 via the pinion gear 32 and the gear 33.

As shown in FIGS. 13 and 14, the cam shaft 34 has a first central shaft 34a, a first cam portion 34b, a second cam portion 34c, and a second central shaft 34d.
The first central axis 34a of the camshaft 34 is coaxial with the rotation axis of the drive wheel 2, and is formed on the central axis of the gear 33 with a rectangular cross section that prevents rotation. The first central shaft 34a is fitted and fixed to the central shaft of the gear 33.

The first cam portion 34b is a cylindrical shaft that is eccentric to the first central shaft 34a.
The second cam portion 34c is a cylindrical shaft that is eccentric to the first central axis 34a and is formed with a phase shift of about 180 degrees with respect to the first central axis 34a with respect to the first cam portion 34b. ..
The second central shaft 34d is a cylindrical shaft that is coaxial with the rotation shaft of the drive wheel 2 like the first central shaft 34a. The second central shaft 34d is rotatably supported by a bearing 38t inserted through the central shaft of the drive wheel 2.

Therefore, the cam shaft 34 rotates coaxially with the rotation axis of the drive wheel 2. However, as will be described later, the rotation of the drive wheel 2 and the rotation of the cam shaft 34 are independent.
A planetary gear 35, in which teeth 35h are formed using a trochoidal curve, is arranged on the first cam portion 34b of the cam shaft 34 via a bearing 34t1.

The planetary gear 35 is provided with a plurality of columnar recesses 35a for coaxially rotating the rotary plate 38. The columnar recess 35a is a recess having a cylindrical space that does not penetrate the motor 31 side.
The drive wheel 2 is fixed to the rotary plate 38. The drive wheel 2 is rotationally driven by rotationally driving the rotary plate 38.
As shown in FIG. 15, the rotary plate 38 is incorporated in the bearing 39 (see FIGS. 13 and 14). The bearing 39 may be a sliding bearing or a ball bearing. On the other hand, the rotary plate 38 is connected to the cam shaft 34 via a bearing 38t.
On the second cam portion 34c of the cam shaft 34, a planetary gear 36 having teeth 36h formed by using a trochoid curve is arranged via a bearing 34t2. The planetary gear 35 and the planetary gear 36 are gears of the same shape, and are axially supported by the first cam portion 34b and the second cam portion 34c, and are attached with a phase shift of 180 degrees.

  The planetary gears 35 and 36 are provided with two cams whose phases are shifted by 180 degrees in order to reduce vibration. In other words, the eccentricity of the planetary gear 36 in the opposite direction to the planetary gear 35 can cancel the movement of the planetary gear 35 due to the eccentricity and suppress vibration, noise and the like.

  The planetary gear 36 has a plurality of through holes 36a coaxially formed therethrough for rotating the rotary plate 38. The insertion holes 36a of the planetary gear 36 are formed at the same intervals as the cylindrical recess 35a of the planetary gear 35.

FIG. 17 is a sectional view taken along line EE of FIG. FIG. 18 is a sectional view taken along line FF of FIG.
The teeth 35h and 36h of the planet gears 35 and 36 mesh with the teeth 37h of the outer gear 37, respectively. The outer gear 37 is a fixed gear.
Since the teeth 35h and 36h of the planetary gears 35 and 36 are formed by using trochoidal curves, respectively, the outer gear 37 that meshes with the teeth is formed into cylindrical teeth 37h. If normal involute gears are used as the planet gears 35 and 36, involute interference occurs, so the teeth 35h and 36h of the trochoid curve and the cylindrical tooth 37h are formed.

The cylindrical tooth 37h is formed by a roller 37h2 which is rotatably supported by a pin 37h1.
As shown in FIG. 18, a roller 38r rotatably supported by a pin 38p fixed to a rotary plate 38 is loosely fitted in the cylindrical recess 35a of the planetary gear 35 and the insertion hole 36a of the planetary gear 36. There is.

As shown in FIGS. 13 and 14, the rotary plate 38 is an annular component and is rotatably supported by the second central shaft 34d of the camshaft 34 via a bearing 38t.
With the above configuration, when the planetary gears 35 and 36 rotate by meshing with the cylindrical teeth 37h of the outer gear 37, the rotary plate 38 is passed through the cylindrical recess 35a and the roller 38r penetrating the insertion hole 36a. Will rotate about the second central axis 34d of the camshaft 34.

As shown in FIG. 14, female screws 38n are threaded on the rotary plate 38 at three positions.
The drive wheel 2 is fixed to the rotary plate 38 by inserting the screws n2 into the three through holes 2s4 penetrating the drive wheel 2 and screwing the screws n2 into the female screws 38n of the rotary plate 38.

  The drive wheel 2 has a disc-shaped bottom plate 2s and a cylindrical wheel portion 2w. The drive wheel 2 is formed of, for example, an elastomer. The drive wheel 2 may be made of a material other than the elastomer. The outer diameter dimension s3 of the wheel portion 2w of the drive wheel 2 is about 50 mm to about 80 mm. That is, the outer diameter dimension s3 (see FIG. 17) of the wheel portion 2w is about 80 mm at maximum, and the minimum outer diameter dimension is set at about 50 mm.

The wheel portion 2w is a portion that comes into contact with the floor surface during traveling, and has a cylindrical surface 2w1 inside. On the other hand, on the outer side of the drive wheel 2, a cylindrical uneven cylindrical surface 2w2 having a concave shape 2wo and a convex shape 2wt is formed.
As shown in FIG. 14, the disc-shaped bottom plate 2s is provided with the above-described three through holes 2s4.

  With the above configuration, when the camshaft 34 rotates, the planetary gears 35 and 36 revolve by the respective operations of the first cam portion 34b and the second cam portion 34c of the camshaft 34 (the respective axes of the planetary gears 35 and 36). (While rotating the part), the teeth 35h and 36h of the outer gear 37 and the teeth 37h of the outer gear 37 are rotated to rotate on their own axes.

That is, the rotation of the planetary gear 35 can be extracted by the difference between the number of teeth 37h of the fixed outer gear 37 and the number of teeth 35h (35h) of the planetary gear 35 (36).
Specifically, the rotational speeds of the planetary gears 35 and 36 are extracted using a rotary plate 38 via a roller 38r penetrating the cylindrical recess 35a and the insertion hole 36a.

The meshing state of the reduction mechanism between the drive wheel 2 and the motor 31 is as shown in FIG. 19 (a). 19 (a) is a schematic vertical cross-sectional view showing the meshing state of the reduction gear mechanism between the drive wheel and the motor, and FIG. 19 (b) shows the bearings on both sides of the reduction gear mechanism and the camshaft and the load. It is a principle view showing how to apply.
Here, when the number of teeth of the pinion gear 32 is z1, the number of teeth of the gear 33 is z2, the number of teeth of the planetary gears 35 and 36 is z3, and the number of teeth of the outer gear is z4, the reduction ratio N2 is expressed by the following equation (5). It is represented by.
N2 = (z2 ÷ z1) × (1 ÷ ((z4-z3) ÷ z3)) (5)

  For example, when the number of teeth of the pinion gear 32 is z1 = 12, the number of teeth of the gear 33 is z2 = 48, the number of teeth of the planetary gears 35 and 36 is z3 = 17, and the number of teeth of the outer gear 37 is z4 = 18, the reduction ratio is N2 = 68.0. With the above configuration, the reduction ratio N2 can be set to about 40 to about 80.

In this case, the reduction ratio N2A of the rotary plate 38, in which the rotation of the cam shaft 34 (z2 = 48) is transmitted via the planetary gears 35 and 36 with respect to the rotation of the cam shaft 34 (z2 = 48), is given by the following equation.
Reduction ratio N2A = 1 ÷ ((z4-z3) ÷ z3)
That is, the rotation speed of the camshaft 34, which is a shaft, is different from the rotation speed of the drive wheels 2 (rotating plate 38).

  As shown in FIG. 17, when the cam shaft 34 rotates in the arrow γ1 direction, the planetary gear 35 fixed to the cam shaft 34 rotates in the same direction (arrow γ1 direction). Since the number of teeth of the planetary gear 35 is z3 = 17 and the number of teeth of the outer gear 37 is smaller than z4 = 18, the planetary gear 35 moves in the arrow γ2 direction opposite to the rotation direction (arrow γ1) of the camshaft 34. It will rotate.

According to the configuration of the second embodiment, the following operational effects are exhibited.
1. A high reduction ratio (for example, a reduction ratio N of about 40 to about 80, preferably 65 to 80) can be obtained only by two-step reduction of the gear 33 and the planetary gear 35 and the planetary gear 35 and the outer gear 37. .. Therefore, it is possible to dispose a highly efficient reduction mechanism inside the drive wheels 2 and 3.

2. As shown in FIGS. 16 to 18, when viewed in the respective axle directions of the drive wheels 2 and 3, the speed reduction mechanisms (32, 33, 34, 35) of the drive wheels 2 and 3 including the motor 31 are respectively driven. It can be accommodated within each of the outer diameter dimensions s3 (see FIG. 17) of a few. Therefore, the rechargeable battery 9, the dust collection case 12, the suction port 14i, and the rotating brush 5 can be arranged at arbitrary positions in the front-rear direction excluding the drive wheels 2 and 3 of the autonomous traveling cleaner S. Therefore, the autonomous traveling vacuum cleaner S can be downsized. Further, the rechargeable battery 9, the dust collection case 12, the suction port 14i, and the rotating brush 5 can be arranged by sufficiently using the left and right directions excluding the regions of the drive wheels 2 and 3, so that the basic function of the autonomous traveling cleaner S is improved. it can.

3. When the autonomous traveling vacuum cleaner S is viewed in the front-rear direction (see FIGS. 1 and 4), as shown in FIG. 12, the motor 31 and the speed reduction mechanism are arranged in the respective width dimensions s4 of the drive wheels 2 and 3. Some or all of the gears (32, 33, 34, 35, 37) can be housed.

4. Since the teeth 35h and 36h of the planetary gears 35 and 36 are formed by using trochoidal curves, respectively, stress concentration can be suppressed and they are strong against stress.

5. Since the gear 33, which is a rotating component, and the planet gears 35 and 36 can be supported at both ends, the structure is strong against external force.

6. Since the planetary gears 35 and 36 that are fixed to the camshaft 34 and have a phase difference of 180 degrees are used, vibration can be suppressed.

7. An impact or an external force is applied to the drive wheels 2 and 3 from the floor surface Y, but the rotary plates 38 to which the drive wheels 2 and 3 are fixed have a cylindrical recess 35a of the planet gears 35 and 36, and an insertion hole 36a. It is connected to the planetary gears 35 and 36 via the fitted roller 38r. Further, since the drive wheels 2 and 3 receive an impact and an external force by the rotating plate 38 and the like, it is possible to prevent the impact and the external force applied to the drive wheels 2 and 3 from being transmitted to the gear portions (32, 33, 34, 35, 37). To be done.

8. In the wheel assembly 20A of the second embodiment, as shown in FIG. 19 (b), the load applied to the drive wheels 2 (3) when the autonomous traveling cleaner S travels, via the rotary plate 38 and the bearing 38t, the cam. It is transmitted to the shaft 34. The load W transmitted to the camshaft 34 is transmitted to the first housing ha and the second housing hb (see FIG. 15) via the bearings 34t1 and 38t, respectively. Therefore, the reduction mechanism provided between the drive wheel 2 and the motor 31 does not have to receive the load W. Therefore, the speed reduction mechanism has high reliability and durability.

On the other hand, in Patent Document 1, as shown in FIG. 23, the wheel hub (32) to which the drive wheels are fixed is supported by the wheel hub bearing (33). FIG. 23 is a vertical cross-sectional view (FIG. 1 of Patent Document 1) showing an in-wheel motor drive device including the motor drive device of Patent Document 1.
The wheel-side rotating member (28) to which the wheel hub (32) is fixed is supported by the outer ring of the bearing (64). The inner ring of the bearing (64) supports one end of the damping part input shaft (25). The other part of the damping part input shaft (25) is rotatably supported by the pump casing (22p) via a rolling bearing (62). Therefore, the load applied to the drive wheel is pumped not only through the wheel hub bearing (33) but also through the wheel side rotating member (28), the bearing (64), the damping section input shaft (25), the rolling bearing (62) and the like. The casing (22p) is receiving. Therefore, the load applied to the drive wheels is received by the mechanical portion, and the reliability of the mechanical portion is lower than that of the second embodiment (the present invention).

9. As shown in FIG. 15, the cam shaft 34 is supported by the first bearing 34t1 and the second bearing 38t. Then, the rotary plate 38 is supported by the second housing hb via the third bearing 39.
A first bearing 38t that supports the camshaft 34 and is arranged between the camshaft 34 and the drive wheel 2 of the wheel, and a second bearing 38t that supports the camshaft 34 and is located closer to the center than the first bearing 38t. By including the bearing 34t1 of FIG. 1, the mechanism for driving the drive wheel 2 can be downsized.

  The diameter dimension 39s of the inner peripheral surface of the third bearing 39 is larger than one of the diameter dimension 38t1 of the outer peripheral surface of the first bearing 38t and the diameter dimension 34s of the outer peripheral surface of the second bearing 34t1, and the one bearing It is arranged to overlap. In the example shown in FIG. 15, the diameter dimension 39s of the inner peripheral surface of the third bearing 39 is larger than the diameter dimension 38t1 of the outer peripheral surface of the first bearing 38t, and the third bearing 39 overlaps with the first bearing 38t. Will be placed. Since the diameter dimension 39s of the inner peripheral surface of the third bearing 39 is larger than either the diameter dimension 38t1 of the outer peripheral surface of the first bearing 38t or the diameter dimension 34s of the outer peripheral surface of the second bearing 34t1, the third dimension The bearing 39 can be placed so as to overlap the first bearing 34t1 or the second bearing 38t.

Conventionally, the wheel fixed to the shaft is rotated, or the wheel is rotatably supported on the fixed shaft via a bearing, and the wheel is rotated independently of the shaft.
On the other hand, in the second embodiment (the present invention), the camshaft 34 of the shaft and the drive wheel 2 (rotary plate 38) rotate independently.
From the above, the speed reducing mechanism of the drive wheel 2 (3) can be made compact.

  On the other hand, in Patent Document 1, as shown in FIG. 1 of Patent Document 1, an external force is applied to the bearing casing (22c) outside the housing via the bearing (64). It is configured to increase in the direction of the shaft (25) and the rotation shaft (35).

10. As described above, it is possible to realize the autonomous traveling type cleaner S having a reduction mechanism that is small in size, capable of high output torque, and has reduced mechanical stress and high mechanical reliability.

  In the second embodiment, the case where two planetary gears 35 and 36 are used has been described, but a single planetary gear may be used.

  Further, although the configuration in which the rotations of the planetary gears 35 and 36 are transmitted to the drive wheels 2 and 3 via the rotary plate 38 has been described, if the rotations of the planetary gears 35 and 36 can be transmitted to the drive wheels 2 and 3, respectively. The driving force may be directly transmitted from the planetary gears 35 and 36 to the driving wheels 2 and 3, respectively. Alternatively, a configuration other than the rotary plate 38 may be used to transmit the rotation of the planetary gears 35 and 36 to the rotary plate 38.

<< Embodiment 3 >>
Next, the wheel assemblies 20B and 30B including the drive wheels 2 and 3 of the autonomous traveling cleaner S of the third embodiment will be described.
The wheel assemblies 20B and 30B of the third embodiment are speed reduction mechanisms that use worm gears and spur gears.
The wheel assembly 20B including the drive wheels 2 and the wheel assembly 30B including the drive wheels 3 are plane-symmetric with respect to the left and right center planes of the autonomous traveling cleaner S and can have the same configuration. Therefore, the wheel assembly 20B. Since the description of the configuration can be similarly applied to the wheel assembly 30B, the description of the wheel assembly 30B will not be repeated.

FIG. 20 is a perspective view of the wheel assembly of the third embodiment as seen obliquely from above and rear.
FIG. 21 is a perspective view of the inside of the wheel assembly with the drive wheels of the third embodiment removed and seen from the upper rear side in the opposite direction of FIG. 20.

In the wheel assembly 20B of the third embodiment, the motor 41 is arranged at a position (eccentric) offset from the rotation axis (rotation center) of the drive wheel 2. As shown in FIG. 21, a first worm gear 42 is fixed to the drive shaft 41j of the motor 41. A first worm wheel 43 that receives the rotation of the first worm gear 42 is fixed to one side of the shaft 44.
A second worm gear 45 is fixed to the other side of the shaft 44.

A second worm wheel 46 is provided so as to mesh with the second worm gear 45 of the shaft 44.
A first spur gear 47 is provided coaxially with the second worm wheel 46.
The first spur gear 47 meshes with teeth 48h of a second spur gear 48 provided coaxially with the drive wheel 2. The drive wheel 2 (see FIG. 20) is fixed to the second spur gear 48.
As a result, the rotation of the motor 41 is transmitted to the first worm wheel 43 via the first worm gear 42.

The rotation of the first worm wheel 43 is transmitted to the second worm gear 45 provided on the opposite side of the first worm wheel 43 via the shaft 44.
The second worm gear 45 transmits rotation to the second worm wheel 46, and is provided coaxially with the drive wheel 2 via a first spur gear 47 fixed coaxially with the second worm wheel 46. The rotation is transmitted to the second spur gear 48. Since the drive wheel 2 is fixed coaxially with the second spur gear 48, the rotation of the motor 41 is transmitted to the drive wheel 2.

A shaft 48j (see FIG. 21) of the second spur gear 48 is rotatably supported by a bearing fixed to a housing (not shown). As a result, the load applied to the drive wheels 2 is transmitted to the housing and is not applied to the reduction mechanism provided between the motor 41 and the drive wheels 2, so that the reduction mechanism is prevented from being worn and the reliability is high.
A shaft (not shown) of the drive wheel 2 is provided separately from the spur gear 48, and the shaft is rotatably supported by a bearing fixed to the housing so that the vibration of the drive wheel 2 is transmitted to the spur gear 48. It may be configured not to be transmitted.

The configurations of the drive wheels 2 and 3 are almost the same as those of the first and second embodiments, and therefore, the same reference numerals are given and shown, and detailed description thereof is omitted. The outer diameter dimension s5 (see FIG. 20) of the wheel portion 2w of the drive wheel 2 is about 50 mm to about 80 mm.
The meshing state of the reduction gear mechanism between the drive wheels 2 and the motor 41 is as shown in FIG. 22. FIG. 22 is a schematic vertical cross-sectional view showing the meshing state of the reduction gear mechanism between the drive wheel and the motor.

Here, the number of threads of the first worm gear 42 is z1, the number of teeth of the first worm wheel 43 is z2, the number of teeth of the second worm gear 45 is z3, the number of teeth of the second worm wheel 46 is z4, and Assuming that the number of teeth of the first spur gear 47 is z5 and the number of teeth of the second spur gear 48 is z6, the reduction ratio N3 is expressed by the following equation (6).
N3 = (z2 ÷ z1) × (z4 ÷ z3) × (z6 ÷ z5) (6)

With the configuration of the wheel assemblies 20B and 30B, it is possible to realize the reduction ratio N3 = about 40 to about 80, respectively.
By using the worm gears (42, 45), high deceleration is possible with a small radius of rotation, which is advantageous in terms of noise and vibration. Further, since the worm gears (42, 45) are small, the size can be reduced, and the reduction mechanism can be completed inside the drive wheels 2, 3.

According to the configuration of the third embodiment, the following operational effects are exhibited.
1. By using the two worm gears, the first worm gear 42 and the second worm gear 45, the reduction ratio can be increased.

2. By using two worm gears and changing the rotation direction twice, the reduction mechanism of the drive wheels 2 and 3 can be downsized.

3. Therefore, as shown in FIGS. 20 and 21, when viewed in the respective axle directions of the drive wheels 2 and 3, the speed reduction mechanisms (42, 43, 44, 45, 42, 43, 44, 45, for the drive wheels 2, 3 including the motors 41, 41A are included. 46, 47, 48) can be housed within the area of the outer diameter dimension s5 (see FIG. 20) of the drive wheels 2, 3, respectively. Therefore, the rechargeable battery 9, the dust collection case 12, the suction port 14i, and the rotating brush 5 can be arranged at arbitrary positions in the front-rear direction excluding the drive wheels 2 and 3 of the autonomous traveling cleaner S. Therefore, the autonomous traveling vacuum cleaner S can be downsized. Moreover, since the rechargeable battery 9, the dust collection case 12, the suction port 14i, and the rotary brush 5 can be arranged by sufficiently using the left and right directions excluding the regions of the drive wheels 2 and 3, the basic function of the autonomous traveling cleaner S can be improved. ..

4. When the autonomous traveling type vacuum cleaner S is viewed in the front-rear direction (see FIGS. 1 and 4), as shown in FIG. 20, the motors 41 and 41A and the speed reduction mechanism are arranged within the width dimensions s6 of the drive wheels 2 and 3, respectively. Some or all of the gears (22, 23, 24, 25) can be housed.

5. By using the two worm gears, that is, the first worm gear 42 and the second worm gear 45, it is possible to increase the reduction ratio and suppress the generation of stress in the gears. Therefore, the number of teeth 48h of the second spur gear 48 and the number of teeth 47h of the first spur gear 47 can be increased.
As described above, conventionally, there has been a demand to use fine teeth for the gears of the reduction mechanism, but since the reduction ratio becomes large, it is necessary to increase the tooth width. Therefore, there is a problem that if the teeth are enlarged so as to withstand the torque, the reduction gear mechanism becomes large.
The present invention solves this problem.

6. From the above, it is possible to realize the autonomous traveling type vacuum cleaner S having a speed reduction mechanism that is small in size, capable of high output torque, and has reduced mechanical stress and high mechanical reliability.
The present invention is not limited to the configurations of the first to third embodiments, and various modifications and concrete forms are possible within the scope of the appended claims.

Two or three drive wheels
31 Motor (travel motor, drive source)
11 Suction Fan 12 Dust Collection Case 14i Suction Port 33 Gear (Reduction Gear, Reduction Mechanism)
34 Camshaft (Shaft)
35 Planetary gears (reduction gears, planetary gears, reduction mechanism)
36 Planetary gears (reduction gears, planetary gears, reduction mechanism)
37 Outer gear (reduction gear, reduction mechanism)
38 Rotating plate (reduction gear, reduction mechanism, final reduction gear)
s3 Outer diameter size s4 Width size S Autonomous traveling type vacuum cleaner Sh Main body (car body)

Claims (2)

A suction fan for generating a negative pressure, a suction port for sucking dust on the surface to be cleaned by the negative pressure of the suction fan, and a dust collection case for collecting dust arranged between the suction fan and the flow path of the suction port And an autonomous traveling vacuum cleaner having at least two wheels for autonomous traveling,
The wheel includes a shaft that is rotated by an input of a drive source and bears a load of a vehicle body, and a reduction mechanism provided between the shaft and the wheel.
The reduction mechanism is
It consists of multiple reduction gears,
When viewed in the direction of the rotation axis of the drive wheels that are respectively rotated by the drive of each traveling motor, the drive wheels are arranged in an area that is less than or equal to the outer diameter of the drive wheels.
When viewed in the front-rear direction, a part or all of each reduction gear constituting the reduction mechanism is located within a region of the width dimension of the drive wheel,
The final traveling reduction gear is decelerated by the reduction gear using an inscribed trochoidal curve. The autonomous traveling vacuum cleaner according to claim 1,
The deceleration mechanism has two planetary gears using a trochoidal curve, which are positioned 180 ° apart from each other.

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