JP2003094904A - Spherical drive wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spherical drive wheel at a very low cost by reducing the annular diameter and increasing the width of bearings to be used, which allows JIS standard parts to be used, for reduction in the part cost of the bearings without the influence on the production cost. SOLUTION: The upper part 1a of a spherical wheel 1 is supported by a top part support roller 2, the outer peripheral part 1b of the spherical wheel 1 is supported by a plurality of outer peripheral part support rollers 3 at intervals in circumferential direction, the outer peripheral part support rollers 3 are rotatably held at the lower end of a generally dome-shaped roller holding part 4 having a small diameter opening part 4a at the upper part thereof, and the small diameter opening part 4a of the roller holding body 4 is rotatably supported with the bearings 7 and rotatingly driven by a rotatingly driving source 5.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spherical drive which is suitably used as a running wheel of various vehicles such as a wheelchair, a serving truck, an aerial work vehicle, an automatic guided vehicle, and the like. It is about the wheel. 2. Description of the Related Art A spherical drive wheel of this type is disclosed in Japanese Patent Application No.
Patent Application No. 178561 exists,
By mounting a plurality of them to the chassis of the vehicle with a certain inclination angle, they can be used as running wheels, vibration during running is small, and running noise due to vibration is also reduced. It has been attracting much attention because it is suitably used for the running wheels of various vehicles. As shown in FIGS. 4 to 6, the spherical drive wheel has an upper portion of a ball wheel 31 supported by a top support roller 32, and a plurality of outer peripheral portions of the ball wheel 31 are spaced apart in the circumferential direction. (Six in the example). Each outer peripheral portion supporting roller 33 is rotatably held by an annular roller holder 34, and the roller holder 34 is rotatably supported by an annular bearing 35 and is rotationally driven by a rotation drive source 36. [0004] When the roller holder 34 is driven to rotate in this manner, the respective outer peripheral support rollers 33 provided on the roller holder 34 are also driven to rotate, whereby the ball wheel 31 has an upper portion on the top support roller 32. The rotating force is applied while being supported. In the above-described conventional spherical driving wheel, the bearing 35 supporting the roller holder 34 surrounds the roller holder 34 from the outer periphery. When 34 is rotationally driven, it receives a very large sliding force. Therefore, this bearing 35
The annular diameter must be larger than the annular diameter of the roller holder 34, and unless the precision is high and the strength is very good, the use cannot be tolerated. However, a bearing 3 capable of withstanding the above-mentioned applications.
No. 5 is not a JIS standard product, but is required to have higher accuracy and higher strength than the JIS standard product. Therefore, the parts cost of the bearing 35 becomes very high, This has an effect on the product cost of the spherical driving wheel, and has a problem that the spherical driving wheel becomes very expensive. Further, in the case of using the above-mentioned conventional spherical driving wheels as running wheels, they must be attached to the chassis S of the vehicle with a certain inclination angle (FIG. 4).
6, the chassis S side of the vehicle is inclined), and when the bearing 35 is made wide, the protective cover 37 of the outer peripheral support roller 33 becomes bulky,
Since the protective cover 37 comes close to the running surface and rides on the undulations or steps of the ground contact surface during running, there is a problem that a wide bearing 35 cannot be used. Therefore, the present invention has been made to solve the above-mentioned problems, and the bearing used has a small annular diameter and may have a wide width, and a JIS standard product sufficiently used. The object of the present invention is to provide a very inexpensive spherical drive wheel by lowering the cost of the parts of the bearing without affecting the product cost. Therefore, in the spherical driving wheel of the present invention, the upper portion 1a of the ball wheel 1 is supported by the top support roller 2, and the outer peripheral portion 1b of the ball wheel 1 is spaced apart in the circumferential direction. Open and supported by a plurality of outer peripheral support rollers 3,
Each outer peripheral support roller 3 is rotatably held at a lower end of a substantially dome-shaped roller holder 4 having a small-diameter opening 4a at an upper portion. The small-diameter opening 4a of the roller holder 4 is rotatably supported by a bearing 7. It is supported and is rotationally driven by a rotational drive source 5. An embodiment of a spherical driving wheel according to the present invention will be described below in detail with reference to the drawings. The spherical driving wheel of the present invention shown in FIGS. 1 to 3 has a fixed inclination angle to a bracket B or the like of a vehicle (not shown) (in the figure, the bracket B side is inclined). Is attached) and the ball wheel 1
And a top support roller 2 for supporting the upper portion 1a of the ball wheel 1 and a plurality (six in this example) of outer periphery supports for supporting the outer periphery 1b of the ball wheel 1 at circumferential intervals. A roller 3, a substantially dome-shaped roller holding member 4 having a small-diameter opening 4a at an upper portion for holding the outer peripheral portion supporting rollers 3 at a lower end thereof at intervals in a circumferential direction, and rotating the roller holding member 4 Rotating drive source 5, an upper cover body 6a covering the top support roller 2, and a lower cover body 6 covering the outer peripheral support roller 3.
b and the small-diameter opening 4 of the roller holder 4
a between the inner portion of the upper cover member 6a and the outer portion of the central cylindrical portion 8 of the upper cover member 6a and rotatably supporting the roller holder 4, and between the upper cover member 6a and the bracket B of the vehicle. And the elastic support means 9 interposed between them. That is, in the spherical driving wheel of the present invention, the upper portion 1a of the ball wheel 1 is supported by the top support roller 2,
An outer peripheral portion 1b of the ball wheel 1 is supported by a plurality of outer peripheral support rollers 3 at intervals in a circumferential direction, and each outer peripheral support roller 3 has a substantially dome-shaped roller holder 4 having a small-diameter opening 4a at an upper portion. The roller holder 4 is rotatably held at its lower end, and the small-diameter opening 4a of the roller holder 4 is rotatably supported by a bearing 7 and driven to rotate by a rotation drive source 5. The ball wheel 1 is made of a solid sphere made of hard elastic rubber or a hollow sphere made of metal or the like coated with hard elastic rubber to reduce vibration during traveling. Or prevent slipping on the running surface,
The generation of running noise due to vibration is reduced. The top support roller 2 includes a pair of rotatable metal rollers 2a and 2b, a roller 2c disposed between the rollers 2a and 2b, and a rotatable roller 2a, 2b and 2c. And a roller shaft 10 to be supported. The roller shaft 10 is attached to a lower portion inside the central cylindrical portion 8 of the upper cover body 6a. Each roller 2
The outer peripheral surfaces of a, 2b, and 2c are tapered surfaces that are inclined along the curvature of the outer peripheral surface of the ball wheel 1. The outer peripheral portion supporting roller 3 includes a pair of rollers 3.
a, 3b, a roller shaft 11 rotatably supporting the rollers 3a, 3b, and the roller shaft 11 rotatably supported near both ends in the longitudinal direction. The outer peripheral surface of each of the rollers 3a and 3b is a tapered surface inclined along the curvature of the outer peripheral surface of the ball wheel 1. The roller holder 4 has a substantially dome shape having a small-diameter opening 4a at the upper portion as described above.
, And a ring gear 13 is attached to the upper end thereof. The ring gear 13 is rotationally driven by the rotary drive source 5 around the ball wheel 1. The small-diameter opening 4a may be a small diameter as compared with the dome diameter. The rotary drive source 5 has a servomotor 14 and a pinion 15 fixed to an output shaft of the servomotor 14, and the pinion 15 is a ring gear 13 of the roller holder 4.
And the rotational force from the servomotor 14 is transmitted. The cover 6 comprises the upper cover 6a and the lower cover 6b as described above. The upper cover body 6a
It has the central cylindrical portion 8 and the servomotor 1 on one side.
4 is provided, and a connecting projection 17 for connecting to the bracket B of the vehicle is provided on the other side. The top support roller 2 is pivotally supported at an inner lower portion, and covers the top support roller 2.
“b” hangs below the upper cover body 6 a and covers the outer peripheral portion supporting roller 3. The bearing 7 has a small-diameter opening 4 a of the roller holder 4.
The upper and lower cover members 6a are sandwiched between an inner portion and an outer portion of the central cylindrical portion 8 of the upper cover body 6a, and are provided in two upper and lower stages, and rotatably support the roller holder 4. Therefore, the annular diameter of the bearing 7 is smaller than that of the small-diameter opening 4 of the roller holder 4.
It can be smaller than a, and a material having high accuracy and excellent strength as in JIS standard products can be used. Furthermore, if it is provided in the upper and lower two stages as described above, J
An IS standard product can be used as one having higher strength. The elastic support means 9 is a spring damper, and is interposed between the upper cover body 6a and the bracket B of the vehicle. The spring damper has a coil spring 19 interposed between a spring receiving piece 18a below the spring shaft 18 of the upper cover body 6a and an upper end Ba of a bracket B inserted through the upper part of the spring shaft 18. The connecting projection 17 of 6a and the lower end Bb of the bracket B are pivotally supported to absorb undulations and steps on the ground contact surface during traveling. Since the spherical driving wheel of the present invention is constructed as described above, the bearing used can have a small annular diameter and a wide width. Therefore, the cost of the bearing is low, the product cost is not affected by the cost of the component, and the cost is very low.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view of one embodiment of a spherical drive wheel of the present invention. FIG. 2 is a plan view of the spherical drive wheel of the present invention shown in FIG. FIG. 3 is an explanatory view showing the spherical driving wheel of the present invention shown in FIG. 1 from below with a ball wheel and a lower cover removed. FIG. 4 is a cross-sectional view of one example of a conventional spherical drive wheel as viewed from the side. FIG. 5 is a plan view of an example of a conventional spherical driving wheel. FIG. 6 is a cross-sectional view of one example of a conventional spherical drive wheel as viewed from below. [Description of Signs] 1 Ball wheel 1a Upper part 1b Outer peripheral part 2 Top support roller 3 Outer peripheral support roller 4 Roller holder 4a Small diameter mouth 5 Rotary drive source 7 Bearing

Claims (1)

Claims 1. An upper portion (1a) of a ball wheel (1) is supported by a top support roller (2), and an outer peripheral portion (1b) of the ball wheel (1) is circumferentially spaced. Supported by a plurality of outer peripheral support rollers (3), and each outer peripheral support roller (3)
Is rotatably held at the lower end of a substantially dome-shaped roller holder (4) having a small-diameter opening (4a) at an upper portion, and the small-diameter opening (4a) of the roller holding body (4) is a bearing (7). A spherical drive wheel rotatably supported by a rotary drive source (5) and rotatably driven by a rotary drive source (5).