JP2014229601A - Rotary connector using irregular shape roller current collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that a cylindrical roller current collector may incline for the rotation axis direction as it rotates, and since slip takes place between the roller current collector and the shaft, or between the roller current collector and an outer peripheral member, electrical noise is generated, contact resistance is destabilized, or the product life is shortened.SOLUTION: Outer peripheral shape of a roller current collector is not the conventional cylindrical shape but an irregular shape where the axial center position of the roller current collector is a large diameter part, both ends of the roller current collector are small diameter parts, and the outer peripheral shape is inclining from the large diameter part to the small diameter parts.

Description

  The present invention includes an outer peripheral member having a circular inner peripheral surface, a shaft that is relatively rotatable with respect to the outer peripheral member, and that is disposed coaxially with the inner peripheral surface in a hollow portion of the outer peripheral member; The present invention relates to a connector that includes a roller current collector that is rotatably disposed between a member and a shaft body, and that electrically connects the outer peripheral member and the shaft body via the roller current collector.

  As a structure for electrically connecting relatively rotating members and supplying a current between them, a roller-collector type rotary connector has been devised.

  The roller-collector-type rotary connector has an outer peripheral member having a circular inner peripheral surface and is rotatable relative to the outer peripheral member, and is disposed coaxially with the inner peripheral surface in a hollow portion of the outer peripheral member. A roller current collector that is rotatably disposed with elastic deformation in the radial direction between the shaft member and the outer peripheral member and the shaft member. When the outer member and the shaft member relatively rotate, the roller current collector is It performs a so-called planetary motion that revolves while rotating in an annular space between the outer peripheral member and the shaft. The roller current collector has a thin cylindrical shape for performing planetary motion with elastic deformation.

JP 2011-222463 A

  However, in the rotary connector having the above structure, the cylindrical roller current collector may be inclined with respect to the rotation axis direction as it rotates. When the roller current collector is inclined with respect to the rotation shaft, slip occurs between the roller current collector and the shaft body or between the roller current collector and the outer peripheral member.

  When the roller current collector is rotated in a state tilted with respect to the rotation axis, the roller current collection will inherently make a planetary movement around the rotation axis in a spiral manner, but beyond the axially movable range of the roller current collection I can't spiral. For this reason, when the movement of the roller current collector in the axial direction is restricted, the force to move the roller current collector in the axial direction is a slip between the roller current collector and the shaft body or between the roller current collector and the outer peripheral member. Will be eliminated. The wear powder generated by this sliding shortens the product life by increasing the electrical noise and increasing the contact resistance.

In addition, the tendency of the roller current collector to be inclined with respect to the rotation axis becomes more conspicuous as the rotation speed becomes higher, and thus has been limited in use at high speed rotation.
Further, when the roller current collector is arranged in parallel with no inclination with respect to the rotation axis, the contact between the rotation axis and the outer peripheral member is geometrically a line contact, but when it is inclined, it is a point. Contact increased the contact resistance, causing instability.

Therefore, it has been a problem to achieve a structure in which the roller current collector does not tilt with respect to the rotation axis during rotation.

  In the present invention, the outer peripheral shape of the roller current collector is not a conventional cylindrical shape, but the center position in the roller current collector axial direction is a large diameter portion, both ends of the roller current collector are small diameter portions, and the shape is inclined from the large diameter portion to the small diameter portion. Or a roller current collector having a different diameter shape having a small diameter portion at the center of the roller current collector axis, a large diameter portion at both ends of the roller current collector, and a shape inclined from the large diameter portion to the small diameter portion. Also, the shaft body and the outer peripheral member are in electrical contact with each other as a shape along the outer peripheral shape of the roller current collector. The outer peripheral shape of the roller current collector can be a valley shape in addition to a linearly inclined mountain shape, and a barrel shape or a valley shape in which an inclined portion extending from a large diameter portion to a small diameter portion is a mountain arc shape. A drum shape with an arc shape can be considered.

  With this shape, it is possible to provide a rotary connector having a structure in which the roller current collector does not tilt with respect to the rotation axis during rotation. In this structure, even if the roller current collector is inclined with respect to the rotation axis in a stationary state, the central axis of the roller current collection is repaired in parallel with the rotation axis as it rotates. Further, this shape limits the movement of the roller current collector in the axial direction, which eliminates the need for a conventional movement suppression mechanism and simplifies the product structure.

Also, since it is always parallel to the axial direction during rotation, the roller current collector and the shaft body or the roller current collector and the outer peripheral member are geometrically always in line contact (actually surface contact) and are also in contact during rotation. Resistance is stable.
Further, since the roller current collector does not tilt even at high speed rotation, it can be used at higher continuous rotation.

Side view of rotary connector for mountain roller collector Front view of rotary connector for angle roller collection Side view of rotary connector for valley-type roller current collector (asymmetric) Side view of rotary connector of drum roller collection

  In the following, an embodiment of the present invention will be described with respect to the case of the mountain roller current collector of FIGS.

The mountain-shaped roller current collector 3 may be made of a material having excellent conductivity and excellent spring characteristics, such as phosphor bronze and beryllium copper.
The shaft body 1 and the outer peripheral member 2 are selected according to the energization current, and copper is generally used for high current applications and brass for low current applications because of good workability.
Moreover, it is preferable to apply gold, silver or the like to the surface of the current-carrying parts of the three parts in order to reduce and stabilize the contact resistance.

  As for the outer peripheral shape of the mountain-shaped roller current collector 3, the central position in the axial direction is a large diameter portion (in this embodiment, the maximum outer diameter portion), both ends of the roller current collector are small diameter portions, and the large diameter portion to the small diameter portion The shape is inclined to The maximum outer diameter dimension is determined in consideration of the fact that the mountain-shaped roller current collector 3 needs to pass through the minimum gap formed by the shaft body 1 and the outer peripheral member 2 when assembling the rotary connector. Even when the mountain-shaped roller current collector 3 is bent to the minimum gap portion size, the maximum outer diameter size is set so that the mountain-shaped roller current collector 3 is restored to the original shape and is in the elastic deformation region. .

The mountain-shaped roller current collector 3 is disposed in the gap between the shaft body 1 and the outer peripheral member 2 with elastic deformation. At this time, the repulsive force (contact pressure) as the spring of the mountain-shaped roller current collector 3 is arranged. ) Must be set appropriately. If the contact pressure is too large, rolling friction at the time of rotation will increase and wear powder will be generated. If it is too small, the contact resistance will increase and the energization will become unstable.
The contact pressure is adjusted by the material, diameter, thickness, and deflection amount of the mountain roller current collector 3.

  Further, a plurality of mountain-shaped roller current collectors 3 can be arranged according to the current capacity.

  The roller current collecting shape may be a valley shape shown in FIGS. In FIG. 3, a valley-type roller current collector that linearly slopes from the large diameter portion to the small diameter portion. The minimum diameter portion does not need to be the center in the axial direction, and may be provided at a position deviated to the left or right from the axial center of the roller current collector 3 as shown in FIG. The inner peripheral surface of the outer peripheral member 5 has a shape that follows the shape of the outer peripheral surface of the roller current collector 3 so as to be in electrical contact with each other, and the outer peripheral surface of the shaft body 4 is also the outer peripheral surface of the roller current collector 3. The shape is in conformity with the shape of each other so that they are in electrical contact with each other.

  FIG. 4 shows an example of a drum-like shape that gently slopes in a circular arc shape from a large diameter portion at both ends of the roller current collector 3 to a small diameter portion in the central portion in the axial direction.

  Although not shown in the drawing, both end portions in the axial direction of the roller current collector are small-diameter portions and the central portion in the axial direction is a large-diameter portion, and it is inclined so as to gradually form a mountain from the large-diameter portion to the small-diameter portion. It may be a barrel shape.

DESCRIPTION OF SYMBOLS 1 Shaft body 2 Outer peripheral member 3 Mountain type roller current collector 4 Shaft body 5 Outer peripheral member 6 Valley type roller current collector (asymmetric)
7 Shaft body 8 Outer peripheral member 9 Drum-type roller current collector

Claims (5)

  An outer peripheral member having a circular inner peripheral surface, a shaft that is relatively rotatable with respect to the outer peripheral member, and is disposed coaxially with the inner peripheral surface in a hollow portion of the outer peripheral member, and the outer peripheral member And a roller current collector rotatably arranged so as to make a planetary movement while elastically deforming in the radial direction between the shaft bodies, and electrically connecting the outer peripheral member and the shaft body via the roller current collectors. In the connector to be connected, a roller current collector having a different diameter, an outer peripheral member formed along the outer peripheral shape of the roller current collector and having an inner peripheral surface in electrical contact with the roller current collector, and similarly the roller current collector A rotary connector comprising: a shaft body having an outer peripheral surface formed so as to conform to the outer peripheral shape of the roller and in electrical contact with the roller current collector.   The diameter of the outer peripheral surface of the roller current collector is such that both end portions have a smaller diameter than the center portion, or both end portions have a larger diameter than the center portion, and between the small diameter portion and the large diameter portion, The inner peripheral surface of the outer peripheral member and the outer peripheral surface of the shaft body are continuously changed along the outer peripheral surface of the roller current collector and are in electrical contact with each other. The rotary connector according to claim 1, wherein the rotary connector is configured.   The outer peripheral shape of the roller current collector has one large-diameter portion at the axial center of the roller current collector, and an inclined portion having the large-diameter portion at the apex extends to the small-diameter portions at both ends of the roller current collector. The rotary connector according to claim 1, wherein the rotary connector is formed.   The outer peripheral shape of the roller current collector is a large diameter portion at both axial end portions of the roller current collector, and an inclined portion having the large diameter portion as a vertex is a small diameter provided at the axial center portion of the roller current collector. The rotary connector according to claim 1, wherein the rotary connector is formed over a portion.   The continuously changing surface between the small diameter portion and the large diameter portion of the roller current collector is formed by a curved surface that changes in an arc from the small diameter portion toward the large diameter portion. Item 5. The rotary connector according to any one of Items 2 to 4.

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