Rotary connector

Abstract

Provided is a rotary connector that is capable of holding a stable conduction state.　A rotary connector 1 comprises: an annular electrically conductive ring 5; an electrically conductive shaft 4 that is inserted into the electrically conductive ring 5 and is provided so as to be rotatable relative to the electrically conductive ring 5; current collectors 6 that are disposed between the electrically conductive ring 5 and the electrically conductive shaft 4 in the radial direction; retainer pins 7 that are disposed between current collectors 6 that are adjacent to each other in the circumferential direction; and a retainer plate 21 that is disposed on at least one axial side of the retainer pins 7 and is provided with an annular guide groove 23, the retainer pins 7 moving along the guide groove 23, wherein the retainer plate 21 has retainer plate recesses 24, 25 that are formed on a bottom surface 23a of the guide groove 23.

Description

Rotary connector

[0001] The present invention relates to a rotary connector, for example, a rotary connector for electrically connecting a rotating side element and a stationary side element in a rotating mechanism.

[0002] In various industrial fields, rotary connectors for electrically connecting a rotating side element and a stationary side element in a rotating mechanism are known. A rotary connector can electrically connect a conductive ring and a conductive shaft through a current collecting element disposed between the conductive ring and the conductive shaft.

[0003] Such rotary connectors are known to include those filled with liquid metals such as mercury and gallium alloys as current collecting elements, and those in which a plurality of roller current collectors having electrical conductivity are arranged. In recent years, from the viewpoints of environmental load due to liquid leakage, risk of electric leakage, etc., rotary connectors to which roller current collectors are applied have attracted attention.

[0004] For example, the rotary connector shown in Patent Document 1 includes an annular outer peripheral member, a shaft body, roller current collectors, a guide plate, and a spacer. The roller current collectors are disposed between the outer peripheral member and the shaft body in the radial direction and are in contact with each of them. The spacer is an insulator and is disposed between adjacent roller current collectors. The guide plate is an annular plate material and has an annular guide groove in which the lower part of the spacer is disposed in an inserted state. When the shaft body rotates, the roller current collectors in contact with the shaft body perform a so-called planetary motion of revolving while rotating. Thereby, even when the shaft body rotates relative to the outer peripheral member, the shaft body and the outer peripheral member can be electrically connected.

[0005] Japanese Unexamined Patent Application Publication No. 2013-152914 (pages 4, 5, and FIG. 1)

[0006] In the rotary connector described in Patent Document 1, the spacer that contacts the planetary-motion roller current collectors also undergoes planetary motion. Since the spacer moves along the guide groove, it can reliably prevent contact between adjacent roller current collectors. On the other hand, if wear particles generated by the contact between the spacer and the guide plate adhere to the rolling surfaces of the outer peripheral member or shaft on which the roller current collectors roll, there is a risk that current flow between the members will be hindered.

[0007] This invention was made in view of these problems, and aims to provide a rotary connector that can maintain a stable electrical current state.

[0008] To solve the aforementioned problems, the rotary connector of the present invention comprises an annular conductive ring, a conductive shaft inserted through the conductive ring and rotatably positioned relative to the conductive ring, current collectors positioned radially between the conductive ring and the conductive shaft, retainer pins positioned between adjacent current collectors in the circumferential direction, and a retainer plate positioned on at least one axial side of the retainer pins and provided with an annular guide groove, wherein the retainer pins move along the guide groove, and the retainer plate has a retainer plate recess formed on the bottom surface of the guide groove. As a result, by forming a space on the bottom surface side of the guide groove with the retainer plate recess, wear particles that are generated and stored are less likely to scatter outwards from the space. This suppresses the adhesion of wear particles to the rolling surface and maintains a stable current-carrying state.

[0009] The retainer plate recess may have a shape that extends along the guide groove. This allows for a wider space to be secured.

[0010] The retainer plate recess may be annular. This makes it easier to capture the generated wear particles into the space, and prevents the stored wear particles from scattering outwards.

[0011] The conductive shaft is a rotating element, and the retainer plate recess may be provided on the inner diameter side of the guide groove. This allows for the reduction of the bottom surface on the inner diameter side of the guide groove, where wear particles are prone to be generated, by the retainer plate recess, thereby suppressing the generation of wear particles.

[0012] The conductive shaft is a rotating element, and the retainer plate recess may be provided on the outer diameter side of the guide groove. This arrangement makes it easier to collect wear particles even if they are scattered due to the orbital motion of the retainer pin or current collector, by using the guide groove provided on the outer diameter side where scattering is more likely to occur.

[0013] The retainer plate recess may be provided on both the inner and outer diameter sides of the guide groove, respectively. This allows for increased volume of space for storing wear particles while suppressing the generation of wear particles.

[0014] The retainer plate may also be a rotating element. This reduces the relative speed between the retainer plate and the retainer pin, thereby suppressing the generation of wear particles.

[0015] The retainer plate may also be a stationary element. This makes it less likely for the generated wear particles to scatter outwards from the space.

[0016] The conductive ring, the conductive shaft, the current collector, the retainer pin, and the retainer plate may be arranged in multiple stages. This allows for a stable energized state to be maintained at each energized point.

[0017] To solve the aforementioned problems, the rotary connector of the present invention comprises an annular conductive ring, a conductive shaft inserted through the conductive ring and rotatably positioned relative to the conductive ring, current collectors positioned radially between the conductive ring and the conductive shaft, retainer pins positioned between adjacent current collectors in the circumferential direction, and a retainer plate positioned at least axially on one side of the retainer pins and provided with an annular guide groove, wherein the retainer pins move along the guide grooves, and the retainer pins have retainer pin recesses formed on the surface facing the bottom surface of the guide grooves. As a result, by forming a space on the bottom surface side of the guide grooves with the retainer pin recesses, wear particles that are generated and stored are less likely to scatter outwards from the space. This suppresses the adhesion of wear particles to the rolling surfaces and maintains a stable current-carrying state.

[0018] This is a perspective view of the rotary connector in Embodiment 1 of the present invention. This is a side cross-sectional view of the rotary connector in Embodiment 1. This is an enlarged view of the main part of Figure 2. This is a cross-section taken along line A-A in Figure 2. This is a side cross-sectional view of the main part of the rotary connector in Modification 1-1. This is a side cross-sectional view of the rotary connector in Modification 1-2. This is a side cross-sectional view of the main part of the rotary connector in Embodiment 2 of the present invention. This is a side cross-sectional view of the main part of the rotary connector in Embodiment 3 of the present invention. This is a side cross-sectional view of the main part of the rotary connector in Embodiment 4 of the present invention. This is a side cross-sectional view of the main part of the rotary connector in Embodiment 5 of the present invention. This is a side cross-sectional view of the main part of the rotary connector in Embodiment 6 of the present invention.

[0019] Embodiments for implementing the rotary connector according to the present invention will be described below based on examples.

[0020] The rotary connector according to Embodiment 1 will be described with reference to Figures 1 to 6. Hereafter, the top and bottom of Figure 2, as viewed from the front, will be referred to as the top and bottom of the rotary connector.

[0021] The rotary connector 1 of this embodiment is applied, for example, to a semiconductor manufacturing machine as a rotating device, and is used to energize a temperature control device that heats a semiconductor substrate, or to energize a thermocouple that measures the temperature of the heated substrate.

[0022] As shown in Figures 1 and 2, the rotary connector 1 comprises a rotating body 2 which is the rotating element, a stationary body 3 which is the stationary element, a plurality of roller current collectors 6 (see Figure 2), a plurality of retainer pins 7 (see Figure 2), and two bearings 8 (see Figure 2). It also has four terminals 9A, 9B, 9C, and 9D for individually energizing the four conductors 90-93 connected to the rotating body 2 and the stationary body 3, respectively. This rotary connector 1 is used in a vertical orientation.

[0023] The rotating body 2 comprises a rotating shaft 20, five retainer plates 21 (see Figure 2), and four inner circumferential electrodes 4 (see Figure 2) that serve as conductive shafts. The conductive shaft of this invention may be an axial body or an annular body as in this embodiment, as long as it is a conductor inserted through a conductive ring, and its shape may be changed as appropriate.

[0024] In the following explanation, of the five retainer plates 21, the one located at the top will be referred to as retainer plate 21U, the one located at the bottom as retainer plate 21L, and the three plates located between retainer plates 21U and 21L in the axial direction will be referred to as retainer plate 21M.

[0025] The rotating shaft 20 is formed in a cylindrical shape from an insulator. The rotating shaft 20 is supported by being fitted into two bearings 8 which are fitted and fixed to the upper and lower ends of the stationary body 3. The shape of the rotating shaft 20 may be changed as appropriate depending on the application; for example, it may be hollow, and a temperature control device may be provided at its tip. In the following description, unless otherwise specified, the axial, radial, and circumferential directions of the rotating shaft 20 will be simply referred to as "axial direction," "radial direction," and "circumferential direction."

[0026] Four through grooves 20a to 20d are formed on the outer diameter side of the rotating shaft 20. The through grooves 20a to 20d are recessed on the inner diameter side of the outer circumferential surface of the rotating shaft 20 and penetrate in the axial direction (see Figure 1). One of the conductors 90 to 93 is inserted through each of the through grooves 20a to 20d.

[0027] The five retainer plates 21 are formed in an annular, flat shape from an insulator and are externally fitted and fixed to the rotating shaft 20.

[0028] The five retainer plates 21 function as spacers for the four inner electrodes 4. Two axially adjacent retainer plates 21 are connected with one inner electrode 4 in between. As a result, each inner electrode 4 rotates together with the rotation axis 20 and the five retainer plates 21. More details about the retainer plates 21 will be described later.

[0029] Each inner electrode 4 is made of a conductive material and is formed in an annular shape with a rectangular cross-section. The outer diameter of each inner electrode 4 is smaller than the outer diameter of the five retainer plates 21. In other words, the five retainer plates 21 protrude outward from each inner electrode 4.

[0030] An annular groove 40 (see Figure 3) is formed on the outer diameter side of each inner circumferential electrode 4, which is recessed on the inner diameter side and opens towards the outer diameter side.

[0031] The fixed body 3 comprises an upper body 30, five spacers 31, a lower body 32, and four outer electrodes 5 acting as a conductive ring, and is formed in a cylindrical shape that surrounds the rotating body 2. In this invention, a conductive ring is defined as one in which at least a part of the annular member surrounding the shaft is conductive. In Figure 1, the upper body 30, the five spacers 31, and the lower body 32 are given a dot pattern.

[0032] In the following explanation, of the five spacers 31, the one located at the top will be referred to as spacer 31U, the one located at the bottom as spacer 31L, and the three spacers located between spacers 31U and 31L in the axial direction will be referred to as spacer 31M.

[0033] The upper body 30 is made of an insulator and is formed in an annular shape with a downward-facing L-shape in cross-section, through which the rotating shaft 20 is rotatably inserted. A bearing 8 is fitted into the radial center of the upper body 30. The upper body 30 is fixed to the uppermost spacer 31U.

[0034] The five spacers 31 are formed in an annular, flat plate shape using an insulator. The uppermost spacer 31U surrounds the uppermost retainer plate 21U. The lowermost spacer 31L surrounds the lowermost retainer plate 21L. The middle spacers 31M surround one of the middle retainer plates 21M.

[0035] Two spacers 31 adjacent to each other in the axial direction are connected with one outer electrode 5 in between.

[0036] The lower body 32 is made of an insulator and is formed in an L-shaped annular form, through which the rotating shaft 20 is rotatably inserted. A bearing 8 is fitted into the radial center of the lower body 32. The lower body 32 is fixed to the lowest spacer 31L.

[0037] Each outer electrode 5 is made of a conductive material and is formed in an annular shape with a rectangular cross-section. Each outer electrode 5 surrounds one of the inner electrodes 4. Each outer electrode 5 has an inner diameter smaller than the inner diameter of the five spacers 31 and protrudes inward from the spacers 31.

[0038] Referring to Figures 3 and 4, between the outer peripheral electrode 5 and the inner peripheral electrode 4 located on its inner diameter side, 18 roller current collectors 6 (see Figure 4) and 18 retainer pins 7 (see Figure 4) are alternately arranged in the circumferential direction. Note that the number of roller current collectors 6 and retainer pins 7 may be changed as appropriate.

[0039] The roller current collector 6 is made of a conductor and is formed in a cylindrical shape, and is sandwiched and held between the outer electrode 5 and the inner electrode 4 in the radial direction.

[0040] The retainer pin 7 is formed in a cylindrical shape from an insulator and is positioned between two adjacent roller current collectors 6 in the circumferential direction. The diameter of the retainer pin 7 is smaller than the outer diameter of the roller current collector 6. Also, the axial length of the retainer pin 7, i.e., its length in the vertical direction, is longer than the axial length of the roller current collector 6.

[0041] Further, the retainer pin 7 is rotatably disposed in an upper guide groove 22 formed in the upper retainer plate 21 and a lower guide groove 23 formed in the lower retainer plate 21, respectively. More specifically, the upper end of the retainer pin 7 is rotatably disposed in the upper guide groove 22, and the lower end of the retainer pin 7 is rotatably disposed in the lower guide groove 23.

[0042] The upper guide groove 22 is formed in a portion of the retainer plate 21 that projects to the outer diameter side of the inner peripheral electrode 4. The upper guide groove 22 is an annular groove that opens downward in the axial direction, that is, toward the lower guide plate 21 adjacent in the axial direction. The upper guide groove 22 is defined by an annular and flat bottom surface 22a extending in the radial and circumferential directions, an inner diameter side surface 22b extending axially upward from the inner diameter edge of the bottom surface 22a, and an outer diameter side surface 22c extending axially upward from the outer diameter edge of the bottom surface 22a. The upper guide groove 22 is provided in the uppermost retainer plate 21U and the three middle retainer plates 21M.

[0043] The lower guide groove 23 is formed on the upper end surface of a portion of the retainer plate 21 that projects to the outer diameter side of the inner peripheral electrode 4. The lower guide groove 23 is an annular groove that opens upward in the axial direction, that is, toward the upper guide plate 21 adjacent in the axial direction. The lower guide groove 23 is defined by an annular and flat bottom surface 23a extending in the radial and circumferential directions, an inner diameter side surface 23b extending axially upward on the inner diameter side of the bottom surface 23a, and an outer diameter side surface 23c extending axially upward on the outer diameter side of the bottom surface 23a. The bottom surface 23a is disposed substantially parallel to the bottom surface 22a. The lower guide groove 23 is provided in the three middle retainer plates 21M and the lowermost retainer plate 21L.

[0044] The length in the vertical direction between the bottom surface 22a of the upper guide groove 22 and the bottom surface 23a of the lower guide groove 23 is slightly longer than the axial length of the retainer pin 7, that is, the length in the vertical direction.

[0045] Further, the width of the upper guide groove 22, that is, the radial length between the inner diameter side surface 22b and the outer diameter side surface 22c, is substantially the same as the radial length between the inner diameter side surface 23b and the outer diameter side surface 23c in the lower guide groove 23. Also, the widths of the upper guide groove 22 and the lower guide groove 23 are slightly longer than the diameter of the retainer pin 7.

[0046] In each retainer plate 21M in the middle stage and the retainer plate 21L in the lowermost stage, retainer plate recesses 24 and 25 are provided which are recessed downward from the bottom surface 23a in the lower guide groove 23, are open upward, and have an annular groove shape and a rectangular cross section when viewed from the circumferential direction.

[0047] The retainer plate recesses 24 and 25 are arranged to be separated in the radial direction. In other words, the bottom surface 23a is left only between the retainer plate recesses 24 and 25 in the radial direction.

[0048] The retainer plate recess 24 is arranged on the inner diameter side with respect to the retainer plate recess 25. The inner circumferential surface of the retainer plate recess 24 is formed flush with the inner diameter side surface 23b in the lower guide groove 23.

[0049] The retainer plate recess 25 is arranged on the outer diameter side with respect to the retainer plate recess 24. The outer circumferential surface of the retainer plate recess 25 is formed flush with the outer diameter side surface 23c in the lower guide groove 23.

[0050] The rotary connector 1 of the present embodiment configured as described above includes four inner circumferential electrodes 4, four outer circumferential electrodes 5, and four stations 9A, 9B, 9C, and 9D are formed by a plurality of roller current collectors 6. Among these, the station 9A is located at the uppermost stage and is arranged in descending order thereafter.

[0051] When the inner electrode 4 rotates, each roller current collector 6 rotates clockwise as indicated by the black arrows and revolves counterclockwise as indicated by the dashed arrows, while its outer surface remains in contact with the outer surface of the inner electrode 4 and the inner surface of the outer electrode 5, in accordance with the rotation of the inner electrode 4. Here, the outer surface of the inner electrode 4 is the rolling surface 4a. The inner surface of the outer electrode 5 is the rolling surface 5a. Furthermore, the outer surface of the roller current collector 6 is the rolling surface 6a.

[0052] As a result, when the inner electrode 4 rotates, the current flow between the inner electrode 4 and the outer electrode 5 is maintained by the interposed roller current collectors 6.

[0053] Furthermore, the portion of the roller current collector 6 located on the inner diameter side is positioned within the groove 40 in the inner circumferential electrode 4. As a result, the vertical movement of the roller current collector 6 is restricted by the groove 40, preventing contact with the retainer plate 21.

[0054] Furthermore, the groove in which a portion of the roller current collector 6 is positioned is not limited to the groove 40 formed in the inner electrode 4, but may also be formed in the outer electrode 5, or only in the outer electrode 5, and may be changed as appropriate. Alternatively, instead of a groove, annular stepped portions may be provided on the inner electrode 4 and the outer electrode 5 facing each other in the axial direction, and the roller current collector 6 may be interposed between these annular stepped portions to hold the roller current collector 6 in the axial direction.

[0055] Furthermore, adjacent roller current collectors 6 in the circumferential direction are prevented from directly contacting each other because a retainer pin 7 is placed between them.

[0056] The retainer pin 7 rotates counterclockwise as indicated by the black arrow, following the rotation of the adjacent roller current collector 6. Furthermore, the retainer pin 7 revolves in the direction of the dashed arrow, pushed by the adjacent and revolving roller current collector 6 and guided by the guide grooves 22 and 23 to align with the direction of the roller current collector 6's revolution.

[0057] Furthermore, even if the retainer pin 7 attempts to move vertically relative to the retainer plate 21 due to disturbances or other reasons, its movement is restricted by the bottom surfaces 22a and 23a. In addition, even if the retainer pin 7 attempts to move radially relative to the retainer plate 21, its movement is restricted by the inner diameter sides 22b and 23b and the outer diameter sides 22c and 23c.

[0058] This prevents the retainer pin 7 from tilting relative to the axis of the retainer plate 21 or from coming out of the guide grooves 22 and 23. In addition, the retainer pin 7 maintains a non-contact state with the inner electrode 4 and the outer electrode 5.

[0059] The retainer pin 7, which rotates on its axis and revolves around the earth, has its lower end surface 7a sliding in contact with the bottom surface 23a of the lower guide groove 23. In addition, the retainer pin 7 has its circumferential surface 7c sliding in contact with the inner diameter side surfaces 22b, 23b and outer diameter side surfaces 22c, 23c of the retainer plate 21.

[0060] As described above, the roller current collector 6 is sandwiched between the inner electrode 4 and the outer electrode 5, and the retainer pin 7 is located between two adjacent roller current collectors 6 in the circumferential direction. In other words, the roller current collectors 6 and the retainer pin 7 are arranged alternately. Furthermore, the rotary connector 1 is structured so that the retainer pin 7 does not directly contact the inner electrode 4 and the outer electrode 5.

[0061] In this case, the rotation direction of the retainer pin 7 is the same as the rotation direction of the inner electrode 4 and the orbital direction of the roller current collector 6 and the retainer pin 7, and the opposite direction to the rotation direction of the roller current collector 6.

[0062] For more details, refer to point P1 in the blown-out section of Figure 4. The portion of the rotating retainer pin 7 that passes through the outer diameter side moves in approximately the same direction as its own revolution. On the other hand, refer to point P2 in the blown-out section. The portion of the rotating retainer pin 7 that passes through the inner diameter side moves in approximately the opposite direction to its own revolution.

[0063] Here, the orbital direction of the retainer pin 7 is defined as positive. The orbital velocity of the retainer pin 7 is V1. The peripheral velocity of the retainer pin 7 due to its rotation is V2. As the retainer pin 7 rotates, the portion passing through the inner diameter moves in a direction almost opposite to the orbital direction. Therefore, the relative velocity of the guide groove 23 with respect to the inner diameter side surface 23b is the sum of the orbital velocity V1 and the peripheral velocity V2 (V1 + V2).

[0064] As a result, in the retainer pin 7, which rotates and revolves, the portion passing through the inner diameter side generates high frictional force and is prone to generating wear particles. On the other hand, the bottom surface 23a of the lower guide groove 23 is reduced by the retainer plate recess 24 on the inner diameter side, so that the bottom surface 23a does not slide against the portion passing through the inner diameter side that is trying to move in the opposite direction at the lower end surface 7a of the retainer pin 7. This suppresses the generation of wear particles.

[0065] On the other hand, although wear particles are likely to be generated in the portion of the inner diameter side surface 23b of the lower guide groove 23 and the circumferential surface 7c of the retainer pin 7 that passes through the inner diameter side, since a retainer plate recess 24 is provided on the inner diameter side, wear particles can be efficiently stored in the retainer plate recess 24 on the inner diameter side. Furthermore, since the inner circumferential surface of the inner diameter side surface 23b and the inner diameter side retainer plate recess 24 are formed flush, wear particles can be efficiently stored in the retainer plate recess 24 on the inner diameter side.

[0066] Thus, from the viewpoint of suppressing the generation of wear particles and storing the generated wear particles, a configuration in which the retainer plate recess is provided on the rotating element side, as in this embodiment, is preferable to a configuration in which the retainer plate recess is provided on the stationary element side.

[0067] Furthermore, the retainer plate 21 is designed to facilitate the collection of wear particles even if they are scattered due to orbital motion, by providing a retainer plate recess 25 on the outer diameter side, thus facilitating the storage of wear particles. In addition, since the outer diameter side surface 23c and the outer circumferential surface of the retainer plate recess 25 on the outer diameter side are formed flush, wear particles can be efficiently stored within the retainer plate recess 25 on the outer diameter side.

[0068] Furthermore, by providing the retainer plate recess 25 on the outer diameter side, wear caused by sliding between the retainer pin 7 and the outer diameter side of the lower guide groove 23 can be reduced.

[0069] Furthermore, each retainer plate 21 rotates together with the inner circumferential electrode 4 in a counterclockwise direction around the axis 20, in other words, in the direction of the retainer pin 7's revolution. In other words, the rotational force of the retainer plate 21, which rotates together with the axis 20, also acts on each retainer pin 7.

[0070] Furthermore, since the retainer plate 21 is a rotating element and rotates in the direction of the retainer pin 7's revolution, the relative speed between the retainer plate 21 and the retainer pin 7 is the difference between the rotational speed of the retainer plate 21 and the movement speed of the retainer pin 7.

[0071] In this way, by making the retainer plate 21 a rotating element, the relative speed with the retainer pin 7, which rotates and revolves, can be reduced compared to the retainer plate 131, which is a stationary element described later, and thus the generation of wear particles can be suppressed.

[0072] As described above, in this embodiment, the rotary connector 1 has a space formed by retainer plate recesses 24 and 25 on the bottom surface 23a side of the lower guide groove 23 that guides the movement of the retainer pin 7, making it difficult for the generated and accumulated wear particles to scatter outwards from the space.

[0073] This prevents wear particles from adhering to the rolling surface 4a of the inner electrode 4, the rolling surface 5a of the outer electrode 5, and the rolling surface 6a of the roller current collector 6, thereby maintaining a stable current supply state.

[0074] Furthermore, a simple structure is achieved by providing retainer plate recesses 24 and 25 in the retainer plate 21, which is equipped with a lower guide groove 23 for guiding the movement of the retainer pin 7, thereby preventing wear particles from adhering to the rolling surfaces 4a, 5a, and 6a. For example, compared to a rotary connector configured to store wear particles using a separate component from the retainer plate, this design prevents increased size and costs due to an increase in the number of components.

[0075] Furthermore, since the adhesion of wear particles to the rolling surfaces 4a, 5a, and 6a can be suppressed, it is possible to prevent an increase in the torque required for the rotation of the rotating body 2.

[0076] Furthermore, since the retainer plate recesses 24 and 25 extend along the guide groove 23, a wider space can be secured. Also, because the bottom surface 23a of the guide groove 23 extends continuously in the circumferential direction, the retainer pin 7 can be moved stably.

[0077] Furthermore, because the retainer plate recesses 24 and 25 are annular in shape, the generated wear particles are easily drawn into the space within the retainer plate recesses 24 and 25, and the accumulated wear particles are less likely to scatter outwards from the space.

[0078] Furthermore, since the rotary connector 1 is equipped with four stages of terminals 9A, 9B, 9C, and 9D, it is possible to maintain a stable energized state at each individual energized point.

[0079] In this embodiment, a structure in which annular retainer plate recesses 24 and 25 are formed on both radial sides of the bottom surface 23a of the lower guide groove 23 has been described. However, the embodiment is not limited to this, and any shape along the lower guide groove 23 may also be formed in the radial center, or only the retainer plate recess 24 may be formed, or only the retainer plate recess 25 may be formed, or only in the radial center may be formed, or it may be a spiral groove shape extending in the circumferential direction, or it may be an end-shaped groove. Even with such a configuration, it is possible to store wear particles.

[0080] Furthermore, in this embodiment, a structure has been described in which the inner circumferential surface of the inner diameter retainer plate recess 24 is formed flush with the inner diameter side surface 23b of the lower guide groove 23. However, the embodiment is not limited to this, and the inner circumferential surface of the inner diameter retainer plate recess 24 may be formed on the inner or outer diameter side of the inner diameter side surface 23b of the lower guide groove 23. The same applies to the outer circumferential surface of the outer diameter retainer plate recess 25 and the outer diameter side surface 23c of the lower guide groove 23.

[0081] Furthermore, in this embodiment, a structure is illustrated in which retainer plate recesses 24 and 25 are formed on the bottom surface 23a of the lower guide groove 23, shaped to follow the lower guide groove 23. However, the embodiment is not limited to this, and retainer plate recesses may also be formed on the bottom surface 22a of the upper guide groove 22. Even with such a configuration, it is possible to prevent the generated and accumulated wear particles from scattering from the space. In particular, by providing the retainer plate recesses on the inner diameter side, i.e., the inner electrode 4 side where wear is more likely to occur, the bottom surface 22a of the upper guide groove 22 can be reduced, thereby suppressing the generation of wear particles.

[0082] Furthermore, although this embodiment was described assuming that the inner electrode 4 is the rotating element and the outer electrode 5 is the stationary element, it is not limited to this, and the inner electrode 4 may be the stationary element and the outer electrode 5 may be the rotating element.

[0083] Even with this configuration, by forming at least one of the retainer plate recesses 24 and 25, wear particles generated and stored can be made less likely to scatter from the space. In particular, by providing the retainer plate recess 25 on the outer diameter side, which is prone to wear, the bottom surface 23a on the outer diameter side of the lower guide groove 23 can be reduced, thereby suppressing the generation of wear particles.

[0084] Furthermore, although this embodiment describes the retainer plate 21 as also serving as a spacer in the rotating body 2, it is not limited to this configuration, and may also serve as a spacer in the fixed body 103, as exemplified by the retainer plate 131 shown as Modification 1-1 in Figure 5. The inner circumferential electrode 4 is fixed to the rotating shaft 20 via the spacer 121.

[0085] The retainer plate 131 has an upper guide groove 132 formed in the portion that protrudes inward from the outer peripheral electrode 5. Furthermore, the retainer plate 131 has a lower guide groove 133 and annular groove-shaped retainer plate recesses 134 and 135 formed in the portion that protrudes inward from the outer peripheral electrode 5.

[0086] Even with this configuration, by creating a space on the bottom surface 133a side of the lower guide groove 133 using retainer plate recesses 134 and 135, it is possible to prevent the generated and accumulated wear particles from scattering outwards from the space.

[0087] Furthermore, since the retainer plate 131 is part of the fixed body 103 and is immobile, wear particles accumulated in the retainer plate recesses 134 and 135 are less likely to scatter.

[0088] Furthermore, although the rotary connector 1 was described in the above embodiment as having a configuration with multiple stations, it is not limited to this, and may be configured with only one station, as shown in the rotary connector 201 illustrated as modified example 1-2 in Figure 6. In other words, the number of stations may be changed as appropriate.

[0089] The rotary connector 201 comprises a conductive shaft 204, which is a rotating element, and a conductive ring 205, which is a stationary element. The upper retainer plate 231U has an upper guide groove 232 formed therein. The lower retainer plate 231L has a lower guide groove 233 and annular groove-shaped retainer plate recesses 234 and 235 formed therein.

[0090] Even with this configuration, by creating a space on the bottom surface 233a side of the lower guide groove 233 using retainer plate recesses 234 and 235, wear particles that are generated and stored are less likely to scatter outwards from the space.

[0091] Although not shown directly, guide grooves and retainer plate recesses may be formed on the retainer plate, which is rotatably mounted integrally with the conductive shaft 204, similar to Embodiment 1.

[0092] Next, the rotary connector according to Embodiment 2 will be described with reference to Figure 7. Note that the description of the same configuration as in Embodiment 1 and therefore redundant will be omitted.

[0093] As shown in Figure 7, in this embodiment, a through hole is formed in the radial center of the retainer plate 321, which has a stepped shape with a smaller diameter at the top and a larger diameter at the bottom. The larger diameter portion at the bottom of this through hole is designated as the large-diameter hole portion 26. In addition, the retainer plate 321 has a through hole 27 that extends radially and communicates with the inner diameter retainer plate recess 24 and the large-diameter hole portion 26.

[0094] With this configuration, the retainer plate 321 can discharge wear particles accumulated in the inner diameter retainer plate recess 24 through the through hole 27 to the large diameter hole 26. This further prevents wear particles from adhering to the rolling surfaces 4a, 5a, and 6a.

[0095] Furthermore, as in the modified example 1-1 above, if the retainer plate is part of the fixed body, a through hole may be formed that is drilled from its outer circumferential surface toward the inner diameter and communicates with the retainer plate recess 135 on the outer diameter side. Even with such a configuration, wear particles can be discharged.

[0096] Furthermore, as in the modified example 1-2 above, if the rotary connector 201 has only one station, through holes may extend in the depth direction of the retainer plate recesses 234 and 235. Even with such a configuration, wear particles can be discharged.

[0097] Next, the rotary connector according to Embodiment 3 will be described with reference to Figure 8. Note that the description of the same configuration as in Embodiment 1 and therefore redundant will be omitted.

[0098] As shown in Figure 8, the retainer plate 421 has retainer plate recesses 424 and 425 that are right-angled triangular and annular groove-shaped when viewed from the circumferential direction.

[0099] More specifically, the inner diameter retainer plate recess 424 is defined by an inner diameter side surface extending axially and a bottom surface that extends from the lower end of the inner diameter side surface, sloping upwards and outwards. In other words, the upper opening is the widest, and it narrows towards the lower and inner diameter sides, meaning its radial length decreases.

[0100] Furthermore, the retainer plate recess 425 on the outer diameter side is defined by an outer diameter side surface that extends axially and a bottom surface that extends inclined upward from the lower end of the outer diameter side surface toward the inner diameter side. In other words, the upper opening is the widest and narrows toward the lower and outer diameter side.

[0101] This makes it possible to reduce the contact area between the lower end surface 7a of the retainer pin 7 and the bottom surface 423a of the lower guide groove 423 compared to the first embodiment.

[0102] Furthermore, the cross-sectional shape of the retainer plate recess may be a right-angled trapezoid, an isosceles triangle, or a curved shape such as a crescent moon; the same effect can be obtained as long as it narrows from top to bottom.

[0103] Next, the rotary connector according to Embodiment 4 will be described with reference to Figure 9. Note that the description of the same configuration as in Embodiment 1 and therefore redundant will be omitted.

[0104] As shown in Figure 9, the retainer plate 521 has retainer plate recesses 524 and 525 that are right-angled trapezoidal and annular groove-shaped when viewed from the circumferential direction.

[0105] More specifically, the inner diameter retainer plate recess 524 is defined by an inner diameter side surface extending in the axial direction, a bottom surface extending outward from the lower end of the inner diameter side surface, and an outer diameter side surface extending inclined inward and upward from the outer diameter end of the bottom surface. In other words, the inner diameter retainer plate recess 524 has the narrowest opening at the top and widens towards the bottom and outer diameter, i.e., its radial length increases.

[0106] Furthermore, the retainer plate recess 525 on the outer diameter side is defined by an outer diameter side extending in the axial direction, a bottom surface extending from the lower end of the outer diameter side towards the inner diameter side, and an inner diameter side extending from the inner diameter end of the bottom surface inclined toward the outer diameter side and upward. In other words, the retainer plate recess 524 on the inner diameter side has the narrowest opening at the top and widens toward the bottom and inner diameter side.

[0107] This makes it more difficult for wear particles accumulated in the retainer plate recesses 524 and 525 to be discharged from the retainer plate recesses 524 and 525.

[0108] Furthermore, the cross-sectional shape of the retainer plate recess may be trapezoidal, isosceles triangular, or have a curved surface such as a crescent shape, and the same effect can be obtained as long as it narrows from the bottom to the top.

[0109] Next, the rotary connector according to Embodiment 5 will be described with reference to Figure 10. Note that the description of the same configuration as in Embodiment 1 and therefore redundant will be omitted.

[0110] As shown in Figure 10, the retainer plate 621 has multiple retainer plate recesses 624 formed on the bottom surface 623a of the lower guide groove 623, which are inclined grooves that extend linearly from the outer diameter side to the inner diameter side and toward the downstream side in the orbital direction of the retainer pin 7.

[0111] Even with this configuration, a wide space can be secured on the bottom surface 623a side of the guide groove 623 by the multiple retainer plate recesses 624. In other words, the retainer plate recesses do not have to extend along the guide groove. To put it another way, the bottom surface of the guide groove does not have to be continuous in the circumferential direction.

[0112] Furthermore, the retainer plate recess may extend inclined from the inner diameter side to the outer diameter side and toward the downstream side in the orbital direction of the retainer pin 7, and may also be a so-called spiral groove shape formed in a curved shape that protrudes toward the outer diameter side or a curved shape that protrudes toward the outer diameter side.

[0113] Furthermore, the retainer plate recess 624 is formed such that a portion of it overlaps radially with a portion of an adjacent retainer plate recess 624 in the circumferential direction, at the same position in the circumferential direction but at a different position in the radial direction. However, it is not limited to this, and the radial overlap is not required.

[0114] Furthermore, while groove-shaped retainer plate recesses have been exemplified in Embodiments 1 to 5, the retainer plate recesses are not limited to these, and may also be dimple-shaped, such as rectangular parallelepipeds or dome-shaped recesses. In the case of such dimple shapes, it is preferable to provide multiple retainer plate recesses smaller than the retainer pins, from the viewpoint of facilitating the movement of the retainer pins and securing space.

[0115] On the other hand, from the viewpoint of facilitating smooth movement of the retainer pin along the guide groove, it is preferable that the retainer plate recess extends along the guide groove. In other words, it is preferable that the bottom surface of the guide groove extends continuously in the circumferential direction.

[0116] Next, the rotary connector according to Embodiment 6 will be described with reference to Figure 11. Note that the description of the same configuration as in Embodiment 1 and therefore redundant will be omitted.

[0117] As shown in Figure 11, the retainer plate 721 has a bottom surface 723a in the guide groove 723 that extends continuously from the inner diameter side surface 23b to the outer diameter side surface 23c. In other words, the retainer plate 721 differs from the retainer plate 21 of the above embodiment 1 in that it does not have a retainer plate recess formed therein.

[0118] The retainer pin 707 has a notched retainer pin recess 770 formed at its lower end. The retainer pin recess 770 is cut in an annular shape along the circumferential and axial direction of the retainer pin 707 and is open toward the axial downward side and the radially outward side.

[0119] In other words, the lower end of the retainer pin 707 is a small-diameter portion 772, which is the remaining portion after the formation of the retainer pin recess 770. The small-diameter portion 772 is smaller in diameter than the large-diameter portion 771 that contacts the roller current collector 6. The lower end surface of the small-diameter portion 772 is the lower end surface 707a, which is the opposing surface that faces the bottom surface 723a of the guide groove 723.

[0120] Even with this configuration, space can be secured on the bottom surface 723a side of the guide groove 723 by the retainer pin recess 770 in each retainer pin 707.

[0121] Furthermore, since the retainer pin 707 has a small diameter portion 772, it is more tolerant of tilting when, for example, the retainer plate 721 tilts slightly, compared to the retainer pin 7 of the first embodiment.

[0122] In this embodiment, the cross-sectional shape of the retainer pin recess 770 is rectangular, but it is not limited to this. Any configuration that allows space to be secured and reduces the area of ​​the lower end surface of the retainer pin, thereby allowing tilting of the retainer plate, may be a right triangle, a quarter circle, or any other shape, and may be modified as appropriate.

[0123] Furthermore, while an annular notch shape was exemplified as the retainer pin recess in this embodiment, it is not limited to this, and a dimple shape that is recessed in the shape of a rectangular parallelepiped or a dome shape may also be used. On the other hand, from the viewpoint of easily accumulating wear particles, a notch shape that is open toward the radial outer diameter side is preferable.

[0124] Furthermore, from the viewpoint of preventing wear particles accumulated in the space from moving to the bottom surface of the guide groove, it is preferable that the retainer plate has a recess as in the above embodiment 1.

[0125] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0126] For example, while embodiments 1 to 6 described above have shown a configuration in which the rotary connector is oriented vertically, the invention is not limited to this configuration, and the rotary connector may be oriented horizontally.

[0127] Furthermore, although the retainer plate was described in embodiments 1 to 6 as functioning as a spacer for the inner or outer electrode, the invention is not limited to this configuration, and the retainer plate may be a separate component from the spacer.

[0128] Furthermore, although the guide grooves in embodiments 1 to 6 were described as being formed on both sides of the retainer pin in the axial direction, the invention is not limited to this configuration, and may be formed on only one side in the axial direction.

[0129] Furthermore, while embodiments 1 to 6 described a configuration in which the conductive shaft is the rotating element and the conductive ring is the stationary element, the invention is not limited to this configuration, and the conductive shaft may be the stationary element and the conductive ring may be the rotating element.

[0130] Furthermore, while embodiments 1 to 5 illustrate a structure in which only the retainer plate recess is formed, and embodiment 6 illustrates a structure in which only the retainer pin recess is formed, it is also possible to have a retainer plate recess formed on the retainer plate and a retainer pin recess formed on the retainer pin. Such a structure makes it easier to secure space.

[0131] Furthermore, if the retainer pin and the retainer plate have different hardnesses, it is preferable to form the recess in the retainer pin or retainer plate that has the higher hardness, from the viewpoint of maintaining the recess in the retainer plate or the retainer pin.

[0132] 1 Rotary connector 4 Inner electrode (conductive shaft) 4a Rolling surface 5 Outer electrode (conductive ring) 5a Rolling surface 6 Roller current collector 6a Rolling surface 7 Retainer pin 21 Retainer plate 23 Lower guide groove (guide groove) 23a Bottom surface 24, 25 Retainer plate recess

Claims

1. A rotary connector comprising: an annular conductive ring; a conductive shaft inserted through the conductive ring and rotatably positioned relative to the conductive ring; current collectors positioned radially between the conductive ring and the conductive shaft; retainer pins positioned between adjacent current collectors in the circumferential direction; and a retainer plate positioned at least axially on one side of the retainer pins and provided with an annular guide groove, wherein the retainer pins move along the guide groove, and the retainer plate has a retainer plate recess formed on the bottom surface of the guide groove.

2. The rotary connector according to claim 1, wherein the retainer plate recess has a shape that extends along the guide groove.

3. The rotary connector according to claim 2, wherein the retainer plate recess is annular.

4. The rotary connector according to claim 2, wherein the conductive shaft is a rotating element, and the retainer plate recess is provided on the inner diameter side of the guide groove.

5. The rotary connector according to claim 2, wherein the conductive shaft is a rotating element, and the retainer plate recess is provided on the outer diameter side of the guide groove.

6. The rotary connector according to claim 2, wherein the retainer plate recess is provided on the inner diameter side and the outer diameter side of the guide groove, respectively.

7. The rotary connector according to any one of claims 1 to 6, wherein the retainer plate is a rotating element.

8. The rotary connector according to any one of claims 1 to 6, wherein the retainer plate is a stationary element.

9. The rotary connector according to claim 1, wherein the conductive ring, the conductive shaft, the current collector, the retainer pin, and the retainer plate are arranged in multiple stages.

10. A rotary connector comprising: an annular conductive ring; a conductive shaft inserted through the conductive ring and rotatably positioned relative to the conductive ring; current collectors positioned radially between the conductive ring and the conductive shaft; retainer pins positioned between adjacent current collectors in the circumferential direction; and a retainer plate positioned at least axially on one side of the retainer pins and provided with an annular guide groove, wherein the retainer pins move along the guide grooves, and the retainer pins have retainer pin recesses formed on the surface facing the bottom surface of the guide grooves.

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