Rotary connector

Abstract

To provide a rotary connector that can stably function over a long period of time.SOLUTION: A rotary connector includes an outer peripheral electrode 30, an inner peripheral electrode 20 inserted into the outer peripheral electrode 30 and arranged to be rotatable, a plurality of roller current collectors 40 disposed between the outer peripheral electrode 30 and the inner peripheral electrode 20 so as to be capable of planetary motion, a bearing 33 that rotatably supports the inner peripheral electrode 20, and a bearing holder 31 that holds the bearing 33, and there are bent portions 50 to 54 in a passage 5 extending from a contact portion between the inner peripheral electrode 20 and the roller current collector 40 to the bearing 33.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] In various industrial fields, a rotary connector used for electrically connecting a rotating element and a stationary element in a rotating mechanism can electrically connect an inner peripheral electrode having conductivity connected to the rotating element and an outer peripheral electrode having conductivity electrically connected to the stationary element through a current collecting element disposed therebetween.

[0003] Such a rotary connector is known to have a current collecting element filled with a liquid metal such as mercury or a gallium alloy, or a plurality of conductive roller current collectors arranged therein. In recent years, a rotary connector to which roller current collectors are applied has attracted attention from the viewpoints of environmental load due to liquid leakage, risk of electric leakage, and the like.

[0004] For example, in the rotary connector disclosed in Patent Document 1, an inner peripheral electrode is inserted into a cylindrical outer peripheral electrode, and cylindrical roller current collectors are evenly arranged between the outer peripheral electrode and the inner peripheral electrode. Also, bearing holders for holding bearings are respectively fixed to both axial ends of the outer peripheral electrode. The inner peripheral electrode is pivotally supported by these bearings so as to be rotatable. Thus, when the rotating element in the rotating mechanism rotates, the inner peripheral electrode rotates following this. Then, each roller current collector in contact with the outer peripheral surface of the inner peripheral electrode also rolls relative to the inner peripheral electrode. At this time, since each roller current collector is also in contact with the inner peripheral surface of the outer peripheral electrode, it rolls relative to the outer peripheral electrode. That is, each roller current collector can electrically connect the inner peripheral electrode and the outer peripheral electrode while performing a planetary motion of revolving around the inner peripheral electrode while rotating itself.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-222463 (page 6, Figure 2) [Overview of the project] [Problems that the invention aims to solve]

[0006] In a rotary connector like the one described in Patent Document 1, the roller current collector is elastically deformable, and the outer diameter of the roller current collector is slightly larger than the radial dimension between the outer surface of the inner electrode and the inner surface of the outer electrode. As a result, the outer surface of the roller current collector makes surface contact with both the outer surface of the inner electrode and the inner surface of the outer electrode, thereby improving the current conduction efficiency.

[0007] Incidentally, because the circumferential dimension of the inner surface of the outer electrode located on the outer diameter side is longer than the circumferential dimension of the outer surface of the inner electrode located on the inner diameter side, the roller current collector rolls along the outer surface of the inner electrode, while being prone to sliding relative to the outer electrode.

[0008] As described above, during use, the roller current collector undergoes elastic deformation and is prone to sliding against the outer electrode, which easily leads to the generation of contaminants such as wear particles and peeling particles at the contact points between the inner electrode, outer electrode, and roller current collector. In particular, if the contact points are coated with plating, contaminants are more likely to be generated. For this reason, roller current collectors such as those in Patent Document 1, whose axial direction is arranged along the vertical direction, are prone to contaminants entering the lower bearing, which can hinder the smooth rotation of the inner electrode and shorten the lifespan of the rotary connector.

[0009] This invention addresses these problems and aims to provide a rotary connector that can function stably over a long period of time. [Means for solving the problem]

[0010] To solve the aforementioned problems, the rotary connector of the present invention is: A rotary connector comprising an outer electrode, an inner electrode inserted into the outer electrode and rotatably positioned, a plurality of roller current collectors arranged to move in a planetary motion between the outer electrode and the inner electrode, a bearing that rotatably supports the inner electrode, and a bearing holder that holds the bearing, The passage extending from the contact point between the inner circumferential electrode and the roller current collector to the bearing has a bent section. According to this design, contaminants are trapped by the bend, preventing them from entering the bearing from the roller current collector. As a result, the bearing is less likely to become jammed with contaminants. Therefore, the rotary connector can function stably over a long period of time.

[0011] The rotary connector is oriented vertically, and the bent portion may be provided on the vertically lower side of the roller current collector. According to this, debris that descends according to gravity is trapped by the bent section, preventing it from moving linearly towards the bearing.

[0012] The bearing may be a shielded bearing, with at least one shielding element provided above it. According to this, shielded bearings are less likely to become jammed with debris that slips through the passages. Therefore, rotary connectors can function stably for longer periods of time.

[0013] The bent portion may be formed by a projection extending in the radial direction. According to this, foreign matter can be trapped by radially extending protrusions, preventing it from moving linearly toward the bearing.

[0014] The aforementioned projection has an inner diameter projection and an outer diameter projection, The inner diameter projection and the outer diameter projection may overlap in the vertical direction. According to this, since the inner diameter direction protrusion and the outer diameter direction protrusion overlap in the vertical direction to form a plurality of bending parts, the passage is formed to extend in a zigzag manner, so it is difficult for foreign matter to reach the bearing. Preferably, since a length of a part of the zigzag of the passage perpendicular to its extending direction is not more than half of the radial direction of the bearing, it is difficult for foreign matter to reach the bearing by the bearing.

[0015] The bending part may be provided with a recess opened upward in the vertical direction. According to this, the recess provided in the bending part has a high ability to hold trapped foreign matter.

[0016] The recess may be annular. According to this, the annular recess has a high efficiency of trapping foreign matter.

[0017] The recess may be formed in the bearing holder. According to this, since the bearing holder is a stationary part that does not rotate, a rotational force does not act on the foreign matter trapped in the recess. Therefore, the recess can reliably hold the foreign matter.

[0018] It may further include a protrusion extending toward the recess. According to this, the protrusion not only prevents the foreign matter from moving linearly toward the bearing, but also easily guides the foreign matter into the recess.

[0019] A part of the protrusion may enter the recess. According to this, the protrusion can form a labyrinth structure together with the recess. Thereby, the protrusion and the recess can more effectively prevent the movement of foreign matter to the bearing side.

Brief Description of the Drawings

[0020] [Figure 1] It is a cross-sectional view of the rotary connector in Example 1 of the present invention. [Figure 2] It is an axial cross-sectional view of the rotary connector in Example 1. [Figure 3]It is an enlarged view of the main part of the rotary connector in Example 1. [Figure 4] It is an enlarged view of the main part of the rotary connector in Example 2 of the present invention. [Figure 5] It is an enlarged view of the main part of the rotary connector in Example 3 of the present invention. [Figure 6] It is an enlarged view of the main part of the rotary connector in Example 4 of the present invention. [Figure 7] It is an enlarged view of the main part of the rotary connector in Example 5 of the present invention. [Figure 8] It is an enlarged view of the main part of the rotary connector in Example 6 of the present invention.

Mode for Carrying Out the Invention

[0021] A mode for carrying out the rotary connector according to the present invention will be described below based on examples.

Example

[0022] The rotary connector according to Example 1 will be described with reference to FIGS. 1 to 3. Hereinafter, the up and down as viewed from the front of FIG. 1 will be described as the up and down of the rotary connector. Specifically, the upper side of the paper surface where the socket is arranged will be described as the upper side of the rotary connector, and the lower side of the paper surface where the cover is arranged will be described as the lower side of the rotary connector.

[0023] The rotary connector 1 of this example is vertically placed and is used, for example, at the rotating part in a semiconductor manufacturing machine as a rotating mechanism. The rotary connector 1 conducts high-frequency electricity supplied from an external power source as a stationary-side element in a semiconductor manufacturing machine to a rotating shaft as a rotating-side element in a semiconductor manufacturing machine.

[0024] As shown in Figure 1, the rotary connector 1 mainly consists of a rotating element 2, a stationary element 3, and a current collector element 4. The rotating element 2, which is connected to the rotating shaft in a semiconductor manufacturing machine, is provided to be able to rotate relative to the stationary element 3 by following the rotation shaft. As the rotating element 2 rotates, the roller current collector 40 in the current collector element 4 is provided to be able to move in a planetary motion around the rotating element 2 while electrically contacting both the rotating element 2 and the stationary element 3. The stationary element 3 is also equipped with a connector 39 that can be connected to an external power supply.

[0025] First, let's explain the rotating element 2. The rotating element 2 consists of an inner electrode 20, a socket 21, and a key 22.

[0026] The inner circumferential electrode 20 is made of a metal or the like and is conductive. As shown in Figures 1 and 3, the inner circumferential electrode 20 comprises, in order from the axial upper side, an upper shaft 20a, a large diameter body 20b, a medium diameter body 20c (see Figure 3), a small diameter body 20d (see Figure 3), and a lower shaft 20e. The axes of these components are aligned in the same straight line.

[0027] A socket 21 is fixed to the upper shaft 20a by screwing it in. Additionally, a key 22 is fitted and fixed to the outer surface of the upper shaft 20a.

[0028] The large-diameter barrel 20b is formed to have a larger diameter than the upper shaft 20a. Furthermore, an annular groove 20f is formed on the outer circumferential surface of the large-diameter barrel 20b, which tapers toward the axial center. The outer circumferential surface of the large-diameter barrel 20b is also plated with a highly conductive material, such as silver.

[0029] Note that the plating is thin and would make the diagrams complicated, so it has been omitted from the illustrations. The same applies to the plating described below.

[0030] The medium-diameter shell 20c (see Figure 3) is formed to be smaller in diameter than the large-diameter shell 20b. The small-diameter shell 20d (see Figure 3) is formed to be smaller in diameter than the medium-diameter shell 20c. The lower shaft 20e is formed to be approximately the same diameter as the upper shaft 20a, and more specifically, approximately the same diameter as the portion in which the bearing 34 is fitted.

[0031] The socket 21 is made of a highly conductive material. A rotating shaft in a semiconductor manufacturing machine is connected to the socket 21 in a locked state. In this state, the rotating shaft is also locked by key coupling with key 22.

[0032] Next, the stationary element 3 will be described. The stationary element 3 mainly consists of an outer electrode 30, a lower bearing holder 31, an upper bearing holder 32, two bearings 33 and 34, a housing 35, and a cover 36. For the sake of explanation, bearings 33 and 34 are referred to as the stationary element 3.

[0033] The outer electrode 30 is formed from a highly conductive material in a flanged cylindrical shape. The outer electrode 30 comprises a cylindrical portion 30a, an outer flange portion 30b, and an inner flange portion 30k which serves as a projection and an inward radial projection.

[0034] The cylindrical portion 30a is formed in a stepped cylindrical shape with the lower part extending in the inward direction. On the inner diameter side of the outer peripheral electrode 30, a large diameter hole portion 30c, a small diameter hole portion 30d, and a medium diameter hole portion 30e are formed in order from the axial upper side.

[0035] An annular groove 30f is formed in the axial center of the large-diameter hole 30c, with the diameter expanding toward the axial center. This annular groove 30f is positioned opposite the annular groove 20f of the inner circumferential electrode 20. Furthermore, the inner circumferential surface of the large-diameter hole 30c is plated with a highly conductive material, such as silver.

[0036] The small-diameter hole portion 30d is located on the inner diameter side of the inner flange portion 30k, communicates with the large-diameter hole portion 30c, and is smaller in diameter than the large-diameter hole portion 30c. The medium-diameter hole portion 30e communicates with the small-diameter hole portion 30d, and is smaller in diameter than the large-diameter hole portion 30c and larger in diameter than the small-diameter hole portion 30d.

[0037] The outer flange portion 30b is formed in an annular and flat shape, extending outward in the direction below the upper edge of the cylindrical portion 30a. The inner flange portion 30k is formed in an annular and flat shape, extending inward in the direction slightly below the axial direction of the cylindrical portion 30a.

[0038] The lower bearing holder 31 is formed from a resin molded product or the like, has high insulating properties, and is formed in a flanged cylindrical shape. The lower bearing holder 31 comprises, in order from the axial upper side, a cylindrical portion 31a, an outer flange portion 31b, and an annular projection 37 as a projection and an inward radial projection.

[0039] The cylindrical portion 31a is formed in a stepped cylindrical shape with its upper end extending in the inward direction. On the inner diameter side of the lower bearing holder 31, a medium diameter hole 31c, a small diameter hole 31d, and a large diameter hole 31e are formed in order from the axial upper side.

[0040] The medium-diameter hole 31c is open in the axial direction upward. The small-diameter hole 31d is the inner diameter side of the annular projection 37, communicates with the medium-diameter hole 31c, and is smaller in diameter than the medium-diameter hole 31c. The large-diameter hole 31e communicates with the small-diameter hole 31d and is open downward, and is larger in diameter than the medium-diameter hole 31c.

[0041] The outer flange portion 31b is formed in an annular and flat shape, extending outward in the radial direction substantially perpendicular to the lower end of the cylindrical portion 31a.

[0042] As shown in Figure 3, the annular projection 37 comprises a bottom portion 37a and an inner diameter cylindrical portion 37b. The annular projection 37 has an annular recess 38 formed therein, which is an annular recess that is open in the axial direction upward, i.e., vertically upward.

[0043] The bottom portion 37a is formed in an annular and flat shape, extending in the inward direction substantially perpendicular to the inner circumferential surface of the medium-diameter hole portion 31c. The inner diameter side cylindrical portion 37b is formed in a cylindrical shape, extending axially upward substantially perpendicular to the inner diameter end of the bottom portion 37a.

[0044] A bearing 33 is fitted into the large-diameter hole 31e. Furthermore, as will be described later, the outer ring 33c of the bearing 33 is in contact with the upper end surface of the large-diameter hole 31e.

[0045] The lower bearing holder 31 is fixed by fitting its cylindrical portion 31a into the medium-diameter hole 30e of the outer peripheral electrode 30. Furthermore, the lower bearing holder 31's outer flange portion 31b abuts against the lower end edge of the outer peripheral electrode 30, thereby regulating its position. This ensures the positioning of the outer ring 33c of the bearing 33.

[0046] The upper bearing holder 32 is formed from a resin molded product or the like, has high insulating properties, and is formed in a stepped cylindrical shape with the upper part extending in the inward direction.

[0047] A bearing 34 is fitted into the medium-diameter hole 32a of the upper bearing holder 32. Since bearings 33 and 34 have the same shape, unless otherwise specified, only bearing 33 will be described in the following explanation, and the explanation of bearing 34 will be omitted.

[0048] The outer electrode 30 is fitted into the large-diameter hole 32c of the upper bearing holder 32. Furthermore, the upper end of the cylindrical portion 30a of the outer electrode 30 is fitted into the annular recess 32d of the upper bearing holder 32. These arrangements ensure radial and axial positioning of the outer electrode 30 relative to the upper bearing holder 32.

[0049] Furthermore, an annular groove 32e is formed at the upper end of the upper bearing holder 32, which is open to the axially upward side and recessed to the axially downward side. This groove 32e increases the creepage distance of the upper bearing holder 32.

[0050] As shown in Figure 3, the bearing 33 is a shielded bearing composed of an inner ring 33a, a plurality of balls 33b, an outer ring 33c, and lip seals 33d and 33e as shielding elements. In other words, the bearing 33 is a shielded bearing in which lip seals 33d and 33e are provided as shielding elements vertically upward and vertically downward.

[0051] The lip seals 33d and 33e are annular in shape, with one end fixed to the inner ring 33a and the lip portion sliding against the outer ring 33c. This makes it difficult for foreign matter to enter the rolling surfaces of the inner ring 33a, ball 33b, and outer ring 33c.

[0052] In more detail, the lower shaft 20e of the inner circumferential electrode 20 is inserted into the inner ring 33a of the bearing 33. Also, the upper end of the inner ring 33a abuts against the lower end surface of the small diameter body 20d.

[0053] The upper shaft 20a of the inner circumferential electrode 20 is inserted into the bearing 34.

[0054] These bearings 33 and 34 allow the inner circumferential electrode 20 to be rotatably supported on the stationary element 3.

[0055] Returning to Figure 1, the housing 35 is insulating and formed in a stepped cylindrical shape. The cover 36 is also insulating and formed in a thin plate shape.

[0056] The housing 35 has an upper bearing holder 32 fitted inside it. A bolt inserted into the communication hole of the housing 35 is screwed into the female thread at the upper end of the upper bearing holder 32, thereby assembling the outer electrode 30 and the upper bearing holder 32 as a single unit.

[0057] Furthermore, a cover 36 is fixed to the lower end of the cylindrical portion of the housing 35 with bolts.

[0058] The connector 39 is fixed to the side wall of the housing 35. The outer electrode 30 and the connector 39 are electrically connected by wires. Power can be supplied to the connector 39 from an external power source (not shown).

[0059] Next, the current collection element 4 will be described. As shown in Figures 1 and 2, the current collection element 4 consists of six roller current collectors 40 (see Figure 2) and a current collector holder 41. Note that in Figure 2, hatching has been added to the annular grooves 20f and 30f.

[0060] The roller current collector 40 is made of metal or the like, has high conductivity, is elastically deformable, and has a barrel-shaped cylindrical form with an outer diameter that widens from both axial ends towards the axial center. Its outer surface is plated with a highly conductive material, such as silver.

[0061] The current collector holder 41 consists of an upper side plate 41a, six pins 41b, and a lower side plate 41c. The upper side plate 41a and the lower side plate 41c are formed in an annular and thin plate shape.

[0062] The pins 41b are highly conductive and elastically deformable. The six pins 41b are arranged equally (see Figure 2), and the upper end of each is fixed to the upper side plate 41a.

[0063] The current collector element 4 is assembled by arranging six roller current collectors 40 in an annular groove 20f of the inner circumferential electrode 20, inserting six pins 41b from the axial upper side through the corresponding roller current collectors 40, and press-fitting the lower ends of the pins 41b into the corresponding communication holes in the lower side plate material 41c.

[0064] Furthermore, as the inner electrode 20 of the current collector element 4 is inserted into the inner diameter side of the outer electrode 30, the current collector holder 41 and pin 41b are elastically deformed and press-fitted into the annular groove 30f of the outer electrode 30. The assembly method can be changed as appropriate; for example, an axially extending introduction groove aligned with each roller current collector 40 may be formed in the outer electrode 30, and the roller current collector 40 may be inserted into the annular groove 30f by passing the roller current collector 40 along this introduction groove.

[0065] Furthermore, in the gap between the annular groove 20f in the inner electrode 20 and the annular groove 30f in the outer electrode 30, the radial dimension at each axial position is slightly shorter than the radial dimension of the roller current collector 40 at the same position.

[0066] As a result, the roller current collector 40, which is elastically deformed by being compressed between the annular groove 20f of the inner electrode 20 and the annular groove 30f of the outer electrode 30, is in surface contact with the annular groove 20f of the inner electrode 20 and the annular groove 30f of the outer electrode 30, rather than line contact. Therefore, during use, the inner electrode 20, the roller current collector 40, and the outer electrode 30 are reliably in electrical contact.

[0067] As shown in Figure 3, a passage 5 is formed between the rotating element 2 and the stationary element 3, connecting the roller current collector 40 to the bearing 33 below.

[0068] The passage 5 is composed of, in order from the roller current collector 40 side, an upper axial section 50, an upper radial section 51, a middle axial section 52, a lower radial section 53, and a lower axial section 54. In addition, the passage 5 has multiple bends formed by the upper axial section 50 and the upper radial section 51, the upper radial section 51 and the middle axial section 52, the middle axial section 52 and the lower radial section 53, and the lower radial section 53 and the lower axial section 54 being approximately perpendicular to each other. In other words, the passage 5 is formed in a zigzag shape by the multiple bends.

[0069] More specifically, the upper axial portion 50 is mainly defined by the outer circumferential surface of the large-diameter body 20b of the inner circumferential electrode 20 and the inner circumferential surface of the lower plate material 41c of the current collector holder 41, which is arranged substantially parallel to this outer circumferential surface and spaced radially apart. As a result, the upper axial portion 50 is open to the roller current collector 40 located on the axially upward side and extends axially downward.

[0070] The upper radial portion 51 is defined by the lower end surface of the large-diameter body 20b of the inner circumferential electrode 20 and the upper end surface of the inner flange portion 30k of the outer circumferential electrode 30, which is arranged substantially parallel to this lower end surface and spaced apart in the axial direction. As a result, the upper radial portion 51 communicates with the lower end of the upper axial portion 50 and extends radially inward, substantially perpendicular to this lower end.

[0071] In other words, the bent portion of the passage 5, which is formed when the upper axial portion 50 and the upper radial portion 51 are perpendicular to each other, is formed by an inner flange portion 30k, which is a projection extending in the radial direction from the cylindrical portion 30a of the outer peripheral electrode 30.

[0072] The central axial portion 52 is mainly defined by the outer circumferential surface of the medium-diameter body 20c of the inner circumferential electrode 20, the inner circumferential surface of the small-diameter hole 30d of the outer circumferential electrode 30 which is arranged substantially parallel to the outer circumferential surface and spaced radially apart, and the inner circumferential surface of the medium-diameter hole 31c of the lower bearing holder 31. The inner circumferential surfaces of the small-diameter hole 30d and the inner circumferential surface of the medium-diameter hole 31c are arranged in the same straight line. As a result, the central axial portion 52 communicates with the inner diameter end of the upper radial portion 51 and extends axially downward, substantially perpendicular to the inner diameter end.

[0073] Furthermore, the central axial portion 52 is in communication with an annular recess 38 that is positioned in the direction of its extension.

[0074] The lower radial portion 53 is defined by the lower end surface of the medium diameter body 20c of the inner circumferential electrode 20 and the upper end surface of the inner diameter cylindrical portion 37b of the annular projection 37, which is arranged substantially parallel to the lower end surface and spaced apart in the axial direction. As a result, the upper radial portion 51 communicates with the lower end of the medium axial portion 52 and extends radially inward, substantially perpendicular to the lower end.

[0075] In other words, the bent portion of the passage 5, which is formed when the central axial portion 52 and the lower radial portion 53 are perpendicular to each other, is formed by an annular projection 37 that extends in the radial direction from the cylindrical portion 31a of the lower bearing holder 31.

[0076] The lower axial portion 54 is mainly defined by the outer circumferential surface of the small-diameter body 20d of the inner circumferential electrode 20 and the inner circumferential surface of the inner diameter side cylindrical portion 37b of the annular projection 37, which is arranged substantially parallel to this outer circumferential surface and spaced radially apart. As a result, it communicates with the inner diameter end of the lower radial portion 53, extends substantially perpendicular to the inner diameter end in the axial downward direction, and opens to the bearing 33 located in the axial downward direction.

[0077] As described above, the rotary connector 1 of this embodiment is configured such that the inner electrode 20 rotates relative to the outer electrode 30 by following the rotation axis of the semiconductor manufacturing machine.

[0078] Furthermore, during this rotation, each roller current collector 40 rolls relative to the outer surface of the large-diameter body 20b on the inner electrode 20, and revolves together with the current collector holder 41 around the inner electrode 20 as an axis.

[0079] At this time, each roller current collector 40 also rolls relative to the inner surface of the large-diameter hole 30c in the outer electrode 30.

[0080] As a result, when the inner electrode 20 is rotating relative to the outer electrode 30, each roller current collector 40 has a region in which current can be conducted. Therefore, the rotary connector 1 can conduct electricity supplied from an external power source to the rotating shaft in the semiconductor manufacturing machine.

[0081] Furthermore, each roller current collector 40 has a barrel-shaped exterior. The annular grooves 20f and 30f are formed along the outer surface of the roller current collector 40. As a result, even if the roller current collector 40 tries to move upward in the axial direction, its movement is restricted by the circumferential surface that defines the annular grooves 20f and 30f.

[0082] Furthermore, when the inner electrode 20 attempts to tilt relative to the axis of the outer electrode 30, the roller current collector 40 is designed to easily follow the circumferential surface defining the annular grooves 20f and 30f.

[0083] Therefore, in the rotary connector 1, the contact area between the roller current collector 40 and the circumferential surface defining the annular grooves 20f and 30f does not change easily. As a result, the rotary connector 1 makes it easier to maintain a nearly constant amount of electricity conducted to the rotating shaft in the semiconductor manufacturing machine supplied from an external power source.

[0084] Furthermore, each roller current collector 40 is pivotally supported by a highly conductive pin 41b. As a result, the allowable current value of the pin 41b is added to the allowable current value of the roller current collector 40, thereby increasing the maximum amount of electricity that can be conducted.

[0085] Furthermore, each roller current collector 40 held by the current collector holder 41 is restricted from being relatively close to each other in the circumferential direction. In other words, the current collector holder 41 prevents damage from occurring due to contact between the roller current collectors 40.

[0086] Furthermore, the bearing 33 is made of metal and is conductive, while the bearing holders 31 and 32 are insulating. Therefore, the bearing holders 31 and 32 can prevent leakage of electricity that has been conducted from the inner circumferential electrode 20 to the bearing 33.

[0087] Furthermore, the rotary connector 1 is cased by a highly insulating housing 35 and cover 36. Therefore, the rotary connector 1 is protected from unintended electrical leakage, electric shock due to contact, etc.

[0088] As each roller current collector 40 undergoes planetary motion, friction, aging deterioration, etc., can generate contaminants such as wear particles and plating detachment particles. These contaminants may descend due to gravity and enter the passage 5.

[0089] As described above, the passage 5 is formed in a zigzag shape by the formation of multiple bends when the upper axial portion 50 and the upper radial portion 51, the upper radial portion 51 and the middle axial portion 52, the middle axial portion 52 and the lower radial portion 53, and the lower radial portion 53 and the lower axial portion 54 are substantially perpendicular to each other.

[0090] More specifically, the bent portion formed by the substantially perpendicular alignment of the upper axial portion 50 and the upper radial portion 51 is located on the vertically lower side of the roller current collector 40, preventing contaminants from descending due to gravity and moving linearly downward in the vertical direction. Similarly, the bent portion formed by the substantially perpendicular alignment of the middle axial portion 52 and the lower radial portion 53 is also located on the vertically lower side of the roller current collector 40, preventing contaminants from descending due to gravity and moving linearly downward in the vertical direction. In this specification, the vertically lower side of the roller current collector 40 is not limited to directly below, but can be any downward direction. This makes it more difficult for contaminants to reach the bearing 33 compared to a configuration in which the passage is formed in a straight line. In this way, the passage 5 is formed in a zigzag shape by multiple bent portions, thereby suppressing the movement of contaminants.

[0091] Furthermore, because the passage 5 is narrow, it is difficult for foreign objects to move toward the bearing 33. From the viewpoint of preventing movement, the degree of narrowness should be such that the length of the passage 5 perpendicular to the direction of extension (i.e., the direction toward the bearing 33) is less than half the radial length of the bearing, preferably less than or equal to the diameter of the ball 33b. In this embodiment, the upper axial portion 50, upper radial portion 51, middle axial portion 52, lower radial portion 53, and lower axial portion 54 that constitute the passage 5 are all narrow, but only a part of them may be narrow.

[0092] Furthermore, debris that descends while being guided to the upper axial portion 50 falls onto the inner flange portion 30k of the outer electrode 30. In other words, in the bent portion formed by the substantially perpendicular alignment of the upper axial portion 50 and the upper radial portion 51, debris falls onto the upper end surface of the inner flange portion 30k extending in the inner radial direction and is trapped, thereby restricting the movement of debris in the passage 5.

[0093] Furthermore, debris that passes through the upper radial portion 51 and descends while being guided to the central axial portion 52 falls into the annular recess 38 formed in the annular projection 37 of the lower bearing holder 31. That is, in the bent portion formed by the approximately perpendicular alignment of the central axial portion 52 and the lower radial portion 53, debris falls into the annular recess 38 formed in the annular projection 37 extending in the inner diameter direction and is trapped, thereby restricting the movement of debris in the passage 5. Moreover, since the annular projection 37 is positioned above the bearing 33 in an overhang shape, it prevents debris from moving linearly toward the bearing 33. Note that the annular recess 38 does not necessarily have to be formed on the annular projection 37; in this case, debris falls into the flat upper end surface of the annular projection 37 extending in the inner diameter direction and is trapped in the bent portion.

[0094] As described above, impurities are trapped by the bends formed in the passage 5, preventing them from entering the bearing 33 from the roller current collector 40. This makes it difficult for impurities to get caught in the bearing 33. Therefore, the rotary connector 1 can function stably over a long period of time.

[0095] Furthermore, since the rotary connector 1 in this embodiment is oriented vertically and a bent portion is provided on the vertically lower side of the roller current collector 40, foreign matter that descends according to gravity is trapped by the bent portion, preventing it from moving linearly toward the bearing.

[0096] Furthermore, since the bent portion formed in the passage 5 is formed by an inner flange portion 30k extending in the inner diameter direction and an annular projection 37, it is possible to prevent foreign matter from moving linearly toward the bearing 33. In addition, because the passage 5 is formed in a zigzag pattern due to the formation of multiple bent portions, it is difficult for foreign matter to reach the bearing 33.

[0097] Furthermore, in the bent portion formed in the passage 5, the annular recess 38 formed in the annular projection 37 is formed in the shape of a groove that is open in the axial direction upward. Therefore, the annular recess 38 has a high capacity to hold trapped foreign matter.

[0098] Furthermore, the annular recess 38, which is formed in a ring shape, can trap foreign objects that fall in at any position in the circumferential direction. Therefore, the annular recess 38 is highly efficient at trapping foreign objects.

[0099] Furthermore, the annular recess 38 formed in the lower bearing holder 31, which is a stationary member, is not subjected to the rotational force of the inner electrode 20. As a result, the contaminants trapped by the annular recess 38 are not subjected to the rotational force of the inner electrode 20. Therefore, the annular recess 38 can reliably hold the contaminants.

[0100] Furthermore, the shielded bearing 33 is less likely to become jammed with foreign objects that pass through the passage 5. As a result, the rotary connector 1 can function stably for a longer period of time.

[0101] Furthermore, even if the large-diameter body 20b and the small-diameter body 20d are continuous in the inner circumferential electrode 20, in other words, if the medium-diameter body 20c is formed to the same diameter as the small-diameter body 20d, the passage 5 is bent by the annular projection 37, thereby preventing foreign matter from descending due to gravity and moving linearly downward in the vertical direction. [Examples]

[0102] Next, the rotary connector according to Embodiment 2 will be described with reference to Figure 4. Note that components identical to those shown in Embodiment 1 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0103] As shown in Figure 4, the inner circumferential electrode 120 is fitted with a projection member 23 that extends downward on its outer diameter side and a pressing member 24 that extends downward on its inner diameter side.

[0104] The projection member 23 is formed in a flanged cylindrical shape and comprises a cylindrical portion 23a as a projection extending toward the annular recess 38, and an inner flange portion 23b as a projection and an outer diameter projection. The cylindrical portion 23a is formed in a cylindrical shape extending in the axial direction. The inner flange portion 23b is formed in an annular and flat shape extending in the inner diameter direction substantially perpendicular to the upper end of the cylindrical portion 23a.

[0105] The projection member 23 is fitted onto the outer circumferential surface of the small-diameter body 120d of the inner circumferential electrode 120. Furthermore, the upper end surface of the inner flange portion 23b of the projection member 23 abuts against the lower end surface of the medium-diameter body 120c of the inner circumferential electrode 120. In addition, the lower end surface of the inner flange portion 23b is arranged substantially flush with the lower end surface of the small-diameter body 120d. That is, the inner flange portion 23b of the projection member 23 extends outward from the small-diameter body 120d of the inner circumferential electrode 120, and the outer diameter end of the inner flange portion 23b protrudes outward from the outer circumferential surface of the medium-diameter body 120c. In other words, the outer diameter end of the inner flange portion 23b constitutes a projection extending outward from the inner circumferential electrode 120.

[0106] The pressing member 24 is formed in a flanged cylindrical shape and comprises a cylindrical portion 24a and an outer flange portion 24b. The cylindrical portion 24a is formed in a cylindrical shape extending in the axial direction. The outer flange portion 24b is formed in an annular and flat shape extending in the outer diameter direction substantially perpendicular to the upper end of the cylindrical portion 24a.

[0107] The pressing member 24 is fitted onto the outer circumferential surface of the lower shaft 120e of the inner circumferential electrode 120. Furthermore, the upper end surface of the outer flange portion 24b of the pressing member 24 abuts across the lower end surface of the small diameter body 120d of the inner circumferential electrode 120 and the lower end surface of the inner flange portion 23b of the projection member 23.

[0108] Furthermore, the lower end edge of the cylindrical portion 24a of the pressing member 24 abuts against the inner ring 33a of the bearing 33, thereby regulating the position of the bearing 33.

[0109] Here, the protruding member 23 is inserted into the annular recess 38 at its lower end, or more specifically, from the axial center of the cylindrical portion 23a to its lower edge.

[0110] As a result, the projection member 23 is positioned in a canopy shape axially above the annular recess 38. Therefore, the projection member 23 not only prevents foreign matter from moving linearly toward the bearing 33, but also facilitates the guidance of foreign matter into the annular recess 38.

[0111] More specifically, the inner circumferential surface of the cylindrical portion 23a is positioned substantially parallel to and radially spaced apart from the inner circumferential surface of the inner diameter side cylindrical portion 37b of the annular projection 37. The lower end surface of the cylindrical portion 23a is positioned spaced apart from the upper end surface of the bottom portion 37a of the annular projection 37. The outer circumferential surface of the cylindrical portion 23a is positioned substantially parallel to and radially spaced apart from the inner circumferential surface of the medium diameter hole portion 31c of the lower bearing holder 31. In other words, the cylindrical portion 23a of the projection member 23 and the annular recess 38 formed in the annular projection 37 constitute a labyrinth structure.

[0112] As a result, in the bent sections formed in the passage 5, foreign matter falls into the inner flange portion 23b of the projection member 23 extending in the outer diameter direction and the annular recess 38 formed in the annular projection 37 extending in the inner diameter direction and is trapped, thereby restricting the movement of foreign matter in the passage 5. Furthermore, because the inner flange portion 23b extending in the outer diameter direction and the annular projection 37 extending in the inner diameter direction overlap vertically to form multiple bent sections, the passage 5 is formed in a zigzag pattern, making it difficult for foreign matter to reach the bearings.

[0113] Furthermore, by having the lower end of the cylindrical portion 23a extending downward from the inner flange portion 23b enter into the annular recess 38 formed in the annular projection 37, a labyrinth structure is formed, which can more effectively prevent the movement of foreign matter toward the bearing 33. [Examples]

[0114] Next, the rotary connector according to Embodiment 3 will be described with reference to Figure 5. Note that components identical to those shown in Embodiments 1 and 2 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0115] As shown in Figure 5, the inner circumferential electrode 220 consists of a large-diameter body 220b and a small-diameter body 220d that are continuous. Furthermore, the small-diameter body 220d has an annular projection 25 that is transversely T-shaped in cross-section and annular in shape, projecting outward from its outer surface.

[0116] The annular projection 25 comprises an annular plate portion 25a as a projection and an outward-radial projection, and a cylindrical portion 25b as a projection extending toward the annular recess 38. The annular plate portion 25a extends outward in a direction substantially perpendicular to the outer circumferential surface of the small-diameter body 220d. The cylindrical portion 25b extends axially upward and downward, substantially perpendicular to the outer diameter end of the annular plate portion 25a.

[0117] The annular projection 25 is positioned in an overhang shape axially above the annular recess 38. The cylindrical portion 25b, together with the annular recess 38 formed in the annular projection 37, constitutes a labyrinth structure.

[0118] As a result, in this embodiment, the annular plate portion 25a of the annular projection 25 is formed by the annular projection 37, creating multiple bends in the passage 5. This causes the passage 5 to extend in a zigzag pattern, making it difficult for foreign objects to reach the bearing 33.

[0119] Furthermore, by having the lower end of the cylindrical portion 25b extending downward from the annular plate portion 25a enter into the annular recess 38 formed in the annular projection 37, a labyrinth structure is formed, which can more effectively prevent the movement of foreign matter toward the bearing 33.

[0120] Furthermore, above the annular projection 25, an annular recess 26 is formed by the upper end of the cylindrical portion 25b and the outer circumferential surface of the small-diameter body 220d, opening upward in the axial direction. In this way, foreign matter can be trapped not only by the annular recess 38 in the stationary element 3, but also by the annular recess 26 in the rotating element 2.

[0121] Furthermore, the annular recess 26 has a longer radial length than the passage 5 between the annular projection 25 and the outer electrode 30, making it easier for impurities to flow into the annular recess 26. [Examples]

[0122] Next, the rotary connector according to Embodiment 4 will be described with reference to Figure 6. Note that components identical to those shown in Embodiments 1 to 3 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0123] As shown in Figure 6, the small diameter body 320d of the inner circumferential electrode 320 has a projection that protrudes outward in the radial direction substantially perpendicular to its outer circumferential surface, and an annular projection 27 as an outward radial projection. The annular projection 27 is positioned in a canopy shape axially above the annular recess 38 formed in the annular projection 37.

[0124] As a result, in this embodiment, the annular projections 27 and 37 form multiple bends in the passage 5, causing the passage 5 to extend in a zigzag pattern, which makes it difficult for foreign objects to reach the bearing 33.

[0125] Furthermore, the annular projection 27, together with the lower end surface of the large-diameter body 220b and the outer circumferential surface of the small-diameter body 320d, defines a radial annular recess 28. Thus, impurities can be trapped not only by the annular recess 38 in the stationary element 3, but also by the radial annular recess 28 in the rotating element 2, more specifically by the upper end surface of the annular projection 27. In addition, the radial annular recess 28 has a longer radial length than the passage 5 between the annular projection 27 and the outer circumferential electrode 30, making it easier for impurities to be trapped by the upper end surface of the annular projection 27. [Examples]

[0126] Next, the rotary connector according to Embodiment 5 will be described with reference to Figure 7. Note that components identical to those shown in Embodiments 1 to 4 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0127] As shown in Figure 7, the small diameter body 420d of the inner circumferential electrode 420 has a projection that protrudes radially from its outer circumferential surface and an annular projection 29 with a transverse L-shaped cross-section that acts as an outer diameter projection.

[0128] The annular projection 29 comprises an annular plate portion 29a and a cylindrical portion 29b. The annular plate portion 29a extends outward in a direction substantially perpendicular to the outer circumferential surface of the small-diameter body 420d. The cylindrical portion 29b extends axially upward in a direction substantially perpendicular to the outer diameter end of the annular plate portion 25a.

[0129] As a result, the annular projection 29 is positioned in a canopy-like shape axially above the annular recess 38. Furthermore, the annular projection 29, together with the outer circumferential surface of the small-diameter body 420d, constitutes the annular recess 426.

[0130] The protrusions described in Examples 2 to 5 above may be separate from the inner circumferential electrode, or they may be integrated with the inner circumferential electrode. [Examples]

[0131] Next, the rotary connector according to Embodiment 6 will be described with reference to Figure 8. Note that components identical to those shown in Embodiments 1 to 5 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0132] As shown in Figure 8, the outer peripheral electrode 530 differs from embodiments 1 to 5 in that it does not have an inner flange portion 30k. That is, on the inner diameter side of the outer peripheral electrode 530, the large diameter hole portion 530c and the medium diameter hole portion 530e are continuous. Also, the axial dimension of the outer peripheral electrode 530 below the large diameter hole portion 530c is shorter than that of embodiments 1 to 5.

[0133] The lower bearing holder 531 is formed in a flanged cylindrical shape. The lower bearing holder 531 comprises a cylindrical portion 531a, an outer flange portion 531b, and an annular projection 537 which serves as both a projection and an inward radial projection.

[0134] The inner circumferential electrode 520 has a large diameter body 520b and a lower shaft 520e that are continuous, and the axial dimension below the large diameter body 520b is shorter than that of the embodiments 1 to 5 described above. In addition, a projection member 523 is fixed to the inner circumferential electrode 520.

[0135] The projection member 523 is formed in a flanged cylindrical shape and comprises a cylindrical portion 523a and an outer flange portion 523b which serves as a projection and an outer radial projection. The cylindrical portion 523a is formed in a cylindrical shape that extends in the axial direction. The outer flange portion 523b is formed in an annular and flat shape that extends in the outer radial direction substantially perpendicular to the upper end of the cylindrical portion 523a.

[0136] The projection member 523 is fitted onto the outer circumferential surface of the lower shaft 520e on the inner circumferential electrode 520, with the outer diameter end of the outer flange portion 523b protruding radially beyond the outer circumferential surface of the large diameter body 520b. In other words, the outer diameter end of the outer flange portion 523b constitutes a projection extending radially from the inner circumferential electrode 520.

[0137] More specifically, the outer flange portion 523b extends substantially parallel to the projection and the upper end surface of the annular projection 537, which is an inward radial projection, on the lower bearing holder 531, and is spaced apart in the axial direction. In addition, the outer diameter edge of the outer flange portion 523b is spaced apart radially from the inner circumferential surface of the medium diameter hole portion 530e on the outer peripheral electrode 530.

[0138] Furthermore, the projection member 523, together with the upper end surface of the bearing 33, defines a radially annular recess 528. The annular projection 537 of the lower bearing holder 531 is inserted into the radially annular recess 528, and the inner diameter end edge of the annular projection 537 is spaced radially apart from the outer circumferential surface of the cylindrical portion 523a of the projection member 523. In other words, the projection member 523 and the annular projection 537 of the lower bearing holder 531 constitute a labyrinth structure.

[0139] As a result, in this embodiment, the outer flange portion 523b and the annular projection 537 of the projection member 523 form multiple bends in the passage 5, causing the passage 5 to extend in a zigzag pattern, which makes it difficult for foreign objects to reach the bearing 33.

[0140] Furthermore, since the annular projection 537 is positioned above the bearing 33 in an overhang shape, it prevents foreign matter from moving linearly toward the bearing 33.

[0141] Furthermore, because the outer flange portion 523b of the projection member 523 extending outward from the inner circumferential electrode 520 and the annular projection 537 extending inward from the lower bearing holder 531 allow for the formation of multiple bent sections with a simple structure, bent sections can be formed even when the passage 5 communicating from the roller current collector 40 to the lower bearing 33 is small in the axial direction.

[0142] Furthermore, since the projection member 523 is separate from the inner circumferential electrode 520, the projection member 523 can be formed from a different material than the inner circumferential electrode. For example, by selecting a material that easily attracts foreign matter, the outer diameter end of the outer flange portion 523b can more easily trap foreign matter, thereby more effectively preventing the movement of foreign matter toward the bearing 33.

[0143] Furthermore, the protrusions described in this embodiment are not limited to being formed by a separate protrusion member from the inner circumferential electrode; they may also be formed integrally with the inner circumferential electrode to facilitate manufacturing.

[0144] Alternatively, an annular recess opening axially upward may be formed on the upper end surface of the outer flange portion 523b or the upper end surface of the lower bearing holder 531, so that foreign matter can be trapped by the annular recess.

[0145] Although embodiments 1 to 6 of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments 1 to 6, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0146] For example, in the above embodiments 1 to 6, the inner and outer electrodes were described as being cased in the housing and cover, but the configuration is not limited to this, and they may be exposed.

[0147] Furthermore, although the roller current collector was described as being barrel-shaped in Examples 1 to 6, it is not limited to this configuration. It may also be cylindrical, or have a shape that tapers from both axial ends towards the axial center, and its shape may be changed as appropriate. Accordingly, the shape of the annular groove in which the roller current collector is arranged may also be changed as appropriate. Moreover, the annular groove does not have to be shaped in line with the roller current collector.

[0148] Furthermore, although the holder pins in Examples 1 to 6 were described as being made of a highly conductive material, the configuration is not limited to this, and they may be made of a highly insulating material.

[0149] Furthermore, although the holder pins in Examples 1 to 6 were described as being elastically deformable, they are not limited to this and may be rigid. With such a configuration, the contact area between the pins and the roller current collector can be reduced by making the pins thinner.

[0150] Furthermore, although the recesses in Examples 1 to 6 were described as having an annular configuration, the invention is not limited to this, and one or more recesses that are not continuous in an annular shape may be formed.

[0151] Furthermore, although the above embodiments 1 to 6 described a configuration in which only one annular recess is formed on the stationary element, the configuration is not limited to this, and multiple recesses may be formed spaced apart in the radial direction. The same applies to the rotating element.

[0152] Furthermore, in the above embodiments 1 to 6, the annular projection and annular recess were described as being formed on the lower bearing holder of the stationary element, but they may also be formed on other elements of the stationary element, such as the outer electrode.

[0153] Furthermore, although the inner electrode, outer electrode, and roller current collector were described as being plated in the above-described examples 1 to 6, the configuration is not limited to this, and any material with high conductivity is acceptable, and plating is not required.

[0154] Furthermore, although the above embodiments 1 to 6 described the bearing as having lip seals on both the upper and lower sides, the configuration is not limited to this; it is sufficient to have at least one lip seal on the upper side, and the lower lip seal may be omitted. [Explanation of symbols]

[0155] 1 Rotary connector 2 Rotating side elements 3 stationary elements 4. Current collection element 5 aisles 20 Inner Circumferential Electrode 23. Protruding member 23a Cylindrical part (protrusion) 23b Inner flange portion (projection, outer radial projection) 24 Pressing member 25 Annular projection 25a Annular plate portion (projection, radial projection) 25b Cylindrical part (protrusion) 26. Ring-shaped indentation (indentation) 27 Annular projection (projection, radial projection) 28 Radial annular recess 29. Annular projection (projection, radial projection) 30 outer electrode 30k Inner flange section (projection, inward radial projection) 31 Lower bearing holder 33 Bearings (shielded bearings) 37 Annular projection (projection, projection in the inner diameter direction) 38. Ring-shaped indentation (indentation) 40 Roller current collector 50 Upper axial section (bent section) 51 Upper radial section (bent section) 52. Central axial section (bent section) 53 Lower radial section (bent section) 54 Lower axial section (bent section) 120 Inner Circumferential Electrode 220 Inner Circumferential Electrode 220b Large diameter barrel 220d Small diameter body 320 Inner Circumferential Electrode 420 Inner Circumferential Electrode 426 Ring-shaped indentation (dent) 520 Inner Circumference Electrode 523 Protruding member 523b Outer flange portion (projection, radial projection) 528 Radial annular recess 537 Annular projection (projection, projection in the inner diameter direction)

Claims

1. A rotary connector comprising an outer electrode, an inner electrode inserted into the outer electrode and arranged to be rotatable relative to it, a plurality of roller current collectors arranged to move in a planetary motion between the outer electrode and the inner electrode, a bearing for enabling relative rotation between the outer electrode and the inner electrode, and a bearing holder for holding the bearing, A projection is provided on the side wall of the passage extending from the contact point between the inner circumferential electrode and the roller current collector to the bearing. The projection is a rotary connector having a radial projection that protrudes radially and covers a portion of the space between the outer and inner rings of the bearing in the axial direction, and an axial projection that protrudes axially from the radial projection toward the opposite side of the bearing.

2. The rotary connector according to claim 1, wherein the rotary connector is oriented vertically, and a bent portion is provided in the passage on the vertically lower side of the roller current collector.

3. The rotary connector according to claim 2, wherein the bearing is a shielded bearing having a shielding element provided at least vertically upward.

4. The projection further has another radial projection that protrudes radially toward the opposite side of the direction of protrusion of the radial projection, The rotary connector according to claim 2 or 3, wherein the radial projection and the other radial projection are superimposed in the vertical direction.

5. The rotary connector according to claim 2 or 3, wherein a recess is provided which is formed by the radial projection and the axial projection and is open vertically upward.

6. The rotary connector according to claim 5, wherein the recess is annular.

7. The rotary connector according to claim 6, wherein the recess is formed in the bearing holder.

8. The rotary connector according to claim 7, wherein the other radial projection has another axial projection that extends toward the recess.

9. The rotary connector according to claim 8, wherein the other axial projection is partially embedded in the recess.

10. A rotary connector comprising: an outer electrode; an inner electrode inserted into the outer electrode and arranged to be rotatable relative to it; a plurality of roller current collectors arranged to be in planetary motion between the outer electrode and the inner electrode; a bearing for enabling relative rotation between the outer electrode and the inner electrode; and a bearing holder for holding the bearing, a) Further comprising a projection member formed of a different material from the inner circumferential electrode and fixed to the inner circumferential electrode side, wherein the projection member has a projection that protrudes into a passage extending from the contact portion between the inner circumferential electrode side and the roller current collector to the bearing, or b) A rotary connector further comprising a projection member formed of a different material from the outer peripheral electrode and fixed to the outer peripheral electrode side, wherein the projection member has a projection that protrudes into a passage extending from the contact portion between the outer peripheral electrode side and the roller current collector to the bearing.

11. The bearing holder has a projection that protrudes into the passage, The rotary connector according to claim 10, wherein the projection of the projection member and the projection of the bearing holder overlap in the axial direction, thereby forming a labyrinth in the passage.

12. The rotary connector according to claim 11, wherein the rotary connector is vertically oriented, and the labyrinth is provided on the vertically lower side of the roller current collector.

13. The rotary connector according to claim 10, wherein the bearing is a shielded bearing having a shielding element provided at least vertically upward.

Images