JP2009168610A - Encoder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an encoder that easily suppresses increase in temperature of each section inside an external cover, suppresses function reduction by heat of various components arranged inside the external cover, and easily improves the reliability against heat. <P>SOLUTION: The encoder 10 includes a rotation sign section 19 that has a pattern for detection and is attached to a rotation section 13 of a base apparatus 10, a detecting section 21 for detecting the pattern for detection of the rotation sign section 19, a printed circuit board 23 having a circuit and an electric component 73 for processing a signal detected by the detecting section 21, and the external cover 25 for covering the rotation sign section 19, the detecting section 21, and the printed circuit board 23. The external cover 25 has an uneven heat exchange section 83 for dissipating heat inside the external cover 25 to the outside of the external cover 25. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an encoder that is mounted on a base device and detects relative rotation between a rotating portion and a non-rotating portion of the base device.

  Conventionally, many encoders that are mounted on a base device such as a motor and detect relative rotation between a rotating part and a non-rotating part are known.

  The encoder includes a rotation code unit that is attached to the rotation unit of the base device, a detection unit that can detect a detection pattern of the rotation code unit, a circuit that processes a signal detected by the detection unit, a substrate having an electrical component, and the like. These members are covered with an exterior cover. By covering each member with an exterior cover, it is protected from external force, and dustproof, waterproof, etc. are secured. This is because if dust, moisture, or the like adheres to these members, the detection accuracy is lowered or normal detection operation cannot be secured.

  When the encoder is mounted on a base device and used, various electrical components mounted on the board generate heat. Although the amount of heat generation differs for each electrical component, there are components that become excessively hot. The heat generated by the heat generation is supplied to the inside of the exterior cover.

  In addition, there are many types of base devices to which an encoder is attached that generate heat during use. For example, in the case of a motor, an electrical component such as a coil for obtaining a rotating magnetic field generates heat, or generates heat due to friction of a rotating part. Since the encoder is directly fixed to the base device, part of the heat generated by the heat generation is transmitted to the encoder and supplied to the inside of the exterior cover.

  Therefore, the temperature of the encoder tends to rise over time during use of the encoder. In particular, in recent years, in order to reduce the size of base devices such as motors, they are often used at higher rotational speeds, and the amount of heat generated from each part tends to increase.

  However, many electrical components and the like mounted on the substrate are likely to deteriorate in function when the temperature is excessively high. Therefore, if the temperature in the exterior cover increases excessively over time using the encoder, problems such as a decrease in detection accuracy are likely to occur.

  The following Patent Document 1 proposes an encoder that suppresses a temperature rise against heat generation inside the encoder during use. Here, the rotation code part is accommodated in the housing, and a fin that stirs the air in the housing is provided on a shaft that is connected to the rotation part of the base device and fixes the rotation code part.

According to this encoder, since the air in the housing can be agitated by the fins, it is easy to suppress the occurrence of excessive temperature rise due to heat generation of some electrical components mounted on the board. ing.
JP 2007-255970 A

  However, in the case of an encoder covered with a conventional exterior cover, heat transmitted from the base device or heat generated in the encoder is stored in various members in the exterior cover, so even if air is circulated, the encoder It became clear that the temperature inside increased easily.

  Therefore, the present invention easily suppresses the temperature rise of each part inside the exterior cover, and suppresses functional deterioration due to the heat of various components arranged inside the exterior cover, thereby easily improving the reliability with respect to heat. It is an object to provide an encoder.

  An encoder of the present invention that solves the above-described problem has a detection pattern, a rotation code unit attached to a rotation unit of a base device, a detection unit capable of detecting the detection pattern of the rotation code unit, An encoder comprising a circuit board for processing a signal detected by a detection unit and a substrate having electrical components, and an outer cover that covers the rotation code unit, the detection unit, and the substrate. An uneven heat exchange part is provided for dissipating heat inside the exterior cover to the outside of the exterior cover.

  According to the encoder of the present invention that solves the above-described problems, the outer cover that covers the rotation sign section, the detection section, and the substrate is provided with an uneven heat exchange section that dissipates heat inside the outer cover to the outside. As a result, a large heat transfer area can be secured, and heat generated inside the exterior cover and heat supplied to the interior of the exterior cover during use are quickly radiated to the outside of the exterior cover by the heat exchange unit. It is possible.

  Therefore, it is possible to provide an encoder that easily suppresses the temperature rise of each part inside the exterior cover, suppresses functional deterioration due to heat of various components arranged inside the exterior cover, and easily improves reliability against heat. It is possible.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  The encoder 10 of this embodiment is an optical modular encoder, and is mounted on various base devices, and the amount of rotation such as the relative rotation angle and the relative rotation speed between the rotating portion and the non-rotating portion of the base device is determined. It is to detect. Here, what is attached to the motor 11 and detects the rotation amount of the motor shaft 13 and the motor housing 15 will be described.

  The encoder 10 includes a frame 17 that can be fixed to the motor housing 15, a rotation code unit 19 that is housed in the frame 17 and can be attached to the motor shaft 13, and a frame that can detect the rotation of the rotation code unit 19. 17, a detection unit 21 directly or indirectly fixed to 17, a printed circuit board 23 having a circuit and an electrical component for processing a signal detected by the detection unit 21 and fixed to the frame body 17, An exterior cover 25 that covers the entire side opposite to the motor housing 15 from the outside is provided.

  The rotation code portion 19 includes a boss portion 27 that can be attached to the motor shaft 13, an annular optical code plate 31 that has an optical pattern 29 around the entire circumference and is fixed around the boss portion 27, and a magnetic pole in the circumferential direction. And a magnetic encoder 33 having a magnetic pattern that changes one or more times and fixed to the end of the boss 27.

  The boss portion 27 is provided with a male screw portion 35 on the outer periphery on the motor 11 side for fixing the rotation sign portion 19 to the frame body 17 before the encoder 10 is attached to the motor 11. A connecting hole 37 that can be connected coaxially with the motor shaft 13 is provided in the direction of the rotation axis, and the end of the motor shaft 13 can be fitted into the connecting hole 37 and fixed with a fixing screw 39. . Therefore, when attaching the rotation sign portion 19 to the motor shaft 13, the motor shaft 13 is fitted into the connecting hole 37 and fixed with the fixing screw 39, and then the male screw portion 35 is detached from the frame body 17. It has become a structure.

  In the rotation code part 19, the boss part 27 is made of an aluminum alloy or the like, and the optical code plate is made of a sufficiently stable material that does not deform at the operating temperature. The magnetic pattern is made of a ferromagnetic material, for example, and is a material that easily demagnetizes when the temperature rises.

  The frame 17 includes a substantially cylindrical frame body 43 having a base end portion 41 that can be positioned and fixed to the motor housing 15, and a substantially fixed body body 43 on the opposite side of the motor housing 15. And a cylindrical support 45. In the frame body 43, a conductive fixing metal 47 used for fixing the printed circuit board 23 and the exterior cover 25 is embedded. The fixed hardware 47 will be described later.

  Inside the frame 17, a boss portion accommodating portion 49 that rotatably accommodates the boss portion 27 of the rotation sign portion 19, and a code portion accommodating portion 51 that rotatably accommodates the optical code plate 31 and the magnetic code body 33. Is formed. The boss portion accommodating portion 49 is provided with a female screw portion 53 that can be screwed with the male screw portion 35 of the boss portion 27.

  Further, a light emitting unit 55 constituting a part of the detecting unit 21 is fixed at a position of the frame body 43 facing the optical code plate 31. The light emitting unit 55 is a divided printed circuit board 23 that is fixed to the base end 41 side of the frame body 43, a light emitting element 57 that is supplied with power from the divided substrate 59 and can emit light, and guides light from the light emitting element 57. And a collimating lens 63 that irradiates the optical code plate 31 with the light from the light emitting element 57 being substantially parallel light.

  In this frame body 17, the frame body 43 and the support body 45 are formed of a resin that is relatively stable even at a high temperature, and the divided printed circuit board 23 and the light emitting element 57 of the light emitting portion 55 are formed relatively stably even at a high temperature. The collimating lens 63 of the light emitting unit 55 is formed of a thermoplastic resin such as polymethyl methacrylate, and is likely to be deformed when the temperature rises.

  The frame body 17 is provided with an opening 65 continuous from the code portion receiving portion 51 at the end opposite to the base end portion 41. A shield plate 67 is fixed to the opening 65 to cover the opening 65. The shield plate 67 is made of a plate member obtained by forming a high magnetic permeability material such as thin soft iron into an irregular shape. The shield plate 67 covers the outer side of the rotation code unit 19 for the purpose of protecting the rotation code unit 19 and preventing electrostatic noise.

  The shield plate 67 has a through hole 69 at a portion not facing the optical pattern 29 and the magnetic pattern. A through hole 69 provided in the central portion enables the fixing screw 39 to be attached to the rotation sign portion 19. Further, a portion corresponding to the light receiving portion 71 described later and other inevitable portions also have through holes (not shown). These through-holes 69 communicate between the inner spaces on both sides of the shield plate 67 so that heat in one inner space of the shield plate 67 can easily diffuse through the through-holes 69 to the other inner space. .

  The printed circuit board 23 is fixed to the end of the support body 45 so as to cover the opening 65. A light receiving unit 71 that constitutes a part of the detection unit 21 is fixed to the rotation code unit 19 side of the printed circuit board 23 at a position facing the optical pattern 29. The light receiving portion 71 is attached in close proximity to the optical code plate 31 through the through hole 69 of the shield plate 67. Further, a magnetic detection unit 21 composed of a Hall element or the like constituting a part of the detection unit 21 is fixed at a position facing the magnetic pattern.

  A circuit for processing detection signals detected by the light receiving unit 71 and the magnetic detection unit 21 and various electrical components 73 are mounted on the opposite side of the printed circuit board 23 from the rotation code unit 19. As the electrical component 73, for example, an analog / digital converter that processes a detection signal, a transmission connector 75 for transmitting a signal such as a rotation angle and a rotation amount generated based on the detection signal to a control unit (not shown), and the like. Etc.

  Various electrical components 73 mounted on the printed circuit board 23 tend to be degraded in function when the temperature rises excessively from the normal use temperature, mainly in capacitors. On the other hand, there are electrical components 73 that easily generate heat during use and emit more heat.

  Such a printed circuit board 23 is fixed to the support body 45 by screws or the like. In this embodiment, at least one conductive fixing screw 48 is screwed and fixed to a fixing metal 47, and the fixing screw 48 is fixed in contact with a signal ground provided on the printed circuit board 23. Thus, the signal ground and the fixed hardware 47 are connected.

  A through hole 77 is provided at the center of the fixed printed circuit board 23 so that the fixing screw 39 can be attached to the rotation sign 19. Further, a gap (not shown) is provided between the periphery and the support body 45 of the frame body 17. The inner spaces on both sides of the printed circuit board 23 are communicated with each other by the through holes 77 and the gaps, and the heat of the inner space on one side of the printed circuit board 23 is easily diffused through the through holes 77 to the inner space on the other side. ing.

  In the encoder 10, the entirety of the frame body 17, the printed circuit board 23, and the like that house the rotation code portion 19 is covered with an exterior cover 25 for the purpose of waterproofing and dustproofing. The exterior cover 25 includes a substantially cylindrical tubular cover portion 79 and an end cover portion 81 provided integrally with one end portion of the tubular cover portion 79. The outer cover 25 is attached by fitting the cylindrical cover portion 79 to the side peripheral surface of the frame body 17 so that the side peripheral surface of the frame body 17 is covered with the cylindrical cover portion 79, and the shield plate 67 and the print cover 25. The entire opening 65 of the frame body 17 on which the substrate 23 is disposed is configured to be covered with the end cover portion 81.

  In the exterior cover 25, the heat of the members such as the frame 17 disposed inside the exterior cover 25 and the heat of the inner space are in accordance with the temperature gradient between these temperatures and the temperature of the outer space of the exterior cover 25. A heat exchanging portion 83 for radiating heat is provided. Here, the heat exchanging unit 83 is provided on the outer surface of the cover main body 85 of the outer cover 25 on the inner surface of the cover main body 85 of the outer cover 25 and the numerous protrusions 87 provided to protrude outward from the cover main body 85. And a large number of ridges provided so as to protrude inward from the cover main body 85.

  These ridges 87 make the heat transfer area between the outer surface and the inner surface of the exterior cover 25 wider than the cover body 85, and the ridges 87 inside the exterior cover 25 radiate the heat of the inner space to the exterior cover 25. It is preferable that the protrusions 87 on the outer side of the outer cover 25 are formed so as to have as large a surface area as possible because the heat of the outer cover 25 is easily radiated to the outer space. It is.

  The position, shape, number, and the like of the ridges 87 can be set as appropriate. Preferably, the ridges 87 on the inner side of the outer cover 25 are provided only on the portion corresponding to the inner space, and the portion adjacent to the frame body 17 is provided. It is preferable that the surface of the cover body 85 is directly brought into contact with the frame body 17 without providing the ridges 87. This is because the heat of the frame body 17 can be efficiently transmitted to the cover body 85. Moreover, it is preferable that the protrusions 87 on the inner side of the exterior cover 25 are formed close to each other as long as they do not contact the printed circuit board 23 and the mounted electrical component 73.

  Furthermore, these ridges 87 may be provided more densely than other parts in a part where heat is easily generated or stays in the frame 17 and the inner space. For example, the ridges 87 may be densely provided in the vicinity of the electrical component 73 that generates a large amount of heat among the electrical components 73 mounted on the printed circuit board 23.

  Such an outer cover 25 is preferably formed of a material having high thermal conductivity, and is preferably formed of a metal, particularly a high permeability metal such as soft iron. This is because electrostatic noise and magnetic noise can be prevented by forming from a material with high magnetic permeability.

  When the cover body 85 is formed of a high magnetic permeability metal, it is particularly preferable that the thickness is 2 mm or more. This is because if the wall thickness is excessively thin, it is difficult to obtain a sufficient magnetic shielding effect. If the thickness is excessively large, the heat capacity of the outer cover 25 increases, and after the temperature of the outer cover 25 rises, the temperature change of the outer cover 25 becomes slow with respect to the amount of heat radiated from the outer cover 25 to the outer space. As a result, the temperature gradient between the frame 17 or the inner space and the exterior cover 25 is reduced, the heat absorption rate by the exterior cover 25 is reduced, and the heat dissipation efficiency is likely to be reduced.

  In this embodiment, the ridge 87 on the outer surface and the ridge 87 on the inner surface and the cover body 85 are integrally formed of the same high permeability metal by casting.

  The exterior cover 25 is fixed to the frame body 17 with screws or the like. In this embodiment, at least one conductive fixing screw 46 is screwed and fixed to a fixing metal 47, and the fixing metal 47 connected to the signal ground of the printed circuit board 23 by the fixing screw 48 and the exterior cover. 25 is connected.

  The end cover portion 81 of the outer cover 25 is provided with a through hole 89 so that the fixing screw 39 can be attached to the rotation sign portion 19 in a state where the outer cover 25 is fixed to the frame body 17. ing. The through-hole 89 is closed by a plug 91 after the rotation sign portion 19 is attached to the motor shaft 13.

  In the encoder 10 having the above-described configuration, when the motor shaft 13 is rotationally driven after being mounted on the motor 11, the rotation code portion 19 attached to the motor shaft 13 is integrally driven and rotated. The rotation angle is detected with high accuracy by the optical code plate 31, and the rotation speed is detected with high accuracy by the magnetic code body 33. Each detected amount detected by these is transmitted to the circuit of the printed circuit board 23 and processed, and a signal such as a rotation angle and a rotation number based on this is generated and transmitted to a processing unit (not shown) and used.

  When the use is started, various electrical components 73 mounted on the printed circuit board 23 generate heat, and the temperature of each electrical component increases with time. Due to the heat generated by the heat generation of the electrical component 73, the temperature of the inner space in the exterior cover 25, the printed circuit board 23, and the frame body 17 rises. In particular, the temperature of the inner space on the end cover portion 81 side of the exterior cover 25 is raised from the printed circuit board 23.

  Further, after the start of use, the temperature of the motor 11 also rises over time due to heat generation of coils in the motor 11 and the like. Then, the temperature of the motor housing 15 and the motor shaft 13 rises. In particular, the motor shaft 13 rises above the temperature of the motor housing 15. Due to these temperature rises, heat is supplied to each member such as the frame 17 and the rotation code portion 19 of the encoder 10 and the inner space. These heats increase the temperature of the inner space in the members such as the frame body 17 and the rotation code portion 19 and the boss portion housing portion 49 and the code portion housing portion 51 of the frame body 17.

  Then, the heat of the frame body 17 is absorbed by the cylindrical cover portion 79 of the exterior cover 25 in contact with the frame body 17 according to the temperature difference, and the heat absorbed by the cylindrical cover portion is converted into the cylindrical cover. Heat is dissipated from the large number of ridges 87 provided outside the portion 79 to the outer space according to the temperature difference from the outer space.

  On the other hand, part of the heat in the inner space in the boss portion accommodating portion 49 and the sign portion accommodating portion 51 of the frame body 17 is transmitted to the shield plate 67, the printed circuit board 23, the frame body 17 and the like, and these temperatures rise. At the same time, the remaining portion is diffused by the air in the inner space and transmitted to the end cover portion 81 side of the printed circuit board 23 via the through hole 89 provided in the shield plate 67 and the through hole 89 provided in the printed circuit board 23. Being raised the temperature of the inner space.

  Then, the heat of the frame body 17 is radiated to the outer space from a large number of ridges 87 provided on the outer side of the cylindrical cover portion 79 in the same manner as described above.

  On the other hand, the heat of the inner space on the end cover portion 81 side of the printed circuit board 23 is absorbed by the exterior cover 25 from a large number of ridges 87 and the like provided inside the end cover portion 81 according to the temperature difference. The heat absorbed by the exterior cover 25 is radiated to the outer space from a large number of ridges 87 provided on the outer side of the end cover portion 81 according to the temperature difference from the outer space.

  As a result, the heat generated in the exterior cover 25 and the heat supplied into the exterior cover 25 are radiated from the heat exchanging portion of the exterior cover 25 having a large number of protrusions 87 to the outer space, Temperature rise can be suppressed.

  According to the encoder 10 as described above, an uneven heat exchange unit for radiating the heat inside the exterior cover 25 to the outside is provided on the exterior cover 25 that covers the rotation code unit 19, the detection unit 21, and the printed circuit board 23. 83 is provided, a wide heat transfer area can be secured, and heat generated inside the outer cover 25 during use or heat supplied to the inner side of the outer cover 25 can be quickly obtained by the heat exchanging unit 83. It is possible to radiate heat to the outside of the exterior cover 25.

  Therefore, it is easy to prevent an excessive temperature rise inside the exterior cover 25, and low heat resistance used for various electrical components 73 mounted on the printed circuit board 23, the detection unit 21, the rotation code unit 19, or the like. It is easy to suppress functional degradation due to heat of various members, and it is easy to improve the reliability of the encoder against heat during use.

  For example, the encoder 10 includes a magnetic encoder 33 having a magnetic pattern, but a ferromagnetic substance is used for the magnetic encoder 33 or the detection unit 21 for detecting the magnetic pattern. Although the ferromagnetic material is easily demagnetized by the temperature rise, if the heat exchange part 83 that can promote heat dissipation is provided in the outer cover 25 of the encoder 10 in this way, the ferromagnetic material is excessively heated during use. It is easy to suppress the demagnetization and maintain the detection accuracy.

  Further, the encoder 10 includes an optical pattern 29, and the light emitting unit 55 of the detection unit 21 includes a collimating lens 63 made of a thermoplastic resin. Although the collimating lens 63 made of a thermoplastic resin is easy to manufacture, it tends to be inferior in heat resistance and is likely to be deformed due to an excessive temperature rise during use. However, if the outer cover 25 of the encoder 10 is provided with the heat exchanging part 83 that can promote heat dissipation, the deterioration of the optical characteristics due to the excessive temperature rise of the collimating lens 63 is suppressed, and the detection accuracy of the optical pattern 29 is suppressed. Easy to maintain.

  Further, in this encoder 10, since the heat exchanging portion 83 is provided on the outer surface of the outer cover 25, it is easy to provide a larger uneven shape, so that the heat transfer area of the surface in contact with the outer space of the outer cover 25 is further increased. It can be secured widely, and the heat of the outer cover 25 can be easily radiated to the outer space.

  Further, since the heat exchanging portion 83 is provided on the inner surface of the outer cover 25, it is possible to secure a wider heat transfer area on the surface in contact with the inner space of the outer cover 25, so that the heat of the inner space is transferred to the outer cover 25. It is easy to absorb heat.

  In particular, since the heat exchanging portion 83 includes a large number of protrusions 87 on both the inner surface and the outer surface of the exterior cover 25, a wider heat transfer area can be secured on both surfaces. And since the uneven | corrugated shape of the heat exchange part 83 consists of many protrusions 87, compared with the case where it forms from a dent etc., it is possible to form an uneven | corrugated shape significantly large. At the same time, since it is easy to ensure the minimum thickness of the exterior cover 25, it is easy to ensure the strength of the exterior cover 25.

  In this encoder 10, the boss part accommodating part 49 in which the rotation sign part 19 is accommodated and the opening 65 of the sign part accommodating part 51 are covered with the shield plate 67 and the printed board 23. 23, the inner space on the boss portion accommodating portion 49 and the sign portion accommodating portion 51 side and the inner space on the end cover portion 81 side communicate with each other, so that the boss portion accommodating portion 49 and the sign portion accommodating portion 51 from the motor 11 side. Even if heat is supplied to the shield plate 67 or the printed board 23, it is easily transmitted from the inner space on the boss portion accommodating portion 49 and the sign portion accommodating portion 51 side to the inner space on the end cover portion 81 side. Therefore, even if the boss part accommodating part 49 of the frame 17 and the opening 65 of the sign part accommodating part 51 are covered with the shield plate 67 or the printed board 23, the inner space on the boss part accommodating part 49 and the sign part accommodating part 51 side. Therefore, it is difficult for heat to stay in the air, and heat is easily radiated to the outside through the exterior cover 25.

  Further, since the electrical component 73 is mounted on the end cover portion 81 side of the printed circuit board 23, the heat generated by the electrical component 73 is supplied to the inner space on the end cover portion 81 side. Therefore, heat is easily radiated to the outside through the end cover portion 81 of the exterior cover 25.

  Further, in this encoder 10, since the exterior cover 25 is made of metal, the thermal conductivity is high, the heat on the inner space side of the outer cover 25 is easily transmitted to the outer side, and the heat of the inner space of the outer cover 25 is efficiently outer. It is possible to dissipate heat. In particular, since it is made of a paramagnetic metal, electromagnetic shielding is possible, and it is easy to prevent false detection of electrostatic noise and magnetic noise from the outside.

  The above embodiment can be appropriately changed within the scope of the present invention. For example, in the above-described embodiment, an example in which a large number of ridges 87 are provided as the heat exchange unit 83 has been described. However, the heat exchange unit 83 is not limited to the ridges 87, and may be formed by a large number of plate-like pieces, You may comprise by many protrusions. In the above description, a large number of ridges 87 are integrally formed of the same material as that of the cover body 85, but each ridge 87 and projections are formed of a material different from that of the cover body 85 and joined to the cover body 85. It is also possible to do. Further, the present invention is not limited to being provided protruding from the cover body 85, and may be configured by providing a large number of recesses.

  Further, in the above description, the example in which the heat exchange unit 83 is provided on both the outer surface and the inner surface of the exterior cover 25 has been described. However, the present invention is not particularly limited, and is provided only on one of the outer surface and the inner surface. It is also possible.

  Moreover, although the example which provided the printed circuit board 23 and the shield board 67 in the opening 65 was demonstrated above, the structure which does not provide the shield board 67 may be sufficient, and the board member which covers the opening 65 was decreased or eliminated. By adopting the configuration, the air in the inner space in the frame body 17 can be easily brought into contact with the exterior cover 25 and heat dissipation can be facilitated.

1 is a perspective view of an encoder according to an embodiment of the present invention. It is sectional drawing of the encoder of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Base apparatus 13 Motor shaft 15 Motor housing | casing 17 Frame 19 Rotation code | symbol part 21 Detection part 23 Printed circuit board 25 Exterior cover 73 Electrical component 81 Heat exchange part

Claims (10)

A rotation code unit having a detection pattern and attached to a rotation unit of a base device, a detection unit capable of detecting the detection pattern of the rotation code unit, and a circuit for processing a signal detected by the detection unit And an encoder comprising a substrate having electrical components, and an outer cover that covers the rotation code portion, the detection portion, and the substrate,
The encoder according to claim 1, wherein the exterior cover is provided with a concavo-convex heat exchanging portion for radiating heat inside the exterior cover to the outside of the exterior cover.   The encoder according to claim 1, wherein the heat exchange unit is provided on an outer surface of the exterior cover.   The encoder according to claim 1, wherein the heat exchange unit is provided on an inner surface of the exterior cover.   The encoder according to claim 2 or 3, wherein the heat exchanging section includes a plurality of ridges.   The frame includes a frame that can be fixed to the base device, the frame having an accommodating portion that opens to the opposite side of the base device and accommodates the rotation encoding portion, and is opened from the rotation encoding portion of the accommodating portion. A side is covered with a plate member, the opening and the plate member are covered with an end cover portion of the exterior cover, and the accommodating portion side of the plate member and the end cover portion side are communicated with each other. The encoder according to any one of claims 1 to 4.   The plate member includes a substrate including a circuit for processing a signal detected by the detection unit and an electrical component, and the electrical component is mounted on the end cover portion side of the substrate. The encoder according to claim 5.   The encoder according to claim 1, wherein the exterior cover is made of metal.   The encoder according to claim 7, wherein the metal is a high permeability metal.   The encoder according to claim 1, wherein the detection pattern includes a magnetic pattern.   The encoder according to any one of claims 1 to 9, wherein the detection pattern includes an optical pattern, and the detection unit includes a lens made of a thermoplastic resin.

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