CN210833587U - Encoder and motor - Google Patents

Abstract

An encoder and a motor including the encoder contribute to improvement of detection accuracy of the encoder. The utility model discloses an encoder is used for having the fixed body and can be for the fixed body around the drive arrangement of the rotatory rotator of central axis, include: a magnet holder attached to the rotating body so as to be rotatable about a central axis, the magnet holder having an outer peripheral-side magnet fixed at a position offset from the central axis; and a sensor unit including a sensor holder attached to a fixed body, an outer circumferential side sensor fixed to a position of the sensor holder facing the outer circumferential side magnet in an extending direction of a central axis, the sensor holder having a first positioning surface and a second positioning surface against which the outer circumferential side sensor is abutted, respectively, a normal line of the first positioning surface being perpendicular to the central axis, the second positioning surface being perpendicular to the first positioning surface.

Description

Encoder and motor

Technical Field

The utility model relates to an encoder and motor including this encoder.

Background

Conventionally, there is a motor including: a motor housing and a stator constituting a fixed body; a rotor constituting a rotating body rotatable around a central axis with respect to the stator; and an encoder, the encoder comprising: a magnet holder attached to the rotating body so as to be rotatable about the central axis, the magnet holder having an outer peripheral-side magnet fixed at a position offset from the central axis; and a sensor unit including a sensor holder attached to the fixed body and a sensor substrate provided on a side of the sensor holder opposite to the magnet holder, and an outer peripheral side sensor connected to the sensor substrate so as to be opposed to the outer peripheral side magnet in an extending direction of the central axis.

In the motor, since the detection accuracy of the outer circumferential sensor is significantly affected by the positional accuracy of the outer circumferential sensor with respect to the outer circumferential magnet, how to improve the detection accuracy of the encoder by improving the positional accuracy of the outer circumferential sensor with respect to the outer circumferential magnet becomes a problem to be solved.

SUMMERY OF THE UTILITY MODEL

The present invention has been made in view of the above problems, and an object of the present invention is to provide an encoder and a motor including the encoder, which can improve the detection accuracy of the encoder.

In order to achieve the above object, the present invention provides an encoder for a driving device having a fixed body and a rotating body rotatable around a central axis with respect to the fixed body, and including: a magnet holder attached to the rotating body so as to be rotatable about the central axis, the magnet holder having an outer peripheral-side magnet fixed at a position offset from the central axis; and a sensor unit including a sensor holder attached to the fixed body, and a peripheral-side sensor fixed to a position of the sensor holder facing the peripheral-side magnet in an extending direction of the sensor holder along the central axis, wherein the sensor holder has a first positioning surface and a second positioning surface against which the peripheral-side sensor is abutted, respectively, a normal line of the first positioning surface is perpendicular to the central axis, and the second positioning surface is perpendicular to the first positioning surface.

Incidentally, in the present application, both the "first positioning surface" and the "second positioning surface" are flat surfaces.

According to the utility model discloses an encoder, the sensor support has first locating surface and the second locating surface that supplies the periphery side sensor butt respectively, the normal line of first locating surface is perpendicular with the central axis, the second locating surface is perpendicular with first locating surface, therefore, through the size according to the periphery side sensor preset first locating surface for the distance of central axis and the distance of second locating surface for the central axis, can utilize first locating surface and second locating surface to fix a position the periphery side sensor in two directions perpendicular and perpendicular to each other with the central axis, help improving the position precision of periphery side sensor for the periphery side magnet in the direction perpendicular with the central axis, thereby improve the detection precision of encoder.

In the encoder of the present invention, it is preferable that the sensor holder has a through hole penetrating the sensor holder along the center axis, the outer peripheral side sensor is fixed in the through hole by an adhesive, and an inner peripheral surface of the through hole has the first positioning surface and the second positioning surface.

According to the encoder of the utility model, the sensor support is provided with the through hole which penetrates through the sensor support along the central axis and is filled with the adhesive, so that the filling range of the adhesive is easy to control, and the interference with surrounding parts caused by the fact that the adhesive exceeds the preset range is avoided; moreover, the outer periphery side sensor is fixed in the through hole, so that the sensor can be protected by the through hole; further, since the inner peripheral surface of the through hole has the first positioning surface and the second positioning surface, the first positioning surface and the second positioning surface can be formed more easily than a case where the first positioning surface and the second positioning surface are formed by providing a protrusion on the sensor holder.

In the encoder of the present invention, it is preferable that the inner peripheral surface of the through hole is provided with a first protrusion portion which protrudes in a direction perpendicular to the central axis and has the first positioning surface, and a second protrusion portion which protrudes in a direction perpendicular to the central axis and the protruding direction of the first protrusion portion and has the second positioning surface.

According to the utility model discloses an encoder is provided with first protruding portion and second protruding portion at the inner peripheral surface of perforating hole, first protruding portion is along the direction outstanding perpendicular with the central axis, and has first locating surface, the second protruding portion is along the direction outstanding perpendicular with the protruding direction of central axis and first protruding portion, and has the second locating surface, consequently, can reduce the area of the part with the periphery side sensor butt of first locating surface and second locating surface, the holistic plane degree of first locating surface and second locating surface is guaranteed easily during processing, thereby improve the periphery side sensor for the periphery side magnet in the orientation perpendicular with the central axis the positioning accuracy.

In the encoder of the present invention, it is preferable that the second protrusion has a receiving portion which overlaps the outer peripheral side sensor from a side opposite to the magnet holder and is bonded to the outer peripheral side sensor by the adhesive.

According to the encoder of the present invention, the second protruding portion has the receiving portion that overlaps the outer peripheral side sensor from the side opposite to the magnet holder and is bonded to the outer peripheral side sensor by the adhesive, and therefore, when the outer peripheral side sensor is fixed to the through hole by the adhesive, the mounting position of the outer peripheral side sensor is easily controlled in the direction of the central axis by the receiving portion of the second protruding portion, thereby improving the mounting efficiency.

In the encoder of the present invention, it is preferable that a third protruding portion is provided on an inner peripheral surface of the through hole so as to face the second protruding portion, and the third protruding portion has a receiving portion that overlaps the outer peripheral side sensor from a side opposite to the magnet holder and is bonded to the outer peripheral side sensor by the adhesive.

According to the encoder of the present invention, the third protruding portion is provided on the inner peripheral surface of the through hole so as to face the second protruding portion, and the third protruding portion has the receiving portion that overlaps the outer peripheral side sensor from the side opposite to the magnet holder and is bonded to the outer peripheral side sensor by the adhesive, so that when the outer peripheral side sensor is fixed to the through hole by the adhesive, the mounting position of the outer peripheral side sensor is controlled more easily in the direction of the central axis by the receiving portion of the second protruding portion and the receiving portion of the third protruding portion, thereby improving the mounting efficiency.

Further, in the encoder of the present invention, it is preferable that the encoder further includes an encoder holder via which the sensor holder is fixed to the fixed body, the sensor assembly further includes a sensor substrate provided on a side of the sensor holder opposite to the magnet holder, the sensor substrate and the sensor holder are positioned with respect to the encoder holder by a positioning pin, one end portion of a flexible printed substrate is connected to a side of the outer circumference side sensor facing the magnet holder, the other end portion of the flexible printed substrate is connected to the sensor substrate, a groove is provided on a surface of the sensor holder facing the magnet holder, the through hole is provided in a region of the groove, a surface of the one end portion of the flexible printed substrate facing the magnet holder is flush with a bottom surface of the groove facing the magnet holder, a conductive shield member is attached to the recess so as to close the through hole.

According to the utility model discloses an encoder, one side towards the magnet holder of periphery side sensor is connected with a tip of flexo printing base plate, be provided with the recess on the surface towards the magnet holder of sensor holder, the perforating hole sets up in the region of recess, the surface towards the magnet holder of a tip of flexo printing base plate flushes with the bottom surface towards the magnet holder of recess, consequently, can regard the bottom surface of the recess that the surface towards the magnet holder of sensor holder was equipped with as the benchmark, fix a position to periphery side sensor for the periphery side magnet on the extending direction of central axis with the help of a tip of flexo printing base plate, help improving the position accuracy of periphery side sensor on the extending direction of central axis for the periphery side magnet, thereby improve the detection precision of encoder.

In the encoder of the present invention, it is preferable that the adhesive is filled in the through hole so that only the one end portion of the flexible printed circuit board is exposed on a side facing the magnet holder.

According to the encoder of the present invention, the adhesive is filled in the through hole so that only one end portion of the flexible printed circuit board is exposed on the side facing the magnet holder, and therefore, the filling amount of the adhesive can be ensured, and the outer peripheral side sensor can be reliably fixed to the through hole.

In the encoder of the present invention, it is preferable that a center magnet is fixed to a position of the magnet holder through which the center axis passes, the outer circumferential side magnet is in a ring shape surrounding the center magnet, a circular hole that passes through the sensor holder with the center axis as a center is provided in the sensor holder, and a center sensor that faces the center magnet via the circular hole in the extending direction of the center axis is provided in the sensor substrate.

In the encoder of the present invention, it is preferable that a portion of the inner peripheral surface of the through hole facing the first positioning surface does not abut against the outer peripheral side sensor in a direction perpendicular to the central axis, and a portion of the inner peripheral surface of the through hole facing the second positioning surface does not abut against the outer peripheral side sensor in a direction perpendicular to the central axis.

According to the present invention, in the inner peripheral surface of the through-hole, the portion opposing to the first positioning surface does not abut against the outer peripheral side sensor in the direction perpendicular to the central axis, and the portion opposing to the second positioning surface does not abut against the outer peripheral side sensor in the direction perpendicular to the central axis, so that the portion opposing to the first positioning surface and the portion opposing to the second positioning surface in the inner peripheral surface of the through-hole can be prevented from affecting the positioning of the outer peripheral side sensor in the direction perpendicular to the central axis.

Further, in order to achieve the above object, the present invention provides a motor, comprising: a motor housing and/or a stator constituting a fixed body; and a rotor constituting the rotating body, and further includes the above-described encoder.

(effects of utility model)

According to the utility model discloses, the sensor support has first locating surface and the second locating surface that supplies the periphery side sensor butt respectively, the normal line of first locating surface is perpendicular with the central axis, the second locating surface is perpendicular with first locating surface, therefore, through the size according to the periphery side sensor preset first locating surface for the distance of central axis and the distance of second locating surface for the central axis, can utilize first locating surface and second locating surface to fix a position the periphery side sensor in two directions perpendicular and perpendicular to each other with the central axis, help improving the position precision of periphery side sensor for the periphery side magnet in the direction perpendicular with the central axis, thereby improve the detection precision of encoder.

Drawings

Fig. 1 is a partial perspective view schematically showing a motor according to an embodiment of the present invention.

Fig. 2 is a partially exploded perspective view schematically showing a motor according to an embodiment of the present invention.

Fig. 3 is a partially cut-away perspective view schematically showing a motor according to an embodiment of the present invention.

Fig. 4 is a plan view schematically showing a sensor module of a motor according to an embodiment of the present invention, as viewed from an output side, with a sensor substrate omitted.

Fig. 5 is a perspective view schematically showing a sensor module of a motor according to an embodiment of the present invention, as viewed from an output side, with a sensor substrate omitted.

Fig. 6 is a perspective view schematically showing a sensor holder in a sensor module of a motor according to an embodiment of the present invention, as viewed from an output side.

(symbol description)

1 Motor

2 rotating shaft

21 motor side rotation axis

22 encoder side rotating shaft

3 Motor body

4 Motor casing

41 cylindrical case

42 bearing support

43 bearing

44 circular recess

45 flange

46 annular wall

47 board

48 through hole

49 gap

10 encoder

11 outer shell

111 end plate part

112 side plate part

113 gap

114 sealing member

12 encoder cover

121 end plate part

122 cylindrical part

123 gap

13 sensor assembly

14 encoder support

141 magnet arrangement hole

142 main body part

143 leg part

144 fixed hole

15 magnet holder

151 magnet holding part

152 fixed part

16 magnet

161 center magnet

162 outer peripheral side magnet

17 sensor

171 center sensor

172 periphery side sensor

174 flexible printed circuit board

50 sensor support

51 bracket positioning hole

52 boss part

53 end plate part

54 side plate part

57 groove

58 through hole

581 first projection

582 second projection

5821 the receiving part

583 third projection

5831 the receiving part

59 round hole

60 sensor substrate

70 fixing part

P1 first location surface

P2 second locating surface

Detailed Description

The motor according to the embodiment of the present invention will be described with reference to fig. 1 to 6, in which, FIG. 1 is a partial perspective view schematically showing a motor according to an embodiment of the present invention, FIG. 2 is a partial exploded perspective view schematically showing a motor according to an embodiment of the present invention, figure 3 is a perspective view partially in section (section a-a of figure 1) schematically showing a motor according to an embodiment of the present invention, FIG. 4 is a plan view schematically showing a sensor assembly of the motor according to the embodiment of the present invention as viewed from the output side, in which the sensor substrate is omitted, fig. 5 is a perspective view schematically showing a sensor assembly of the motor according to the embodiment of the present invention as viewed from the output side, fig. 6 is a perspective view schematically showing a sensor holder in a sensor module of a motor according to an embodiment of the present invention, as viewed from an output side, with a sensor substrate omitted.

(Overall Structure)

As shown in fig. 1 to 3, the motor 1 includes a motor body 3 and an encoder 10. The motor body 3 includes a motor housing 4 that houses a rotor and a stator (not shown). The rotor has a rotational axis 2. One end of the rotary shaft 2 is an output shaft (not shown) protruding outward from the motor housing 4. In the present specification, the central axis (rotation axis) of the rotating shaft 2 is denoted by symbol L. Further, the center axis L corresponds to a rotation axis of the magnet holder 15 described below. The direction in which the output shaft protrudes from the motor case 4 is an output side L1, and the opposite side to the output side is an opposite output side L2. The encoder 10 is fixed to an end of the opposite-output side L2 of the motor main body 3, and detects the rotation of the rotation shaft 2.

(rotating shaft)

As shown in fig. 3, the rotary shaft 2 includes a motor-side rotary shaft 21 and an encoder-side rotary shaft 22 fixed to an end of the non-output side L2 of the motor-side rotary shaft 21. The motor-side rotating shaft 21 and the encoder-side rotating shaft 22 rotate integrally. In the present embodiment, the motor-side rotating shaft 21 is made of a magnetic material, and the encoder-side rotating shaft 22 is made of a non-magnetic material. If the encoder-side rotating shaft 22 is made of a non-magnetic material, magnetic noise that enters the encoder 10 from the motor main body 3 side through the encoder-side rotating shaft 22 can be reduced. The encoder-side rotating shaft 22 may be made of a magnetic material. In this case, the encoder-side rotary shaft 22 and the motor-side rotary shaft 21 may be integrated. That is, the rotary shaft 2 may be formed of one member.

(Motor casing)

As shown in fig. 1, the motor housing 4 includes a cylindrical housing 41 extending in the extending direction of the central axis L, and a bearing holder 42 fixed to an end portion of the non-output side L2 of the cylindrical housing 41. The cylindrical housing 41 and the bearing holder 42 are substantially rectangular when viewed from the extending direction of the center axis L.

As shown in fig. 2 and 3, a bearing 43 is held on the inner peripheral side of the bearing holder 42. The bearing 43 rotatably supports an end portion of the output side L1 of the encoder side rotary shaft 22.

As shown in fig. 2 and 3, a circular recess 44 recessed toward the output side L1 is formed in the surface of the non-output side L2 of the bearing holder 42, and a flange 45 is formed on the outer peripheral side of the circular recess 44. An annular wall 46 protruding toward the opposite-to-output side L2 along the edge of the circular recess 44 is formed on the inner peripheral edge of the flange 45. An annular plate 47 is attached to the bottom of the circular recess 44 so as to press the outer peripheral portion of the bearing 43 from the opposite-output side L2. The encoder-side rotating shaft 22 protrudes to the opposite output side L2 through a through hole 48 provided in the center of the plate 47. The plate 47 is fixed to the bottom of the circular recess 44 by three screws. Notches 49 are formed in three places at equal angular intervals on the outer peripheral edge of the plate 47. A leg 143 of the encoder holder 14 described later is disposed in the notch 49.

The motor case 4 is made of a conductive metal such as aluminum, for example.

(encoder)

As shown in fig. 2 and 3, the encoder 10 includes: an outer case 11 fixed to the bearing bracket 42; an encoder cover 12 disposed inside the outer case 11; a sensor unit 13 disposed inside the encoder cover 12; an encoder bracket 14 supporting the sensor assembly 13; a magnet holder 15 disposed on the inner peripheral side of the encoder holder 14; and a magnet 16 (rotary magnet) held by the magnet holder 15. The magnet holder 15 is fixed to the tip of the non-output side L2 of the encoder side rotating shaft 22. Therefore, the magnet 16 rotates integrally with the encoder-side rotary shaft 22. The sensor assembly 13 includes a sensor 17 opposite the magnet 16. In the present embodiment, a magnetoresistive element is used as the sensor 17.

(outer case)

As shown in fig. 2 and 3, the outer case 11 includes an end plate portion 111 that is substantially rectangular when viewed from the center axis L direction, and a side plate portion 112 that rises from the outer peripheral edge of the end plate portion 111 to the output side L1. The side plate portion 112 is formed with a notch 113 for passing a wire connected to the sensor unit 13. The outer housing 11 and the bearing holder 42 are fixed by interposing the seal member 114 between the flange 45 and the end surface of the output side L1 of the side plate portion 112, and screwing fixing members such as screws, not shown, into the corners of the four locations.

(encoder cover)

As shown in fig. 2 and 3, the encoder cover 12 includes an end plate portion 121 having a circular shape when viewed from the direction of the center axis L, and a cylindrical portion 122 rising from the outer peripheral edge of the end plate portion 121 to the output side L1. A notch 123 for passing a wire connected to the sensor unit 13 is formed in the cylindrical portion 122 at a position radially overlapping the notch 113 of the outer case 11. As shown in fig. 3, the encoder cover 12 is assembled to the bearing holder 42 such that the edge of the cylindrical portion 122 fits to the inner circumferential side of the annular wall 46 formed along the edge of the circular recess 44 of the bearing holder 42. The end face of the output side L1 of the cylindrical portion 122 abuts against the plate 47 disposed at the bottom of the circular recess 44 except for the portion where the notch 123 is formed. Here, although a part of the annular wall 46 in the circumferential direction is cut out, the cut-out portion of the annular wall 46 is at an angular position different from the notch 49 formed in the outer peripheral edge of the plate 47. Therefore, the gap between the encoder cover 12 and the bearing bracket 42 is closed except for the notch 123.

The encoder cover 12 is made of a magnetic material having conductivity. For example, the encoder cover 12 is formed of iron, permalloy, or the like. In this way, by covering the sensor unit 13 holding the sensor 17 with the encoder cover 12 formed of a magnetic material, the sensor 17 and the encoder circuit can be shielded from magnetic noise such as a disturbance magnetic field. Also, the encoder cover 12 is installed with almost no gap from the bearing bracket 42. Therefore, the electromagnetic wave noise can be suppressed from entering the sensor unit 13 side from the gap with the bearing holder 42.

(encoder bracket)

As shown in fig. 2 and 3, the encoder bracket 14 includes a main body portion 142 formed with a circular magnet disposition hole 141, and a leg portion 143 protruding to the outer peripheral side from an end portion of the output side L1 of the main body portion 142. The end face of the output side L1 of the leg portion 143 protrudes to the output side L1 than the end face of the output side L1 of the main body portion 142. The leg portions 143 are formed at three locations at equal angular intervals in the circumferential direction. The encoder bracket 14 is positioned such that the center axis L of the encoder-side rotary shaft 22 rotatably held at the center of the bearing bracket 42 and the magnet arrangement hole 141 are coaxially arranged, and such that the leg 143 is arranged in the notch 49 formed in the outer peripheral edge of the plate 47. The encoder bracket 14 abuts against the bearing bracket 42 via the leg portion 143. The encoder bracket 14 is fixed to the bearing bracket 42 by screwing the leg portion 143 to the bottom surface of the circular recess 44 using a fixing screw, not shown.

As shown in fig. 2, in the encoder holder 14, fixing holes 144 for fixing the sensor unit 13 are formed in three locations on the end surface of the opposite-to-output side L2 of the main body portion 142. The sensor unit 13 is provided so as to abut against a positioning projection (not shown) provided on an end surface of the non-output side L2 of the main body 142 and projecting toward the non-output side L2, and is fixed to the encoder bracket 14 via a fixing member such as a screw (not shown).

(magnet Assembly)

As shown in fig. 3, the magnet holder 15 includes a substantially disk-shaped magnet holding portion 151 and a cylindrical fixing portion 152 projecting from the center of the magnet holding portion 151 to the output side L1. The front end of the encoder-side rotating shaft 22 is pressed into the fixing portion 152, fixed to the fixing portion 152 with an adhesive, or fixed with a fixing screw from a direction perpendicular to the output side L1. Further, a shield wall is provided between the magnet holding portion 151 and the fixing portion 152. The magnet 16 includes a circular center magnet 161 fitted into a recess formed in the center of the magnet holding portion 151, and an annular outer peripheral magnet 162 fitted into a step formed on the outer peripheral side of the center magnet 161. The center magnet 161 is magnetized with a pair of N and S poles in the circumferential direction. On the other hand, the outer-peripheral-side magnet 162 is magnetized with a plurality of pairs of N poles and S poles alternately in the circumferential direction.

As shown in fig. 3, when the encoder holder 14 is fixed to the bearing holder 42, the distal end of the encoder-side rotating shaft 22 is disposed at the center of the magnet disposition hole 141 of the encoder holder 14. Therefore, the magnet holder 15 fixed to the front end of the encoder-side rotating shaft 22 is disposed at the center of the magnet arrangement hole 141. The center magnet 161 and the outer circumferential magnet 162 are disposed toward the opposite-output side L2 in the magnet disposition hole 141, and are disposed coaxially with the center axis L of the encoder-side rotating shaft 22 as the center.

(sensor component)

As shown in fig. 2 and 3, the sensor assembly 13 includes: a sensor holder 50; a sensor substrate 60 mounted on the sensor holder 50; a sensor 17 electrically connected to the sensor substrate 60; and a fixing member 70 for fixing the sensor substrate 60 to the sensor holder 50.

As shown in fig. 2, the sensor substrate 60 is substantially circular and includes a notch cut linearly at an outer peripheral edge. Further, substrate positioning holes for positioning the sensor holder 50 are formed at two locations on the sensor substrate 60.

As shown in fig. 3, the sensor holder 50 includes an end plate portion 53 facing the sensor substrate 60, and a side plate portion 54 rising from an outer peripheral edge of the end plate portion 53 to the opposite output side L2. As shown in fig. 2, the end plate portion 53 is linearly cut and the side plate portion 54 linearly extends at a portion of the sensor holder 50 that overlaps the notch of the sensor substrate 60 in the extending direction of the central axis L. As shown in fig. 4 to 6, holder positioning holes 51 corresponding to substrate positioning holes of the sensor substrate 60 are formed at two locations of the end plate portion 53. The sensor substrate 60 is positioned with respect to the sensor holder 50 by inserting the fixing member 70 into the substrate positioning hole and the holder positioning hole 51. Here, the fixing member 70 is a spring pin, and the use of a spring pin as the fixing member 70 can prevent the sensor substrate 60 from loosening with respect to the sensor holder 50.

As shown in fig. 4 to 6, the sensor holder 50 is provided with boss portions 52 for passing fixing screws, not shown, therethrough at three locations corresponding to the fixing holes 144 of the encoder holder 14. In the present embodiment, the front end surface of the boss portion 52 is an abutment surface that abuts against a positioning projection (not shown) provided on the end surface of the opposite-to-output side L2 of the encoder holder 14. In the sensor substrate 60, fixing holes for passing fixing screws are formed at three locations corresponding to the boss portion 52 and the fixing holes 144. The sensor unit 13 is fixed to the encoder bracket 14 by passing three fixing screws through the fixing holes of the sensor substrate 60 and the boss portion 52 of the sensor bracket 50, respectively, and screwing the leading ends thereof into the fixing holes 144. Since the leg 143 of the encoder bracket 14 abuts against the bearing bracket 42, the sensor unit 13 is fixed to the bearing bracket 42 via the encoder bracket 14.

As shown in fig. 3 to 5, in the sensor assembly 13, the sensor 17 includes a center sensor 171 and an outer peripheral side sensor 172. The center sensor 171 is provided on the sensor substrate 60, and is opposed to the center magnet 161 in the extending direction of the center axis L. The outer peripheral side sensor 172 is fixed to a position of the sensor holder 50 facing the outer peripheral side magnet 162 in the extending direction of the central axis L, and is electrically connected to the sensor substrate 60. Specifically, the center sensor 171 is provided on a surface of the sensor substrate 60 on a side facing the magnet holder 15 (i.e., the output side L1), the sensor holder 50 is provided with a circular hole 59 that is centered on the central axis L and penetrates the sensor holder 50 along the central axis L, and the center sensor 171 faces the center magnet 161 via the circular hole 59; one end of a flexible printed board 174 is connected to one side (i.e., the output side L1) of the outer peripheral side sensor 172 facing the magnet holder 15, and the other end of the flexible printed board 174 is connected to the sensor substrate 60. Further, although not shown, two hall elements are mounted near the center sensor 171 on a surface of the sensor substrate 60 facing the side of the magnet holder 15 (i.e., the output side L1), and the two hall elements are disposed at angular positions separated by 90 degrees.

In the encoder 10, a predetermined gap is formed between the surface of the output side L1 of the center sensor 171 and the center magnet 161 and between the surface of the output side L1 of the outer circumferential side sensor 172 and the outer circumferential side magnet 162. The center sensor 171 and the two hall elements and the center magnet 161 arranged in the vicinity thereof function as an absolute encoder based on the output period of the center sensor 171 obtained by determining one rotation of the two hall elements. On the other hand, the outer-peripheral-side sensor 172 and the outer-peripheral-side magnet 162 obtain outputs of a plurality of cycles by one rotation, and thus function as an incremental encoder. The encoder 10 can perform high-resolution and high-precision position detection by processing the outputs of the two sets of encoders.

(fixing and positioning structure of outer circumference sensor)

As shown in fig. 4 to 6, the sensor holder 50 has a through hole 58 (in the illustrated example, a substantially rectangular shape, but not limited thereto) that penetrates the sensor holder 50 (in the illustrated example, the end plate portion 53) along the center axis L, and the outer-peripheral-side sensor 172 is fixed in the through hole 58 by an adhesive.

As shown in fig. 4, a first protrusion 581 and a second protrusion 582 are provided on the inner circumferential surface of the through hole 58. The first protrusion 581 protrudes in a direction perpendicular to the central axis L, and has a first positioning plane P1 having a normal perpendicular to the central axis L. The second protrusion 582 protrudes in a direction perpendicular to the central axis L and the protruding direction of the first protrusion 581, and has a second positioning plane P2 perpendicular to the first positioning plane P1. The first positioning plane P1 and the second positioning plane P2 are respectively abutted by the outer circumferential sensor 172. The second protrusion 582 has a receiving portion 5821, and the receiving portion 5821 overlaps the outer peripheral side sensor 172 from the side opposite to the magnet holder 15 (i.e., the output side L1), and is bonded to the outer peripheral side sensor 172 by an adhesive. In the inner peripheral surface of the through hole 58, the portion facing the first positioning plane P1 does not abut against the outer peripheral side sensor 172 in the direction perpendicular to the center axis L, and the portion facing the second positioning plane P2 does not abut against the outer peripheral side sensor 172 in the direction perpendicular to the center axis L.

As shown in fig. 4, a third projection 583 is provided on the inner peripheral surface of the through-hole 58 so as to face the second projection 582. The third protruding portion 583 has a receiving portion 5831, and the receiving portion 5831 overlaps the outer peripheral side sensor 172 from the side opposite to the magnet holder 15 (i.e., the output side L1), and is bonded to the outer peripheral side sensor 172 by an adhesive.

As shown in fig. 4 to 6, a recess 57 is provided on the surface of the sensor holder 50 facing the magnet holder 15, a through-hole 58 and a circular hole 59 are provided in the area of the recess 57, and the surface of one end portion of the flexible printed substrate 174 facing the magnet holder 15 is flush with the bottom surface of the recess 57 facing the magnet holder 15. In the through hole 58, an adhesive is filled so that only one end portion of the flexible printed circuit board 174 is exposed on the side facing the magnet holder 15.

Further, although not shown, a shield member, which is a flexible plate material and is formed of a conductive nonmagnetic metal such as aluminum, is attached to the recess 57 of the sensor holder 50 so as to cover the through hole 58, for example, via a conductive adhesive.

(main technical effects of the present embodiment)

According to the motor 1 of the present embodiment, the sensor holder 50 has the first positioning plane P1 and the second positioning plane P2 against which the outer circumferential side sensor 172 abuts, respectively, the normal line of the first positioning plane P1 is perpendicular to the center axis L, the second positioning plane P2 is perpendicular to the first positioning plane P1, therefore, by setting the distance of the first positioning plane P1 from the center axis L (see D1 in fig. 4) and the distance of the second positioning plane P2 from the center axis L (see D2 in fig. 4) in advance according to the size of the outer periphery side sensor 172, the position of the outer periphery side sensor 172 can be positioned in two directions perpendicular to the center axis L and each other by the first positioning plane P1 and the second positioning plane P2, which contributes to improving the positional accuracy of the outer periphery side sensor 172 with respect to the outer periphery side magnet 162 in the direction perpendicular to the center axis L, thereby improving the detection accuracy of the encoder 10.

Further, according to the motor 1 of the present embodiment, since the one end portion of the flexible printed board 174 is connected to the side of the outer peripheral side sensor 172 facing the magnet holder 15, the recessed groove 57 is provided on the surface of the sensor holder 50 facing the magnet holder 15, the through-hole 58 is provided in the region of the recessed groove 57, and the surface of the one end portion of the flexible printed board 174 facing the magnet holder 15 is flush with the bottom surface of the recessed groove 57 facing the magnet holder 15, the outer peripheral side sensor 172 can be positioned with respect to the outer peripheral side magnet 162 in the extending direction of the central axis L with the one end portion of the flexible printed board 174 as a reference (for example, in a state where the outer peripheral side sensor 172 connected to the one end portion of the flexible printed board 174 is fixed in the through-hole 58 with an adhesive, a flat-plate-like tool is brought into contact with the bottom surface of the recessed groove 57 and the one end portion of the flexible printed, thereby positioning the outer peripheral side sensor 172 with respect to the outer peripheral side magnet 162 in the extending direction of the center axis L), contributes to improving the positional accuracy of the outer peripheral side sensor 172 with respect to the outer peripheral side magnet 162 in the extending direction of the center axis L, thereby improving the detection accuracy of the encoder 10.

The present invention has been described above by way of example with reference to the accompanying drawings, and it is to be understood that the specific implementations of the present invention are not limited to the above-described embodiments.

For example, in the above-described embodiment, the encoder 10 is applied to the motor 1, but the present invention is not limited to this, and the encoder 10 may be applied to a driving device other than the motor 1 having a fixed body and a rotating body rotatable around a central axis with respect to the fixed body.

In the above embodiment, the outer periphery side sensor 172 is fixed to the through hole 68 of the sensor holder 50 by the adhesive, but the present invention is not limited to this, and the outer periphery side sensor 172 may be fixed to the through hole 68 of the sensor holder 50 by a double-sided tape or the like.

In the above embodiment, the outer circumferential sensor 172 is provided in the through hole 68 of the sensor holder 50, but the present invention is not limited thereto, and a recess, a notch, or the like may be formed in the sensor holder 50 instead of the through hole.

In the above embodiment, the first positioning surface P1 and the second positioning surface P2 are provided on the inner peripheral surface of the through hole 68 of the sensor holder 50, but the present invention is not limited to this, and a protrusion having the first positioning surface P1 and the second positioning surface P2 may be provided on the sensor holder 50.

It should be understood that the present invention can freely combine the respective components of the embodiments or appropriately change or omit the respective components of the embodiments within the scope thereof.

Claims (11)

1. An encoder for a drive device having a fixed body and a rotating body rotatable about a central axis with respect to the fixed body, comprising: a magnet holder attached to the rotating body so as to be rotatable about the central axis, the magnet holder having an outer peripheral-side magnet fixed at a position offset from the central axis; and a sensor unit including a sensor holder attached to the fixed body, and an outer peripheral side sensor fixed to a position of the sensor holder facing the outer peripheral side magnet in an extending direction of the central axis,

the sensor holder has a first positioning surface and a second positioning surface against which the outer circumferential side sensor is abutted,

the normal of the first locating surface is perpendicular to the central axis,

the second positioning surface is perpendicular to the first positioning surface.

2. The encoder of claim 1,

the sensor holder has a through hole penetrating the sensor holder along the center axis,

the outer peripheral side sensor is fixed in the through hole by an adhesive,

the inner peripheral surface of the through hole has the first positioning surface and the second positioning surface.

3. The encoder of claim 2,

a first protruding part and a second protruding part are arranged on the inner circumferential surface of the through hole,

the first protruding portion protrudes in a direction perpendicular to the central axis and has the first positioning face,

the second protruding portion protrudes in a direction perpendicular to the central axis and the protruding direction of the first protruding portion, and has the second positioning surface.

4. The encoder of claim 3,

the second protruding portion has a receiving portion that overlaps the outer peripheral side sensor from a side opposite to the magnet holder and is bonded to the outer peripheral side sensor by the adhesive.

5. The encoder of claim 4,

a third protruding portion is provided on an inner peripheral surface of the through hole so as to face the second protruding portion,

the third protruding portion has a receiving portion that overlaps the outer peripheral side sensor from a side opposite to the magnet holder and is bonded to the outer peripheral side sensor by the adhesive.

6. The encoder according to any of the claims 2 to 5,

the encoder further comprises an encoder support which is,

the sensor holder is fixed to the fixed body via the encoder holder,

the sensor assembly further includes a sensor substrate,

the sensor substrate is disposed on an opposite side of the sensor holder from the magnet holder,

the sensor substrate and the sensor holder are positioned with respect to the encoder holder using positioning pins,

one end portion of a flexible printed board is connected to a side of the outer peripheral side sensor facing the magnet holder, the other end portion of the flexible printed board is connected to the sensor substrate,

a recess is provided in the surface of the sensor holder facing the magnet holder,

the through-hole is arranged in the region of the recess,

a surface of the one end portion of the flexible printed substrate facing the magnet holder is flush with a bottom surface of the groove facing the magnet holder,

a conductive shield member is attached to the recess so as to close the through hole.

7. The encoder of claim 6,

the adhesive is filled in the through hole so that only the one end portion of the flexible printed circuit board is exposed on a side facing the magnet holder.

8. The encoder of claim 6,

a central magnet is fixed at a position where the central axis of the magnet holder passes through,

the outer peripheral side magnet has a ring shape surrounding the center magnet,

the sensor support is provided with a round hole which takes the central axis as the center and penetrates through the sensor support along the central axis,

a center sensor is provided on the sensor substrate, the center sensor being opposed to the center magnet via the circular hole in an extending direction of the center axis.

9. The encoder of claim 2,

in the inner peripheral surface of the through hole, a portion facing the first positioning surface does not abut against the outer peripheral side sensor in a direction perpendicular to the center axis, and a portion facing the second positioning surface does not abut against the outer peripheral side sensor in a direction perpendicular to the center axis.

10. The encoder of claim 1,

the drive means is a motor which is driven by a motor,

the motor includes:

a motor housing and/or a stator constituting the fixed body; and

a rotor constituting the rotating body.

11. A motor, comprising: a motor housing and/or a stator constituting a fixed body; and a rotor constituting the rotating body, characterized by further comprising: the encoder of any one of claims 1 to 9.

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