JP2012005336A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor for preventing looseness and dropout of an energizing member energizing a bearing mechanism.SOLUTION: In an engaged recess 873 of a bearing holder 8 on which the energizing member 9 is installed, an inner side face 873a directed to an upper direction (installation direction A) of the engaged recess 873 is an inclined face inclined to a direction detached from a parallel face 872 toward the upper direction from an end of a parallel face 872-side. The inclined face functions as a displacement compensation portion 14 compensating displacement of the installation direction A between the inner side face 873a and a tip portion 915a of a second engaged piece 915 in a state where a first engaged piece 914 is engaged with a lower end face of the bearing holder 8. Even if there is dispersion of a position and a size in the engaged recess 873 of the bearing holder 8, the second engaged piece 915 is engaged with the inner side face 873a and the looseness and dropout of the energizing member 9 can be prevented.

Description

  The present invention relates to a motor in which one shaft end of a rotating shaft is supported by a bearing that can slide in the axial direction of the rotating shaft.

  In the lead screw motor, since the load side member on the screw nut side meshing with the lead screw moves in the direction of the rotation axis as the rotation shaft rotates, a large thrust force acts on the rotation shaft from the load side. Therefore, the rotary shaft is supported by bearings from both sides in the axial direction so that it can withstand a large thrust force. A lead screw motor having such a rotating shaft bearing structure is disclosed in Patent Document 1.

  In the lead screw motor disclosed in Patent Document 1, the bearing that supports the shaft end on the opposite side of the rotating shaft is supported so as to be movable in the axial direction by a bearing holder fixed to the motor case. A biasing member is attached to the bearing holder from a direction orthogonal to the rotation axis, and the bearing is biased toward the shaft end of the rotation shaft by the biasing member. In addition, a mechanism for preventing the urging member from coming off from the bearing holder is provided, and this mechanism for preventing the detachment is formed on the side of the urging member when the urging member is attached to the bearing holder. The hook is configured to fit into a positioning stopper formed on the bearing holder side.

JP 2007-202388 A

  Here, due to manufacturing errors or the like, the hooks of the hooks and the hook holes may not be reliably formed, and there is a case that the backlash occurs between them. When backlash occurs between these, the contact position between the bearing supporting the shaft end of the rotating shaft opposite to the output side and the biasing member varies, and the biasing force of the bearing by the biasing member is not stable. There is.

  An object of the present invention is to urge a bearing that supports a shaft end of a rotating shaft so as to be slidable in the rotating axis direction, and to urge the bearing in the rotating axis direction. An object of the present invention is to propose a motor in which a biasing member can bias a bearing with a stable biasing force by mounting the member without backlash.

In order to solve the above problems, the motor of the present invention is
A bearing supporting the shaft end of the rotating shaft from the axial direction side of the rotating shaft;
A bearing holder that supports the bearing so as to be movable in the axial direction;
A biasing member that is mounted on the bearing holder from a mounting direction that intersects the axial direction, and biases the bearing toward the shaft end of the rotary shaft;
The biasing member has a main body portion attached to the bearing holder in a state slidable in a direction along the mounting direction, and a first bent portion extending from the main body portion in a direction crossing the mounting direction. An engagement protrusion, and a second engagement protrusion extending in a direction intersecting the mounting direction from the main body portion in a direction opposite to the mounting direction,
The bearing holder includes a first engagement portion in which the first engagement protrusion is engaged from the same direction as the attachment direction, and a tip portion of the second engagement protrusion that is opposite to the attachment direction. When the second engaging portion engaged from the direction and the biasing member are mounted on the bearing holder in the mounting direction, the second engaging protrusion is directed in a direction along the mounting direction. A guide surface that guides to the second engaging portion in a state of being elastically deformed by,
In the state where the first engagement protrusion is engaged with the first engagement part, the displacement in the mounting direction between the second engagement part and the tip of the second engagement protrusion is compensated. It has the position shift compensation part which performs.

  According to the present invention, when the urging member is attached to the bearing holder, the urging member is attached to the bearing holder up to a position where the first engaging protrusion abuts the first engaging portion on the bearing holder side. Is done. When the urging member is mounted, the second engaging protrusion of the urging member slides on the guide surface of the bearing holder in a bent state, and the first engaging protrusion becomes the first engaging portion. In the hit state, it elastically returns from the guide surface, and engages with the second engagement portion from the side opposite to the mounting direction. Here, when the first engagement protrusion is engaged with the first engagement part, the displacement deviation between the second engagement protrusion and the tip of the second engagement part is compensated by the displacement deviation compensation part. Therefore, the biasing member is attached to the bearing holder without rattling. As a result, variation in the contact position between the bearing and the urging member is prevented, so that the urging force of the bearing by the urging member can be stabilized.

  In the present invention, as the misalignment compensation portion, the second engagement portion of the bearing holder extends from the end on the guide surface side in a direction inclined at an angle of less than 90 degrees with respect to the mounting direction. A surface configuration can be employed. For example, when the second engagement portion is a surface perpendicular to the mounting direction from the guide surface side, the second engagement portion is in a state in which the first engagement protrusion is in contact with the first engagement portion. There is a possibility that a state where the mating protrusion is securely engaged with the second engaging portion without rattling may not be formed. That is, even if the second engagement protrusion is longer than the specified dimension due to a manufacturing error or the like, and the first engagement protrusion comes into contact with the first engagement part, the tip of the second engagement protrusion When the portion is on the guide surface, the engagement state between the second engagement protrusion and the second engagement portion cannot be formed. Conversely, if the second engagement protrusion is too short, the tip of the second engagement protrusion is moved from the second engagement part in the mounting direction when the first engagement protrusion is in contact with the first engagement part. It will be separated and an engagement state without a backlash between them cannot be made. On the other hand, in the present invention, the second engaging portion of the bearing holder is an inclined surface inclined at an angle of less than 90 degrees with respect to the mounting direction. Therefore, by appropriately setting the position and angle of the inclined surface, the tip of the second engaging protrusion that elastically returns to the inclined surface side even if the length of the second engaging protrusion varies. The part can be engaged with any part of the inclined surface without rattling. Further, even when the formation position of the second engagement portion that is the inclined surface is varied, the tip end portion of the second engagement protrusion can be engaged with the second engagement portion without rattling. Further, in a state where the biasing member is mounted on the bearing holder, the first engagement portion and the second engagement portion on the bearing holder side are caused by the first engagement projection and the second engagement projection of the biasing member. The part during which is formed is in a state of being sandwiched from both sides in the mounting direction. Therefore, the urging member is fixed to the bearing holder without rattling in either the mounting direction or the opposite direction. As a result, variation in the contact position between the bearing and the urging member is prevented, so that the urging force of the bearing by the urging member can be stabilized.

  In the present invention, a configuration in which the tip end portion of the second engaging protrusion of the biasing member is bent so as to be elastically deformed and contracted in the mounting direction is adopted as the misalignment compensation unit. it can. In this case, in a state where the first engagement protrusion hits the first engagement part, the distal end surface of the second engagement protrusion is elastically restored along the second engagement part, and the distal end surface is By elastically deforming and contracting in the mounting direction, a state in which the second engaging portion is engaged without backlash is formed. That is, the amount of contraction due to the elastic deformation of the tip end portion of the second engagement projection portion absorbs the positional deviation between the tip end portion of the second engagement projection portion and the second engagement portion, so that the biasing member can be supported without rattling. Can be fixed to a holder. Also in this case, in a state where the urging member is mounted on the bearing holder, the first engagement portion on the bearing holder side and the first engagement protrusion and the second engagement protrusion of the urging member Since the portion while the second engaging portion is formed is sandwiched from both sides in the mounting direction, the urging member is loose in both the mounting direction and the opposite direction with respect to the bearing holder. It is fixed without sticking. As a result, variation in the contact position between the bearing and the urging member is prevented, so that the urging force of the bearing by the urging member can be stabilized.

In the present invention, in order to mount the biasing member on the bearing holder from the mounting direction intersecting the axial direction, the bearing holder includes an end surface extending along the mounting direction, and a parallel surface parallel to the end surface. A main body portion of the biasing member includes an end plate portion that is slidable on the end surface, and a hook portion that is opposed to the end plate portion and is slidable on the parallel surface,
The first engagement protrusion is provided on the end plate portion, the second engagement protrusion is provided on the hook portion, and the parallel surface of the bearing holder is the guide surface. It is desirable.

  Further, in the present invention, the bearing holder includes a side end surface that continues between the end surface and the parallel surface, and the main body portion of the biasing member includes the end plate portion, the hook portion, and the like. It is desirable that a side plate portion that can slide the side end face is provided between them. By doing so, the urging member slides along the end surface, the parallel surface, and the side end surface of the bearing holder during mounting, so that the mounting direction is stabilized.

  In this case, in order to form the second engagement portion, the bearing holder includes an engagement recess that is recessed from the parallel surface toward the end surface, and the second engagement portion is the engagement portion. It is desirable to be provided on the inner peripheral surface of the recess.

  In this case, the bearing is supported so as to be movable in the axial direction in a state of being inserted into a bearing holding through-hole formed in the bearing holder, and the engagement recess is configured to hold the bearing. It is desirable that it is formed at a position separated from the through hole. In this way, since the wall is interposed between the engaging recess and the bearing holding through hole, the bearing is supported so that it can move even when a recess that is recessed toward the end surface is formed as the engaging recess. It is possible to prevent the bearing holding through hole from being deformed or damaged by a load applied to the bearing.

  In the motor of the present invention, an urging member is attached to the bearing holder that supports the bearing that supports the shaft end of the rotating shaft, and the bearing is attached to the rotating shaft end by the urging member. It is fast. When the urging member is attached to the bearing holder, the first engagement protrusion on the urging member side hits the first engagement part on the bearing holder side from the attachment direction, and the second engagement protrusion on the urging member side Is engaged with the second engaging portion on the bearing holder side from the direction opposite to the mounting direction, and a state is formed in which the urging member does not come off in the mounting direction and the reverse direction.

  Further, a displacement correction between the second engagement protrusion on the urging member side and the second engagement portion on the bearing holder side to compensate for a mutual displacement caused by a manufacturing error thereof. Since the first engaging protrusion on the biasing member side hits the first engaging part on the bearing holder side, the second engaging protrusion on the biasing member side is reverse to the mounting direction. It is possible to reliably engage with the second engagement portion on the bearing holder side from the direction without rattling. Therefore, the urging member is fixed to the bearing holder without rattling in either the mounting direction or the opposite direction. As a result, variation in the contact position between the bearing and the urging member is prevented, so that the urging force of the bearing by the urging member can be stabilized.

It is the front view and right view of the motor to which this invention is applied. It is explanatory drawing for demonstrating the structure which supports a bearing. It is a perspective view of a bearing holder and a biasing member. It is explanatory drawing of a bearing holder. It is explanatory drawing of a biasing member. It is explanatory drawing for demonstrating a position shift compensation part. It is the elements on larger scale which show the mounting structure of the urging | biasing member with respect to the bearing holder in another motor to which this invention is applied. It is explanatory drawing for demonstrating the position shift compensation part in the motor of FIG.

  A motor to which the present invention is applied will be described below with reference to the drawings.

[overall structure]
FIG. 1A is a front view of a motor to which the present invention is applied, and its upper half portion is shown in cross section. FIG. 1B is an end view when the motor is viewed from the non-output side.

  Referring to these drawings, the motor 1 is, for example, a PM type stepping motor, and includes a cylindrical motor case 2, a stator 3 assembled coaxially on the inner peripheral surface of the motor case 2, and a stator. 3 is provided with a rotor 4 arranged coaxially, and a rotating shaft 41 constituting the rotor 4 is fixed coaxially at the center of the rotor 4. The output side (front end side) of the rotating shaft 41 protrudes from the output side end surface of the motor case 2, and the protruding portion of the rotating shaft 41 serves as a lead screw 41 a. The shaft end on the output side of the rotating shaft 41 is supported from the output side by the bearing mechanism 5, and the shaft end on the counter-output side of the rotating shaft 41 is supported from the counter-output side by the bearing mechanism 6.

  The output-side bearing mechanism 5 is attached to the distal end portion 71 of the frame 7 fixed to the distal end surface of the motor case 2. The bearing mechanism 5 includes a sphere 51 that supports the shaft end 411 on the output side of the rotating shaft 41, and a bearing 52 that supports the sphere 51. The bearing mechanism 6 on the counter-output side is supported by a bearing holder 8 fixed to the rear end surface on the counter-output side of the motor case 2 so as to be slidable in the axial direction L. A biasing member 9 is mounted on the bearing holder 8 from a mounting direction A orthogonal to the axial direction L, and the bearing mechanism 6 is biased toward the rotating shaft 41 by the biasing member 9.

  In this example, the stator 3 assembled on the inner peripheral surface of the motor case 2 includes a first stator set 32 and a second stator set 33 connected in tandem in the axial direction L of the rotating shaft 41. These are connected coaxially in the axial direction L.

  Each of the stator sets 32 and 33 includes an annular drive coil 31 wound around a resin insulator 34 and stator cores 35 disposed on both sides in the axial direction L of the rotation shaft 41 of the drive coil 31. The stator core 35 includes an inner core 36 located inside the stator 3 in the axial direction L of the rotation shaft 41 and an outer core 37 located outside. The inner core 36 and the outer core 37 are each provided with a plurality of pole teeth arranged in the circumferential direction along the inner circumferential surface of the insulator 34, and the pole teeth formed on the inner core 36 and the outer core 37 correspond to the drive coil 31. They are arranged so as to alternately enter in the circumferential direction.

  The rotor 4 includes a rotating shaft 41 and an annular first permanent magnet 42 and a second permanent magnet 43 that are attached to the outer peripheral surface portion of the counter-output side portion of the rotating shaft 41. The permanent magnets 42 and 43 are alternately magnetized with S and N poles in the circumferential direction. The first permanent magnet 42 is opposed to the inner peripheral surface of the first stator set 32 with a predetermined gap, and the second permanent magnet 43 is opposed to the inner peripheral surface of the second stator set 33 with a predetermined gap. is doing.

  A cutout portion 10 is formed on the outer peripheral surface portion of the motor case 2, and a terminal block 13 including terminal pins 11 and 12 protrudes from the cutout portion 10. Further, terminal portions of the drive coils 31 of the stator sets 32 and 33 are drawn out from the notch 10 and are wound around the terminal pins 11 and 12, respectively.

(Non-output side bearing mechanism)
FIG. 2A is an enlarged view showing a rear end portion of the motor 1 to which the bearing mechanism 6 is attached, and an upper half portion thereof is shown in cross section. FIG. 2B is a partial sectional view showing the bearing mechanism 6, and FIG. 2C is an explanatory view for explaining the mounting of the biasing member 9 to the bearing holder 8.

  Referring to these drawings, the bearing mechanism 6 is made of metal or ceramic that is pressed in a line contact state with a conical recess 412 formed at the shaft end on the opposite side of the rotary shaft 41. A spherical body 61 and a disk-shaped resin bearing 62 provided with a conical recess 62a that supports the spherical body 61 in a line contact state from the non-output side are provided. A bearing holding through hole 81 is formed in the bearing holder 8 so as to penetrate in the axial direction L of the rotary shaft 41, and the bearing 62 slides in the axial direction L of the rotary shaft 41 with respect to the bearing holding through hole 81. Supported as possible.

  The urging member 9 attached to the bearing holder 8 is formed with an urging plate portion 91 that is bent toward the output side along the axial direction L of the rotating shaft 41. The front end 91a of the urging plate 91 enters the bearing holding through hole 81 from the opposite output side and urges the rear end surface of the bearing 62 toward the front of the motor. As shown in FIG. 2C, the urging member 9 is mounted on the bearing holder 8 from the mounting direction A orthogonal to the rotation axis 41 line.

(Bearing holder)
3A is a perspective view of the output side of the bearing holder 8 and the urging member 9 as viewed obliquely from below, and FIG. 3B is the opposite output side of the bearing holder 8 and the urging member 9 from obliquely upward. FIG. 4 (a), (b), (c), (d), and (e) are respectively an end view when the bearing holder 8 is viewed from the non-output side, a plan view when viewed from above the motor, and the output side. It is the end view at the time of seeing, a front view, and a longitudinal cross-sectional view.

  If it demonstrates with reference to these figures, the bearing holder 8 will be provided with the rectangular planar shape, for example, consists of a sintered compact made from SUS. The bearing holder 8 has left and right side end faces 82 having the same length in the motor width direction and extending in parallel in the up and down direction, an upper end face 83 in which the upper ends of the left and right side end faces 82 are continuous, and lower ends of the left and right side end faces 82. A continuous lower end surface (first engagement portion) 84 is provided, and its end surface shape is rectangular as a whole. A shallow groove 815 is formed on the end surface 85 of the bearing holder 8 on the counter-output side so as to extend upward from the lower end edge in the central region of the bearing holder 8 in the motor width direction. The groove 815 extends with a constant width from the lower end surface 84 of the bearing holder 8 toward the upper end surface 83, and a circular bearing holding through hole 81 is formed in the middle of the groove 815. The position of the bearing holding through hole 81 is shifted from the central portion of the bearing holder 8 toward the lower end, that is, toward the lower end surface 84. In the bearing holder 8, a position adjusting through hole 86 is formed at a position on the upper edge of the groove 815. The position adjusting through hole 86 passes through a jig when the bearing holder 8 is fixed to the motor case 2. This is used to adjust the position.

  A stepped portion 871 having a constant width is formed along the left and right side end surfaces 82 on the output side end surface 87 of the bearing holder 8. In the stepped portion 871, the thickness of the bearing holder 8 is slightly reduced. An end surface on the output side of the stepped portion 871 is a parallel surface (guide surface) 872 parallel to the end surface 85 on the opposite output side of the bearing holder 8. The stepped portion 871 is formed between the stepped portion 871 and the end surface on the non-output side of the motor case 2 when the output end surface 87 of the bearing holder 8 is brought into contact with the motor case 2 and the bearing holder 8 is fixed to the motor case 2. A gap is formed so that a hook portion 913 of an urging member 9 described later can be inserted therebetween. Since the stepped portion 871 is cut out at a position where the bearing holding through hole 81 is formed, the width dimension of the bearing holder 8 can be reduced.

  In the stepped portion 871, a part of each stepped portion 871 on both sides is further recessed toward the end surface 85 on the opposite output side below the bearing holding through hole 81, that is, on the lower end surface 84 side. An engagement recess 873 is formed. The inner side surface (second engagement portion) 873a facing upward in the engagement recess 873 is inclined at an angle of less than 90 degrees in the direction away from the parallel surface 872 upward from the end on the side of the parallel surface 872 (that is, And an inclined surface which is inclined toward the opposite side toward the inner side surface 873b. An inner side surface 873b facing downward of the engaging recess 873 is formed substantially perpendicular to the parallel surface 872 to form a vertical surface, and a bottom surface 873c of the engaging recess 873 is formed substantially parallel to the parallel surface 872. It constitutes a parallel plane. The engaging recess 873 is formed at a position separated from the bearing holding through-hole 81, and a relatively thick wall is interposed between the engaging recess 873 and the bearing holding through-hole 81 compared to other portions. ing. Therefore, even when the concave portion that is recessed toward the opposite end face 85 is formed as the engaging concave portion 873, the bearing holding through hole 81 that supports the bearing 62 in a movable manner is deformed or deformed by a load applied to the bearing 62. Damage is prevented.

(Biasing member)
5 (a), (b), (c), (d), (e), and (f) are perspective views of the urging member 9 as viewed from the lower side of the output side, respectively, as viewed from the opposite output side. They are an end view, a plan view seen from above the motor, an end view seen from the output side, a front view, and a longitudinal sectional view. The configuration of the biasing member 9 will be described with reference to FIGS. 3 and 5.

  The urging member 9 is a plate spring member made of a metal plate processed into a predetermined shape so as to have a spring property, for example. The main body portion 92 includes an end plate portion 911 having a rectangular shape as a whole, an urging plate portion 91 that is obliquely cut and raised from the end plate portion 911 toward the output side, and an end plate portion 911. A pair of side plate portions 912 bent to the output side from the left and right edges in the motor width direction, and a pair of hook portions 913 bent inward from the output sides of the pair of side plate portions 912, respectively. The end plate portion 911 has a size that overlaps the end face 85 on the opposite side of the bearing holder 8. The side plate portion 912 has a width dimension substantially the same as the dimension in the axial direction L of the rotation shaft 41 of the left and right side end faces 82 of the bearing holder 8, and is perpendicular to the end plate portion 911 or slightly more perpendicular. It is bent deeply. Further, as shown in FIG. 1B, the opposite side surfaces of the motor case 2 in the motor width direction are flat surfaces, and the dimension between the pair of side plate portions 912 in the motor width direction is the motor case. The width is set to be smaller than the width between the two opposite side portions. Therefore, when the urging member 9 is attached to the bearing holder 8, the pair of side plate portions 912 and the pair of hook portions 913 do not protrude outward from the opposite side portions of the motor case 2. The hook portion 913 is formed so that the dimension in the motor width direction is slightly narrower than the width dimension of the parallel surface 872 of the stepped portion 871. The hook portion 913 is bent slightly deeper than perpendicular to the side plate portion 912, and the angle formed by the side plate portion 912 and the hook portion 913 is an acute angle. The tip end portion 91 a of the urging plate portion 91 is bent shallowly so as to be substantially parallel to the end plate portion 911.

  A first engagement piece (first engagement protrusion) 914 that bends and extends toward the output side is provided at the center of the lower end edge of the end plate portion 911 in the motor width direction. The first engagement piece 914 is rectangular, and the width dimension in the motor width direction is shorter than the width dimension of the end plate portion 911. Further, the length dimension of the first engagement piece 914, that is, the dimension in the direction from the end plate portion 911 toward the output side is shorter than the dimension of the lower end surface 84 of the bearing holder 8 in the motor axial direction. The first engagement piece 914 is bent substantially perpendicular to the end plate portion 911.

  Further, a second engagement piece (second engagement protrusion) that extends at the lower end edge of the hook portion 913 in a downward direction (a direction opposite to the attachment direction A) and bends to the opposite output side that intersects the attachment direction A. ) 915 is provided. In this example, the second engagement piece 915 is bent 30 degrees from the hook portion 913 toward the end plate portion 911 side. The second engagement piece 915 has a rectangular shape, and its tip 915a is parallel to the first engagement piece 914. In this example, as shown in FIG. 5D, a rounded corner is provided at the outer corner of the tip 915a in the motor width direction. Since the urging member 9 is made of a metal plate so as to have a spring property, not only the urging plate portion 91 but also the pair of side plate portions 912, the pair of hook portions 913, and the first engagement. Each of the piece 914 and the second engagement piece 915 also has a spring property.

(Mounting the biasing member to the bearing holder)
In the motor 1, after the stator 3 is housed in the motor case 2, the frame 7 is fixed to the motor case 2. Then, the rotor 4 is passed through the inside of the stator 3, and the shaft holder on the output side of the rotary shaft 41 is supported by the bearing mechanism 5, and the bearing holder 8 is spot welded to the end on the opposite side of the motor case 2. Fix it. Thereafter, the spherical body 61 and the bearing 62 are mounted on the bearing holding through hole 81 of the bearing holder 8 from the non-output side to constitute the bearing mechanism 6, and the bearing 62 of the rotary shaft 41 is formed in the bearing holding through hole 81. The state is supported so as to be slidable in the direction of the axial direction L.

  Here, as shown in FIG. 2C, the biasing member 9 is mounted on the bearing holder 8 from the mounting direction A orthogonal to the axial direction L of the rotating shaft 41.

  More specifically, the end plate portion 911 of the urging member 9 is slid upward from below along the opposite end surface 85 of the bearing holder 8, and the pair of side plate portions 912 of the urging member 9 are bearings. The holder 8 is slid upward along the left and right side end faces 82, and the hook portion 913 and the second engagement piece 915 of the biasing member 9 are moved upward along the parallel surface 872 of the bearing holder 8 from below. Slide towards. That is, when the urging member 9 is attached to the bearing holder 8, in this embodiment, the urging member 9 is used as the guide holder 8 while using the end surface 85, the pair of side plate portions 912 and the parallel surface 872 of the bearing holder 8 as a guide surface. Attach to. Since the groove 815 is formed on the end face 85 on the opposite side of the bearing holder 8, the urging plate portion 91 extends along the groove 815 when the urging member 9 is attached to the bearing holder 8. Slide. Further, as shown in FIG. 1B, the rear end surface of the motor case 2 is exposed at the lower end side of the bearing holder 8, that is, the side where the biasing member 9 starts to be mounted. Using the exposed rear end surface as a guide, the hook portion 913 of the urging member 8 can be inserted into the gap between the rear end surface of the motor case 2 and the stepped portion 871.

  Here, the urging member 9 can be attached to the bearing holder 8 up to a position where the first engagement piece 914 contacts the lower end surface 84 of the bearing holder 8. Further, when the urging member 9 is mounted, the parallel surface 872 of the bearing holder 8 is slid in a state where the second engagement piece 915 of the urging member 9 is bent, that is, elastically deformed to the output side. Further, in a state where the first engagement piece 914 hits the lower end surface 84 of the bearing holder 8, the second engagement piece 915 is elastically restored to the non-output side and is fitted into the engagement recess 873, and the second The distal end portion 915a of the engagement piece 915 contacts the inner side surface 873a of the engagement recess 873 and engages from the side opposite to the mounting direction A. As a result, the end plate portion 911 is overlaid on the end face 85 on the counter-output side of the bearing holder 8, and the mounting of the biasing member 9 to the bearing holder 8 is completed.

  When the urging member 9 is attached to the bearing holder 8, the bearing holder 8 is in a state of being elastically sandwiched between the end plate portion 911 and the hook portion 913. Further, since the side plate portion 912 is elastically deformed to the outside, the shape restoring force acts as a force for maintaining the state in which the urging member 9 is held by the bearing holder 8.

  Further, the urging plate portion 91 is in a state where the tip end portion 91 a falls into the bearing holding through hole 81 and urges the bearing 62 toward the rotating shaft 41 by the tip end portion 91 a. More specifically, since the groove 815 is formed in the end face 85 on the opposite output side of the bearing holder 8, as shown in FIG. 2B, the end plate portion 911 of the bearing holder 8 and the biasing member 9 There is a gap G in the axial direction L of the rotary shaft 41. Therefore, the tip end portion 91 a of the biasing plate portion 91 falls into the bearing holding through hole 81 without interfering with the bearing holder 8 and biases the bearing 62.

  When the biasing member 9 is attached to the bearing holder 8, the portion between the inner side surface 873 a of the engaging recess 873 and the lower end surface 84 of the bearing holder 8 in the bearing holder 8 is the second engaging piece 915 and the first engaging portion 915. It will be in the state clamped by the engagement piece 914. That is, when the urging member 9 is mounted on the bearing holder 8, the second engagement piece 915 is elastically engaged with the inner side surface 873 a of the engagement recess 873, so that the engagement recess 873 in the bearing holder 8 is thereby obtained. The portion between the inner side surface 873a and the lower end surface 84 is sandwiched between the first engagement piece 914 and the second engagement piece 915.

  When a force is applied to slide the biasing member 9 downward (in the direction opposite to the mounting direction A) with respect to the biasing member 9 after the motor 1 is assembled, the movement is as follows. The two engagement pieces 915 are blocked by the engagement between the engagement concave portion 873 and the inner side surface 873a.

(Position displacement compensation unit)
Here, the inner side surface 873a that is inclined toward the upper side of the engagement recess 873 has a second engagement with the inner side surface 873a in a state where the first engagement piece 914 is engaged with the lower end surface 84 of the bearing holder 8. It functions as a misalignment compensator 14 that compensates for misalignment in the mounting direction A with the tip 915a of the piece 915.

  FIG. 6 illustrates the engagement state between the lower end surface 84 of the bearing holder 8 and the first engaging piece 914 of the biasing member 9 and the inner side surface 873a of the bearing holder 8 and the second engaging piece 915 of the biasing member 9. It is explanatory drawing of. In this example, when the second engagement piece 915 of the urging member 9 is formed in a predetermined dimension, the urging member 9 is mounted on the bearing holder 8 as shown by a solid line in FIG. When the lower end surface 84 of the bearing holder 8 and the first engaging piece 914 of the urging member 9 are engaged with each other and the urging member 9 is positioned in the bearing holder 8 in the mounting direction A, (2) The tip 915a of the engagement piece 915 is in the middle of the inner surface 873a of the engagement recess 873, that is, approximately at the boundary between the inner surface 873a and the bottom surface 873c and the boundary between the inner surface 873a and the parallel surface 872. It will be in the state engaged with the position.

  On the other hand, when the length dimension of the second engagement piece 915 is formed short due to a dimensional tolerance of parts at the time of manufacturing the biasing member 9, the biasing member 9 is positioned. As shown by the alternate long and short dash line, the distal end portion 915a of the second engagement piece 915 fitted in the engagement recess 873 is engaged with the side closer to the bottom surface 873c of the inner side surface 873a of the engagement recess 873. . On the other hand, when the length of the second engagement piece 915 is long, when the urging member 9 is positioned, the second engagement piece 915 is inserted into the engagement recess 873 as shown by the dotted line. The distal end portion 915a of the two engaging pieces 915 is in a state of being engaged with the side of the inner side surface 873a of the engaging recess 873 close to the parallel surface 872.

  Further, as indicated by a solid line in FIG. 6B, the position and size of the engagement recess 873 are formed at a predetermined position and size, and the inner side surface 873a of the engagement recess 873 is provided at the predetermined position. In this case, when the biasing member 9 is positioned, the distal end portion 915a of the second engagement piece 915 is in the middle of the inner side surface 873a of the engagement recess 873, that is, the inner side surface 873a and the bottom surface 873c. And a substantially intermediate position of the boundary portion between the inner surface 873a and the parallel surface 872 is engaged. On the other hand, when the position of the inner surface 873a is lower than a predetermined position due to the dimensional tolerance of the parts and the like, when the urging member 9 is positioned, as shown by the one-dot chain line, The distal end portion 915a of the two engaging pieces 915 is in a state of being engaged with the side of the inner side surface 873a of the engaging recess 873 close to the bottom surface 873c. On the other hand, when the position of the inner surface 873a is higher than the predetermined position, when the biasing member 9 is positioned, the tip 915a of the second engagement piece 915 is engaged as shown by the dotted line. It will be in the state engaged with the side close | similar to the parallel surface 872 of the inner surface 873a of the joint recessed part 873. FIG.

  Here, when the second engagement piece 915 is formed to be shorter than a predetermined dimension, or when the position of the inner surface 873a is below the predetermined position, the inner surface 873a is an inclined surface. Otherwise, that is, when the inner surface 873a is a surface perpendicular to the mounting direction A from the parallel surface 872, the lower end surface 84 of the bearing holder 8 and the first engagement piece 914 of the biasing member 9 are When engaged and the urging member 9 is positioned in the bearing holder 8 in the mounting direction A, a gap is generated between the distal end portion 915a of the second engagement piece 915 and the inner side surface 873a of the engagement recess 873. End up. On the other hand, in this example, the inner side surface 873a is an inclined surface and functions as the position deviation compensation unit 14, and therefore, the front end portion 915a of the second engagement piece 915 and the inner side surface 873a of the engagement recess 873 are used. Can be engaged.

  Further, when the second engagement piece 915 is formed longer than a predetermined dimension, or when the position of the inner surface 873a is above the predetermined position, the inner surface 873a must be an inclined surface. In other words, when the inner surface 873a is a surface perpendicular to the mounting direction A from the parallel surface 872, the lower end surface 84 of the bearing holder 8 and the first engagement piece 914 of the biasing member 9 are engaged. When the urging member 9 is positioned in the bearing holder 8 in the mounting direction A, the second engagement piece 915 is not fitted into the engagement recess 873 and rides on the parallel surface 872. End up.

  When the second engaging piece 915 rides on the parallel surface 872, a situation occurs in which the urging member 9 falls off in a direction opposite to the mounting direction A. On the other hand, in this example, the inner side surface 873a is an inclined surface and functions as the misalignment compensation unit 14. Therefore, when the biasing member 9 is attached to the bearing holder 8, the second engagement piece 915 is provided. Can be lowered into the engagement recess 873, and the tip end portion 915a of the second engagement piece 915 and the inner side surface 873a of the engagement recess 873 are engaged with each other without a gap. be able to.

  The position and inclination angle of the inner side surface 873a are set appropriately in view of dimensional tolerances. For example, in the case where the second engagement piece 915 is formed long, the radius from the bending start position to the tip end portion 915a of the second engagement piece 915 with the bending start position B of the second engagement piece 915 as the center. The slope portion on the side of the parallel surface 872 of the inner side surface 873a overlaps the arc. Further, when the second engagement piece 915 is formed short, the dimension from the bending start position to the tip end portion 915a of the second engagement piece 915 is set to a radius around the bending start position B of the second engagement piece 915. And the inclined surface on the side of the bottom surface 873c of the inner side surface 873a overlaps the arc.

  As described above, according to this example, even when the dimension of the second engagement piece 915 is varied, or when the bearing holder 8 is manufactured, the position and size of the engagement recess 873 are varied. Even when the lower end surface 84 of the bearing holder 8 and the first engagement piece 914 of the urging member 9 are engaged with each other and the urging member 9 is positioned in the bearing holder 8 in the mounting direction A, The front end portion 915 a of the two engaging pieces 915 can be fitted into the engaging recess 873. Further, the tip end portion 915a of the second engagement piece 915 dropped into the engagement recess 873 and the inner side surface 873a of the engagement recess 873 can be engaged with each other without a gap.

  As a result, it is possible to avoid a situation in which the tip end portion 915a of the second engagement piece 915 and the inner side surface 873a of the engagement recess 873 are not engaged, so that the urging member 9 falls off in the direction opposite to the mounting direction A. Can be prevented. Further, since the biasing member 9 can be prevented from rattling, it is possible to prevent the biasing member 9 from dropping in the direction opposite to the mounting direction A due to the load in the axial direction L generated on the rotating shaft 41. Furthermore, since the biasing member 9 can be prevented from rattling, variation in the contact position between the bearing 62 and the biasing member 9 is prevented, and the biasing force of the bearing 62 by the biasing member 9 is stabilized. Can do.

  In this example, the engaging recess 873 is provided on the parallel surface 872 of the bearing holder 8, but it can also be provided on the end face 85 on the opposite side of the bearing holder 8. In this case, the second engagement piece 915 is formed by being obliquely cut and raised from the end plate portion 911 of the biasing member 9 toward the output side intersecting the mounting direction A. Further, in the engagement recess provided in the end surface 85 on the opposite output side, the inner surface (second engagement portion) facing upward (mounting direction A) is moved upward from the end on the end surface 85 side to the end surface 85. The inclined surface is inclined at an angle of less than 90 degrees away from the direction. Even in this case, in the engaging recess, the inner side surface that is inclined upward functions as the misalignment compensation unit 14, so that the distal end portion of the second engaging portion and the inner side surface of the engaging recess are engaged. be able to.

  In this example, the inner side surface 873a of the engaging recess 873 is a flat inclined surface, but it can also be an inclined concave curved surface or an inclined convex curved surface.

(Another example of the biasing member mounting structure)
FIG. 7 is an explanatory view showing another example of the mounting structure of the urging member with respect to the bearing holder, and only its main part is shown. In this example, the configuration is the same as that of the motor shown in FIGS. 1 to 6 except for the configuration of the inner side surface 873a ′ of the engagement recess 873 ′ of the bearing holder 8 and the second engagement piece 915 ′ of the biasing member 9. Yes. Accordingly, only the engagement recess 873 ′ of the bearing holder 8 and the second engagement piece 915 ′ of the biasing member 9 will be described, and the other description will be omitted.

  In this example, the inner side surface 873a ′ facing upward (mounting direction A) of the engaging recess 873 ′ is formed perpendicular to the parallel surface 872. On the other hand, the biasing member 9 is bent so that the tip end portion 915a ′ of the second engagement piece 915 ′ can be elastically deformed and contracted in the mounting direction A. More specifically, the second engagement piece 915 ′ protrudes from the hook portion 913 toward the first engagement piece 914 so as to be inclined toward the end plate portion 911, and then the tip end portion 915a ′ is the first engagement portion 915a ′. Curved in a direction away from the end plate portion 911 toward the one engagement piece 914. Further, the tip 915a ′ can be elastically deformed and contracted in the vertical direction (mounting direction A) by a force that is weaker than the elastic return force that the first engagement piece 914 bends in the direction intersecting the mounting direction A. It is configured as follows. In the motor 1 ′ of this example, the tip portion 915 a ′ functions as the misalignment compensation unit 14 ′.

  FIG. 8 is an explanatory diagram for explaining the misregistration compensation unit 14 ′ in the motor 1 ′ of this example. Also in this example, the urging member 9 can be attached to the bearing holder 8 up to a position where the first engagement piece 914 contacts the lower end surface 84 of the bearing holder 8. Further, when the biasing member 9 is mounted, the second engagement piece 915 ′ of the biasing member 9 slides on the parallel surface 872 of the bearing holder 8 in a bent state, that is, in a state of being elastically deformed to the output side. . Then, in a state where the first engagement piece 914 hits the lower end surface 84 of the bearing holder 8, the second engagement piece 915 ′ is elastically restored to the non-output side and is fitted into the engagement recess 873 ′. The distal end portion 915a ′ of the second engagement piece 915 ′ abuts on the inner side surface 873a ′ of the engagement recess 873 ′ and engages from the side opposite to the mounting direction A. As a result, the end plate portion 911 is overlaid on the end face 85 on the counter-output side of the bearing holder 8, and the mounting of the biasing member 9 to the bearing holder 8 is completed.

  Here, as shown in FIG. 8A, when the second engagement piece 915 ′ is formed with a predetermined dimension, or when the position of the inner surface 873a ′ is at the predetermined position, In a state where the first engagement piece 914 hits the lower end surface 84 of the bearing holder 8, the distal end portion 915 a of the second engagement piece 915 ′ is caused by the elastic return force that the first engagement piece 914 is bent in a direction intersecting the mounting direction A 'Is pressed against the corners of the engaging recess 873' and the parallel surface 872, the front end 915a 'is appropriately shrunk in the vertical direction and fits into the engaging recess 873', and the inner surface 873a of the engaging recess 873 ' It abuts with no gap and enters an engaged state.

  Further, as shown in FIG. 8B, when the second engagement piece 915 ′ is formed shorter than the predetermined dimension, or when the position of the inner side surface 873a ′ is below the predetermined position. In the state where the first engagement piece 914 hits the lower end surface 84 of the bearing holder 8, the tip end portion 915 a ′ is fitted in the engagement recess 873 ′ while extending in the vertical direction, and the engagement recess 873 ′. The inner surface 873a ′ of the first and second inner surfaces 873a ′ comes into contact with no gap and is brought into an engaged state.

  Further, as shown in FIG. 8C, when the second engagement piece 915 ′ is formed longer than a predetermined dimension, or when the position of the inner side surface 873a ′ is higher than the predetermined position. In the state where the first engagement piece 914 hits the lower end surface 84 of the bearing holder 8, the second engagement piece 915 is caused by the elastic return force that the first engagement piece 914 bends in the direction intersecting the mounting direction A. ′ End portion 915a ′ is pressed against the corner portion of the parallel surface 872 with the engagement recess portion 873 ′, so that the end portion 915a ′ contracts in the vertical direction and fits into the engagement recess portion 873 ′. It abuts on the inner side surface 873a ′ without any gap and enters an engaged state. In other words, when the second engagement piece 915 ′ is formed with a predetermined size, or when the position of the inner side surface 873a ′ is at the predetermined position, the second engagement piece 915 ′ is further contracted in the vertical direction and engaged. It falls into the recess 873 ′ and engages with the inner side surface 873a ′ of the engagement recess 873 ′ without a gap.

  As described above, if the shape of the tip end portion 915a ′ of the second engagement piece 915 ′ is appropriately set in consideration of the dimensional tolerance, the size of the second engagement piece 915 ′ is set when the biasing member 9 is manufactured. Even when the variation occurs, or even when the position and size of the engaging recess 873 ′ vary when the bearing holder 8 is manufactured, the lower end surface 84 of the bearing holder 8 and the biasing member 9 When the first engagement piece 914 is engaged and the biasing member 9 is positioned in the bearing holder 8 in the mounting direction A, the tip end portion 915a ′ of the second engagement piece 915 ′ is moved into the engagement recess 873 ′. Can be depressed. Moreover, the front-end | tip part 915a 'of 2nd engagement piece 915' dropped into engagement recessed part 873 'and the inner surface 873a' of engagement recessed part 873 'can be engaged without gap.

  As a result, it is possible to avoid a situation in which the tip end portion 915a ′ of the second engagement piece 915 ′ and the inner side surface 873a ′ of the engagement recess 873 ′ are not engaged, so that the biasing member 9 is opposite to the mounting direction A. Can be prevented from falling off. In addition, since the biasing member 9 can be prevented from rattling, variation in the contact position between the bearing 62 and the biasing member 9 is prevented, and the biasing force of the bearing 62 by the biasing member 9 is stabilized. Can do.

  In this example, the inner side surface 873a ′ of the engaging recess 873 ′ may be configured as an inclined surface that is inclined upward in a direction away from the parallel surface 872.

(Other embodiments)
Each of the above examples relates to a stepping motor, but a motor to which the present invention can be applied is not limited to a stepping motor.

1. 1 'motor 2. motor case 3. stator 4. rotor 5. bearing mechanism 6. bearing mechanism 7. frame 8. bearing holder 9. biasing member 14. 14.' Misalignment compensation unit, 31 / drive coil, 32/33 / stator assembly, 34 / insulator, 35 / stator core, 36 / inner core, 37 / outer core, 41 / rotating shaft, 41a / lead screw, 42/43 / permanent Magnet, 51 / sphere, 52 / bearing, 61 / sphere, 62 / bearing, 62a / recess, 71 / tip, 81 / through hole for holding bearing, 82 / side end face, 83 / upper end face, 84 / lower end face ( 1st engaging portion), 85-end face on the opposite output side, 86-through hole for position adjustment, 87-end face on the output side, 91-biasing plate part, 91a-tip part, 92-body part, 411-shaft Edge, 412 ・ Recess, 815 ・ Groove, 871 ・ Step, 872・ Parallel surface (guide surface), 873/873 ′ / engagement recess, 873a / 873a ′ / inner side surface (second engagement part), 873c / bottom surface, 873b / inner side surface, 911 / end plate part, 912 / side plate , 913 · hook portion, 914 · first engagement piece (first engagement protrusion), 915 · 915 '· second engagement piece (second engagement protrusion), 915a · 915a' · tip, A / Mounting direction, B / Bending start position, G / Gap, L / Axial direction

Claims (7)

A bearing supporting the shaft end of the rotating shaft from the axial direction side of the rotating shaft;
A bearing holder that supports the bearing so as to be movable in the axial direction;
A biasing member that is mounted on the bearing holder from a mounting direction that intersects the axial direction, and biases the bearing toward the shaft end of the rotary shaft;
The biasing member has a main body portion attached to the bearing holder in a state slidable in a direction along the mounting direction, and a first bent portion extending from the main body portion in a direction crossing the mounting direction. An engagement protrusion, and a second engagement protrusion extending in a direction intersecting the mounting direction from the main body portion in a direction opposite to the mounting direction,
The bearing holder includes a first engagement portion in which the first engagement protrusion is engaged from the same direction as the attachment direction, and a tip portion of the second engagement protrusion that is opposite to the attachment direction. When the second engaging portion engaged from the direction and the biasing member are mounted on the bearing holder in the mounting direction, the second engaging protrusion is directed in a direction along the mounting direction. A guide surface that guides to the second engaging portion in a state of being elastically deformed by,
In the state where the first engagement protrusion is engaged with the first engagement part, the displacement in the mounting direction between the second engagement part and the tip of the second engagement protrusion is compensated. A motor having a position shift compensation unit. In claim 1,
The second engaging portion of the bearing holder is an inclined surface extending from the end on the guide surface side in a direction inclined at an angle of less than 90 degrees with respect to the mounting direction;
The motor according to claim 1, wherein the inclined surface is the misalignment compensation unit. In claim 1 or 2,
The tip of the second engaging protrusion of the biasing member is bent so that it can be elastically deformed and contracted in the mounting direction,
The motor according to claim 1, wherein the tip portion is the misalignment compensation unit. In any one of claims 1 to 3,
The bearing holder includes an end surface extending along the mounting direction and a parallel surface parallel to the end surface;
The main body portion of the urging member includes an end plate portion that is slidable on the end surface, and a hook portion that is opposed to the end plate portion and is slidable on the parallel surface,
The first engagement protrusion is provided on the end plate portion,
The second engagement protrusion is provided on the hook portion,
The motor according to claim 1, wherein the parallel surface of the bearing holder is the guide surface. In claim 4,
The bearing holder includes a side end surface that continues between the end surface and the parallel surface;
The motor according to claim 1, wherein the main body portion of the biasing member includes a side plate portion that can slide the side end surface between the end plate portion and the hook portion. In claim 4 or 5,
The bearing holder includes an engagement recess that is recessed from the parallel surface toward the end surface,
The motor, wherein the second engagement portion is provided on an inner peripheral surface of the engagement recess. In claim 6,
The bearing is supported so as to be movable in the axial direction in a state of being inserted into a bearing holding through hole formed in the bearing holder,
The motor according to claim 1, wherein the engaging recess is formed at a position spaced apart from the bearing holding through hole.

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