JP5425676B2 - Motor side pressure application mechanism - Google Patents

Description

  The present invention relates to a motor side pressure applying mechanism, and more specifically, a pressure in a direction intersecting the axial direction of a rotating shaft by an urging member with respect to a rotating shaft of a motor that rotates and drives a disk-shaped recording medium such as a CD or DVD. The present invention relates to a structure for applying (side pressure).

  In a motor device that rotates a disk-shaped recording medium, a support bearing (hereinafter also simply referred to as a “bearing”) that rotatably supports the rotating shaft of the motor is sintered and oil-impregnated that can rotate at high speed without lubrication. Many bearings are used. In order to make the rotation of the rotary shaft supported by the sintered oil-impregnated bearing smooth, a clearance is required so that an oil film is formed between the rotary shaft and the inner peripheral surface of the bearing. However, there is a problem that the rotating shaft is swayed by the presence of this clearance, and the turntable on which the disc-shaped recording medium is placed vibrates. Such vibration of the turntable causes a reading error (so-called sound skipping) on the signal recording surface of the disk-shaped recording medium in an optical pickup device or a magnetic head device in which such a motor device is mounted. In particular, in an on-vehicle optical pickup device or the like, vibrations are also applied to the car itself, so that reading errors frequently occur.

  Therefore, as a means for suppressing vibration of the rotating shaft during motor driving, for example, as described in Patent Document 1 and Patent Document 2, a lateral pressure in a direction intersecting the axial direction is applied to the rotating shaft of the motor. The configuration is known. According to this type of motor side pressure applying mechanism, a biasing member (Patent Document 1 is called a torsion coil spring and Patent Document 2 is called a wire spring) is a side pressure bearing (Patent Document 1 is a ring member, Patent Document 2). Is called a slip ring), a pressing biasing force is applied to the side pressure bearing in a direction crossing the axial direction, and a side pressure is applied to the rotating shaft through the side pressure bearing. The As a result, the rotating shaft is pressed against the inner peripheral surface of the sintered oil-impregnated bearing, so that the rattling of the rotating shaft due to the clearance as described above is suppressed, and a reading error caused by vibration of the turntable. Is prevented from occurring.

JP-A-8-87825 Japanese Patent Application Laid-Open No. 2002-374651

  In the side pressure applying mechanism of the motor described in Patent Document 1, the urging member (torsion coil spring) is in contact with the outer peripheral surface of the side pressure bearing so that the side pressure bearing (ring member) is substantially orthogonal to the axial direction of the rotation shaft. Energized in the direction. However, in such a configuration, when used in an on-vehicle optical pickup device or the like, the urging member abutting on the outer peripheral surface of the side pressure bearing due to a disturbance such as a sudden impact is the axis of the rotation shaft of the motor. It moves up and down along the direction. Therefore, the urging member comes off from the outer peripheral surface of the side pressure bearing, for example, the urging member rides on the side pressure bearing (hereinafter, the state in which the urging member rides on the side pressure bearing and This may simply be expressed as “carrying the urging member (to the side pressure bearing)”.

  On the other hand, Patent Document 2 describes a configuration in which a protrusion protruding radially outward from an upper end portion is formed on a side pressure bearing (slip ring). In this way, the urging member (wire spring) that is in contact with the outer peripheral surface of the side pressure bearing is positioned below the protrusion, so that the urging member can be prevented from riding on the side pressure bearing. However, in such a configuration, since the biasing member is caught by the protrusion of the side pressure bearing, when the biasing member moves up and down due to a disturbance such as a sudden impact, the side pressure bearing also moves up and down accordingly ( The urging member moves so as to lift the side pressure bearing), and the side pressure bearing may contact the turntable and cause noise. There are also concerns that sufficient strength of the protrusions cannot be secured, and the molding cost of the side pressure bearing increases.

  In view of the above situation, the problem to be solved by the present invention is that a side pressure application mechanism that applies a side pressure to a rotating shaft of a motor by a biasing member via a side pressure bearing causes a side pressure application due to a disturbance such as a sudden impact. It is an object of the present invention to provide a side pressure applying mechanism for a motor that reliably prevents the urging member from being detached from the bearing.

  In order to solve the above-described problems, the present invention provides a urging member in which a side pressure bearing is loosely inserted into a rotation shaft of a motor rotatably supported via a support bearing and abuts on an outer peripheral surface of the side pressure bearing. In the motor lateral pressure applying mechanism in which a lateral pressure in a direction crossing the axial direction is applied to the rotating shaft, a driven body is fixed to the rotating shaft, and the driven body has a base end thereof. A restricting portion that protrudes from the side end surface and restricts the movement of the urging member in the axial direction of the rotating shaft is formed.

  According to the side pressure applying mechanism of the motor according to the present invention, the restricting portion that restricts the movement of the urging member in the axial direction of the rotation shaft within the predetermined range is provided in the driven body that rotates by driving the motor. Therefore, it is possible to reliably prevent the biasing member from being detached from the side pressure bearing due to a disturbance such as a sudden impact.

  In the present invention, the biasing member has a contact portion extending from a contact position with the side pressure bearing, and the restricting portion is formed above the contact portion, and the proximal end surface It is preferable that the protruding length from the distance between the base end side end surface of the driven body and the front end side end surface of the lateral pressure bearing is greater than the length obtained by subtracting the diameter of the biasing member. In addition, the base end side end surface of the driven body refers to the end surface on the most base end side (side pressure bearing side) when the restriction portion is not formed.

  If comprised in this way, the space | interval between a control part and the bearing for side pressures becomes smaller than the diameter of a biasing member. That is, there is no gap for the urging member to enter between the driven body and the side pressure bearing, so that the urging member does not run on the side pressure bearing. Therefore, it can prevent more reliably that a biasing member will remove | deviate from the bearing for side pressure by disturbances, such as sudden impact.

  It is preferable that the minimum distance from the axis of the rotating shaft to the restricting portion is larger than the radius of the outer peripheral surface of the side pressure bearing in contact with the urging member.

  With this configuration, the restricting portion that rotates together with the driven body is positioned on the radially outer side of the side pressure bearing. Therefore, even if the side pressure bearing moves in the axial direction, the side pressure There is no contact between the bearing for use and the restricting portion located outside thereof. That is, the contact between the restricting portion and the side pressure bearing can be reliably prevented.

  In the present invention, it is preferable that the restricting portion is formed to project annularly from a base end side end surface of the driven body. The term “annular” includes all shapes in which the restricting portion is connected in the rotational direction of the driven body. In other words, it includes those in which the planar shape of the restricting portion is not “perfect circle”.

  If comprised in this way, regardless of the rotational direction position of the driven body, there will be a restricting portion on the biasing member (on the driven body side). The movement of the member can be reliably prevented.

  According to the present invention, the driven body fixed to the rotating shaft of the motor is provided with the restricting portion that restricts the movement of the urging member in the axial direction of the rotating shaft within the predetermined range. It is possible to reliably prevent the urging member from being detached from the side pressure bearing due to disturbance such as the above.

It is a top view of the motor device to which the side pressure giving mechanism of the motor concerning one embodiment of the present invention is applied. It is sectional drawing (AA sectional view taken on the line in FIG. 1) of the motor apparatus to which the lateral pressure applying mechanism of the motor according to one embodiment of the present invention is applied. It is an enlarged view for demonstrating the structure of the control part formed in the turntable (the C section enlarged view in FIG. 2).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a motor device 1 to which a motor side pressure applying mechanism according to an embodiment of the present invention is applied, and FIG. 2 is a sectional view thereof (a sectional view taken along line AA in FIG. 1). FIG. 3 is an enlarged view for explaining the configuration of the restricting portion 72 (an enlarged view of the C portion in FIG. 2). For the sake of explanation, FIG. 1 shows a state in which the turntable 70 is removed, and the outer shape of the turntable 70 and the restricting portion 72 (cross-hatched area) formed on the turntable 70 are shown by dotted lines. In the following description, the vertical direction is the direction of the axis (indicated by X in FIG. 2) of the rotating shaft 12 of the motor 10, and unless otherwise specified, means the vertical direction of the rotating shaft 12 in FIG. Shall. Further, the upper side (turntable 70 side) in FIG. 2 is defined as a “tip side (output side)” and the lower side (motor 10 side) is defined as a “base end side (counter output side)”.

  The motor apparatus 1 rotates a turntable 70 on which a disk-shaped recording medium is placed, and is mounted on a reproducing apparatus (for example, an optical pickup apparatus) for the disk-shaped optical recording medium.

  In the motor side pressure applying mechanism provided in the motor device 1, the side pressure bearing 40 is loosely inserted into the rotating shaft 12 of the motor 10, and the linear biasing member 50 is brought into contact with the outer peripheral surface of the side pressure bearing 40. Thus, a pressing urging force is applied in a direction intersecting the axial direction of the rotating shaft 12. That is, the motor side pressure applying mechanism applies a side pressure to the rotating shaft 12 in a direction intersecting the axial direction via the side pressure bearing 40 by the abutting linear urging member 50. is there. Specifically, the direction intersecting the axial direction indicates a direction substantially orthogonal to the axial direction in the present embodiment. By applying this lateral pressure, the rotating shaft 12 is pressed against the inner peripheral surface of the support bearing 14, and thus rattling of the rotating shaft 12 due to the clearance between the rotating shaft 12 and the support bearing 14 is suppressed. Each configuration will be specifically described below.

  The motor 10 is a DC motor with a brush. The structure will be described with reference to FIG. The motor 10 includes a rotor member and a stator member. The rotor member includes a rotor core 20, a drive coil 22, a commutator 24, and a rotary shaft 12 to which these are fixed. The stator member includes a brush 26, a magnet 30 fixed to the inner periphery of the motor case 32, and the like.

  The rotating shaft 12 of the motor 10 is rotatably supported by a support bearing 14 which is a sintered oil-impregnated bearing whose output side (upper end side) is fixed to a motor case 32. As shown, the support bearing 14 is a radial bearing. The clearance between the inner surface of the through hole of the support bearing 14 and the outer peripheral surface of the rotary shaft 12 is set to a size necessary for at least oil film formation, so that the rotary shaft 12 can be smoothly rotated. And the support bearing 14 are reduced in frictional resistance as much as possible.

  The base end (lower end, that is, the opposite output side) of the rotary shaft 12 is supported by a thrust bearing 16. A core holder 18 made of an insulating member is fixed to the rotary shaft 12, and a plurality of (for example, six salient poles) rotor cores 20 are attached to the core holder 18. A drive coil 22 is wound around each rotor core 20 by a predetermined number. Each drive coil 22 is electrically connected to a commutator (commutator) 24 fixed to the base end side of the rotating shaft 12 via a core holder 18.

  The commutator 24 is provided in equal divisions corresponding to the number of poles of the motor 10 (the number of salient poles of the rotor core 20) so as to surround the outer peripheral surface of the core holder 18. In this embodiment, the outer peripheral surface of the commutator 24 is equally divided in the circumferential direction by slits formed at three locations, and a commutator segment (not shown) is arranged in each divided part. . One end of each drive coil 22 is electrically connected to each commutator segment.

  On the outside of the commutator 24, a pair of brushes 26 (one not shown) sliding on the outer periphery of the commutator 24 are fixed to the motor case 32 while being embedded in a resin brush holder 28.

  A magnet (permanent magnet) 30 is fixed to the inner peripheral surface of the motor case 32 so as to face the rotor core 20 with a certain gap. In the present embodiment, the number of salient poles of the rotor core 20 is six, and the number of salient poles is four.

  When the motor 10 having the above configuration is supplied with power to the drive coil 22 from a power supply unit (not shown) via the brush 26 and the commutator 24 (each commutator segment), the magnetic force generated between the drive coil 22 and the magnet 30 is generated. As a result, the rotating shaft 12 rotates in a predetermined direction.

  In the motor 10, the motor case 32 is fixed to the metal frame 60 using two screws 34 inserted through motor mounting holes (not shown). As a result, the motor 10 is attached in close contact with the lower surface of the frame 60. A through hole 601 is formed in the frame 60, and the rotating shaft 12 of the motor 10 protrudes upward through the through hole 601.

  A side pressure bearing 40 is loosely inserted into the rotating shaft 12 protruding from the frame 60 (the side pressure bearing 40 can slide smoothly up and down along the rotating shaft 12 and is not loosened to a large extent. And is placed on the support bearing 14. Furthermore, a turntable 70 on which a disk-shaped recording medium, which is a driven body of the motor device 1, is fixed is fixed to the tip (upper end, that is, the output side) of the rotating shaft 12. Thereby, the rotating shaft 12 and the turntable 70 rotate integrally. As shown in FIG. 2, the side pressure bearing 40 that is loosely inserted into the rotating shaft 12 is located at a height that protrudes from the frame 60.

  Similar to the support bearing 14, the side pressure bearing 40 is a member made of sintered oil-impregnated alloy, and is formed on a large diameter portion 42 having a relatively large outer circumference and a large diameter portion 42. A through hole 46 for loosely inserting the rotary shaft 12 is formed at the center thereof. The small diameter portion 44 is a portion with which the urging member 50 abuts.

  The biasing member 50 is a so-called wire spring formed of a metal wire having a predetermined diameter, and both end portions thereof are respectively connected to a first locking portion 61 and a second locking portion 62 provided on the frame 60. It is attached by being locked. When the urging member 50 is attached, the locking portion to which the urging member 50 is locked first is the first locking portion 61, and the locking portion to be locked later is the second locking portion 62. It is.

  The urging member 50 is locked to these locking portions as follows. First, one end of the urging member 50 is inserted into a first locking portion 61 formed as a circular through hole in the frame 60 and locked by a predetermined method. In addition, since the 1st latching | locking part 61 is a latching | locking part with which the urging | biasing member 50 is latched initially, what kind of latching structure may be sufficient as it. For example, any method can be appropriately selected as long as it is a method capable of locking one end of the biasing member 50 to the frame 60 so as not to rattle, such as welding, screwing, and caulking.

  Subsequently, the other end 50 a of the urging member 50 is locked to the second locking portion 62 so as to turn the outside of the motor device 1. In the present embodiment, a substantially L-shaped through hole is employed as the second locking portion 62. The through hole is composed of a long hole portion 62a that is long in the vertical direction in FIG. 1 and a short short hole portion 62b. Correspondingly, the other end 50a of the urging member 50 is bent into a shape having a step corresponding to the thickness of the frame 60 (see FIG. 2). When the bent other end 50a is inserted into the long hole portion 62a and the hand is released, the other end 50a is caught by the short hole portion 62b and locked by the elastic force of the biasing member 50.

  The urging member 50 whose both end portions (portions indicated by R1 in FIG. 1) are locked to the first locking portion 61 and the second locking portion 62 is substantially centered in a bent state like a bow. The portion is in contact with the outer peripheral surface of the small diameter portion 44 of the side pressure bearing 40. Thus, the rotating shaft 12 is urged while being pressed in the direction of the arrow B shown in FIG. 1 by the urging member 50 via the side pressure bearing 40. Further, as can be seen from FIG. 2, in the present embodiment, the biasing member 50 has a large diameter of the side pressure bearing 40 in a predetermined range extending substantially horizontally from a position where the biasing member 50 contacts the small diameter portion 44 of the side pressure bearing 40. It is bent into a shape having a step so that it can be placed on the portion 42. Hereinafter, a portion extending horizontally from the contact position with the side pressure bearing 40 is referred to as a contact portion 52.

  Thus, since the contact portion 52 of the urging member 50 is positioned on the large diameter portion 42 of the side pressure bearing 40, the urging member 50 faces upward in the axial direction of the side pressure bearing 40 when the motor 10 rotates. Movement is restricted. In particular, when used in an on-vehicle optical pickup device or the like, it is used in an environment in which vibration is generated. Therefore, the side pressure bearing 40 rotates around the rotary shaft 12 due to vibration, Easy to move in the direction. In order to cope with this, in this embodiment, the biasing member 50 restricts the rotation and movement of the side pressure bearing 40.

  The urging member 50 does not necessarily have to have a shape having such a step. That is, the contact portion 52 that extends substantially horizontally from the contact position with the side pressure bearing 40 may be in contact with the frame 60.

  The urging member 50 attached in such a state that the side pressure bearing 40 is urged in this way restricts the upward movement of the rotary shaft 12 in the axial direction by the restriction portion 72 formed on the turntable 70 that is the driven body. Has been.

  The restricting portion 72 is a portion that protrudes toward the urging member 50 from the proximal end surface 71 of the synthetic resin turntable 70, and is located above the abutting portion 52 of the urging member 50. In addition, the base end side end surface 71 of the turntable 70 is the end surface on the most base end side when the restricting portion 72 is not formed. As shown in FIG. 1, the restricting portion 72 is formed in an “annular shape” with a predetermined width in the planar shape, but the “annular shape” in the present invention refers to the restricting portion 72 in the rotation direction of the turntable 70. It includes all connected shapes. That is, the restriction part 72 includes a shape whose planar shape is not a perfect circle. In the present embodiment, the restricting portion 72 is formed in an “annular shape” whose planar shape is a perfect circle. When the restricting portion 72 is formed in such an “annular shape”, the center of gravity of the turntable 70 and the center of the turntable 70 coincide with each other. Can do.

  The restricting portion 72 restricts the upward movement of the urging member 50 in the axial direction within a predetermined range. Specifically, within the range from the state in which the contact portion 52 of the urging member 50 is separated from the restriction portion 72 and located on the large diameter portion 42 (normal state) to the state in which the contact portion 52 is in contact with the restriction portion 72. It is. If comprised in this way, even if the urging | biasing member 50 moves to the axial direction upwards by a vibration etc., the urging | biasing member 50 will be returned to the original position by hitting the control part 72. That is, it is possible to reliably prevent the contact portion 52 of the urging member 50 from riding on the side pressure bearing 40.

  Further, since the restricting portion 72 can be integrally formed with the synthetic resin turntable 70, the manufacturing process can be simplified. Furthermore, after the urging member 50 is attached, the turntable 70 is fixed to the rotating shaft 12 as usual, so that the urging member 50 can be prevented from climbing onto the side pressure bearing 40, and assembly is also simple.

  Next, the protrusion length of the restricting portion 72 necessary for more reliably preventing the biasing member 50 from riding on the side pressure bearing 40 will be described with reference to FIG. When the restricting portion 72 is formed above the abutting portion 52 of the urging member 50 as in the present embodiment, the protruding length P of the restricting portion 72 from the base end side end surface 71 is the length of the turntable 70. The distance G between the proximal end surface 71 and the distal end surface 41 of the side pressure bearing 40 may be set to be larger than the length obtained by subtracting the diameter D of the urging member 50. That is, the relationship P> (GD) should be satisfied. By setting in this way, the gap Gs (Gs = GP) between the restricting portion 72 and the tip end surface 41 of the side pressure bearing 40 becomes smaller than the diameter D of the urging member 50, and the urging member There is no gap for 50 to enter. Therefore, it is possible to more reliably prevent the urging member 50 (contact portion 52) from riding on the side pressure bearing 40. That is, by adopting such a lateral pressure applying mechanism, it is possible to obtain an excellent high quality motor device that is not affected by disturbance such as sudden impact.

  For example, in this embodiment, the diameter D of the urging member 50 is set to 0.40 mm, and the gap G between the proximal end surface 71 of the turntable 70 and the distal end surface 41 of the side pressure bearing 40 is set to 2.45 mm. . In such a case, the protrusion length P of the restricting portion 72 may be larger than 2.05 mm.

  Even if the restricting portion 72 is formed above the side pressure bearing 40 (small diameter portion 44), if the relationship of P> (GD) is established, the side pressure bearing 40 can be provided. It is possible to reliably prevent the urging member 50 from climbing up. In the present invention, the urging member 50 is a wire spring and has a circular cross section. Therefore, D shown in FIG. 3 is the diameter of the wire spring. However, the biasing member 50 is not limited to a circular wire spring. Therefore, the “diameter D of the urging member 50” when the urging member 50 has a non-circular cross section refers to the height (length) or width dimension of the rotating shaft 12 in the axial direction.

  Next, the formation position of the suitable control part 72 in radial direction is demonstrated. In the restricting portion 72, the distance Rc from the inner peripheral surface to the axis X of the rotating shaft 12 (the rotation center of the rotating shaft 12) is a portion where the urging member 50 contacts the side pressure bearing 40, that is, the radius of the small diameter portion 44 It may be formed so as to be larger than Rb (the relationship of Rc> Rb is established). In other words, the restricting portion 72 may be formed at a position that does not overlap the small diameter portion 44 of the side pressure bearing 40 in the radial direction. In this way, even if the side pressure bearing 40 moves up and down (moves in the axial direction of the rotary shaft 12) due to vibration or the like, the restricting portion 72 is prevented from contacting the side pressure bearing 40. Is possible.

  However, the restricting portion 72 is preferably formed as close to the center of the turntable 70 as possible. This is because the more the position where the restricting portion 72 is formed, the more the moment of inertia of the rotating turntable 70 increases and the load on the motor 10 increases.

  In consideration of the above points, the formation position of the restricting portion 72 in the radial direction is a position that does not overlap the small diameter portion 44 of the side pressure bearing 40 in the radial direction (a position where the relationship of Rc> Rb is established), and as much as possible. It is preferable that it is near the center of the turntable 70.

  In the present embodiment, it has been described that the restricting portion 72 is formed in an annular shape as shown in FIG. 1, but in the case of such an annular shape (not a perfect circle), What is necessary is just to make it the minimum distance from the axis to the control part 72 larger than the radius of the small diameter part 44 of the bearing 40 for side pressure. That is, if the entire restriction portion 72 does not overlap the small diameter portion 44 in the radial direction, the contact between the restriction portion 72 and the side pressure bearing 40 can be reliably prevented.

  In the present embodiment, the restricting portion 72 is formed in an “annular shape” connected in the rotation direction of the turntable 70. If the restricting portion 72 has a shape divided in the rotation direction of the turntable 70, the upward movement of the urging member 50 in the axial direction may not be suppressed depending on the rotation direction position of the turntable 70. . On the other hand, if the restricting portion 72 is formed in an annular shape as in the present embodiment, the restricting portion is always placed on the urging member 50 regardless of the rotational direction position of the turntable 70 that is the driven body. 72 will exist. Therefore, it is possible to reliably prevent the upward biasing member 50 from moving in the axial direction.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  For example, in the above embodiment, the upward movement in the axial direction of the urging member 50 is restricted within a predetermined range by the restriction portion 72 formed on the turntable 70. In order to further enhance the prevention effect, the frame 60 may be further provided with a restricting portion.

  Moreover, although the said embodiment demonstrated using a wire spring as the urging | biasing member 50, if a linear urging | biasing member, such as a torsion coil spring, was used, it is technical of this invention. Thoughts are applicable.

DESCRIPTION OF SYMBOLS 1 Motor apparatus 10 Motor 12 Rotating shaft 14 Support bearing 40 Side pressure bearing 41 Front end side end surface 50 Energizing member 70 Turntable (driven body)
71 Base end side end surface 72 Restriction part

Claims (4)

A side pressure bearing is loosely inserted into the rotation shaft of the motor rotatably supported through the support bearing, and intersects the axis direction with respect to the rotation shaft by an urging member that contacts the outer peripheral surface of the side pressure bearing. In the side pressure applying mechanism of the motor to which the side pressure in the direction to be applied is applied,
A driven body is fixed to the rotating shaft,
A motor side pressure applying mechanism, wherein the driven body is formed with a restricting portion that protrudes from an end surface on a base end side thereof and restricts movement of the urging member in an axial direction of the rotating shaft.   The biasing member has a contact portion extending from a contact position with the side pressure bearing, and the restricting portion is formed above the contact portion and has a protruding length from the proximal end surface. 2 is larger than a length obtained by subtracting a diameter of the urging member from a distance between a proximal end surface of the driven body and a distal end surface of the side pressure bearing. Motor side pressure application mechanism.   3. The motor according to claim 1, wherein a minimum distance from the axis of the rotating shaft to the restricting portion is larger than a radius of an outer peripheral surface of a portion of the side pressure bearing where the urging member abuts. Side pressure application mechanism.   4. The motor side pressure applying mechanism according to claim 1, wherein the restricting portion is formed to project annularly from a base end side end surface of the driven body. 5.

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