CN213185780U - Gear drive motor - Google Patents

Abstract

Providing a gear drive motor, the utility model discloses a gear drive motor's a mode has: a motor; a transmission mechanism for transmitting the power of the motor; and a sliding mechanism connected with the transmission mechanism. The slide mechanism includes: a lead screw connected to the transfer mechanism and rotating around the sliding axis; a slide nut into which the lead screw is inserted; a nut frame holding a slide nut; a cylindrical guide frame surrounding the nut frame from the outside in the radial direction; and a movement restricting section. The outer peripheral surface of the nut frame is provided with a projection projecting radially outward. The guide frame is provided with a guide wall that guides the protrusion. The guide wall has: a pair of 1 st wall surfaces that are circumferentially opposed to each other with a gap for accommodating the projection therebetween and extend in the axial direction; and a 2 nd wall surface facing one side in the axial direction and connected to the 1 st wall surface at an intersection. The movement restricting portion restricts the movement of the nut frame to one side in the axial direction with respect to the guide frame in a state where the protrusion is located at the intersecting portion.

Description

Gear drive motor

Technical Field

The utility model relates to a gear drive motor.

Background

In recent years, electronic devices have been required to be miniaturized and to have multiple functions, and it is desired to drive components incorporated in the electronic devices to realize various functions. For example, in order to enable photographing from various angles in a smartphone in which a camera is incorporated, a smartphone in which a geared motor for rotating the camera is incorporated inside the smartphone has been developed (for example, patent document 1). Recently, the functions of electronic devices have been advanced more and more, and not only the components inside the electronic devices need to be rotated about an axis, but also the electronic devices need to be extended and retracted in an axial direction.

Patent document 1: japanese patent laid-open publication No. 2019-47589

In increasingly miniaturized electronic apparatuses, the space for providing a driving device for moving parts is very limited. Therefore, it is difficult to incorporate the geared motor for the sliding motion and the geared motor for the rotating motion into the electronic apparatus, respectively.

SUMMERY OF THE UTILITY MODEL

One aspect of the present invention has been made in view of the above problems, and an object thereof is to provide a geared motor capable of performing a sliding operation and a rotating operation.

The utility model discloses a gear drive motor's a mode has: a motor that rotates a motor shaft extending along a motor axis; a transmission mechanism that transmits power of the motor; and a sliding mechanism connected to the transmission mechanism. The sliding mechanism includes: a lead screw connected to the transmission mechanism and rotating around a sliding axis; a sliding nut inserted by the lead screw; a nut frame that holds the slide nut; a cylindrical guide frame surrounding the nut frame from a radially outer side; and a movement restricting section. The outer peripheral surface of the nut frame is provided with a projection projecting radially outward. A guide wall that guides the protrusion is provided on the guide frame. The guide wall has: a pair of 1 st wall surfaces that are circumferentially opposed to each other with a gap therebetween for accommodating the projection and extend in an axial direction; and a 2 nd wall surface facing one side in the axial direction and connected to the 1 st wall surface at an intersection. The movement restricting portion restricts movement of the nut frame to one side in the axial direction with respect to the guide frame in a state where the protrusion is located at the intersecting portion.

In the above-described gear transmission motor, a slit is provided in the guide frame, the slit including: a 1 st slot extending in an axial direction; and a 2 nd slit which is continuous with the 1 st slit at the intersection and extends in the circumferential direction, wherein an inner wall surface of the 1 st slit includes a pair of the 1 st wall surfaces, and an inner wall surface of the 2 nd slit includes the 2 nd wall surface.

In the geared motor according to the above aspect, the 1 st slit extends to both axial sides with respect to the intersecting portion and opens in one axial direction.

In the above-described gear motor, the 1 st end portion of the lead screw is supported by the 1 st bearing portion, the nut frame has an opposed surface axially opposed to the 1 st bearing portion, and the 1 st bearing portion and the opposed surface are in contact with each other in a state where the projection is positioned at the intersection portion and function as the movement restricting portion.

In the gear motor according to the above aspect, the 2 nd end portion of the lead screw is supported by the 2 nd bearing portion and the 3 rd bearing portion arranged in the axial direction, and at least one of the 2 nd bearing portion and the 3 rd bearing portion is a bearing.

In the gear motor of the above aspect, both the 2 nd bearing portion and the 3 rd bearing portion are bearings.

In the gear transmission motor according to the above aspect, the transmission mechanism includes: a planetary gear mechanism connected to the motor shaft; and a gear train that transmits power from the planetary gear mechanism to the slide mechanism, the gear train having a drive gear that is connected to a carrier of the planetary gear mechanism and rotates about the motor axis, the carrier and the drive gear being separate from each other.

According to an aspect of the present invention, there is provided a gear transmission motor capable of performing a sliding motion and a rotating motion.

Drawings

Fig. 1 is a sectional view of a geared motor according to an embodiment, showing the geared motor in a rotational movement restriction state.

Fig. 2 is a perspective view of a geared motor according to an embodiment, showing the geared motor in a rotational movement restriction state.

Fig. 3 is a cross-sectional view of one embodiment of a geared motor showing a switching point state of the geared motor.

Fig. 4 is a perspective view of the geared motor according to the embodiment, showing the geared motor in a switching point state.

Fig. 5 is a sectional view of the geared motor according to the embodiment, showing the geared motor in a sliding movement restriction state.

Fig. 6 is a perspective view of the geared motor according to the embodiment, showing the geared motor in a sliding movement restriction state.

Fig. 7 is a sectional view of a slide mechanism according to a modification.

Description of the reference symbols

1: a geared motor; 2: a transfer mechanism; 4: a gear train; 5. 105: a sliding mechanism; 10: a frame; 15: a guide frame; 20: a motor; 20 b: a motor shaft; 32: a planetary gear mechanism; 34 c: 2 nd planetary carrier (planet carrier); 41: a drive gear; 51: a lead screw; 51 a: an upper end (1 st end); 51 b: a lower end (2 nd end); 53. 153: a sliding nut; 55. 155: a nut frame; 55 f: an outer peripheral surface; 56: a pin (protrusion); 57a, 157 a: opposite surfaces; 59A: a 1 st bearing portion; 59B: a 2 nd bearing portion; 59C: a 3 rd bearing part; 70: sewing; 70 a: a guide wall; 71: 1, sewing; 71 a: the 1 st wall surface; 72: a 2 nd seam; 72 a: the 2 nd wall surface; 75: an intersection portion; j1: a motor axis; j3: a sliding axis; s: a movement restricting section.

Detailed Description

Hereinafter, a gear transmission motor according to an embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention.

In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system. In the following description, unless otherwise specified, the direction (Z-axis direction) parallel to the motor axis J1 is simply referred to as "axial direction" or "vertical direction", the + Z side is simply referred to as "one axial side" or "upper side", and the-Z side is simply referred to as "the other axial side" or "lower side". The vertical direction in this specification is a direction set for convenience of description, and is not limited to a posture when the geared motor is used.

Fig. 1, 3, and 5 are sectional views of the geared motor 1, and fig. 2, 4, and 6 are perspective views of the geared motor 1. Fig. 1 and 2 show the geared motor 1 in the rotational movement restricted state, fig. 3 and 4 show the geared motor 1 in the switching point state, and fig. 5 and 6 show the geared motor 1 in the sliding movement restricted state.

As described later, the geared motor 1 slides the output portion 55c by driving the motor 20 in the rotational movement restriction state. The geared motor 1 rotates the output portion 55c by driving the motor 20 in the sliding movement restriction state. The gear motor 1 in the switching point state is a transition state between the rotational movement restriction state and the sliding movement restriction state. In the switching point state, the geared motor 1 slides the output portion 55c when the motor 20 is rotationally driven in one direction, and rotates the output portion 55c when the motor is rotationally driven in the other direction.

As shown in fig. 1, the geared motor 1 includes a motor 20, a transmission mechanism 2 for transmitting power of the motor 20, a slide mechanism 5 connected to the transmission mechanism 2, a frame 10, a lid 19, a bracket 6, and a pair of coil springs 7. The geared motor 1 of the present embodiment is mounted on a thin electronic device in which the dimension in the Y axis direction is suppressed.

The transmission mechanism 2 has a planetary gear mechanism 32 and a gear train 4. The gear train 4 has a drive gear 41, an intermediate gear 42, and a pinion gear 43. The motor 20, the planetary gear mechanism 32, and the drive gear 41 are arranged along a motor axis J1. The intermediate gear 42 is disposed along an intermediate axis J2. The slide mechanism 5 and the pinion 43 are arranged along the slide axis J3.

The motor axis J1, the intermediate axis J2, and the slide axis J3 extend parallel to each other in the Z-axis direction. That is, the intermediate axis J2 and the slide axis J3 are parallel to the motor axis J1. The motor axis J1, the intermediate axis J2, and the slide axis J3 are linearly arranged in the X-axis direction when viewed from the axial direction.

Hereinafter, each part of the geared motor 1 will be described in detail.

< frame >

As shown in fig. 2, the frame 10 includes a frame body 11 that supports the motor 20, the transmission mechanism 2, and the slide mechanism, a tubular guide frame 15 that extends upward from the frame body 11, and a pair of support plate portions 13 that protrude laterally from the frame body 11. The guide frame 15 functions as a part of the slide mechanism 5. The guide frame 15 will be described in detail later.

The frame body 11 has a box shape opened downward. The transmission mechanism 2 is housed inside the frame body 11. A motor insertion hole 12 into which the motor 20 is inserted is provided in the upper surface 11b of the frame body 11. The frame body 11 is open downward. The opening on the lower side of the frame body 11 is covered with a lid 19.

As shown in fig. 1, the support plate portion 13 is plate-shaped along a plane perpendicular to the slide axis J3. The pair of support plate portions 13 protrude toward opposite sides in a direction perpendicular to the slide axis J3 (in the X-axis direction in the present embodiment). The support plate portion 13 is provided with a through-insertion hole 13a penetrating in the axial direction. The frame 10 is supported on the bracket 6 on the support plate 13.

< bracket >

The bracket 6 supports a frame 10. The bracket 6 is fixed to a case or the like of an electronic device on which the geared motor 1 is mounted, at a fixing portion not shown. That is, the geared motor 1 is fixed to the electronic device in the bracket 6.

The bracket 6 has a bracket main body 6b and a pair of support shafts 6 a. The carriage main body 6b is plate-shaped along a plane perpendicular to the slide axis J3. The bracket body 6b is disposed below the motor 20, the transmission mechanism 2, the slide mechanism 5, the frame 10, and the lid 19 with a gap therebetween.

A pair of support shafts 6a extend upward from the upper surface of the bracket main body 6 b. The pair of support shafts 6a extends in parallel with the slide axis J3. A retaining flange 6f is provided at the upper end of the support shaft 6 a. The pair of support shafts 6a are inserted into insertion holes 13a provided in the support plate portions 13 of the frame 10, respectively. The retaining flange 6f is located above the support plate 13. The diameter of the retaining flange 6f is larger than the diameter of the insertion hole 13 a. Therefore, the retaining flange 6f functions as a retaining member for preventing the support shaft 6a from coming off the through-insertion hole 13 a.

The pair of coil springs 7 are inserted through the support shafts 6a, respectively. The coil spring 7 is disposed between the lower surface of the support plate portion 13 and the upper surface of the bracket main body 6b in a moderately compressed state. The coil spring 7 presses the frame 10 upward with respect to the bracket 6, and stabilizes the position of the frame 10. When a downward force is applied to the frame 10 or each portion supported by the frame 10, the coil spring 7 is compressed by the force. This can suppress excessive downward force from being applied to the frame 10 or each part supported by the frame 10.

< Motor >

The motor 20 is supported on the frame 10. The motor 20 is, for example, a stepping motor. The motor 20 includes a substantially cylindrical motor main body 20a centered on a motor axis J1, and a motor shaft 20b extending downward from the motor main body 20a along the motor axis J1.

A rotor connected to the motor shaft 20b and a stator surrounding the rotor are provided inside the motor main body 20 a. The motor shaft 20b extends in the axial direction about a motor axis J1. The motor shaft 20b is rotated about a motor axis J1 by the motor 20.

< planetary Gear mechanism >

The planetary gear mechanism 32 is located directly below the motor 20. The planetary gear mechanism 32 is connected to the motor shaft 20 b. The planetary gear mechanism 32 decelerates the power output from the motor 20 and transmits the power to the gear train 4.

The planetary gear mechanism 32 has a case 35, a 1 st sun gear 33a, 3 1 st planet gears 33b, a 1 st carrier 33c, a 2 nd sun gear 34a, 32 nd planet gears 34b, and a 2 nd carrier (carrier) 34 c.

The housing 35 is fixed to the frame 10. That is, the planetary gear mechanism 32 is supported on the frame 10 in the case 35. The housing 35 has a cylindrical portion 35a extending in the axial direction about the motor axis J1, and a bottom portion 35b located at the lower end of the cylindrical portion 35 a. An internal gear is provided on the inner peripheral surface of the cylindrical portion 35 a. The internal gear of the cylindrical portion 35a meshes with the 1 st planetary gear 33b and the 2 nd planetary gear 34 b. Further, a center hole 35c for fixing the 5 th bearing 35d is provided in the center of the bottom portion 35 b. As the 5 th bearing portion 35d, a slide bearing is used.

The 1 st sun gear is fixed to the motor shaft 20b and rotates together with the motor shaft 20b about the motor axis J1. The 3 1 st planetary gears 33b are arranged at equal intervals in the circumferential direction of the motor axis J1. The 3 1 st planetary gears 33b are meshed with the 1 st sun gear 33 a. The 3 1 st planetary gears 33b revolve in the circumferential direction of the motor axis J1 in accordance with the rotation of the 1 st sun gear 33 a.

The 1 st carrier 33c rotatably supports 3 1 st planetary gears 33 b. The 1 st carrier 33c rotates about the motor axis J1 in accordance with the revolving rotation of the 3 1 st planetary gears 33b about the motor axis J1.

The 2 nd sun gear 34a is fixed to the 1 st carrier 33 c. The 2 nd sun gear 34a rotates together with the 1 st carrier 33c about the motor axis J1.

The 3 nd planetary gears 34b are arranged at equal intervals in the circumferential direction of the motor axis J1. The 3 nd 2 nd planetary gears 34b are meshed with the 2 nd sun gear 34 a. The 32 nd planetary gears 34b revolve in the circumferential direction of the motor axis J1 with the rotation of the 2 nd sun gear 34 a.

The 2 nd carrier 34c rotatably supports 32 nd planetary gears 34 b. The 2 nd carrier 34c rotates about the motor axis J1 as the 3 nd planetary gear 34b revolves about the motor axis J1.

The 2 nd carrier 34c has a lower protruding column portion 34 e. The columnar portion 34e is columnar centered on the motor axis J1. The columnar portion 34e penetrates through the central hole 35c of the case 35. Further, the columnar portion 34e is rotatably supported by the 5 th bearing portion 35 d. A holding hole 34d extending in the vertical direction is provided in the lower surface of the columnar portion 34 e.

< Gear train >

The gear train 4 transmits power from the planetary gear mechanism 32 to the slide mechanism 5. The gear train 4 has a drive gear 41, an intermediate gear 42, and a pinion gear 43. The drive gear 41, the intermediate gear 42, and the pinion gear 43 are arranged in this order in the X-axis direction and transmit power. In the present embodiment, the number of teeth of the drive gear 41 is the same as that of the pinion gear 43. Therefore, the gear train 4 of the present embodiment does not perform deceleration and acceleration.

The drive gear 41 includes a gear body 41c, a coupling projection 41a provided on an upper surface of the gear body 41c, and a drive shaft 41b provided on a lower surface of the gear body 41 c. The gear body 41c is a gear centered on the motor axis J1. The gear body 41c meshes with the pinion 43. The drive shaft 41b extends downward along the motor axis J1. The drive shaft 41b is rotatably supported by the 4 th bearing unit 18 fixed to the lid unit 19. As the 4 th bearing part 18, a sliding bearing impregnated with a lubricating oil can be used.

The coupling protrusion 41a extends upward along the motor axis J1. The connecting boss portion 41a is inserted into a holding hole 34d provided in the 2 nd carrier 34c of the planetary gear mechanism 32. The coupling protrusion 41a is provided with a D-cut surface for rotation prevention. The hole shape of the holding hole 34d is formed to be substantially the same as the outer diameter of the coupling convex portion 41 a. The drive gear 41 rotates around the motor axis J1 integrally with the 2 nd carrier 34c by being connected to the 2 nd carrier 34 c.

According to the present embodiment, the 2 nd carrier 34c and the drive gear 41 are separate from each other. The 2 nd carrier 34c and the drive gear 41 are members that rotate integrally about the motor axis J1, and therefore may be formed as one member. However, if the 2 nd carrier 34c and the drive gear 41 are one member, the drive gear 41 is supported from above by the planetary gear mechanism 32. Therefore, the positional accuracy of the drive gear 41 depends on the dimensional accuracy of the internal structure of the planetary gear mechanism 32, and the inter-gear distances in the gear train 4 are likely to vary.

According to the present embodiment, the 2 nd carrier 34c and the drive gear 41 are separated from each other, so that the columnar portion 34e of the 2 nd carrier 34c can be rotatably supported by the 5 th bearing portion 35 d. That is, the 5 th bearing 35d can be disposed between the drive gear 41 and the 2 nd carrier 34c in the axial direction. Therefore, the 5 th bearing 35d can maintain the positional accuracy of the drive gear 41 directly above the drive gear 41, and can suppress variation in the inter-gear distance in the gear train 4 to improve the transmission efficiency. Further, in the present embodiment, the drive gear 41 is rotatably supported by the 4 th bearing portion 18 located immediately below. That is, since the drive gear 41 is rotatably supported by the 4 th bearing part 18 and the 5 th bearing part 35d directly above and below, the inter-gear distance in the gear train 4 can be more reliably increased.

In addition, if the 2 nd carrier 34c and the drive gear 41 are one member, it is necessary to pass the drive gear 41 through the inside of the case 35 in the step of assembling the planetary gear mechanism 32. Therefore, not only the assembly process is complicated, but also design of the drive gear 41 is restricted so as to pass through the central hole 35c of the housing 35. In contrast, according to the present embodiment, the 2 nd carrier 34c and the drive gear 41 are separated from each other, so that the assembly process can be simplified. Further, the diameter of the drive gear 41 can be increased, and the degree of freedom in designing the drive gear 41 can be improved.

The intermediate gear 42 is rotatably supported on an intermediate shaft 11a extending downward from the frame 10. The intermediate shaft 11a extends along an intermediate axis J2. Thus, the intermediate gear 42 rotates about the intermediate axis J2. The intermediate gear 42 is disposed between the drive gear 41 and the sub-gear 43. The intermediate gear 42 meshes with the drive gear 41 and the pinion gear 43, and transmits power from the drive gear 41 to the pinion gear 43.

The pinion 43 is fixed to a lead screw 51 of the slide mechanism 5. The drive gear 41 rotates together with the lead screw 51 about the slide axis J3.

< sliding mechanism >

The slide mechanism 5 is connected to an external device, not shown, and transmits power to the external device. The slide mechanism 5 includes a screw 51 extending in the axial direction, a slide nut 53 inserted into the screw 51, a nut frame 55 holding the slide nut 53, and a cylindrical guide frame 15 surrounding the nut frame 55 from the outside in the radial direction.

The lead screw 51 extends along a slide axis J3. The lead screw 51 is connected to the transmission mechanism 2 and is rotated about the slide axis J3 by the power of the motor 20 transmitted through the transmission mechanism 2.

The screw 51 has a screw portion 51c having a male screw provided on an outer peripheral surface thereof, an upper end portion 51a positioned above the screw portion 51c, and a lower end portion 51b positioned below the screw portion 51 c. That is, the lower end (2 nd end) 51b is an end located on the opposite side of the upper end (1 st end) 51 a. The upper end portion 51a is supported by the 1 st bearing portion 59A. The lower end portion 51B is supported by the 2 nd bearing portion 59B and the 3 rd bearing portion 59C arranged in the axial direction. Further, a pinion 43 is fixed to the lower end portion 51 b.

The slide nut 53 has a nut hole 53a having a thread groove on an inner peripheral surface thereof. The lead screw 51 is inserted into the nut hole 53 a. In addition, the external thread of the lead screw 51 meshes with the thread groove of the nut hole 53 a. The slide nut 53 is fixed to a nut frame 55.

The slide nut 53 converts the direction of the power transmitted from the lead screw 51. The rotation of the slide nut 53 is restricted, and the lead screw 51 is rotated in a state where the slide nut 53 is allowed to move in the axial direction, whereby the slide nut 53 moves in the axial direction.

On the other hand, the slide nut 53 may be transmitted to the rear stage without switching the direction of the power transmitted from the screw shaft 51. When the screw shaft 51 is rotated in a state where the rotation of the slide nut 53 is permitted and the axial movement of the slide nut 53 is restricted, the slide nut 53 is rotated together with the screw shaft 51.

The nut frame 55 supports the slide nut 53. The nut frame 55 moves or rotates in the axial direction integrally with the slide nut 53.

The nut frame 55 includes a cylindrical portion 55a, an inner protruding portion 57 protruding radially inward from the inner peripheral surface of the cylindrical portion 55a, a fixing flange 55c positioned at the upper end of the cylindrical portion 55a, and a pin (protrusion) 56 provided on the outer peripheral surface 55f of the cylindrical portion 55 a. The fixed flange 55c is fixed with a driving object of the geared motor 1. That is, the fixing flange 55c functions as an output portion.

The cylindrical portion 55a is cylindrical and extends in the axial direction around the slide axis J3. The cylindrical portion 55a surrounds the screw 51 from the radially outer side. The inner protruding portion 57 is provided in a lower region of the inner peripheral surface of the cylindrical portion 55 a. The inner protruding portion 57 has an opposing surface 57a facing upward (one axial side) and a lower surface 57b facing downward (the other axial side). The facing surface 57a faces the outer ring of the 1 st bearing portion 59A in the axial direction. The lower surface 57b contacts the upper end surface of the slide nut 53.

As shown in fig. 2, the pin 56 projects radially outward from the outer peripheral surface 55f of the cylindrical portion 55 a. The pin 56 is circular when viewed from the protruding direction. The pin 56 of the present embodiment is integrally provided on the outer peripheral surface 55f of the cylindrical portion 55 a. However, the pin 56 may be a member separate from the cylindrical portion 55a, and may be inserted and fixed into a through hole provided in the cylindrical portion 55 a.

The guide frame 15 has a cylindrical shape having a circular inner peripheral surface 15a when viewed from the axial direction. The inner peripheral surface 15a of the guide frame 15 radially faces the outer peripheral surface 55f of the nut frame 55. The inner diameter of the guide frame 15 is slightly larger than the outer diameter of the nut frame 55. Therefore, the nut frame 55 can slide in the axial direction or the circumferential direction with respect to the guide frame 15. The guide frame 15 guides the axial movement and rotation of the nut frame 55.

A slit 70 is provided in the guide frame 15. The slit 70 radially penetrates the guide frame 15. The slot 70 has a guide wall 70a that guides the pin 56. That is, the guide frame 15 is provided with a guide wall 70 a. The guide wall 70a is an inner wall surface of the slit 70.

The pin 56 is inserted into the slot 70. In the movement of the nut frame 55 relative to the guide frame 15, the pin 56 is guided by the guide wall 70a to move inside the slit 70.

The slit 70 has a 1 st slit 71 and a 2 nd slit 72 intersecting each other at an intersection 75.

The 1 st slit 71 extends in the axial direction. The 1 st slit 71 opens to the upper side at the upper end of the guide frame 15. The inner wall surface of the 1 st slit 71 includes a pair of 1 st wall surfaces 71a extending in the axial direction. The pair of 1 st wall surfaces 71a are circumferentially opposed to each other with a gap for receiving the pin 56.

As shown in fig. 1 and 2, in the rotational movement restriction state, the pin 56 is housed in the 1 st slot 71. In the rotational movement restricting state, the 1 st slit 71 restricts rotation of the pin 56 about the slide axis J3 by the pair of 1 st wall surfaces 71 a. Thereby, the 1 st slit 71 restricts the rotation of the nut frame 55. In addition, since the 1 st slit 71 extends in the axial direction, the slide nut 53 is allowed to move in the axial direction. Therefore, when the lead screw 51 is rotated in the rotational movement restriction state, the slide nut 53 and the nut frame 55 move in the axial direction with respect to the guide frame 15.

The 2 nd slit 72 extends in the circumferential direction. The 2 nd slit 72 extends all over and half way circumferentially of the sliding axis J3. One peripheral end of the 2 nd slit 72 is located at the intersection 75. That is, the 2 nd slit 72 is connected to the 1 st slit 71 at an intersection 75. The inner wall surface of the 2 nd slit 72 includes a 2 nd wall surface 72a facing upward (one axial side). The 2 nd wall surface 72a is connected to the 1 st wall surface 71a at an intersection 75. Here, the direction in which the screw shaft 51 rotates to move the slide nut 53 upward is referred to as a 1 st rotation direction T1. The direction in which the 2 nd slit 72 extends from the intersection 75 coincides with the 1 st rotation direction T1.

As shown in fig. 5 and 6, in the sliding movement restriction state, the pin 56 is housed in the 2 nd slit 72. In the sliding movement restriction state, the 2 nd slit 72 restricts the downward sliding movement of the pin 56 by the 2 nd wall surface 72 a. Further, the upward movement of the nut frame 55 is restricted by a movement restricting portion S described later. Therefore, the 2 nd wall surface 72a and the movement restricting portion S restrict the axial movement of the nut frame 55. Also, since the 2 nd slit 72 extends in the axial direction, the slide nut 53 is allowed to move in the circumferential direction. Therefore, when the lead screw 51 is rotated in the sliding movement restriction state, the slide nut 53 and the nut frame 55 rotate together with the lead screw 51 with respect to the guide frame 15.

In the present embodiment, the surface facing the 2 nd wall surface 72a and facing downward in the 2 nd slit 72 does not restrict the upward sliding movement of the pin 56.

The 1 st bearing portion 59A is a ball bearing having an inner ring, an outer ring, and rolling elements interposed therebetween. The inner ring of the 1 st bearing portion 59A is fixed to the upper end 51a of the lead screw 51. On the other hand, the outer ring of the 1 st bearing portion 59A is opposed to and in contact with the inner surface of the cylindrical portion 55a of the nut frame 55 in the radial direction. However, the outer ring of the 1 st bearing portion 59A is not fixed to the inner surface of the cylindrical portion 55 a. When the nut frame 55 moves in the axial direction together with the slide nut 53, the outer peripheral surface of the outer ring of the 1 st bearing portion 59A slides in the axial direction on the inner surface of the cylindrical portion 55 a.

The outer ring of the 1 st bearing portion 59A axially faces an opposing surface 57a of an inner protruding portion 57 provided on the inner surface of the cylindrical portion 55 a. In the rotational movement restriction state shown in fig. 1, when the screw shaft 51 is rotated in the 1 st rotational direction T1, the slide nut 53 and the nut frame 55 move upward. Accordingly, the outer ring of the 1 st bearing portion 59A gradually approaches the facing surface 57a and comes into contact with it shortly, thereby bringing it into the switching point state shown in fig. 3 and 4. When the screw shaft 51 is further rotated in the 1 st rotation direction T1 after reaching the switching point state, the slide nut 53 and the nut frame 55 are rotated while maintaining contact between the outer ring of the 1 st bearing portion 59A and the facing surface 57a, and the sliding movement restriction state shown in fig. 5 and 6 is achieved.

As shown in fig. 3 and 4, in the switching point state, the 1 st bearing portion 59A and the opposing surface 57a contact each other with the pin 56 positioned at the intersection 75 of the slits 70. The first bearing portion 59A contacts the facing surface 57a, whereby the nut frame 55 is restricted from moving upward relative to the guide frame 15. Thus, the 1 st bearing portion 59A and the opposed surface 57a function as the movement restricting portion S. That is, the slide mechanism 5 includes a movement restricting portion S that restricts the movement of the nut frame 55 upward relative to the guide frame 15.

The 2 nd bearing portion 59B and the 3 rd bearing portion 59C rotatably support the lower end portion 51B of the screw 51. The 2 nd bearing portion 59B and the 3 rd bearing portion 59C are arranged in this order from the upper side to the lower side. That is, the 2 nd bearing portion 59B is located above the 3 rd bearing portion 59C. Each of the 2 nd bearing portion 59B and the 3 rd bearing portion 59C is a ball bearing having an inner ring, an outer ring, and rolling elements interposed therebetween.

As described above, the 1 st bearing portion 59A is provided at the upper end portion 51a of the lead screw 51. The outer ring of the 1 st bearing portion 59A slides in the axial direction against the inner surface of the cylindrical portion 55a facing radially outward. Therefore, the outer ring and the inner surface of the cylindrical portion 55a need to be fitted with a sufficient gap to reduce sliding resistance. As a result, the 1 st bearing portion 59A tends to insufficiently support the upper end portion 51a of the screw shaft 51 with respect to the tilting of the screw shaft 51.

In this way, when the member is moved to one side in the axial direction by the rotation of the screw, the outer ring of the bearing cannot be fixed to the moving line of the moving member, and therefore, it is difficult to reliably support the rotation of both end portions of the screw. The geared motor 1 of the present embodiment is designed in view of such problems, and one of the purposes is to improve the reliability of the rotational support of the lead screw 51.

According to the present embodiment, the lower end portion 51B of the screw 51 is supported by a plurality of bearing portions (the 2 nd bearing portion 59B and the 3 rd bearing portion 59C) arranged in the axial direction. Therefore, the lead screw 51 can be effectively inhibited from falling. In addition, according to the present embodiment, the 2 nd bearing portion 59B and the 3 rd bearing portion 59C are ball bearings. Therefore, even when the fitting clearance between the inner ring and the outer ring of the second bearing portion 59B and the third bearing portion 59C is reduced to suppress the tilting of the screw 51, the rotation efficiency of the second bearing portion 59B and the third bearing portion 59C is less likely to be reduced.

The outer rings of the 2 nd bearing portion 59B and the 3 rd bearing portion 59C are held on the inner peripheral surface of the bearing support hole 16 provided in the frame 10. The bearing support hole 16 axially penetrates along the slide axis J3. The lower end 51b of the screw 51 is inserted through the bearing support hole 16.

An annular rib 16c extending in the circumferential direction is provided on the inner circumferential surface of the bearing support hole 16. The annular rib 16C is located between the 2 nd bearing portion 59B and the 3 rd bearing portion 59C. The annular rib 16c has an upper stepped surface 16a facing upward and a lower stepped surface 16b facing downward. The upper step surface 16a contacts the outer ring of the 2 nd bearing portion 59B. On the other hand, the lower stepped surface 16b contacts the outer ring of the 3 rd bearing portion 59C.

The inner ring of the 2 nd bearing portion 59B contacts the lower end of the screw portion 51c of the screw shaft 51. The inner ring of the 2 nd bearing portion 59B contacts the lower surface of the screw portion 51c, and holds the lower end portion 51B of the screw shaft 51 in a state of being pressed downward with respect to the outer ring. The inner ring of the 3 rd bearing portion 59C is bonded and fixed to the lead screw 51 in a state of being pressed upward with respect to the outer ring. Therefore, the 2 nd bearing portion 59B and the 3 rd bearing portion 59C support the lead screw 51 in a state where the play is removed in the direction in which the inner rings approach each other.

According to the present embodiment, the 2 nd bearing portion 59B and the 3 rd bearing portion 59C hold the screw shaft 51 in a state where the play is removed in the opposite directions. Therefore, the backlash of the screw 51 in the thrust direction can be suppressed.

In the present embodiment, the case where both the 2 nd bearing portion 59B and the 3 rd bearing portion 59C are bearings is exemplified. However, if either one of the 2 nd bearing portion 59B and the 3 rd bearing portion 59C is a bearing, the backlash in the thrust direction of the screw shaft 51 can be suppressed. As an example, a case where the 2 nd bearing portion is a slide bearing and the 3 rd bearing portion is a bearing will be described. In this case, the upper end surface of the 2 nd bearing portion is brought into contact with the lower end of the screw portion 51c of the screw shaft 51. Further, the inner ring of the 3 rd bearing portion is adhesively fixed to the lower end portion 51b of the screw shaft 51 in a state of being pressed upward with respect to the outer ring.

< Effect >

According to the present embodiment, the moving direction of the pin 56 is restricted by the 1 st wall surface 71a and the 2 nd wall surface 72a of the slit 70. Thus, when the pin 56 passes through the intersecting portion 75, the moving direction of the pin 56 can be changed from the axial direction to the circumferential direction or from the circumferential direction to the axial direction. According to the present embodiment, by rotating the lead screw 51 in one direction using only one motor 20, the slide nut 53 and the nut frame 55 can be sequentially moved in the axial direction and the rotational direction.

According to the present embodiment, the 1 st slit 71 extends axially on both sides with respect to the intersecting portion 75 and opens axially on one side (upper side). Therefore, in the assembly process of the geared motor 1, the pin 56 can be inserted from the opening on the upper side of the 1 st slot 71, and the assembly process can be simplified. In the molding of the guide frame 15, the 1 st slit 71 may be opened to the upper side by post-processing without opening the upper end portion of the 1 st slit 71. Through such steps, the guide frame 15 with high dimensional accuracy can be manufactured while suppressing warpage of the guide frame 15 during molding.

According to the present embodiment, the nut frame 55 has the facing surface 57a facing the 1 st bearing portion 59A in the axial direction. The 1 st bearing portion 59A and the opposing surface 57a contact each other in a state where the pin 56 is positioned at the intersection portion 75, and function as the movement restricting portion S. By providing the movement restricting portion S in the slide mechanism 5, the movement of the nut frame 55 upward relative to the guide frame 15 is restricted, and the nut frame 55 can be rotated about the slide axis J3.

According to the present embodiment, the 1 st bearing portion 59A that supports the upper end portion of the screw 51 constitutes the movement restricting portion S. When the nut frame 55 rotates about the slide axis J3, the 1 st bearing portion 59A and the facing surface 57a constituting the movement restricting portion S rotate together. Therefore, when the nut frame 55 is rotated while the movement restricting portion S is caused to function, the driving efficiency can be improved without generating sliding resistance. The contact surface between the 1 st bearing portion 59A and the facing surface 57a constituting the movement restricting portion S is circular with the slide axis J3 as the center. Therefore, by causing the movement restricting portion S to function, the nut frame 55 can be stably held with respect to the slide axis J3.

In the present embodiment, the 1 st bearing portion 59A located at the upper end portion 51a of the screw shaft 51 is used as a part of the movement restricting portion S. However, the movement restricting portion S may not be a bearing portion as long as a part thereof protrudes radially outward from the upper end portion 51a of the screw shaft 51 and axially faces the facing surface 57 a.

According to the present embodiment, the movement restricting portion S that suppresses the movement of the nut frame 55 upward relative to the guide frame 15 is provided at a portion other than the guide wall 70a of the slit 70. Therefore, as described above, even in the case of the configuration in which the 1 st slit 71 extends in the vertical direction with respect to the intersecting portion 75, the moving direction of the nut frame 55 can be switched by the pin 56 reaching the intersecting portion 75.

< modification example >

Fig. 7 is a sectional view of a slide mechanism 105 according to a modification that can be employed in the above embodiment. Fig. 7 shows the geared motor 1 in the above-described embodiment in the state of the switching point corresponding to fig. 3. The slide mechanism 105 of the present modification differs from the above-described embodiment mainly in that a coil spring 107 is incorporated in the slide mechanism 105. The same reference numerals are given to the same constituent elements as those of the above embodiment, and the description thereof will be omitted.

The slide mechanism 105 of the present modification includes a screw shaft 51, a slide nut 153 inserted into the screw shaft 51, a nut frame 155 surrounding the slide nut 153 from the radial outside, a cylindrical guide frame 15 surrounding the nut frame 155 from the radial outside, a holding member 158 fixed to the lower end portion of the nut frame 155, and a coil spring 107 housed inside the nut frame 155.

As in the above embodiment, the pin 56 is provided on the outer peripheral surface of the nut frame 155. Further, the guide frame 15 is provided with a slit 70 into which the pin 56 is inserted. In the movement of the nut frame 155 relative to the guide frame 15, the pin 56 is guided by the guide wall 70a to move inside the slit 70.

The slide nut 153 has a nut hole 153a provided with a thread groove on an inner circumference. The screw 51 is inserted into the nut hole 153 a. Further, a plurality of ridges 153b projecting radially outward and extending in the axial direction are provided on the outer peripheral surface of the slide nut 153.

The nut frame 155 includes a cylindrical portion 155a, an inner protruding portion 157 that protrudes radially inward from the inner circumferential surface of the cylindrical portion 155a, and the pin 56. The inner protrusion 157 has an opposing surface 157a and a lower surface 157 b. The facing surface 157a faces the outer ring of the 1 st bearing portion 59A in the axial direction. As in the above embodiment, as the nut frame 155 moves upward with the rotation of the screw shaft 51, the outer ring of the 1 st bearing portion 59A comes into contact with the facing surface 157a of the inner protrusion 157, and the movement of the nut frame 155 upward is restricted.

A plurality of concave grooves 155p extending in the axial direction are provided in a region on the inner peripheral surface of the cylindrical portion 155a and below the inner protruding portion 157. The ridge 153b of the slide nut 153 is inserted into the groove 155 p. By inserting the ridge 153b into the groove 155p, relative rotation between the slide nut 153 and the nut frame 155 can be suppressed, while relative axial movement can be allowed.

The holding member 158 protrudes radially inward from the lower end of the cylindrical portion 155 a. The holding member 158 is in contact with the lower end surface of the slide nut 153. The holding member 158 restricts the movement of the nut frame 155 upward relative to the slide nut 153.

The screw shaft 51 penetrates and inserts the coil spring 107 into the nut frame 155. The upper end of the coil spring 107 contacts the lower surface 157b of the inner protrusion 157. In addition, the lower end portion of the coil spring 107 contacts the upper surface of the slide nut 153. The coil spring 107 is disposed between the inner protrusion 157 and the slide nut 153 in a moderately compressed state. The coil spring 107 presses the nut frame 155 upward with respect to the slide nut 153.

According to the present modification, the coil spring 107 is compressed when a downward force is applied to the nut frame 155. This can suppress the nut frame 155 from being excessively forced downward, and can suppress damage to the nut frame 155, the slide nut 153, and the screw shaft 51.

While the embodiment and the modified examples of the present invention have been described above, the configurations and combinations thereof in the embodiment are only examples, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the scope of the present invention. The present invention is not limited to the embodiments.

Claims (7)

1. A gear transmission motor is characterized in that,

the gear transmission motor has:

a motor that rotates a motor shaft extending along a motor axis;

a transmission mechanism that transmits power of the motor; and

a sliding mechanism connected with the transmission mechanism,

the sliding mechanism includes:

a lead screw connected to the transmission mechanism and rotating around a sliding axis;

a sliding nut inserted by the lead screw;

a nut frame that holds the slide nut;

a cylindrical guide frame surrounding the nut frame from a radially outer side; and

a movement limiting part which is used for limiting the movement of the sliding block,

a projection projecting outward in the radial direction is provided on the outer peripheral surface of the nut frame,

a guide wall guiding the protrusion is provided on the guide frame,

the guide wall has:

a pair of 1 st wall surfaces that are circumferentially opposed to each other with a gap therebetween for accommodating the projection and extend in an axial direction; and

a 2 nd wall surface facing one side in the axial direction and connected to the 1 st wall surface at an intersection portion,

the movement restricting portion restricts movement of the nut frame to one side in the axial direction with respect to the guide frame in a state where the protrusion is located at the intersecting portion.

2. The geared motor of claim 1,

a slit is provided on the guide frame,

the seam comprises:

a 1 st slot extending in an axial direction; and

a 2 nd slit connected to the 1 st slit at the intersection and extending in a circumferential direction,

the inner wall surface of the 1 st slit includes a pair of the 1 st wall surfaces,

the inner wall surface of the 2 nd slit includes the 2 nd wall surface.

3. The geared motor of claim 2,

the 1 st slit extends to both axial sides with respect to the intersection and is open in the axial direction at one side.

4. The gear transmission motor according to any one of claims 1 to 3,

the 1 st end of the screw is supported by the 1 st bearing portion,

the nut frame has an opposite surface axially opposed to the 1 st bearing portion,

the 1 st bearing portion and the opposing surface are in contact with each other in a state where the projection is positioned at the intersection portion, and function as the movement restricting portion.

5. The gear transmission motor according to any one of claims 1 to 3,

the 2 nd end part of the screw is supported by a 2 nd bearing part and a 3 rd bearing part which are arranged along the axial direction,

at least one of the 2 nd bearing portion and the 3 rd bearing portion is a bearing.

6. The geared motor of claim 5,

the 2 nd bearing portion and the 3 rd bearing portion are both bearings.

7. The gear transmission motor according to any one of claims 1 to 3,

the transmission mechanism includes:

a planetary gear mechanism connected to the motor shaft; and

a gear train that transmits power from the planetary gear mechanism to the slide mechanism,

the gear train has a drive gear connected to a carrier of the planetary gear mechanism and rotating about the motor axis,

the carrier and the drive gear are separate from each other.

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