JP5395158B2 - Geared motor - Google Patents

Description

  The present invention relates to a geared motor in which an output shaft of a motor and an input shaft of a gear reducer are orthogonal to each other or in a different direction, and more particularly to a geared motor using a face gear as a first gear of a gear reducer.

A gear reducer that uses a face gear or a hypoid gear to extract power in a direction perpendicular to or different from the output shaft of an electric motor is known.
The face gear is a spur gear or a disc-shaped gear that meshes with a helical gear, and is used for an orthogonal axis or a staggered axis.
On the other hand, a hypoid gear is a conical gear that transmits motion between staggered shafts, and is a gear similar to a spiral bevel gear with the shafts of large and small gears offset.
For example, Patent Documents 1 and 2 are known as conventional geared motors using face gears.

  As a face gear conventionally used, a face gear 100 as shown in FIG. 10 is known. The face gear 100 is formed in a disk shape, and an attachment hole 102 for attaching the face gear 100 to the driven shaft 101 is provided at the center. At the outer edge portion of the flat surface 103 of the face gear 100, a gear cutting portion 104 protruding in the axial direction from the flat surface 103 is provided so as to extend in an annular shape. The gear cutting portion 104 is provided with a plurality of driven side meshing teeth 105. The driven side meshing teeth 105 extend in a direction perpendicular to the axis of the face gear 100.

A spur gear 107 is attached to the output shaft 106 of the electric motor extending in a direction orthogonal to the driven shaft 101, and the drive side meshing meshed with the driven side meshing tooth 105 of the face gear 100 on the outer peripheral surface of the spur gear 107. A plurality of teeth 108 are provided.
When the output shaft 106 is rotated by driving the electric motor, as shown in FIG. 11, the driving-side meshing teeth 108 of the spur gear 107 are pressed one by one against the driven-side meshing teeth 105 of the face gear 100, and the face gear 100 is axially moved. Rotate around.

  However, in the face gear 100, each drive side meshing tooth 108 of the spur gear 107 is pressed against each one of each driven side meshing tooth 105 in the face gear 100. Therefore, after the predetermined drive-side meshing tooth 108 is pressed against the driven-side meshing tooth 105, the drive-side meshing tooth 108 located next to the drive-side meshing tooth 108 is pressed against the driven-side meshing tooth 105. The rotational speed of the face gear 100 becomes slow. Then, the face gear 100 whose rotational speed has become slow increases in rotational speed when the drive-side meshing teeth 108 are pressed against the driven-side meshing teeth 105. Therefore, the rotational speed of the face gear 100 becomes slow or fast, and there is a problem that the face gear 100 cannot be smoothly rotated.

Therefore, as shown in FIG. 12, there is known a face gear 200 provided with driven-side meshing teeth 205 that are inclined at an equal angle with respect to the outer peripheral surface. These driven-side meshing teeth 205 are formed so as to be convex toward the arrow W direction.
The output shaft 206 of the electric motor is arranged such that its axis extends in a direction perpendicular to the axis of the driven shaft 201 and intersects the axis of the driven shaft 201. The meshing teeth 205 of the face gear 200 are meshed with a bevel gear 207 attached to the output shaft 206 of the electric motor. A plurality of meshing teeth 208 extending spirally about the axis of the oblique gear 207 are provided on the outer peripheral surface of the oblique gear 207, and the meshing teeth 208 are meshing teeth of the face gear 200 as shown in FIG. 205 is engaged to transmit rotation (see Patent Document 1).
Also in Patent Document 2, rotation is transmitted between a face gear arranged in an orthogonal direction and a helical pinion of a motor.

JP-A-9-123021 JP 2007-74789 A

In such an orthogonal shaft geared motor using a conventional face gear, it is necessary to change the specifications of the pinion and the gear or to change the positional relationship between the pinion and the gear when changing the reduction ratio. .
Therefore, in order to change the reduction ratio, it is necessary to newly prepare a motor pinion or a gear case, and there is a problem that the reduction ratio cannot be changed after both the motor pinion and the gear case are shared.

  An object of the present invention is to solve the above-described problems and to provide a geared motor that can very easily change a reduction ratio between a cylindrical gear provided on an output shaft of a motor and a face gear meshing with the cylindrical gear.

In order to solve the above-mentioned problems, the present invention provides a face gear in which annular gears with different numbers of teeth are formed on both sides of a disc-shaped body, and a pinion shaft having a tooth width that can mesh with gears on both sides of the face gear. And a gear ratio reducer is built in the gear reducer so as to be reversible, and the reduction ratio can be changed by reversing the face gear .

According to the present invention , a geared motor can be obtained in which the reduction gear ratio can be changed very easily by reversing and mounting the face gear . Therefore, even if the first stage reduction ratio is changed, it is possible to design to share both the motor and the gear case parts, thereby reducing the cost.

(A) It is a front view which opens the inside of a reduction gear and shows the geared motor which set the reduction ratio of the 1st step | paragraph to 1/5 by embodiment of this invention. (B) is the sectional view on the AA line of (a). (A) It is a front view which shows the geared motor which set the reduction ratio of the 1st step | paragraph to 1/8 by embodiment of this invention open | released the inside of a reduction gear. (B) is the BB sectional drawing of (a). It is the elements on larger scale which show the cylindrical gear and face gear of FIG.1 (b). It is the elements on larger scale which show the cylindrical gear and face gear of FIG.2 (b). FIG. 1A is a perspective view showing meshing of a cylindrical gear and a face gear in FIG. 1A, wherein the cylindrical gear is a helical gear, and the face gear is geared so as to mesh with the helical gear. is there. FIG. 2A is a perspective view showing meshing of the cylindrical gear and the face gear of FIG. 2A, and the cylindrical gear is a helical gear, and the face gear is geared so as to mesh with the helical gear. is there. It is a graph which shows the limit line of the crown gear by the offset of the geared motor which set the reduction ratio of the 1st step to 1/5. It is a graph which shows the limit line of the crown gear by the offset of the geared motor which set the reduction ratio of the 1st step to 1/8. The face gear of this invention is shown, (a) is a front view, (b) is a right side view of (a), and (c) is a rear view of (a). It is a top view which shows the conventional face gear. It is the elements on larger scale of FIG. It is a top view which shows the conventional face gear. It is the elements on larger scale of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIGS. 1A and 1B are examples of a geared motor in which the reduction ratio of the first-stage reduction gear employed in the gear reducer is 1/5. FIGS. 2A and 2B are gear reductions. This is an example of a geared motor in which the reduction ratio of the first reduction gear employed in the machine is 1/8.

  In FIGS. 1A and 1B and FIGS. 2A and 2B, reference numeral 1 denotes a geared motor. The geared motor 1 includes a motor 20 and a gear reducer 30, and is connected via a mounting bolt 21. The motor 20 is assembled to the gear reducer 30. A cylindrical gear 22 is provided as a pinion integrally or separately on the output shaft 20a of the motor 20, and the cylindrical gear 22 is set to a constant length L. The cylindrical gear 22 is an involute spur gear or a helical gear.

  An output shaft 20 a of the motor 20 is inserted into a case 31 of the gear reducer 30, and a face gear (also referred to as a crown gear) 32 serving as a first stage gear provided in the case 31 of the gear reducer 30 is the cylinder. The gear 22 is meshed. The face gear 32 is formed by annularly forming a tooth surface on the peripheral edge of one surface of a disk-shaped main body, and a first reduction shaft 33 provided as an axis orthogonal to or intersecting with the output shaft 20a of the motor 20. It is supported by. The first reduction shaft 33 is rotatably supported via bearings 33a and 33b provided in the case 31 of the gear reducer 30. The first reduction shaft 33 is provided with a first reduction shaft (input shaft) 33 of the gear reducer 30 in a direction offset in parallel with a constant width H from a direction orthogonal to the output shaft 20a of the motor 20. Yes.

  A gear 34 is attached to the first reduction shaft 33, and a gear 35 that meshes with the gear 34 is supported by the second reduction shaft 36. The two speed reducing shafts 36 are supported via bearings 36a and 36b provided on the inner wall surface of the case 31. A gear 37 is mounted on the two reduction shaft 36, and a gear 38 that meshes with the gear 37 is supported by the output shaft 39. The output shaft 39 is rotatably supported via bearings 39a and 39b provided in the case 31 of the gear reducer 30. Oil seals 40 are provided at both ends of the output shaft 39 to seal between the inner surface of the case 31.

  The case 31 of the gear reducer 30 includes a gear case 31a and a gear flange 31b. A first reduction shaft (input shaft) 33 of the gear reducer 30 is disposed in a direction orthogonal to the output shaft 20a of the motor 20 or in a direction offset in parallel with a constant width H from the orthogonal direction. Thus, the rotation of the output shaft 20a of the motor 20 is extracted from the output shaft 39 of the gear reducer 30 in a direction orthogonal to the output shaft 20a or in a direction orthogonal to the surface including the output shaft 20a.

FIGS. 1A and 1B are examples of a geared motor in which the reduction ratio of the first stage is set to 1/5. As shown in FIG. 3, when the reduction ratio is 1/5, the outside of the face gear 32A is shown. Since the diameter decreases, the cylindrical gear 22 provided on the output shaft 20 a of the motor 20 meshes with the cylindrical gear 22 and the tooth surface 32 a at a position away from the motor 20.
2 (a) and 2 (b) are examples of a geared motor in which the reduction ratio of the first stage is 1/8. As shown in FIG. 4, when the reduction ratio is 1/8, the outer diameter of the face gear 32B is shown. Therefore, the tooth surface 32b meshes with the cylindrical gear 22 provided on the output shaft 20a of the motor 20 at a position close to the motor 20.
FIG. 5 shows the cylindrical gear 22 provided on the output shaft 20a of the motor 20 that meshes with the face gear 32A. FIG. 6 shows the cylindrical gear 22 provided on the output shaft 20a of the motor 20 that meshes with the face gear 32B. Is shown.
The position of the cylindrical gear 22 meshes at a position offset in parallel with a certain width H on the horizontal plane from a position orthogonal to the axis of the face gear 32A (or the face gear 32B).

  As for the tooth surface of the face gear 32A (or the face gear 32B), the tooth root interference appears when the inner diameter is reduced, and the tip of the tooth appears when the outer diameter is increased. Depending on the specifications of the cylindrical gear 22, the tip of the tooth may not appear. Therefore, the effective tooth width and dimensions of the face gear 32A (or the face gear 32B) are determined in consideration of the point where the tooth root interference and the tip of the tooth appear. As can be seen from FIGS. 7 and 8, as the offset amount is increased, the tooth root interference limit line and the tip tip limit line on the pitch line approach each other, and the tooth width of the face gear 32A (or the face gear 32B). Will be subject to restrictions.

  Further, when the reduction ratio is 1/5, the tooth width is more easily affected by the offset amount. Therefore, normally, the necessary tooth width is determined from the gear strength required at the time of use, and the offset amount H at which the effective tooth width can be obtained with the reduction ratio 1/5 is determined. The face gear 32B having a reduction ratio of 1/8 is designed with the offset amount H determined above. In this case, the offset amount / module is designed to 7.5 according to the relationship of the gear strength, so that the shaft of the cylindrical gear 22 and the shaft of the face gear 32A (or the face gear 32B) can be changed even if the reduction ratio is changed. It is possible to design without changing the positional relationship.

Next, the meshing of the face gear 32A or the face gear 32B with the cylindrical gear 22 as a pinion provided on the output shaft 20a of the motor 20 will be described.
A gear having annular gears on both sides of a disc-shaped body is used as the first gear (of a gear reducer) that meshes with a cylindrical gear 22 provided on the output shaft 20a of the motor 20.
The gear cutting shape is a shape that meshes with the cylindrical gear 22 of the motor 20. In other words, if the cylindrical gear 22 (motor shaft pinion) is a spur gear, if the cylindrical gear 22 is a helical gear, the gear is engaged so as to mesh with the helical gear.
For the face gear 32 that is the first stage gear (of the gear reducer) that meshes with the cylindrical gear 22, a plurality of gears having different numbers of teeth are prepared and appropriately selected according to a desired reduction ratio. To.

  At that time, the cylindrical gear 22 as the output shaft 20a of the motor 20 is set to an effective tooth width sufficient to mesh from the gear having the largest number of teeth to the gear having the smallest number of teeth among the first stage gears. Also, the offset amount of the cylindrical gear 22 and the first gear as the output shaft 20a of the motor 20 is set to 0 or a certain amount, and the first gear of any reduction ratio is geared so as to mesh with the cylindrical gear 22 with the offset amount. . By designing in this way, it is possible to change only the meshing position without changing the positional relationship between the axial positions of the cylindrical gear 22 and the first gear.

  According to the above embodiment, when the face gear 32A is applied as the face gear 32 and the first stage reduction ratio is set to 1/5, the face gear 32A is placed in the case 31 of the gear reducer 30 with the first reduction shaft. Assemble to 33. Then, the face gear 32A is meshed with a cylindrical gear 22 provided on the output shaft 20a of the motor 20. The face gear 32A meshes with the cylindrical gear 22 at a predetermined position within the range of the cylindrical gear 22 in the length direction. The first stage reduction ratio can be set to 1/5. The rotation transmitted to the face gear 32A is transmitted to the first reduction shaft 33 and rotates the gear 34. The rotation of the gear 34 is transmitted to the gear 35 meshed with the gear 34 to rotate the second reduction shaft 36. Then, the gear 37 supported by the second reduction shaft 36 is rotated, and the gear 38 meshed with the gear 37 is rotated. Thus, the rotation of the gear 38 is extracted outside through the output shaft 39 supporting the gear 38. The rotation taken out from the output shaft 39 is taken out as a rotation in a direction perpendicular to the output shaft 20a of the motor 20 from an axis that is different from the output shaft 20a of the motor 20.

  When changing the reduction ratio at the first stage to 1/8, the face gear 32B is assembled to the first reduction shaft 33 instead of the face gear 32A. In this way, the face gear 32B meshes with the cylindrical gear 22 at a predetermined position within the range of the cylindrical gear 22 in the length direction. The face gear 32B meshes with the cylindrical gear 22 closer to the root of the cylindrical gear 22 than the face gear 32A. Therefore, the mounting position of the face gear 32B can be meshed with the cylindrical gear 22 simply by mounting the face gear 32B on the same first reduction shaft 33 as the face gear 32A. Therefore, the face gear 32A (or the face gear 32B) having a different diameter can be appropriately assembled and used without changing the case 31 of the gear reducer 30.

FIG. 9 shows a modification of the face gear, and shows the face gear 32 in which the face gear 32A and the face gear 32B are formed on the front and back of one disk.
By using this face gear 32, the number of face gears 32 can be halved.

  According to the above embodiment, the design is made such that the effective tooth width of the cylindrical gear 22 of the motor 20 is made large and the offset amount H is made the same so that the reduction gear ratio can be engaged to 1/5 to 1/8. As a result, the position of the motor 20 and the first reduction shaft 33 can be made the same even if the first stage reduction ratio is changed. Therefore, even if the first stage reduction ratio is changed, the motor 20 and the gear case 31a The gear flange 31b can be used in common, and only the face gear 32A and the face gear 32B can be changed.

  The present invention is not limited to the above-described embodiment. For example, even when the cylindrical gear 22 is a spur gear, the same common design is possible by setting the offset amount H to 0 or a small value. It is. In addition, it cannot be overemphasized that it can change suitably and implement within the range which does not change the gist of the present invention.

1 geared motor 20 motor 20a output shaft 22 cylindrical gear 30 gear reducer 31 case 31a gear case 31b gear flange 32, 32A, 32B face gear 33 first reduction shaft 34, 35, 37, 38 gear 36 second reduction shaft 39 output shaft

Claims (1)

A face gear having annular tooth cutting surfaces with different numbers of teeth on both sides of a disc-shaped body, and a motor having a pinion shaft having a tooth width that can mesh with the gears on both sides of the face gear. A geared motor characterized in that it is incorporated in a gear reducer so that it can be reversed, and the reduction ratio can be changed by reversing the face gear .

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