JP3925053B2 - Geared motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a geared motor including a servo motor and a gear reducer used in equipment and labor-saving equipment.
[0002]
[Prior art]
In recent years, geared motors are used not only for power supplies such as conveyors, but also for various purposes. In addition to demands for miniaturization, weight reduction, space saving, and cost reduction, there is a need for geared motors that require high-speed positioning. There was a geared motor that combined a servomotor and a spur gear reducer. And since oil is mainly used for high speed operation, oil having a lower viscosity than grease has been used as the lubricating oil for the gear reducer.
[0003]
[Problems to be solved by the invention]
However, geared motors with high-speed positioning are often used in a nearly constant positional relationship, and impact force is applied to the tooth surface of a specific gear when stopped. Especially in the case of a spur gear, it is necessary to receive the impact force with a single gear. Therefore, measures such as enlarging gears were necessary.
[0004]
In addition, even when a conventional gear reducer and a servo motor are combined to perform a high-speed positioning operation, a positioning error occurs due to backlash on the gear reducer side, and it is impossible to stop at a predetermined position. there were.
[0005]
In addition, the temperature of the lubricating oil rises due to the high-speed positioning operation, and the viscosity of the oil further decreases and the lubricating oil may leak from the output shaft side of the gear reducer.
[0006]
Furthermore, if the motor and the speed reducer are configured separately as in the conventional geared motor, the outer shape of the geared motor becomes complicated, and the output shaft of the speed reducer is often eccentric from the mounting position of the geared motor. There is a problem in that the degree of freedom in design is reduced due to restrictions on installation on equipment, such as inability to install symmetrically.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a geared motor that is small, easy to handle, excellent in reliability, and high in positioning accuracy at high speed.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention is configured such that the rotary shafts of the servo motor and the gear reducer are housed in parallel in a substantially rectangular parallelepiped casing divided in a direction orthogonal to the rotary shaft, and the output shaft of the gear reducer On the center line of the short side of the casing, and is configured to be substantially flush with the surface of the casing by a hollow shaft that penetrates, and all the gears of the gear reducer are configured by helical gears, and each pinion shaft of the gear reducer suppressing the axial gap, which has to allow attachment of symmetric reduce gear backlash, the output shaft on the housing a short side of the center line, substantially flush to the structure and the housing surface penetrating the hollow shaft ( (Equipment left and right symmetrical) improves the workability of attachment to the equipment, and all gears are made of helical gears to improve the meshing rate and suppress the axial clearance of each pinion shaft.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In order to solve the above-described problems, the present invention provides a geared motor in which a servo motor and a speed reducer are combined. In the geared motor, all gears of the gear speed reducer are constituted by helical gears, and the axial direction of each pinion shaft of the gear speed reducer The gap is reduced and gear backlash is reduced. By making all gears into helical gears, the meshing rate can be improved, and the impact force per piece can be reduced, so that the life of the gears is extended. be able to. Moreover, positioning accuracy can be improved by suppressing the axial gap of the helical gear.
[0010]
Further, the rotation shafts of the servo motor and the gear reducer are accommodated in parallel in a substantially rectangular parallelepiped case divided in two in a direction perpendicular to the rotation axis, and the output shaft of the gear reducer is placed on the center line of the short side of the case. , to configure substantially flush with the casing surface through the hollow shaft, the bulge can be thinned in the thickness direction of no casing, providing an output shaft of the reduction gear on the center line of the housing a short side, equipment The attachment workability to can be improved.
[0011]
Also, in the case where a screw portion is provided on one side of the housing and the screw portion is rotated to suppress the axial gap of each pinion shaft of the gear reducer, the shaft can be rotated by rotating the screw portion without disassembling the housing. The direction gap can be easily fine-tuned.
[0012]
In addition, with an oil seal that seals both ends of the output shaft of the gear reducer, oil does not leak from the output shaft of the geared motor even at high speed operation, and a geared motor with excellent reliability can be obtained.
[0013]
Furthermore, if it is used for high-speed positioning applications, it is not necessary to enlarge the gear reducer, and it is possible to obtain a geared motor with high positioning accuracy that is small, has a long life and is excellent in environmental resistance.
[0014]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0015]
1 and 2, reference numeral 1 denotes a substantially rectangular parallelepiped housing, which is composed of a gear cover 1a and a gear case 1b that are divided into two vertically, 2 is a servo motor, 3 is a gear reducer, and all gears are helical gears 4. It is composed. Reference numeral 5 denotes a pinion shaft, a two-stage pinion shaft 5a, a third-stage pinion shaft 5b, and hollow output shafts 5c and 6 penetrating the housing by the final-stage pinion shaft, ball bearings for rotatably supporting each pinion shaft 5; Is a thin plate shim for adjusting the axial gap of each pinion shaft 5, and 8 is an oil seal attached to both ends of the output shaft 5c.
[0016]
The rotation shafts of the servo motor 2 and the gear reducer 3 are arranged in a horizontal row parallel to each other, and are housed so as to be orthogonal to the dividing surface of the housing 1, and the gears are sequentially engaged to reduce the speed.
[0017]
Further, the output shaft 5c of the gear reducer 3 is disposed so as to be on the center line of the short side of the casing 1, and oil (not shown) is sealed in the casing 1 as lubricating oil for the gear surface.
[0018]
In this way, the rotation shafts of the motor and reducer are arranged in a horizontal row in the housing in parallel, and the gears are sequentially decelerated, so the thickness can be reduced in the thickness direction of the housing, and the center of the short side of the housing Since the penetrating hollow shaft is almost flush with the housing surface on the line, it can be symmetric with respect to the mounting side. Further, the casing is a substantially rectangular parallelepiped and does not protrude, so that it is easy to secure a mounting space and the mounting work can be facilitated.
[0019]
However, an axial gap is generated between each pinion shaft 5 of the gear reducer 3 housed in the housing 1 and the housing 1 due to the dimensional accuracy and assembly accuracy of each component. Even if the backlash between the tooth surfaces is suppressed by increasing the size of the gear and the processing accuracy, if there is this backlash in the axial direction, the backlash will appear as a backlash on the backlash, resulting in poor positioning accuracy.
[0020]
Therefore, in order to suppress axial backlash, the gear cover 1a and the pinion shafts 5 or the bearings 6 (the gear case 1b and the pinion shafts 5 or the bearings 6) are combined with several shims 7 having different thicknesses to form gears. The gear backlash of the speed reducer 3 is adjusted to 90 minutes or less to improve positioning accuracy. Further, by making all the gears into the helical gears 4, the meshing rate is 2 or more, and the impact force per sheet is reduced to ensure the long life of the gears and high reliability.
[0021]
As another method of suppressing the axial play, a screw portion 9 may be provided around the ball bearing 6 of each pinion shaft 5 of the gear cover 1a (or the gear case 1b). In this case, a recess for rotating the screw portion 9 is provided. If a plurality of 9a are provided, it is not necessary to disassemble the housing each time when adjusting the axial backlash, and the axial backlash can be easily finely adjusted from the outside simply by rotating the screw portion 9 in the recess 9a. .
[0022]
Even if the oil viscosity decreases due to the temperature rise of the gear reducer 3 due to the high-speed positioning operation, the oil seals 8 are provided at both ends of the output shaft 5c, so that oil leakage can be prevented, and the reliability is high. Can be used.
[0023]
Furthermore, if it is used for high-speed positioning applications, it is not necessary to enlarge the gear reducer, and a small geared motor with high positioning accuracy can be obtained.
[0024]
【The invention's effect】
As apparent from the above-described embodiment, according to the first aspect of the invention, the output shaft is configured on the center line of the short side of the casing and is substantially flush with the casing surface by the hollow shaft that penetrates (the configuration is bilaterally symmetrical). ), The mounting workability to the device can be improved, and there is no protrusion, and the thickness can be reduced in the thickness direction of the housing, so that the space saving and the mounting workability to the device can be improved. By making all gears into helical gears, the meshing rate can be improved and the impact force per sheet can be reduced, and the life of the gears can be extended. Moreover, the positioning accuracy as a geared motor can be improved by suppressing the axial gap of the helical gear.
[0025]
Further, if a screw portion having a plurality of recesses is provided around the bearing of each pinion shaft on one side of the housing, the axial gap of the helical gear can be easily finely adjusted from the outside.
[0026]
Thus, a geared motor that is small, easy to handle, excellent in reliability, and high in positioning accuracy in high-speed operation can be obtained.
[Brief description of the drawings]
FIG. 1 is a sectional view of a geared motor according to an embodiment of the present invention. FIG. 2 is a detailed plan view of a screw portion according to the present invention.
1, 1a, 1b Housing (Gear cover, Gear case)
2 Servo motor 3 Gear reducer 4 Hasuba gear 5, 5a, 5b, 5c Pinion shaft (2-stage pinion shaft, 3-stage pinion shaft, output shaft)
8 Oil seal 9 Screw part

Claims (1)

The rotary shafts of the servomotor and gear reducer are housed in parallel in a substantially rectangular parallelepiped case divided in two in a direction perpendicular to the rotation axis, and the output shaft of the gear reducer passes through the center line of the short side of the case. The hollow shaft is almost flush with the housing surface, and all gears of the gear reducer are made of helical gears to reduce the axial clearance of each pinion shaft of the gear reducer and reduce gear backlash. A geared motor characterized by enabling left-right symmetrical mounting .

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