RU2571313C1 - Reduction motor - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: electric motor contains the housing which accommodates the stator, a rotor and the planetary and lantern reducer. The rotor of the electric motor is an input shaft of the reducer on the ends of which two coaxial eccentric sections are formed. On the named sections the reducer pinions are installed, while the space between pinions is used for the stator accommodation.

EFFECT: electric motor has high efficiency, small overall dimensions, high bearing ability and durability, and also has high precision of positioning or rotation of the output shaft.

4 cl, 2 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to drive devices, and more particularly to a gear motor (gear motor). The present invention is applicable in mechanical engineering, in particular as a drive for links of robotic devices, control elements of hydraulic systems, actuators, as well as in the field of instrumentation.

BACKGROUND

The use of geared motors has become widespread in industry. The creation of modern machines and devices requires the use of geared motors that meet the highest requirements of efficiency, accuracy, reliability and efficiency. Some industries, such as instrumentation and robotics, are particularly in need of high-precision rotary electric motors with small overall dimensions and a long service life.

From the patent source US 4620796 (IPC index A47J 43/04) a gear motor for a household mixer is known. The specified electric motor contains a drive that has an output shaft with a gear wheel mounted on it, connected to two other gear wheels mounted in series with each other with the formation of a linear gear. The rotation of the output shaft through the gears is transmitted to the drum holding the nozzle of the mixer. The disadvantage of such a gear motor is the large overall dimensions, short service life, low gear ratio and large friction losses.

From a patent source US 5631511 (IPC index F16H 1/32) a two-speed gear motor is known. The specified electric motor contains a housing, a stator located in the specified housing, and a hollow rotor mounted for rotation in the stator and connected to the flange. The flange is connected to the gearbox, formed by gears sequentially placed one after another (in-line gearbox), as well as the first electromagnetic clutch, the drive part of which is connected to the output shaft of the rotary electric motor. The second electromagnetic clutch is connected directly to the specified output shaft. The disadvantages of such a gear motor are low reliability and low bearing capacity, as well as a low gear ratio and large friction losses in gearing of gears.

From a patent source SU 1754990 (IPC index F16H 1/48) a gear motor is known for use in servo drives of aircraft products, which has a housing with an electric motor and gear set in it. The specified gearbox is made in the form of a planetary gearbox type 2K-N. The electric motor contains a stator, fixedly connected to the housing, and a rotor, which is mounted on the hub with the possibility of rotation relative to the stator. On the specified hub, the central (solar) wheel of the planetary gearbox is made. The planetary gearbox also contains an external gear wheel fixedly mounted in the motor housing, and satellites mounted for rotation relative to the central (solar) wheel and the outer wheel of the planetary gearbox. In addition, the planetary gear contains a carrier connected to the satellites with the possibility of transmitting their rotation to the output shaft of the gear motor. The disadvantages of the specified gear motor include a short service life and low bearing capacity. In addition, the specified motor has a high noise level during operation.

The closest analogue to the claimed gear motor is a gear motor of the output rotary device manufactured by Nabtesco Corporation (JP), in accordance with the patent source US 7988581 (IPC index F16H 1/32). The specified electric motor contains a housing, as well as a motor and a planetary-pinion gear (gearbox type K-H-V). The motor shaft through a system of gears is connected to the eccentric input shaft of the gearbox with the possibility of transmitting rotation. Satellites are mounted on the eccentric shaft adjacent to each other. When the eccentric shaft rotates, the satellites perform plane-parallel motion and interact with the cylindrical surfaces of their radially arranged holes with their fingers, which ensure the transmission of torque from the satellites to the output shaft of the gearbox. Thus, the rotation of the output link of the rotary device with reduced speed. However, such a gear motor is also not without drawbacks, among which are low reliability and large overall dimensions. In addition, the manufacture of the eccentric shaft is carried out in a complex multi-stage method using high-precision equipment, which increases the complexity of manufacturing such a gear motor.

Thus, there is a need for a gear motor that is easy to manufacture, has a compact size and provides a large gear ratio.

SUMMARY OF THE INVENTION

The objective of the present invention is to provide a reliable gear motor with high bearing capacity, smoothness, as well as with high accuracy of positioning or rotation.

This problem is solved by the proposed gear motor, which contains a housing, a stator, which is fixedly mounted in the housing, a rotor, which is rotatably mounted in the housing, and a gearbox, which is placed in the housing with the possibility of transmitting rotation from the rotor to the output shaft. In the proposed electric motor, the rotor has at least two eccentric cylindrical sections, and the gearbox contains at least two satellites that are rotatably mounted on these eccentric sections of the rotor and in which through holes of the satellites are made, at least two sprocket wheels that are fixedly mounted in the housing with the possibility of interaction with satellites, bearing fingers that pass through the specified holes of the satellites and are installed in these holes with the possibility of ne roll along their inner surface and transmit forces from the satellites, and the gear shaft, which is mounted in the housing with the possibility of rotation and forms a fixed connection with the specified carrier fingers. In the proposed electric motor, the rotor is mounted on the gearbox shaft with the possibility of rotation relative to this shaft, and these eccentric cylindrical sections of the rotor are made coaxial. The technical result achieved by the proposed gear motor is to simplify the design and increase the mechanical efficiency. In addition, the proposed motor provides a large number of gear ratios of the gearbox and a smooth stroke of the output shaft with high accuracy of its positioning or rotation.

According to one particular embodiment, the gear satellites are mounted at the ends of the rotor. The location of the satellites at the ends of the rotor can further reduce the diametrical size of the electric motor and make it more compact.

According to another particular embodiment, the output shaft of the gearbox is hollow and has an internal thread. The thread profile can be special, trapezoidal or triangular. The execution of the output shaft hollow provides the possibility of placing inside the shaft of the electric cable, pneumatic or hydraulic lines for transmission from the stationary part of the product to the rotary, and the internal thread allows you to connect the proposed gear motor with a roller screw transmission and integrate them into the product to ensure conversion of the rotational motion of the output the shaft of the electric motor in the translational motion of the output link of the roller-screw transmission without increasing the dimensions whom products in the axial direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is one of the preferred embodiments of the present invention, and for clarity, the description of such an option has links to the accompanying drawings, in which:

FIG. 1 shows a main sectional view of one of the embodiments of the proposed electric motor, indicating the main components, and

FIG. 2 shows a quarter sectional view along line AA shown in FIG. one.

The images shown in the drawings are made to scale, as a result of which the aspect ratios of the given parts are reliably reproduced.

DETAILED DESCRIPTION OF THE INVENTION

According to one of the preferred embodiments, the geared motor 1 comprises a housing 2, a stator 3, which is installed in the housing 2 using adhesive bonding, a rotor 4, which is rotatably placed in the stator 3. Permanent magnets M are placed around the perimeter of the central part of the rotor 4. The housing 2 is made of separate sections interconnected to form a single structure. The electric motor 1 also includes a planetary-pinion gearbox, the input shaft of which is the rotor 4. The rotor 4 is a hollow shaft with coaxial eccentric sections made at the ends 5. Bearings 6 are placed on the eccentric sections 5, on which the satellites 7 are mounted. In this case, the eccentric sections 5 satellites 7 are located at a distance from each other, forming a space for installing the stator 3. Thus, the compact arrangement of the stator 3 electric motor spruce 1 and reduce its transverse (diametrical) size. The peculiarity of the performance of the satellites 7 is that they have a cylindrical cavity with a diameter comparable to the diameter of the satellite in which the bearings are installed 6. Thus, it is possible to install more durable bearings of a larger size without increasing the transverse overall dimension of the housing 2. Installing larger bearings allows you to increase the bearing capacity and durability of the electric motor 1. In addition, the use of two coaxial eccentric sections 5 significantly reduces t vibration during operation of the electric motor 1, since it allows to avoid the formation of a pair of centrifugal oppositely directed forces and as a consequence of the unbalanced moment of such a pair of forces. The alignment of the sections 5 allows to simplify the manufacture of the rotor 4, since the manufacture of such sections can be carried out in one technological operation.

The output shaft 10 of the electric motor is installed in bearings 8, 9, which provide the possibility of rotation of the shaft 10 relative to the housing 2. The rotor 4 is mounted on the shaft 10 in the bearings 11, which allows mutual rotation of the rotor 4 and the output shaft 10. Bearings 11 to further reduce the diametrical overall the size of the electric motor 1 can be made in the form of needle bearings. To facilitate the design, the output shaft 10 is hollow, while electric cables of a pneumatic or hydraulic line (not shown) can transit in the cavity of the output shaft 10. On the output shaft 10, the flanges 12 are fixedly mounted with the cylindrical fingers 13 of the gearbox fixed in them. The fingers 13 are located around the circumference and interact with the satellites 7, in particular, they pass into the cylindrical holes of the satellites 7 with the possibility of rolling along the inner surface of these holes. The housing 2 has cylindrical sections 14, 15, in which recesses are made for the lobes 16, forming the sprocket wheel of the planetary sprocket gearbox of the electric motor 1. The electric motor 1 also contains sections 18, 19 of the housing 2, in which the bearings 8, 9 of the output shaft 10 are indicated sections 18, 19 are attached to sections 14, 15 of the housing 2. Bearings 8, 9 on the output shaft 10 are fixed from axial movement by nuts 24. The electric motor 1 also includes covers 26, 27. There are seating surfaces in the covers 26, 27 and on the output shaft 10 under seal 30. Seal Nia seal 30 allow the inner space of the motor 1, excluding penetration of liquids, dirt and dust. In some cases, using a suitable seal, the motor 1 may operate under water. The elements of the housing 2 are pulled together by screws and studs, centered on each other in diameter, and their relative angular position relative to each other is provided by centering fingers (not shown). The output shaft 10 has internal slots (not shown) on which a pulley 31 is mounted for fastening to the external device driven by the electric motor 1. According to other embodiments, the output end of the shaft 10 may be solid or hollow, may have a key, splines, and may also have a square cross section or a hexagonal cross section. The specified shape of the output end can be any, and its features are determined only by the mating connecting part of the external device driven by the electric motor 1.

The proposed electric motor operates as follows.

An electric current is supplied to the stator windings 3 via electric cables, as a result of which a rotating magnetic field of the stator is formed. This rotation leads to a corresponding rotation of the rotor 4, the magnetic field of which rushes behind the rotating magnetic field of the stator. The rotation of the rotor 4 leads to the movement of the satellites 7. The satellites 7 are rolled along the sprocket wheel formed by the sprockets 16 and perform plane-parallel movement. When the satellites 7 roll over the sprocket wheel, their inner cylindrical surfaces transmit the force by the cylindrical surfaces of the fingers 13. Such a transfer of force causes the fingers 13 and the shaft 10 to be fixedly connected to them around the central axis of the shaft. Thus, the rotation of the rotor 4 through the satellites 7 and the fingers 13 is transmitted to the output shaft 10. On the output shaft 10 can be installed the input link of another device, for example a nut of a screw-screw transmission, for which a thread can be made on the inner surface of the shaft 10, so that the rotation of the shaft 10 can then be converted into translational movement.

The proposed motor has a high efficiency, has a compact design, high accuracy of positioning or rotation of the output shaft and a long service life. The proposed motor also has more favorable economic characteristics, since at a sufficiently high efficiency, cost reduction is achieved, which is achieved by integrating the stator and rotor into the motor housing, eliminating additional rotor bearings, a coupling and reducing the total number of parts, as well as due to structural simplification and reduce requirements for precision manufacturing of parts included in the electric motor.

In conclusion, it should be noted that the given embodiment does not describe all possible embodiments of the proposed electric motor, and the requested scope of legal protection is limited solely by the attached claims.

Claims (4)

1. A gear motor that contains
motor housing
a stator which is fixedly mounted in said housing,
a rotor that is rotatably mounted in the stator,
the gearbox, which is placed in the specified housing with the possibility of transmitting the rotation of the rotor, and
the rotor has at least two eccentric cylindrical sections,
and the gearbox contains
at least two satellites which are rotatably mounted on said eccentric portions of the rotor and in which through holes of the satellites are made,
at least two sprocket wheels, which are fixedly mounted in the housing in cooperation with the satellites,
bearing fingers that pass through the indicated holes of the satellites and are installed in these holes with the possibility of rolling along their inner surface and with the possibility of transmitting force from the satellites, and
the gearbox shaft, which is mounted in the housing for rotation and forms a fixed connection with the specified bearing fingers,
moreover, the rotor is mounted on the gearbox shaft with the possibility of rotation relative to this shaft, and these eccentric cylindrical sections of the rotor are made coaxial. 2. The electric motor according to claim 1, wherein said satellites are mounted at the ends of the rotor. 3. The electric motor according to claim 1, in which the gear shaft is hollow and has an internal thread. 4. The electric motor according to claim 3, in which the specified internal thread has a special, trapezoidal or triangular profile.

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