RU2683587C1 - Built into electric motor magnetic gearbox - Google Patents

Abstract

FIELD: electrical equipment.SUBSTANCE: invention relates to the electrical equipment, to the magnetic non-contact planetary gear reducers intended for driving of actuators and devices with the simultaneous rotation frequency reduction. Built into the electric motor magnetic planetary gearbox includes housing, stationary and movable central gear wheels made of magnetically soft materials, carrier, eccentrically located gear satellite of magnetically soft material, bearings, support surfaces, against which the satellite is resting, the central wheels and the satellite toothed surfaces are made with the same pitch, the difference between the number of teeth of the satellite and the number of teeth of the central wheels is minimal. Magnetization system is made in the form of a permanent magnet or excitation winding with the axial biasing. Central wheels are made with two gear rims with external teeth, equal to the number of teeth integral with the output shaft, which are installed in the housing with the ability to perform rotational movement. Support surfaces are located on the central wheel, the mating support surfaces are made on the satellite. Satellite is made with two gear rims internal teeth with equal numbers of teeth with a minimum difference in the number of teeth from the number of teeth on the central wheels, is placed in the housing with the ability to perform the axis plane-parallel movement relative to the central wheels without rotation relative to its own symmetry.EFFECT: technical result consists in reduction of the axial dimensions.1 cl, 1 dwg

Description

FIELD OF THE INVENTION

The invention relates to electrical engineering, in particular to magnetic non-contact planetary gearboxes designed to drive actuators and devices with simultaneous reduction of the rotational speed.

State of the art

Known are contactless magnetic planetary gearboxes for driving actuators with simultaneous reduction of the rotational speed, comprising a housing, fixed and movable gear central wheels made of soft magnetic materials, a carrier, an eccentrically arranged gear satellite made of soft magnetic material, a magnetization system in the form of a permanent magnet or an excitation winding with axial magnetization , magnetic circuit, counterweights, bearings, bearing surfaces for stellite (Antenna drive mechanism. Description a certificate of invention No.301749 IPC H02Q 1/12, Bulletin No. 14 04/10/1971; magnetic planetary gear shown in Fig. II.26 p. 140 of the book “Mechanisms with magnetic coupling.” L., “Engineering” (Leningradskoe department), 1973. Aut.: Ganzburg LB et al., Electromagnetic planetary gearbox, shown in Fig. p. II.27 on p. 140 in the same place).

In such gearboxes, the magnetic flux of the magnetization is closed not only through the working gap between the gear surfaces of the satellite and the central wheels, but also through an additional magnetic circuit between the housing and the movable central wheel. This circumstance leads to a decrease in the magnetic conductivity of the magnetic circuit of the gearbox, an increased consumption of active materials (permanent magnet, winding copper, magnetically soft material, etc.), and, as a result, an increase in mass and overall dimensions, and also worsens the specific energy performance of the gearboxes, such as torque, braking torque, maximum torque, etc.

Also known is a magnetic planetary gearbox comprising a housing, fixed and movable gear central wheels made of soft magnetic materials, a carrier, an eccentrically arranged gear satellite made of soft magnetic material, a magnetization system in the form of a permanent magnet or an excitation winding with axial magnetization, a magnetic circuit, bearings, bearing surfaces for the satellite , the mating supporting surfaces on which the satellite rests are made in the housing, the gear surfaces of the central wheel and the satellite are made with the same pitch, the central wheels with equal numbers of teeth are mounted motionless in the housing (on the stator), the satellite is made with two gear crowns with equal numbers of teeth with a minimum difference in the number of teeth from the number of teeth on the central wheels and is connected to the output shaft through a device capable of transmit misaligned rotational movement, for example, through an articulated device (RU 2545509 C2, 04/10/2015) (prototype).

The disadvantages of this device is the need for an additional device that can transmit misaligned rotational motion and the associated significant geometric dimensions of the gearbox in the axial direction.

Disclosure of invention

The objective of the invention is to reduce the axial dimensions of the planetary magnetic gear.

This is achieved by the fact that, in contrast to the known technical solution, the central wheels are made with two gear rims with external teeth with equal numbers of teeth and with the same pitch along with the output shaft, which are installed in the housing with the ability to rotate, the satellite is made with two gear rims external teeth with equal numbers of teeth and with the same pitch equal to the tooth pitch on the central wheels with a minimum difference in the number of teeth from the number of teeth on the central wheels, supporting surfaces, with the possibility to make a plane-parallel movement relative to the central wheels response abutment surfaces arranged at the satellite,

Description of drawings

The drawing shows a longitudinal section of the active part of the proposed magnetic gear.

The implementation of the invention

The proposed magnetic planetary gearbox is mounted in the design of the electric motor 1 and placed on the intermediate flange of the electric motor 2 under the cover 3. It contains a central wheel made integral with the output shaft 4 with two gear crowns with external teeth with equal numbers of teeth and with the same pitch t _z of soft magnetic material with the number of teeth Z1 and a cylindrical undercut, on which the satellite rests. The central wheel rests on the bearings 5 in the cover 3.

The satellite is assembled in a non-magnetic casing 6 and is composed of two gear rims of soft magnetic material in the form of a hollow cylinder 7 with internal teeth with the number of teeth Z2 with the same pitch t _z , a permanent magnet 8 with axial magnetization between them. At the ends of the satellite through non-magnetic rings 9 are placed supporting surfaces 10, through which the satellite is supported by mating cylindrical recesses on the central wheel. A protrusion with a rectangular protrusion (boss) is made at the end of one of the supporting surfaces (Fig. To the right), which enters the reciprocal recess in the crosspiece 11 with a sliding fit. The crosspiece 11, in turn, has a rectangular protrusion in the diametrical direction from the side opposite to the recess, directed perpendicular to the direction of the recess. This protrusion, in turn, is included in the recess, made in the diametrical direction in the intermediate flange of the motor 2.

The planetary carrier has a rolling support 12 mounted on the output shaft of the electric motor through an eccentric sleeve 13.

The gearbox operates as follows. The magnetic flux of permanent magnets is closed along the magnetic circuit formed by two gear rims of the satellite from magnetically soft material, an air gap between the gear rims of the central wheel and the satellite. In this case, under the action of the attractive forces of the gear surfaces of the central wheel and satellite, due to the magnetic field of the permanent magnet, the satellite is in an eccentric position with an eccentricity e, determined by the dimensions of the outer diameter of the rolling bearings d ₁ (cylindrical grooves on the central wheel and the diameter of the supporting surfaces on the satellite d _2. Recent designed in such a way that remained guaranteed δ air gap _E between the surfaces of the central wheel and satellite . Because the facing serrated surfaces are arranged eccentrically, the main part of the magnetic flux would be concentrated in the area of the minimum air gap δ _min. The dimensions of the air gap δ _min, the eccentricity e, the diameters of bearings d ₁ and d _2, the number of teeth and pitch gear surfaces on the satellite and central wheels must satisfy the relations:

e = (d ₂ -d ₁ /) 2;

δ _min = (Z2-Z1) t _z / 2π-e.

The value of δ _{min is} taken within 0.1 ... 0.15 mm. The interaction of the magnetic flux of the gear surfaces of the satellite and the central wheels determines the force action between them. When the carrier is stationary, the satellite is in an eccentric position relative to the central wheels, because has two degrees of freedom relative to the intermediate flange of the electric motor 2 due to the sliding fit between mutually perpendicular protrusions and recesses on the satellite, the cross and the intermediate flange. The interaction of the gear surfaces of the satellite and the central wheel through the forces of magnetic attraction causes a braking moment on the output shaft of the magnetic gearbox, because the satellite cannot rotate about its axis of symmetry. (The said protrusions and recesses keep the satellite from rotational movement). When the carrier rotates, due to the difference in the number of teeth of the gear surfaces on the central wheel, the central wheel will rotate about its axis at a speed determined by the ratio:

n = n _water (Z2-Z1) / Z1,

where n is the rotation speed of the central wheel, rpm

n _water - carrier rotation speed, rpm

Thus, in the proposed device there is a reduction in the rotation speed of the carrier i = Z1 / (Z2-Z1) times.

To ensure the rotation conditions of the central wheel without slipping relative to the supporting surfaces on the satellite, the number of teeth on the central wheel and the satellite should be connected with the diameters by the ratio:

e / d ₁ = (Z2-Z1) / Z1;

d ₂ = d ₁ + 2e.

The rotation of the central wheel without slipping relative to the supporting surfaces on the satellite can be achieved by placing between the supporting surfaces of the rolling bearings. However, there is no need to comply with the above ratios between the numbers of gear teeth and the geometric parameters of the bearing surfaces.

In the proposed magnetic gearbox, in contrast to the known one, there is no additional device capable of transmitting non-coaxial rotational motion having significant dimensions in the axial direction. Thus, the proposed device in comparison with the known ceteris paribus has smaller overall dimensions in the axial direction.

Claims (1)

A magnetic planetary gearbox built into an electric motor containing a housing, fixed and movable gear central wheels made of soft magnetic materials, a carrier, an eccentrically arranged gear satellite made of soft magnetic material, a magnetization system in the form of a permanent magnet or an excitation winding with axial magnetization, bearings, bearing surfaces, on which are supported by the satellite, the gear surfaces of the central wheels and the satellite are made with the same pitch, the difference between the number of teeth of the satellite and the number of teeth The number of teeth of the central wheels is minimal, characterized in that the central wheels are made with two gear rims with external teeth equal to the number of teeth at the same time with the output shaft, which are installed in the housing with the ability to rotate, the supporting surfaces are placed on the central wheel, the mating supporting surfaces are made on satellite, the satellite is made with two gear rims with internal teeth with equal numbers of teeth with a minimum difference in the number of teeth from the number of teeth on the central stake ah is arranged in the housing with the possibility to make a plane-parallel movement relative to the central axis of the wheel, without rotation about its own symmetry.

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