JPH0678494A - Motor - Google Patents

Abstract

PURPOSE:To provide a motor in which rotation is converted to linear motion to be used by providing a screw member in a sleeve shaft and using the shaft formed with a spiral groove in the inner periphery as a motor shaft. CONSTITUTION:A rotor 4 is forwardly or reversely rotatably supported in a cylindrical motor case 3. A shaft 5 is of a sleeve shape with a spiral groove 5a directed axially in an inner periphery, and the rotor 4 is rotated in a predetermined direction by energizing a coil 8. A screw member 11 in which a spiral protrusion 11a is so formed on the outer periphery as to be engaged with the groove 5a is provided, and a body to be driven is moved to a predetermined position as the shaft 5 is forwardly or reversely rotated. That is, since the interior of a motor is used without necessity of a motion converting mechanism provided outside the motor which has been heretofore required, the motor can be reduced in size, weight, cost and noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor structure suitable for converting rotary motion of a motor shaft into linear motion for use.

[0002]

2. Description of the Related Art In modern times, a motor is used as a power source for many electric devices which require rotary motion or linear motion regardless of its size. The usage of the motor is roughly classified into a method in which the rotation of the motor shaft is transmitted to the rotated body through a gear train or the like as the rotational force and the rotated body is rotated, or the rotation of the motor shaft is a worm gear or a rack and pinion. There is known a method of converting into linear (reciprocating) motion by a conversion mechanism such as the above and using it. For example, in the latter usage, it is effectively used as a mechanism that linearly moves a driven body forward and backward within a predetermined range, such as a mechanism that electrically moves up and down the window glass of an automobile or the like to open and close it. There is.

Conventionally, such as opening and closing the window glass of an automobile,
As a mechanism for linearly moving the driven body forward and backward, a worm gear is fixed to the tip of the motor shaft, and the rotational movement of the motor shaft is almost perpendicular to the motor shaft via the worm that cooperates with this worm gear. A mechanism for converting into a linear motion in a direction is known.

[0004]

In such a conventional mechanism, it is necessary to provide a mechanism, such as a worm and a worm gear, for converting the rotation of the motor shaft into the linear motion of the driven body, separately from the motor itself. Therefore, downsizing and cost reduction of the entire device including such a mechanism cannot be achieved. Further, when the conversion mechanism is formed on the outside in this way, there is a problem in soundproofing that noise is relatively likely to be generated such as a meshing sound of gears of the conversion mechanism.

[0005]

The present invention has been made in view of the above points, and a sleeve shaft having a spiral groove extending in the axial direction on an inner peripheral surface thereof is used as a motor shaft, and the spiral shaft is provided in the sleeve shaft. A screw member that engages with the groove and that moves forward and backward in the axial direction inside the sleeve shaft in accordance with the forward and reverse rotation of the sleeve shaft is provided.

[0006]

By such means, when the motor is biased and the motor shaft, that is, the sleeve shaft rotates in either forward or reverse direction, the screw member arranged inside the shaft engages with the spiral groove of the sleeve shaft. To move in either the forward or reverse axial direction. The length of movement of the shaft in the axial direction can be easily controlled by controlling the energizing time of the motor.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 indicates a motor capable of rotating in the forward and reverse directions according to the present invention, and a rotor 4 has a pair of shafts 5 thereof in a cylindrical motor case 3 in which an end opening 1a is closed by an end plate 2. It is provided by being rotatably supported by a proper bearing 6 so as to be rotatable in the forward and reverse directions. The shaft 5 has a sleeve-like shape (hereinafter referred to as a sleeve shaft) which is hollow in the axial direction and has a spiral groove 5a extending in the axial direction on the inner peripheral surface thereof. The several cores 7 are fixed at substantially equal angular intervals. The spiral groove means a thread groove or a groove formed by forming a concave portion or a convex portion in a spiral shape, and a member engaged with the groove as the shaft 5 rotates is the shaft 5
A groove having a shape that receives a moving force in the axial direction. A commutator 9 is fixed to the shaft 5 in parallel with the core 7. The commutator 9 is electrically connected to the coil 8, and an electric brush (not shown) arranged in contact with the commutator 9 applies an alternating current to the coil 7 via the commutator 9.

On the other hand, an annular magnet (or a magnet in which a plurality of magnet pieces divided in half or the like are arranged in a substantially annular shape) 10 is fixed to the inner peripheral surface of the motor case 3 so as to face the outer peripheral surface of the rotor 4. Has been done. The magnet 10 has magnetic poles of different polarities arranged alternately in the angular direction, and rotates the rotor 4 in a predetermined direction in cooperation with electromagnetic waves of alternating polarities formed in the rotor 4 by energizing the coil 8. The configuration relating to the rotation of these magnets and rotors may be the same as the configuration of a conventionally known motor.

As described above, the spiral groove 5a is formed on the inner peripheral surface of the sleeve shaft 5 so as to form a thread-like projection and depression in the axial direction. The spiral projection is formed so as to mesh with the spiral groove 5a. A member for forming an outer peripheral surface 11a (referred to as a screw member for convenience of description) 11
Are provided so as to be movable in the shaft 5 in the axial direction in the forward and reverse directions. In the illustrated example, the protrusion 11a of the screw member 11 is formed over substantially the entire length in the axial direction of the screw member 11, but may have a length that partially engages with the spiral groove 5a on the inner peripheral surface of the shaft 5. . The screw member 11 is supported by a thrust bearing or the like (not shown) so as to be rotatable in the forward and reverse directions and movable in the axial direction. For example, by directly or indirectly connecting the driven body to be linearly moved to the tip of the screw member 11, the driven body can be linearly moved according to the movement of the screw member 11.

In this manner, the screw member 11 can be appropriately moved in the forward and reverse directions according to the forward and reverse rotations of the shaft 5 to move the driven body to a predetermined position. The degree of movement of the screw member (or the moving position)
Can convert the number of rotations of the shaft 5 into a pulse by a pulse generating means such as a Hall element, and count the number of pulses to turn on / off the motor to control, and the screw member 11 for one rotation of the shaft 5 can be controlled. The moving distance of can be arbitrarily set by changing the pitch ratio of the shaft 5 to the spiral groove 5a. The motor is a stepping motor,
It is not particularly limited as long as it is a motor capable of on / off control such as a pulse motor.

[0011]

As described above, according to the present invention, by rotating the motor forward and backward, the screw member inside the motor is directly linearly moved in the forward and reverse directions, and the driven member is connected to the screw member to drive the screw member. It is possible to easily obtain a linear motion of the body. According to such a motor according to the present invention, since the motion conversion mechanism outside the motor which is conventionally required is not required and the inside of the shaft of the motor is used, it is possible to reduce the size and weight of the device, reduce the cost, and reduce the cost. Noise reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a motor according to the present invention.

[Explanation of symbols]

 1 Motor 4 Rotor 5 Shaft 6 Bearing 11 Screw

Claims (1)

[Claims] 1. A sleeve shaft having a spiral groove formed in the inner peripheral surface in the axial direction is used as a motor shaft, and the spiral groove is engaged with the inside of the sleeve shaft. A motor provided with a screw member that moves forward and backward in the axial direction.