Hybrid step motor

A hybrid step motor comprises a stator, a rotor assembly, a magnet and a mandrel. The rotor assembly and the magnet are mounted on the mandrel and are disposed in the stator. The proportion of a stator outer diameter to a stator inner diameter is 1:0.475 to 1:0.6. The proportion of the stator outer diameter to a rotor outer diameter is 1:0.5125 to 1:0.5875. The proportion of a first rotor thickness to a magnet thickness to a second rotor thickness is 0.236:0.09:0.236 optimally. The proportion of the rotor outer diameter to a magnet outer diameter is 0.54:0.45. By such arrangements, the optimal proportion is formed and the output efficiency is improved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a step motor which rotates by using magnetic field and electricity, and more particularly to a hybrid step motor which has low iron loss and high output efficiency with scaled inner and outer diameters of stator, rotor assembly and magnet under the condition that silicon steel sheets are unsaturated.

2. Description of the Prior Art

Many products are provided with a motor which is mainly provided for driving the structure to rotate, so as to control the continuous rotation, or angle change, or even the extension and positioning of the length of the structure. The quality of the motor lies on the proportion of an input power to an output efficiency, however, the size of the stator, rotor assembly and magnet of the current motor is unstandardized, and the specifications of the motors manufactured by the manufacturers are usually made according to the performance and convenience of processing, or integer. As a result, the efficiencies of such motors are different, and the specifications are not optimal, so that such motors have low efficiency and large iron loss, and will waste energy, or even a larger motor is needed to finish the same work, so that the cost is relatively high.

The present invention is an improved hybrid step motor which comprises a stator, a rotor assembly and a magnet, and the rotor assembly is disposed in the stator after clipping the magnet.

Therefore, finding a step motor which utilizes the smallest input power to produce the largest output efficiency so as to reduce iron loss has become an important issue for the manufacturers.

SUMMARY OF THE INVENTION

The technical problems that needed to be solved:

The size of the stator, rotor assembly and magnet of the conventional hybrid step motor is unstandardized and unscaled, the efficiencies of the motors manufactured by the manufacturers are different, and the specifications are not optimal, so that such motors have low efficiency and will waste energy.

The technical characteristics for solving the problems:

The present invention provides a hybrid step motor which comprises a stator, a rotor assembly, a magnet and a mandrel. The rotor assembly and the magnet are mounted on the mandrel and are disposed in the stator. The proportion of a stator outer diameter of the stator to a stator inner diameter is 1:0.475 to 1:0.6, for example, when the stator outer diameter is 55 mm, the stator inner diameter is 30.4398 mm. The proportion of the stator outer diameter to a rotor outer diameter is 1:0.5125 to 1:0.5875, for example, when the rotor outer diameter is 29.945 mm, a first rotor length is 13 mm, and a second rotor length is 13 mm. The proportion of the first rotor thickness to a magnet thickness to the second rotor thickness is 0.236:0.09:0.236 optimally, for example, when the first thickness and second rotor thickness are 13 mm, the magnet thickness is 5 mm. In addition, the proportion of the rotor outer diameter to a magnet outer diameter is 0.54:0.45, for example, when the rotor outer diameter is 29.945 mm, the magnet outer diameter is 25 mm. By such arrangements, the optimal proportion is formed and the output efficiency is improved.

The advantages of the present invention compared with the prior art:

The scaled stator outer diameter, stator inner diameter, rotor thickness, rotor outer diameter, magnet outer diameter and magnet thickness of the stator, rotor assembly and magnet can obtain the best specification configuration, and can improve the output efficiency and reduce iron loss.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 1-6, a hybrid step motor in accordance with the present invention comprises a stator10, a rotor assembly20, a magnet30and a mandrel40.

The stator10is formed with a stator outer diameter11having a magnetic space12. In a periphery of the magnetic space12is provided a plurality of stator poles13that are spaced at intervals, and inner peripheries of the stator poles13form a stator inner diameter14. The proportion of the stator outer diameter11to the stator inner diameter14is 1:0.475 to 1:0.6, the error is ±0.0375 mm, and the proportion of the stator outer diameter11to the stator inner diameter14is 1:0.55 optimally. When the stator outer diameter11is 55 mm, the stator inner diameter14is 30.4398 mm.

The rotor assembly20comprises a first rotor20A and a second rotor20B which are made of silicon steel sheets and are round-shaped. The rotor assembly20is formed with a rotor outer diameter21. The first rotor20A is formed with a first rotor thickness22A along the axial direction, and the second rotor20B is formed with a second rotor thickness22B along the axial direction. The first and second rotors20A and20B are mounted on the mandrel40and are disposed in the magnetic space12of the stator10. The proportion of the stator outer diameter11to the rotor outer diameter21is 1:0.5125 to 1:0.5875, the error is ±0.0375 mm, and the proportion of the stator outer diameter11to the rotor outer diameter21is 1:0.54 optimally. The rotor outer diameter21is 29.945 mm, the first rotor thickness22A is 13 mm, and the second rotor thickness22B is 13 mm.

The magnet30is formed with a magnet outer diameter31and is axially formed with a magnet thickness32along the axial direction. The magnet30is mounted on the mandrel40and is located between the first rotor20A and the second rotor20B. The proportion of the first rotor thickness22A to the magnet thickness32to the second rotor thickness22B is 0.236:0.09:0.236 optimally, and the error is ±0.0375 mm. When the first rotor thickness and second rotor thickness22A and22B are 13 mm, the magnet thickness32is 5 mm. In addition, the proportion of the rotor outer diameter21to the magnet outer diameter31is 0.54:0.45, and the error is ±0.025 mm. When the rotor outer diameter21is 29.945 mm, the magnet outer diameter31is 25 mm.

The mandrel40is provided for mounting the rotor assembly20and the magnet30, and making the rotor assembly20and the magnet30receive in the magnetic space12of the stator10.

By the above-mentioned structure, the present invention has the following advantages: the scaled stator10, rotor assembly20and magnet30can obtain the best specification configuration, and low iron loss can improve the output efficiency and save energy.