Motor

Abstract

The invention provides a motor which comprises a shell, a motor shaft which is accommodated in the shell and partially extends out of the shell, a stator fixedly connected to the shell and a rotor fixedly connected to the motor shaft, and the motor shaft comprises a first end part accommodated in the shell and a second end part extending out of the shell. The shell comprises a main body part and a cover plate which covers the main body part and is close to the first end part of the motor shaft, the motor shaft is of a hollow structure and comprises an accommodating cavity, the motor further comprises a magnetic ring at least partially accommodated in the accommodating cavity and a signal acquisition device which is fixedly arranged on the cover plate and is opposite to the magnetic ring, and the rotor drives the motor shaft and the magnetic ring to rotate. The signal acquisition device determines the motion position of the rotor by identifying the magnetic field position signal provided by the magnetic ring, the motor is more compact in structure, and the axial length of the motor is effectively shortened.

Description

Technical field

[0001] The present invention relates to the field of motors, and in particular to a brushless motor. [Background Technology]

[0002] The rapid development of the artificial intelligence and robotics industries is placing stricter demands on motors due to space and energy efficiency requirements. Motors are moving towards higher integration, smaller size, higher load capacity, and faster response. In existing brushless motors, when current flows through the stator coil, a rotating magnetic field is formed. The permanent magnets in the rotor are acted upon by this rotating magnetic field, generating a rotational torque in the direction of the magnetic field, which in turn drives the rotor to rotate, thus achieving motor operation.

[0003] However, the motor of the prior art has a rotating encoding magnetic ring to provide a magnetic field position signal, so that the rotary encoder can identify the relative position between the motor stator and rotor, thereby realizing the electronic commutation of the motor. The rotating encoding magnetic ring for providing the motor rotor position is directly fixed to the outside of the central axis of the motor, which increases the axial length of the motor.

[0004] Therefore, it is necessary to provide a new motor to solve the above technical problems. [Summary of the invention]

[0005] The object of the present invention is to provide a motor with a compact structure and a tendency towards miniaturization.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the present invention is as follows: a motor, comprising a housing, a motor shaft accommodated in the housing and partially extending out of the housing, a stator fixedly connected to the housing, and a rotor fixedly connected to the motor shaft, the motor shaft comprising a first end accommodated in the housing and a second end extending beyond the housing, the housing comprising a main body and a cover plate covering the main body near the first end of the motor shaft, the motor shaft being a hollow structure, the motor shaft comprising a receiving cavity, the motor further comprising a magnetic ring at least partially accommodated in the receiving cavity and a signal acquisition device mounted and fixed on the cover plate and opposite to the magnetic ring, the rotor driving the motor shaft and the magnetic ring to rotate, and the signal acquisition device determining the movement position of the rotor by identifying the magnetic field position signal provided by the magnetic ring.

[0007] Preferably, the motor further comprises a magnet mounting seat received in the receiving cavity, and the magnetic ring is mounted and fixed on the magnet mounting seat.

[0008] Preferably, at least half of the magnetic ring in the extension direction of the motor shaft is accommodated in the accommodation cavity of the motor shaft.

[0009] Preferably, the motor shaft is made of magnetic conductive material.

[0010] Preferably, the rotor includes a permanent magnet sleeved on the motor shaft, and the permanent magnet is a permanent magnet with radial 4 poles or more.

[0011] Preferably, the stator includes a stator core fixed to the inner surface of the shell and a stator coil arranged between the stator core and the permanent magnet, and the stator coil is attached to the inner surface of the stator core.

[0012] Preferably, the stator core is an annular magnetic conductive structure, and the stator core is formed by stacking a plurality of silicon steel sheets, and the plurality of silicon steel sheets are fixed by bonding to form the stator core, or the plurality of silicon steel sheets are fixed by riveting to form the stator core.

[0013] Preferably, the magnetic ring is a magnetic structure with two or more radial poles.

[0014] Preferably, the motor includes a first bearing fixed between the housing and the motor shaft, the first bearing is close to the second end of the motor shaft, the first bearing is a rolling bearing, the first bearing includes a first surface connected to the housing and a second surface connected to the motor shaft, and the motor shaft drives the second surface of the first bearing to rotate.

[0015] Preferably, the motor further includes a second bearing fixed between the housing and the first end portion of the motor shaft, and the motor shaft rotates relative to the second bearing.

[0016] Compared with the related art, the motor provided by the present invention includes a housing, a motor shaft housed in the housing and partially extending out of the housing, a stator fixedly connected to the housing, and a rotor fixedly connected to the motor shaft. The motor shaft includes a first end housed in the housing and a second end extending beyond the housing. The housing includes a main body and a cover plate covering the main body near the first end of the motor shaft. The motor shaft is a hollow structure. The motor shaft includes a receiving cavity. The motor also includes a magnetic ring at least partially received in the receiving cavity and a signal acquisition device mounted and fixed on the cover plate and opposite to the magnetic ring. The rotor drives the motor shaft and the magnetic ring to rotate. The signal acquisition device determines the movement position of the rotor by identifying the magnetic field position signal provided by the magnetic ring. The motor of the present invention forms a receiving cavity by setting the motor shaft of the motor as a hollow structure. The magnetic ring for providing the magnetic field position signal is at least partially received in the receiving cavity. This effectively reduces the axial length of the motor, making the structure of the motor more compact and tending to miniaturization.

Brief Description of the Drawings

[0017] Figure 1Schematic diagram of the three-dimensional structure of the motor of the present invention;

[0018] Figure 2 For example Figure 1 A partially exploded view of the motor shown;

[0019] Figure 3 For example Figure 1 An exploded view of the motor shown;

[0020] Figure 4 For the Figure 1 Cross-sectional view along line AA. [Specific implementation method]

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] Please also see Figure 1-4 The present invention provides a motor 100 that can be used in dexterous fingers or joints of a robot. The motor 100 includes a housing 1, a motor shaft 2 housed within the housing 1 and partially extending out of the housing 1, a stator 3 fixedly connected to the housing 1, a rotor 4 fixedly connected to the motor shaft 2, a magnetic ring 5 connected to the motor shaft 2 for providing a magnetic field position signal, a magnet mounting base 6 for mounting the magnetic ring 5, a signal acquisition device 7 for detecting the magnetic field position signal, a first bearing 8 mounted on one side of the housing 1, and a second bearing 9 mounted on the other side of the housing 1.

[0023] The housing 1 includes a main body 11 and a cover plate 12 covering one end of the main body 11. The main body 11 is a barrel-shaped structure. The main body 11 is a three-section structure. The main body 11 includes a first main body portion 111, a second main body portion 112, and a third main body portion 113 connected in sequence. The first main body portion 111, the second main body portion 112, and the third main body portion 113 are fixed by welding or glue. The first main body portion 111 and the second main body portion 112 at least partially overlap and form a receiving portion 114 for receiving the first bearing 8. The stator 3 is mounted and fixed to the second main body portion 112. The second main body portion 112 is provided with a second receiving portion 115 for receiving the stator 3. The third main body portion 113 is fixedly connected to the cover plate 12.

[0024] The motor shaft 2 is a hollow structure, including a receiving cavity 20. The motor shaft 2 is made of a magnetically conductive material. The motor shaft 2 includes a first end 21 housed within the housing 1 and proximate to the cover plate 12, and a second end 22 extending beyond the housing 1. The cover plate 12 covers the side of the main body 11 proximate to the first end 21 of the motor shaft 2. The motor shaft 2 is provided with an abutment protrusion 23, against which the first bearing 8 abuts. The second bearing 9 is mounted on the first end 21 and clamped between the first end 21 and the third main body 113.

[0025] The stator 3 includes a stator core 31 fixed to the inner surface of the housing 1 and a stator coil 32 attached to the inner surface of the stator core 31. The stator core 31 is a ring-shaped magnetic conductive structure composed of a plurality of stacked silicon steel sheets 311. The plurality of silicon steel sheets 311 are bonded together to form the stator core 31, or riveted together to form the stator core 31. The stator 3 has a slotless structure, resulting in minimal vibration during speed regulation of the motor 100, and a more stable structure and performance.

[0026] The rotor 4 includes a permanent magnet 41 sleeved on the motor shaft 2. The permanent magnet 41 is a radial 4-pole or more permanent magnet, for example, a 6-pole permanent magnet. The permanent magnet 41 is arranged in an annular structure and is attached and coated on the outside of the motor shaft 2. Preferably, the material of the permanent magnet 41 is sintered neodymium iron boron. The stator coil 32 is located between the stator core 31 and the permanent magnet 41. The rotor 4 of the motor 100 is a permanent magnet structure with a simple structure, no brush friction, and fast dynamic response.

[0027] The magnetic ring 5 is disposed at the first end portion 21 of the motor shaft 2 and is at least partially accommodated in the accommodating cavity 20. Preferably, at least half of the magnetic ring 5 is accommodated in the accommodating cavity 20 of the motor shaft 2 in the extension direction of the motor shaft 2. Of course, the magnetic ring 5 can also be completely accommodated in the accommodating cavity 20. In this case, the axial length of the motor 100 can be minimized. The magnetic ring 5 has a radially 2-pole or more magnetic structure, for example, it can have a 4-pole magnetic structure.

[0028] The magnetic ring 5 can be directly fixed to the receiving cavity 20 of the motor shaft 2 by gluing, or the magnetic ring 5 can be fixed to the motor shaft 2 via the magnet mounting seat 6, and the magnetic ring 5 is installed and fixed in the magnet mounting seat 6. The magnet mounting seat 6 is completely received and installed in the receiving cavity 20, that is, the end surface of the magnet mounting seat 6 does not extend beyond the end surface of the motor shaft 2.

[0029] The signal acquisition device 7 is installed and fixed on the cover plate 12 and is opposite to the magnetic ring 5, that is, the signal acquisition device 7 is aligned with the magnetic ring 5. When the rotor 4 rotates, the motor shaft 2, the magnet mounting seat 6, and the magnetic ring 5 are driven to rotate synchronously. The signal acquisition device 7 determines the movement position of the rotor 4 by identifying the magnetic field position signal provided by the magnetic ring 5, and realizes electronic commutation of the motor 100 according to the determined relative position between the stator 3 and the rotor 4.

[0030] The first bearing 8 is fixed between the housing 1 and the motor shaft 2, and is positioned near the second end 22 of the motor shaft 2. The first bearing 8 is a rolling bearing, comprising a first surface 81 connected to the housing 1 and a second surface 82 connected to the motor shaft 2. The motor shaft 2 drives the second surface 82 of the first bearing 8 to rotate. The first surface 81 is stationary relative to the housing 1. Specifically, a plurality of balls may be positioned between the first surface 81 and the second surface 82 to enable partial rotation of the first bearing 8.

[0031] The second bearing 9 is fixed between the housing 1 and the first end portion 21 of the motor shaft 2 . The motor shaft 2 rotates relative to the second bearing 9 , that is, the second bearing 9 is stationary relative to the housing 1 .

[0032] Compared with the related art, the motor provided by the present invention includes a housing, a motor shaft housed in the housing and partially extending out of the housing, a stator fixedly connected to the housing, and a rotor fixedly connected to the motor shaft. The motor shaft includes a first end housed in the housing and a second end extending beyond the housing. The housing includes a main body and a cover plate covering the main body near the first end of the motor shaft. The motor shaft is a hollow structure. The motor shaft includes a receiving cavity. The motor also includes a magnetic ring at least partially received in the receiving cavity and a signal acquisition device mounted and fixed on the cover plate and opposite to the magnetic ring. The rotor drives the motor shaft and the magnetic ring to rotate. The signal acquisition device determines the movement position of the rotor by identifying the magnetic field position signal provided by the magnetic ring. The motor of the present invention forms a receiving cavity by setting the motor shaft of the motor as a hollow structure. The magnetic ring for providing the magnetic field position signal is at least partially received in the receiving cavity. This effectively reduces the axial length of the motor, making the structure of the motor more compact and tending to miniaturization.

[0033] The above description is only an embodiment of the present invention. It should be pointed out that those skilled in the art can make improvements without departing from the creative concept of the present invention, but these improvements all fall within the scope of protection of the present invention.

Claims

1. A motor comprising a housing, a motor shaft received in the housing and partially extending out of the housing, a stator fixedly connected to the housing, and a rotor fixedly connected to the motor shaft, wherein the motor shaft comprises a first end received in the housing and a second end extending beyond the housing, the housing comprises a main body and a cover plate provided on the main body near the first end of the motor shaft, wherein: The motor shaft is a hollow structure and includes a receiving cavity. The motor also includes a magnetic ring at least partially received in the receiving cavity and a signal acquisition device mounted and fixed on the cover plate and opposite to the magnetic ring. The rotor drives the motor shaft and the magnetic ring to rotate, and the signal acquisition device determines the movement position of the rotor by identifying the magnetic field position signal provided by the magnetic ring.

2. The motor according to claim 1, characterized in that: The motor further comprises a magnet mounting seat received in the receiving cavity, and the magnetic ring is mounted and fixed on the magnet mounting seat.

3. The motor according to claim 1, characterized in that: At least half of the magnetic ring is accommodated in the accommodation cavity of the motor shaft in the extending direction of the motor shaft.

4. The motor according to claim 1, characterized in that: The motor shaft is made of magnetic conductive material.

5. The motor according to claim 1, characterized in that: The rotor includes a permanent magnet sleeved on the motor shaft, and the permanent magnet is a permanent magnet with four or more radial poles.

6. The motor according to claim 5, characterized in that: The stator includes a stator core fixed to the inner surface of the housing and a stator coil arranged between the stator core and the permanent magnet. The stator coil is attached to the inner surface of the stator core.

7. The motor according to claim 6, characterized in that: The stator core is an annular magnetic conductive structure, and is formed by stacking a plurality of silicon steel sheets. The plurality of silicon steel sheets are fixed by bonding to form the stator core, or the plurality of silicon steel sheets are fixed by riveting to form the stator core.

8. The motor according to claim 1, characterized in that: The magnetic ring is a magnetic structure with two or more radial poles.

9. The motor according to claim 1, characterized in that: The motor includes a first bearing fixed between the housing and the motor shaft, the first bearing is close to the second end of the motor shaft, the first bearing is a rolling bearing, the first bearing includes a first surface connected to the housing and a second surface connected to the motor shaft, and the motor shaft drives the second surface of the first bearing to rotate.

10. The motor according to claim 9, characterized in that: The motor further includes a second bearing fixed between the housing and the first end portion of the motor shaft, and the motor shaft rotates relative to the second bearing.

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