CN210246580U

CN210246580U - Brushless direct-drive linear servo actuator

Info

Publication number: CN210246580U
Application number: CN201920956730.7U
Authority: CN
Inventors: Inventor Has Waived The Right To Be Mentioned The; 不公告发明人
Original assignee: Suzhou Fugna Mechatronics Co ltd
Current assignee: Suzhou Fugna Mechatronics Co ltd
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2020-04-03
Anticipated expiration: 2029-06-25

Abstract

The utility model provides a brushless straight line servo actuator that drives, including stator, active cell and shell, the stator is a pair of armature, and the mirror image is arranged in the active cell both sides, the integrative stator that seals that covers of shell to locate to form the active cell cavity in active cell, the active cell has an output to stretch out the shell to output direction linear motion can be followed. And a displacement signal transmitter is arranged on one side of the rotor, and a signal receiver is arranged in a cover arranged outside the shell on the side and used for detecting displacement signals of the rotor transmitter. The utility model discloses the executor has high reliability, high accuracy, low-cost characteristics.

Description

Brushless direct-drive linear servo actuator

Technical Field

The invention relates to a brushless direct-drive linear servo actuator, belongs to the field of brushless motors, and particularly relates to a brushless direct-drive linear servo actuator with integrated armature and stator sealing, moving magnetic steel and position feedback.

Background

In the field of air intake and exhaust application of internal combustion engines, continuous upgrading of emission regulations requires further accurate, rapid and reliable control of oil consumption and combustion emission, for example, an exhaust gas recirculation valve, an electrically-controlled adjustable turbocharging technology and the like are adopted to regulate and control an engine. These adjustment functions require the use of actuators that are resistant to high temperatures, vibrations, corrosion, and have high accuracy, reliability, and longevity. Meanwhile, the large-scale batch application field is sensitive to the manufacturing cost, and as the rotating motor is widely applied and has low manufacturing cost, the linear motion is generally obtained by preferably converting the mechanical structure of the rotating motor.

In the disclosed patent US9322365B2, in order to control the exhaust gas recirculation valve of an engine, a brushed rotating electric machine is first amplified by a two-stage gear and then the rotary motion is converted into linear motion by an eccentric cam mechanism. The conversion of the mechanical structure can generate linear thrust with enough stroke by using a low-power motor, and is low in cost. However, for harsh application environments of the exhaust gas recirculation valve, the above technical solutions have many defects, such as high machining precision required by the mechanical conversion structure, precision of the gear, precision of the relative position of the gear assembly, and precision of the cam mechanism. The patent US9614413B2 is disclosed for further optimization of the relevant problems. Meanwhile, considering that the use temperature becomes poor, a certain gap must be left between mechanical parts to avoid blocking, and considering the mechanical amplification factor, the small gap can be amplified into a larger motion error at the output end; the moving part is further abraded after the high-frequency long-term work, and the precision is further reduced. Meanwhile, the displacement sensor needs to be arranged at the output end independently, the interference of surrounding signals is considered, the arrangement difficulty is high, and the precision is difficult to guarantee. Mechanical components are also subject to high temperatures, load impacts, etc., which are often the source of product failure. Resulting in a significant reduction in system life and reliability. In view of cost, this type of scheme generally employs a brush motor, and since the carbon brush is worn, the service life of the brush motor is limited by the service life of the carbon brush, which makes it difficult to meet the application requirements of the internal combustion engine with high reliability.

The above solution, if a brushless motor is used, as disclosed in patent US7323835B2, converts the rotational movement of the motor into a linear movement by means of a screw structure. While carbon brush life limitations can be eliminated, the cost of the electronic portion of the actuator is greatly increased due to the need for electronic commutation and control. Said patent is aimed at minimizing the cost of the electronic part by optimizing the arrangement of the hall sensors. For high temperature applications in internal combustion engines, electronic reliability is greatly reduced with increasing temperature, and once a 125 ℃ device rating is breached, electronic component costs are further increased. In order to ensure the displacement accuracy of the output end, a displacement sensor is usually additionally arranged at the output end, which not only increases the difficulty of electronic arrangement, but also increases the cost. Moreover, the said patent solution also fails to avoid the drawbacks of the mechanical transformation structure described above.

In another patent (patent No. CN 104377843B) disclosed by the present applicant, a brushless direct drive rotary torque actuator is disclosed, which can convert the rotary motion into a linear output by a cam plate structure (see patent CN 203822497U). The brushless direct-drive torque rotary actuator can realize the same control mode as a brush motor due to the limited corner, does not need electronic phase change, and simultaneously directly integrates a rotary position sensor inside, thereby meeting the application of high temperature and high reliability and having low cost of a drive controller. But still cannot be disengaged from the mechanical switching mechanism. Mechanical structure precision and reliability problems still exist. Still not the most desirable solution.

Although various professionals have searched for the field of brushless direct-drive linear motors, no technology has been available that meets the above-mentioned demanding application areas. For example, in the earliest patent US4195277, linear motion of the moving magnet steel structure is achieved by arranging a magnet steel magnetized perpendicular to the moving direction on one side of an armature stator, or arranging a magnet steel magnetized perpendicular to the moving direction between two sets of armature stators arranged oppositely. However, such a structure has low output efficiency and lacks of specific industrial application value. Further, the published patent CN101451520B discloses a stator composed of two sets of multi-pole windings and arranged with armatures oppositely, and a rotor structure composed of at least one pair of magnetic steels is arranged in the middle, such design is used for compressor application, and under the action of alternating current, the rotor reciprocates to realize air compression. The structure has the advantages of complex mechanism, large volume and high manufacturing cost, can not ensure the reliability and the service life of the motor under severe application environment conditions, and can not realize the stroke displacement feedback control of the motor. Therefore, the application requirements of high reliability, high precision and low cost cannot be satisfied.

Disclosure of Invention

The invention aims to provide a brushless direct-drive linear servo actuator with a stator and armature integrated covering structure, moving magnetic steel and stroke displacement feedback. The concrete structure is as follows:

the utility model provides a brushless direct-drive linear servo actuator, includes stator, active cell and shell, the stator is a pair of armature, and the mirror image is arranged in the active cell both sides, the integrative stator that covers of shell to at active cell department formation active cell cavity, the active cell has an output to stretch out the shell to can follow output direction linear motion.

On the basis of the technical scheme, the rotor can slide along the inner wall of the shell in the rotor cavity, a displacement signal transmitter is arranged on one side of the rotor in sliding contact with the shell, a cover is further arranged outside the shell on the side, the shell is connected with the cover, a receiver matched with the displacement signal transmitter is arranged in the cover, and the transmitter and the receiver are uniformly distributed on the mirror symmetry central plane of the stator armature.

On the basis of the technical scheme, the shell is connected with the cover cap in a buckling mode.

On the basis of the technical scheme, furthermore, a sealing groove is further formed in the joint of the shell and the outer cover, and a sealing element is arranged in the sealing groove.

On the basis of the technical scheme, further, the rotor comprises a frame and magnetic steel fixed in the frame, the output end of the rotor extends from the frame, and the frame can slide along the inner wall of the shell.

On the basis of the technical scheme, further, a bushing is arranged between the contact surface of the rotor frame and the inner wall of the shell, and the bushing is made of a wear-resistant and load-resistant material.

On the basis of the technical scheme, furthermore, a counter bore is formed in the rotor frame, the magnetic steel is arranged in the counter bore in a positioning mode, and the counter bore area of the rotor frame is made of soft magnetic materials.

On the basis of the technical scheme, a bushing is further arranged between the output end of the rotor and the contact surface of the shell.

On the basis of the technical scheme, further, the stator armature comprises an iron core with at least 3 stator poles and a framework surrounding at least one stator pole, coils are wound in the framework, and the coils of the pair of armatures are connected end to end.

On the basis of the technical scheme, further, the shell is provided with an installation opening on the opposite side of the output end of the rotor, and the installation opening is provided with a matched sealing cover.

The invention has the beneficial effects that: the stator of the actuator is arranged in a mirror symmetry mode by a pair of armatures and a rotor, the force which is born by the rotor and perpendicular to the mirror symmetry center plane is balanced, and only the push-pull force in the moving direction of the rotor is born. And the rotor is different from a common rotor armature and shell mechanical assembly structure, and the air gap between the rotor and the stator is greatly changed after errors are accumulated and superposed. The stator armature is integrally sealed by the shell, the formed rotor cavity and the stator pole are positioned and molded by the mold, the position precision is very high, the friction force of the rotor in the shell is very small, and the abrasion of the sliding surface is greatly reduced, so that the service life and the reliability of a sliding system are prolonged, and the actual effective output of the system is increased. When the bushings are arranged between the contact surfaces of the rotor frame and the inner wall of the shell and between the output end of the rotor and the contact surface of the shell, the bushings are made of wear-resistant and load-resistant materials, the bearing capacity of the system can be further improved, and the friction force is reduced.

The actuator stator is integrally covered and sealed by the shell, heat generated by the armature coil of the stator can be conducted through the completely covered integrally covered and sealed shell, the heat dissipation performance is greatly enhanced, and the reliability and the service life are increased.

The transmitter and the receiver are uniformly arranged on the mirror symmetry central plane of the stator, the magnetic field component of the magnetic field generated by the stator armature and the rotor magnetic steel at the position along the mirror symmetry central plane and perpendicular to the movement direction is almost zero, and the receiver is not interfered by the magnetic field of the actuator completely when the receiver detects by the component. Meanwhile, the rotor directly moves without any mechanical conversion gap or mechanical conversion error, and stepless displacement control at any position can be realized. This ensures high accuracy of the actuator over long periods of operation.

The actuator stator is integrally covered and sealed through the shell, the component forming precision is high, the structure is simple and compact, the number of integral components is small, the processing and assembly are simple and reliable, a complex electronic driver is not needed in a limited stroke range, and the actuator can be controlled like a common brush actuator. Therefore, the whole production, manufacture and use cost is low. Is particularly suitable for mass application.

Drawings

Fig. 1 is an isometric view of a first embodiment actuator of the present invention.

Fig. 2 is a top view of a first embodiment actuator of the present invention.

Fig. 3 is a left side view of the actuator of the first embodiment of the present invention.

Fig. 4 is a plan sectional view of the actuator stator B-B of the first embodiment of the present invention.

FIG. 5 is a plan cross-sectional view of a first embodiment actuator B-B of the present invention.

Fig. 6 is a plan cross-sectional view of a first embodiment actuator C-C of the present invention.

Fig. 7 is a plan sectional view of a first embodiment actuator a-a of the present invention.

Fig. 8 is a top view of a second embodiment actuator of the present invention (no cover, no mover).

Fig. 9 is a front view of an actuator mover according to a third embodiment of the present invention.

Fig. 10 is a cross-sectional view of a third embodiment actuator mover D-D of the present invention.

The reference numbers in the figures illustrate:

1-a stator; 2-a mover; 3-covering the cover; 4-sealing the cover; 5-air gap; 6-a seal; 10-an iron core; 101-a stator pole; 102-stator pole shoe; 11-a backbone; 12-copper wire; 13-a housing; 131-a moving cavity; 132-an output aperture; 133-a gripper; 134-sealing groove; 14-mover sleeve; 15-output end bushing; 16-mirror symmetry plane; 21-a mover frame; 22-magnetic steel; 23-an output terminal; 24-a transmitter; 31-a connector; 311-PCB fixing column; 312-fastener; 32-a receiver; 33-PCB board.

Detailed Description

Fig. 1 is an isometric view of a brushless direct drive linear servo actuator according to a first embodiment of the present invention. The specific implementation mode is as follows: the actuator comprises a stator 1 (not visible in this figure), a mover 2, a cover 3, a cover 4 and a housing 13. The stator 1 comprises a pair of armatures and is integrally covered and sealed by a shell 13, the shell 13 can be made of plastic or other materials capable of being covered and cured, a rotor cavity 131 is formed in the shell 13, the rotor 2 is installed in the rotor cavity 131 from an installation opening in the shell 13, and the rotor cavity 131 is closed by a sealing cover 4. The mover cavity 131 relatively limits the mover 2 and ensures that the mover moves up and down in the mover cavity 131 along the Z-axis direction. A cover 3 is arranged on the side of the housing 13.

Fig. 2 is a top view of the brushless direct-drive linear servo actuator according to the first embodiment of the present invention, and fig. 3 is a left side view of the brushless direct-drive linear servo actuator according to the first embodiment of the present invention.

FIG. 4 is a sectional plan view of the stator B-B of the brushless direct drive linear servo actuator according to the first embodiment of the present invention. The specific implementation mode is as follows: the actuator stator 1 comprises a pair of armatures which are arranged in a mirror image mode relative to a mirror image symmetry central plane 16, each armature comprises an iron core 10, a framework 11 and a copper wire 12, the frameworks 11 are sleeved on middle poles of 3 stator poles 101 of the iron cores 10, and the copper wires 12 are wound in winding grooves of the frameworks 11. The copper wires 12 of the two sets of armatures may be connected end to form a single phase, such that when current is passed, the stator poles 101 arranged opposite each other with the mirror symmetry center plane 16 produce N, S opposite excitation magnetic fields. Stator pole shoe 102 design has the chamfer, and middle pole shoe is different with both sides pole shoe chamfer design, the chamfer design compromises the magnetic circuit design needs, ensures output performance, and the maximize reduces stator core 10's weight simultaneously, provides the biggest wire winding space of copper line 12, guarantees higher groove fullness rate.

FIG. 5 is a sectional view of a first embodiment of a brushless direct drive linear servo actuator B-B in plan view. The specific implementation mode is as follows: two sets of armatures are integrally covered and sealed through the shell 13 to form a firm integrated structure, a rotor cavity 131 and an output hole 132 used for extending out the output end 23 are formed in the shell 13, two sides of the rotor 2 are matched with the rotor cavity 131 to ensure that the rotor 2 is installed and positioned on the mirror symmetry central plane 16 of the stator 1, and therefore an even air gap 5 is formed between the rotor 2 and the stator pole shoes 102 on the two sides. The mover 2 includes a mover frame 21 and a magnetic steel 22, and the mover frame 21 extends to form an output end 23, and extends out of the actuator through an output hole 132 for connecting with a driven mechanism. The magnetic steel 22 has two pairs of poles alternating perpendicular to the central plane of mirror symmetry 16 and N, S. The cover 4 closes the mover cavity 131 after the mover 2 is mounted in the stator 1.

Fig. 6 is a C-C plane sectional view of a first embodiment brushless direct drive linear servo actuator 1 of the present invention, wherein the actuator stator 1 comprises two sets of armatures arranged in a mirror image relative to a mirror image center plane 16. The armature comprises an iron core 10, a framework 11 and a copper wire 12. The armature is integrally enclosed by housing 13 to form a solid one-piece structure and to form a rotor cavity 131. The mover 2 is matched with the mover cavity 131, so that the mover 2 is ensured to be positioned and installed on the mirror symmetry central plane 16 of the stator 1. So that the mover 2 has a uniform air gap 5 with the end surfaces of the stators 10 at both sides. A displacement signal emitter 24 is arranged at one side of the mover 2, and the center of the emitter 24 is located on the central plane of mirror symmetry 16. The housing 13 on the side on which the transmitter 24 is arranged is fitted with a cover 3, on which side the housing 13 forms a cover interface for connection with the cover. A PCB board 33 is disposed inside the cover 3, and the PCB board 33 is positioned by PCB fixing posts 311 on the cover 3. The PCB 33 has a receiver 32 arranged thereon, the receiver 32 being centrally arranged on the central plane of mirror symmetry 16, opposite the internal transmitter 24. When the mover 2 moves relative to the stator 1, the receiver 32 receives the variation signal from the transmitter 24 on the mover 2, so as to calculate and output the precise displacement of the mover 2 relative to the stator 1. The cover 3 has a connector 31 on the outside for electrical connection to the outside. The matching position of the stator 1 and the cover 3 is provided with a plurality of grippers 133, and the matching position of the cover 3 and the gripper 133 of the stator 1 is provided with a plurality of buckles 312, so that the stator 1 and the cover 3 are installed and matched. The matching part of the stator 1 and the cover 3 is simultaneously provided with a sealing groove 134, and a sealing element 6, such as a sealing ring or glue, is filled in the sealing groove 134 so as to realize the internal sealing of the cover.

Fig. 7 is a sectional view of a first embodiment of the brushless direct-drive linear servo actuator a-a according to the present invention, wherein the mover 2 is movable up and down along the Z-axis direction relative to the stator 1, and the housing 13 has an output hole 132 corresponding to the output mechanism opening of the mover 2. The side of the mover 2 opposite to the cover 3 is provided with a transmitter 24. The emitters 24 are arranged centrally on the central plane of mirror symmetry 16. When the mover 2 is in the stroke center position (as shown in the figure position), the receiver 32 is arranged directly above said transmitter 24.

In the brushless direct-drive linear servo actuator according to the first embodiment of the present invention, the components of the magnetic force between the mover 2 and the stator 1 perpendicular to the central plane 16 of mirror symmetry of the stator have the same magnitude and opposite directions. Thus, the mover 2 is theoretically not subjected to any force perpendicular to said central plane 16 of mirror symmetry of the stator, but only to a push-pull force in the moving direction of the mover. And the rotor is different from a common rotor armature and shell mechanical assembly structure, and the air gap between the rotor and the stator is greatly changed after errors are accumulated and superposed. The stator armature is integrally covered and sealed by the shell 13, the formed rotor cavity 131 and the stator pole shoe 102 are positioned and molded by a mold, the position precision is very high, and therefore the friction force of the rotor 2 in the stator cavity 131 is extremely small. The wear of the sliding surface is greatly reduced, thereby prolonging the service life and the reliability of the sliding system and simultaneously increasing the actual effective output of the system.

The transmitter 24 is arranged on the mirror-symmetrical center plane 16, and the magnetic field generated by the stator armature and the rotor magnet steel 22 at this position has a component of the magnetic field along the mirror-symmetrical center plane 16 and perpendicular to the direction of movement that is almost zero and is completely free of the actuator magnetic field when the receiver 32 detects this component. Meanwhile, the rotor 2 is in direct drive motion, no mechanical conversion gap exists, no mechanical conversion error exists, and stepless displacement control at any position can be realized. High accuracy of the operation of the actuator can be ensured over a long period of time.

The stator of the actuator is integrally covered and sealed by the shell, heat generated by the armature coil of the stator can be conducted through the completely covered integrally covered and sealed shell 13, the heat dissipation performance is greatly enhanced, and the reliability and the service life are increased.

The actuator stator is integrally covered and sealed through the shell 13, the component forming precision is high, the structure is simple and compact, the number of integral components is small, the processing and assembly are simple and reliable, a complex electronic driver is not needed in a limited stroke range, and the actuator can be controlled like a common brush actuator. Therefore, the whole production, manufacture and use cost is low. Is particularly suitable for mass application.

Fig. 8 is a structural plan view of a rotor of a brushless direct-drive linear servo actuator according to a second embodiment of the present invention (without a cover and without a rotor). The specific implementation mode is as follows: the main difference between the second embodiment and the first embodiment is that the side of the rotor cavity 131 of the housing 13 is provided with a liner 14, and the inner side of the output hole 132 is provided with an output end liner 15. The

bushings

14 and 15 are made of wear-resistant and load-resistant materials, and this arrangement can further increase the load-bearing capacity and wear resistance, thereby further reducing the actual frictional force and improving the reliability of the system.

Fig. 9 and fig. 10 are a front view and a D-D cross-sectional view of a mover of an actuator according to a third embodiment of the present invention, and the embodiment is as follows: the overall structure of the mover in the third embodiment of the present invention is similar to that in the first and second embodiments, and the difference features are that the positions for arranging the magnetic steels 22 at both sides of the mover frame 21 are counterbores, the center of the frame 21 does not penetrate through, at least 2 pieces of magnetic steels are respectively attached to the counterbores at both sides of the frame, and N, S alternating magnetic fields are formed. The counter bore area of the rotor frame 21 is made of soft magnetic materials. The arrangement scheme can greatly enhance the mechanical strength of the rotor structure, effectively position the magnetic steel and ensure the position precision of the components. Meanwhile, the use amount of the magnetic steel is reduced in a necessary mechanical space. The cost is reduced.

The above description is only a preferred embodiment of the present invention, and the brushless direct-drive linear servo actuator of the present invention is not limited to the above-mentioned embodiment, and therefore, the scope of the present invention is not limited thereto. Under the above inventive concept, the structural derivation transformation performed by the contents of the present specification and the accompanying drawings is directly or indirectly applied to other technical fields, and is included in the scope of the present invention.

Claims

1. A brushless direct-drive linear servo actuator is characterized in that: including stator, active cell and shell, the stator is a pair of armature, and the mirror image is arranged in the active cell both sides, the integrative stator that covers of shell to at active cell department formation active cell cavity, the active cell has an output to stretch out the shell to can follow output direction linear motion.

2. The brushless direct drive linear servo actuator as claimed in claim 1, wherein: the rotor can slide along the inner wall of the shell in the rotor cavity, a displacement signal transmitter is arranged on one side of the rotor in sliding contact with the shell, a cover is further arranged outside the shell on the side, the shell is connected with the cover, a receiver matched with the displacement signal transmitter is arranged in the cover, and the transmitter and the receiver are uniformly distributed on the mirror symmetry central plane of the stator armature.

3. A brushless direct drive linear servo actuator as claimed in claim 2, wherein: the shell is connected with the cover cap by means of buckling connection of the shell and the cover cap.

4. The brushless direct-drive linear servo actuator as claimed in claim 3, wherein a sealing groove is further formed at a connection part of the housing and the outer cover, and a sealing member is arranged in the sealing groove.

5. The brushless direct drive linear servo actuator as claimed in claim 4, wherein: the rotor comprises a frame and magnetic steel fixed in the frame, the output end of the rotor extends from the frame, and the frame can slide along the inner wall of the shell.

6. The brushless direct drive linear servo actuator as claimed in claim 5, wherein: and a lining is arranged between the contact surface of the rotor frame and the inner wall of the shell.

7. The brushless direct drive linear servo actuator as claimed in claim 5, wherein: the rotor frame is provided with a counter bore, the magnetic steel is positioned in the counter bore, and the counter bore area of the rotor frame is made of soft magnetic materials.

8. A brushless direct drive linear servo actuator as claimed in any one of claims 1 to 7, wherein: and a lining is arranged between the rotor output end and the contact surface of the shell.

9. A brushless direct drive linear servo actuator as claimed in any one of claims 1 to 7, wherein: the stator armature comprises an iron core with at least 3 stator poles and a framework surrounding at least one stator pole, coils are wound in the framework, and the coils of the pair of armatures are connected end to end.

10. A brushless direct drive linear servo actuator as claimed in any one of claims 1 to 7, wherein: the shell is provided with a mounting opening on the opposite side of the output end of the rotor, and the mounting opening is provided with a matched sealing cover.