Method for press fitting an actuator and press fitting apparatus according to the method

Abstract

The present application relates to a kind of executioner's press mounting method and press mounting equipment according to the press mounting method.Change-over disc and stator assembly are arranged in the corresponding position of press mounting equipment, it is positioned and mutually opposite;Rotor assembly is pre-rotated to predetermined angle;Change-over disc and stator assembly are mutually close;Let the excitation coil of stator be connected with external power supply and keep;Change-over disc and stator assembly are mutually pressed and are completed press mounting.The press mounting equipment according to the above method is from bottom to top in turn base, stator assembly mounting plate, change-over disc mounting plate, the side of stator assembly mounting plate towards up is equipped with stator assembly positioning column, the side of change-over disc mounting plate towards down is equipped with change-over disc positioning block, and stator assembly mounting plate and change-over disc mounting plate are equipped with lifting cylinder and guide mechanism between them.The above method and equipment, by energizing the excitation coil of stator, make rotor assembly freely deflect in the excitation magnetic field of stator, and then maximumly eliminate the angle precision deviation of commutator and rotor magnetic pole.

Description

Technical Field

[0001] This invention relates to a press-fitting method for an actuator and a press-fitting apparatus according to the press-fitting method. Background Technology

[0002] Linear actuators are devices that convert electrical energy into mechanical energy, widely used in industrial automation, automotive, aerospace, and medical equipment. The power unit of a linear actuator typically consists of a rotor, stator, commutator, and protective cover. The manufacturing process usually involves injection molding the large ball bearing and stator together, assembling the rotor and stator assemblies, externally welding them to form a welded disc, and finally press-fitting the commutator disc using press-fitting equipment. The commutator is a key mechanical and electrical component in the actuator, its main function being to achieve the periodic conversion of current direction to ensure continuous and stable motor operation. The commutator, in conjunction with carbon brushes, converts externally input DC or AC current into a current form suitable for motor operation. In existing technologies, the press-fitting process for commutators typically uses mechanical positioning for each component. However, mechanically positioned commutators and rotor poles still exhibit some angular accuracy deviations, leading to problems such as unstable torque output, reduced efficiency, difficulty in speed control, difficulty in starting, and accelerated wear. Summary of the Invention

[0003] The purpose of this invention is to overcome the aforementioned deficiencies of the prior art and provide a press-fitting method for linear actuators. This method can compensate for the commutation angle of the rotor assembly, thereby effectively improving the commutation accuracy of the actuator. Simultaneously, a press-fitting device employing the above-described press-fitting method is also provided.

[0004] The technical solution of the press-fitting method of the present invention is as follows: the commutator and stator assembly are respectively placed in the corresponding positions of the press-fitting equipment, and the positioning structure is used to position them so that they are facing each other; the rotor assembly is pre-rotated to a predetermined angle; the commutator and stator assembly are brought closer to each other; before the commutator and stator assembly come into contact and until the press-fitting is completed, the excitation coil of the stator is connected to the external power supply and maintained; the commutator and stator assembly are pressed together to complete the press-fitting.

[0005] After adopting the above method, before the press-fitting is completed, the rotor assembly is allowed to deflect freely in the excitation magnetic field of the stator by energizing the excitation coil of the stator, thereby eliminating the angular accuracy deviation of the commutator and rotor magnetic poles to the greatest extent.

[0006] A further technical solution of the pressing method of the present invention is to perform a reset operation on the components of the pressing equipment before and after pressing.

[0007] The technical solution of the press-fitting equipment using the above-mentioned press-fitting method of the present invention is as follows: the press-fitting equipment includes a frame and a stator assembly mounting plate that are fixedly connected to each other, and a commutator mounting plate that can move away from and closer to the stator assembly mounting plate. A commutator positioning structure is provided on the side of the commutator mounting plate that is close to the stator assembly mounting plate, and a stator assembly positioning structure is provided on the side of the stator assembly mounting plate that is close to the commutator mounting plate.

[0008] The above structure ensures that the commutator and stator assembly are positioned by positioning structures in the aforementioned method, and that their positions are directly opposite each other after positioning.

[0009] A further technical solution of the present invention is: the press-fitting equipment includes a frame, a base, a commutator mounting plate, and a stator assembly mounting plate. The frame, base, and stator assembly mounting plate are fixedly connected to each other. The entire equipment consists of a horizontally arranged base, a stator assembly mounting plate, and a commutator mounting plate from bottom to top. The upward-facing side of the stator assembly mounting plate is provided with a stator assembly positioning post, and the downward-facing side of the commutator mounting plate is provided with a commutator positioning block. A lifting cylinder and a guide mechanism are provided between the stator assembly mounting plate and the commutator mounting plate.

[0010] A further technical solution of the present invention is as follows: a pin cylinder is provided on the side of the stator assembly mounting plate away from the commutator mounting plate, the pin cylinder is provided with a rotor pin, the rotor pin can pass through the stator assembly mounting plate and extend towards the commutator mounting plate; a pressing cylinder is provided on the side of the commutator mounting plate away from the stator assembly mounting plate, the pressing cylinder is provided with a commutator pressing head, the commutator pressing head can pass through the commutator mounting plate and extend towards the stator assembly mounting plate.

[0011] The above structure can ensure the realization of the proximity and pressing function of the commutator and stator assembly in the aforementioned method.

[0012] A further technical solution of the present invention is as follows: a pin cylinder is provided on the base, the pin cylinder drives the rotor pin to rise and fall, a first through hole is provided in the middle position of the stator assembly mounting plate, the rotor pin can pass through the first through hole, an adjustable stroke cylinder is provided above the commutator mounting plate and fixed on the frame, the adjustable stroke cylinder is provided with a downwardly extending commutator pressing head, a second through hole is provided in the middle position of the commutator positioning block and the commutator mounting plate, the commutator pressing head can pass through the second through hole.

[0013] A further technical solution of the present invention is: an external power supply terminal is provided on the commutator mounting plate at the position of the stator excitation coil power input terminal of the stator assembly that is correctly placed, the external power supply terminal is electrically connected to an external power source, the external power supply terminal protrudes below the commutator mounting plate, and the external power supply terminal has a retractable structure. Attached Figure Description

[0014] The specific content of the present invention will be further explained below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the actuator after press-fitting in this embodiment.

[0016] Figure 2 This is a schematic diagram of the press-fitting equipment in this embodiment when a workpiece is provided.

[0017] Figure 3 : A schematic diagram of the press-fitting equipment in this embodiment when there is no workpiece being processed. Detailed Implementation

[0018] As shown in the figure, the press-fitting equipment of the present invention includes a frame 4, a base 1, a commutator mounting plate 3, and a stator assembly mounting plate 2, which are fixedly connected to each other. The entire equipment consists of a horizontally arranged base 1, a stator assembly mounting plate 2, and a commutator mounting plate 3, arranged from bottom to top.

[0019] The base 1 is equipped with a pin cylinder 11, which drives the rotor pin 12 to rise and fall. The pin cylinder 11 is controlled by the first control valve 51.

[0020] The stator assembly mounting plate 2 is fixed to the base 1 at its lower part via support columns located at the four corners, and fixed to the frame 4 on its upper side. A stator assembly positioning column 21 is provided on the upward-facing side of the stator assembly mounting plate 2, and a first through hole 22 is provided in the middle of the stator assembly mounting plate 2, through which the rotor pin 12 can pass. A lifting cylinder 23 and a guide column 24 are also fixedly connected to the stator assembly mounting plate 2.

[0021] The commutator mounting plate 3 is connected to the piston rods of the two lifting cylinders 23 on both sides. It also has guide sleeves 34 that mate with the two guide posts 24, allowing the guide posts 24 to pass through the guide sleeves 34 and connect to the stator assembly mounting plate 2. The lifting cylinders 23 are controlled by a second control valve 52. A commutator positioning block 31 is provided on the downward-facing side of the commutator mounting plate 3. A second through hole 32 is provided in the middle of the commutator positioning block 31 and the commutator mounting plate 3. Two downward-extending retractable probes 33 are also provided on the commutator mounting plate 3 opposite the stator excitation coil power input terminal 63 of the stator assembly 6. These two retractable probes 33 are electrically connected to an external power source.

[0022] An adjustable stroke cylinder 41, fixed to the frame 4, is provided above the steering wheel mounting plate 3. The adjustable stroke cylinder 41 has a downwardly extending steering wheel pressing head 42, which can pass through the second through hole 32. The adjustable stroke cylinder is controlled by a first control valve 51.

[0023] In the above embodiments, the frame 4, base 1, and stator assembly mounting plate 2 are fixedly connected to each other, forming the main support structure of the equipment. Besides the connection method described in the above embodiments, the base 1, stator assembly mounting plate 2, and frame 4 can also be fixedly connected using other forms of mechanical structures that do not affect the pressing process. For example, the frame, base, and stator assembly mounting plate can be manufactured as a single unit, or two of them can be manufactured as a single unit and then fixedly connected to the other. In the above embodiments, the base 1 serves as a mounting platform for the ejector cylinder 11 and a support platform for the entire device. When there are other forms of ejector cylinder mounting platforms and device support platforms, the base can be omitted. For example, the ejector cylinder can be mounted upside down on the stator assembly mounting plate, using support feet as the support platform for the device. However, the structure described in this embodiment is more suitable for tooling implementation.

[0024] As can be seen from the above analysis, the lifting cylinder 23 and guide column 24 of this embodiment can be installed on any of the mutually fixed components of the frame 4, base 1, and stator assembly mounting plate 2. However, considering the positional relationship of each component, the distance between the stator assembly mounting plate 2 and the commutator mounting plate 3 is closer, with no other components obstructing the way. Furthermore, considering the convenience of assembly and maintenance, it is more suitable to install them on the stator assembly mounting plate 2. Two lifting cylinders 23 and two guide columns 24 are symmetrically installed on both sides of the pressing working channel. This avoids the pressing working channel and provides symmetrical lifting force.

[0025] The guide column 24 and its mating guide sleeve 34 provide guidance, forming a guiding mechanism that guides the commutator 7 to the position where it is pressed into the stator assembly 6, while also ensuring the accuracy of the commutator mounting plate's lifting. This guiding mechanism can also employ other structural forms, such as guide rail and guide groove pairs. Alternatively, if the lifting accuracy of the lifting cylinder 23 is improved, this guiding mechanism can be eliminated; however, this would significantly increase the cost of the lifting cylinder, resulting in an overall cost increase even without the guiding mechanism.

[0026] In this embodiment, the external power supply terminal fixed to the commutator mounting plate 3 is a retractable probe 33, which is electrically connected to the external power supply via a wire. This design ensures that after the probe 33 contacts and connects with the stator excitation coil power input terminal 63 of the mating stator assembly 6, the commutator mounting plate 3 can continue to move to complete its subsequent work, while maintaining a stable electrical connection between the probe 33 and the stator assembly 6. Other structural forms, such as elastic contacts, can also be used for this external power supply terminal. However, compared to the retractable probe, other structural forms are less tightly integrated with the device, and the reliability of the electrical connection to the corresponding power terminal of the stator assembly is lower.

[0027] In this embodiment, the press-fit cylinder set on the frame 4 is an adjustable stroke cylinder 41, which can preset the stroke of the commutator press-fit head 42 according to the assembly depth requirements of the commutator 7 and the stator assembly 6, so as to ensure the press-fit accuracy.

[0028] Considering the structure of the stator assembly 6 and the commutator 7 involved in this invention and the influence caused by their weight, in this embodiment, the press-fitting working channel is set in a vertical direction, the stator assembly mounting plate 2 on which the heavier stator assembly 6 is placed in the lower vertical direction, and the commutator mounting plate 3 on which the lighter commutator 7 is placed in the upper vertical direction. This ensures the concentricity of the rotor assembly 61 in the stator assembly 6, prevents the rotor assembly 61 from coming out of the stator assembly 6 during the press-fitting process, and ensures the rationality of the entire press-fitting process.

[0029] The above structure is based on the following press-fitting method.

[0030] Before implementing the press-fitting method, the rotor assembly 61 and stator assembly 62 need to be assembled first, and then welded from the outside to form a welding plate 64, thereby forming a rotor-stator assembly, namely the stator assembly 6 described in the above embodiment.

[0031] Then, position the commutator mounting plate 3 at its initial position of maximum stroke, position the rotor pin 12 at its initial position of minimum stroke, and position the commutator pressing head 42 at its initial position of being higher than the commutator mounting plate 3.

[0032] The initial position can be achieved by the components naturally returning to their initial position after the previous pressing operation is completed. Alternatively, the first control valve 51 and the second control valve 52 can be manually operated to return the corresponding components to their initial position.

[0033] First, the steering wheel 7 is placed on the steering wheel positioning block 31 on the steering wheel mounting plate 3, and the steering wheel positioning block 31 is used to position and clamp the steering wheel 7. The stator assembly 6 is placed on the stator assembly mounting plate 2, and the stator assembly 6 is positioned by the stator assembly positioning post 21.

[0034] Since the commutator positioning block 31 is inverted and mounted on the downward-facing side of the commutator mounting plate 3, the commutator 7 is mounted on the downward-facing side of the commutator mounting plate 3. Since the stator assembly positioning post 21 is positioned upright on the upward-facing side of the stator assembly mounting plate 2, the stator assembly 6 is mounted on the upward-facing side of the stator assembly mounting plate 2. Therefore, the commutator 7 and the stator assembly 6 are positioned directly opposite each other in the press-fitting working channel.

[0035] Then, the rotor assembly 61 is pre-rotated to a predetermined angle manually.

[0036] The term "manual" refers to rotation by hand, rotation by manually operating a mechanism, or pre-rotation of the rotor assembly 61 using an automatic mechanism. The "predetermined angle" here refers to the angle at which the rotor assembly needs to be rotated to its final position according to existing technology. However, since this invention will further adjust this angle in subsequent processes, a relatively large error range is allowed for the aforementioned predetermined angle.

[0037] Then, bring the commutator 7 and stator assembly 6 closer together.

[0038] Here, the second control valve 52 needs to be operated to retract the piston rod of the lifting cylinder 23, driving the steering wheel mounting plate 3 to move downward. In this way, the steering wheel 7, which is placed below the steering wheel mounting plate 3, will move towards the stator assembly 6, and finally, under the guidance of the guide mechanism, contact and engage with the stator assembly 6, and enter the position for press-fitting with the stator assembly 6.

[0039] During this process, the stator's excitation coil is connected to an external power source.

[0040] The retractable probe 33, fixed to the commutator mounting plate 3, moves downwards along with the commutator mounting plate 3. Because its position is directly opposite the stator excitation coil power input terminal 63 of the stator assembly 6 and protrudes below the commutator mounting plate 3, the probe 33 will first contact and establish an electrical connection with the stator excitation coil power input terminal 63 before the commutator 7 contacts the stator assembly 6. As the commutator mounting plate 3 descends further, the probe 33 will retract upon contact with the stator excitation coil power input terminal 63, maintaining contact and electrical connection with the stator excitation coil power input terminal 63, without hindering the further descent of the commutator mounting plate 3 and the commutator 7.

[0041] The aforementioned retractable probe 33 consists of several concentric shells nested together, with built-in elastic elements, thereby achieving the retractable function.

[0042] In this embodiment of the method, probe 33 is always electrically connected to an external power source. Thus, when probe 33 contacts the power input terminal 63 of the stator's excitation coil, the stator's excitation coil is connected to the external power source.

[0043] Predictably, this method only requires keeping the stator excitation coil energized during the contact and pressing of the commutator and stator assembly. That is, from the moment the commutator and stator assembly come into contact, or even just before contact, until the pressing is complete, the stator excitation coil needs to remain energized. However, since the retractable probe can already connect and disconnect its electrical connection to the stator excitation coil at appropriate times, it's more efficient to keep it continuously energized rather than precisely switching the probe on and off at precise moments, thus simplifying the overall structure.

[0044] After the stator's excitation coil is energized, it generates an excitation magnetic field, which acts on the rotor assembly located within it, causing the rotor assembly to deflect naturally within the excitation magnetic field. The deflected rotor assembly has no or minimal angular accuracy deviation from the already positioned commutator compared to existing technologies.

[0045] Next, the commutator 7 and stator assembly 6 will be pressed together.

[0046] In this embodiment, the specific operation is as follows: the first control valve 51 is operated, causing the ejector cylinder 11 to drive the rotor ejector 12 to rise. The rotor ejector 12 passes through the first through hole 22 on the stator assembly mounting plate 2 and then presses against the welding plate on the stator assembly 6. At this time, the rotor ejector 12 slightly presses against the rotor assembly 61 to achieve temporary positioning, preventing the rotor assembly from shifting when the commutator mounting plate descends. Then, the adjustable stroke cylinder 41 drives the commutator pressing head 42 to descend. The commutator pressing head 42 passes through the second through hole 32 on the commutator mounting plate 3 and the commutator positioning block 31 until the commutator pressing head 42 abuts against the commutator 7. Then, the commutator 7 is pressed down, and finally the commutator 7 is connected to the rotor assembly 61 in the stator assembly 6, thereby completing the component press-fitting into an actuator.

[0047] Finally, all components were reset in sequence, and the actuator that had been press-fitted was removed.

[0048] The reset sequence of each component is as follows: First, operate the second control valve 52. The lifting cylinder 23 drives the reversing plate mounting plate 3 and its reversing plate positioning block 31 to rise. At this time, the rotor ejector pin 12 and the reversing plate pressing head 42 still apply force to the actuator that has been pressed in from above and below. Thus, as the reversing plate positioning block 31 rises, it can smoothly separate from the reversing plate 7. Then, operate the first control valve 51. The ejector pin cylinder 11 drives the rotor ejector pin 12 to descend. Then, the adjustable stroke cylinder 41 drives the reversing plate pressing head 42 to rise, releasing the restriction on the actuator that has been pressed in. Subsequently, the actuator is removed from the equipment. After all components have completed their actions, each component naturally returns to its initial position.

[0049] In this embodiment, the first control valve 51 and the second control valve 52 are operated manually. Therefore, controlling the movement of the ejector cylinder 11 and the adjustable stroke cylinder 41 by the same first control valve 51 simplifies the structure, reduces the number of manual operations, and also reduces the possibility of erroneous operation. Of course, the movement of the ejector cylinder 11 and the control of the adjustable stroke cylinder 41 can also be separated and controlled by separate control valves. Based on this, further improvements to the equipment can achieve automated operation.

Claims

1. A method for press-fitting an actuator, characterized in that: The commutator and stator assembly are placed in their respective positions on the press-fitting equipment and positioned so that they are facing each other. The rotor assembly is pre-rotated to a predetermined angle. The commutator and stator assembly are brought closer together. Before the commutator and stator assembly come into contact and until the press-fitting is completed, the excitation coil of the stator is connected to the external power supply and kept in place, so that the rotor assembly naturally deflects in the excitation magnetic field. The angle accuracy deviation between the deflected rotor assembly and the already positioned commutator is eliminated to the greatest extent. The commutator and stator assembly are pressed together to complete the press-fitting.

2. The press-fitting method for an actuator according to claim 1, characterized in that: Before the commutator and stator assembly are pressed together, the rotor pins are first slightly pressed against the rotor assembly to achieve temporary positioning.

3. The press-fitting method for an actuator according to claim 1, characterized in that: Before and after pressing, the components of the pressing equipment must be reset.

4. A pressing device according to the method of claim 1, 2, or 3, characterized in that: The press-fitting equipment includes a frame and a stator assembly mounting plate that are fixedly connected to each other, and a commutator mounting plate that can move away from and closer to the stator assembly mounting plate. The commutator mounting plate has a commutator positioning structure on the side near the stator assembly mounting plate, and a stator assembly positioning structure on the side near the commutator mounting plate. An external power terminal is provided on the commutator mounting plate at the position of the stator excitation coil power input terminal of the correctly placed stator assembly, which is electrically connected to an external power source. The external power terminal protrudes below the commutator mounting plate and has a retractable structure.

5. The pressing equipment according to claim 4, characterized in that: A pin cylinder is provided on the side of the stator assembly mounting plate away from the commutator mounting plate. The pin cylinder is equipped with a rotor pin, which can pass through the stator assembly mounting plate and extend towards the commutator mounting plate. A press-fit cylinder is provided on the side of the commutator mounting plate away from the stator assembly mounting plate. The press-fit cylinder is equipped with a commutator press-fit head, which can pass through the commutator mounting plate and extend towards the stator assembly mounting plate.

6. A pressing device according to the method of claim 1, 2, or 3, characterized in that: The press-fitting equipment includes a frame, a base, a commutator mounting plate, and a stator assembly mounting plate. The frame, base, and stator assembly mounting plate are fixedly connected to each other. The entire equipment consists of a horizontally arranged base, a stator assembly mounting plate, and a commutator mounting plate, arranged from bottom to top. The upward-facing side of the stator assembly mounting plate has a stator assembly positioning post, and the downward-facing side of the commutator mounting plate has a commutator positioning block. A lifting cylinder and a guide mechanism are provided between the stator assembly mounting plate and the commutator mounting plate. An external power terminal is provided on the commutator mounting plate, directly opposite the stator excitation coil power input terminal of the correctly positioned stator assembly. This external power terminal is electrically connected to an external power source and protrudes below the commutator mounting plate. This external power terminal has a retractable structure.

7. The pressing equipment according to claim 6, characterized in that: The base is equipped with a pin cylinder, which drives the rotor pin to rise and fall. The stator assembly mounting plate has a first through hole in the middle, through which the rotor pin can pass. Above the commutator mounting plate is an adjustable stroke cylinder fixed to the frame. The adjustable stroke cylinder has a downwardly extending commutator pressing head. The commutator positioning block and the middle of the commutator mounting plate have a second through hole, through which the commutator pressing head can pass.

8. The pressing equipment according to claim 7, characterized in that: The ejector cylinder and the adjustable stroke cylinder are both controlled by the first control valve, while the lifting cylinder is controlled by the second control valve.

9. The pressing equipment according to claim 8, characterized in that: The external power terminal is a retractable probe.

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