A fully automatic assembling machine for deep groove ball bearings

Abstract

The present invention relates to the technical field of bearing production, and discloses a full-automatic bearing assembling machine for deep groove ball bearings, comprising: a bearing table, and a feeding unit arranged on the bearing table; the feeding unit includes an outer ring feeding pipe and an inner ring feeding pipe fixedly installed on the bearing table, the inner diameter of the outer ring feeding pipe is equal to the outer diameter of the bearing outer ring, the inner diameter of the inner ring feeding pipe is equal to the outer diameter of the bearing inner ring, and an assembling mechanism arranged on the bearing table, the assembling mechanism includes a large disk and a small disk rotatably arranged on the bearing table, and the small disk is located above the large disk. The present invention adopts the technical means of combining the feeding unit and the assembling mechanism, and uses the co-rotation of the large disk and the small disk to successively push the bearing outer ring and the bearing inner ring into the discharge hole, completing the combination process of the bearing outer ring and the bearing inner ring, overcoming the deficiencies of the prior art and improving the practicability of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing production, and more specifically, it relates to a full-automatic bearing assembly machine for deep groove ball bearings. Background Art

[0002] Due to its advantages of small frictional resistance and high rotational speed, the deep groove ball bearing can be used on parts that can withstand radial loads or combined loads with both radial and axial actions simultaneously, and can also be used on parts that can withstand axial loads. It is the most widely used rolling bearing. Since the consumption of deep groove ball bearings is large, a device that can produce deep groove ball bearings fully automatically is needed.

[0003] Although the existing full-automatic bearing assembly machines for deep groove ball bearings can complete the production of deep groove ball bearings well and have high production efficiency, in the actual operation process, due to the use of a large number of cylinders as the driving units in this existing technology, the cost is high, the overall equipment volume is large, the operation is complex, the requirements for the site and personnel are high, the overall failure rate of the device is increased, and the overall manufacturing and maintenance costs are increased. Summary of the Invention

[0004] The present invention discloses a full-automatic bearing assembly machine for deep groove ball bearings, which solves the technical problems in bearing production in the related art.

[0005] The present invention discloses a full-automatic bearing assembly machine for deep groove ball bearings, including: a bearing table;

[0006] A feeding unit, arranged on the bearing table; the feeding unit includes an outer ring feeding pipe and an inner ring feeding pipe fixedly installed on the bearing table. The inner diameter of the outer ring feeding pipe is equal to the outer diameter of the bearing outer ring, and the inner diameter of the inner ring feeding pipe is equal to the outer diameter of the bearing inner ring;

[0007] A bearing assembly mechanism, arranged on the bearing table; the bearing assembly mechanism includes a large disc and a small disc rotatably arranged on the bearing table, and the small disc is located above the large disc. The discharge end of the outer ring feeding pipe is arranged above the large disc, and the discharge end of the inner ring feeding pipe is arranged above the small disc. A first feeding hole is penetrated through the large disc, second feeding holes are penetrated through both the large disc and the small disc, and a discharge hole is penetrated through the bearing table;

[0008] A moving assembly, arranged on the bearing table, for driving the large disc and the small disc to rotate in the same direction.

[0009] Preferably, the moving component includes two rotating shafts rotatably connected to the bearing platform. The two rotating shafts are respectively fixedly connected to the large disc or the small disc, and synchronous wheels are fixedly connected to the upper ends of the two rotating shafts. The two synchronous wheels are in driving cooperation through a synchronous belt. A driving device for driving one of the rotating shafts to rotate is fixedly installed on the lower surface of the bearing platform.

[0010] Preferably, the driving device is set as a servo motor, and the output shaft of the servo motor is fixedly connected to one of the rotating shafts.

[0011] Preferably, a positioning unit is arranged on the bearing platform. The positioning unit includes a slideway fixedly installed on the bearing platform. The slideway is arranged directly below the discharge hole. A positioning block is fixedly connected to the side of the slideway away from the bearing platform. A positioning groove is formed in the positioning block. The slideway is inclined at a first set angle, and the positioning block is inclined at a second set angle, and the first set angle is greater than the second set angle.

[0012] Preferably, a bead feeding unit is arranged on the bearing platform. The bead feeding unit includes an automatic bead separator fixedly installed on the bearing platform. The discharge end of the automatic bead separator is located directly above the positioning block.

[0013] Preferably, a reset component is arranged on the slideway. The reset component includes a mounting frame fixedly connected to the lower side of the slideway. A pressing rod is rotatably connected to the mounting frame. One end of the pressing rod close to the positioning block has a protrusion. A through groove for the protrusion to pass through is formed through the positioning block. A triangular block is fixedly connected to the end of the pressing rod away from the positioning block. A spring is arranged between the mounting frame and the pressing rod. One end of the spring is fixedly connected to the mounting frame, and the other end of the spring is fixedly connected to the pressing rod. A push rod is fixedly connected to the rotating shaft away from the servo motor.

[0014] Preferably, a buffer pad is fixedly connected to the inner side of the positioning block. The buffer pad is made of rubber material.

[0015] Preferably, two extraction grooves are formed through the positioning block, and the two extraction grooves are symmetrically arranged.

[0016] Preferably, an infrared scanner is installed on the lower side of the automatic bead separator.

[0017] Preferably, a plurality of support feet are fixedly connected to the lower side of the bearing platform, and the plurality of support feet are symmetrically arranged.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The present invention adopts the technical means of combining a feeding unit and a fitting mechanism, and utilizes the co-rotation of a large disc and a small disc to successively push a bearing outer ring and a bearing inner ring into a discharge hole, completing the combination process of the bearing outer ring and the bearing inner ring, overcoming the deficiencies of the prior art and improving the practicality of the device.

[0020] 2. The present invention adopts the technical means of mutual cooperation between a push rod and a triangular block, and intermittently presses the triangular block by rotating the push rod to automatically engage the bearing balls and the bearing inner ring, further improving the practicality of the device. Brief Description of the Drawings

[0021] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 is a schematic diagram of the overall structure of the present invention for showing the feeding unit and the fitting mechanism;

[0023] Figure 3 is a schematic diagram of the overall structure of the present invention for showing the moving component;

[0024] Figure 4 is a schematic diagram of the overall structure of the present invention for showing the positioning unit and the bead feeding unit;

[0025] Figure 5 is a schematic diagram of the overall structure of the present invention for showing the reset component.

[0026] In the figure: 100, bearing platform; 101, support feet; 200, feeding unit; 300, fitting mechanism; 400, moving component; 500, positioning unit; 600, bead feeding unit; 601, automatic bead separator; 602, infrared scanner; 700, reset component;

[0027] 201, outer ring feeding pipe; 202, inner ring feeding pipe;

[0028] 301, large disc; 302, small disc; 303, first feeding hole; 304, second feeding hole; 305, discharge hole;

[0029] 401, rotating shaft; 402, synchronous pulley; 403, synchronous belt; 404, servo motor;

[0030] 501, slideway; 502, positioning block; 503, buffer pad; 504, extraction groove;

[0031] 701, mounting bracket; 702, extrusion rod; 703, triangular block; 704, spring; 705, push rod. Detailed Embodiment

[0032] Reference will now be made to example embodiments to discuss the subject matter described herein. It should be understood that discussing these embodiments is only to enable those skilled in the art to better understand and thus implement the subject matter described herein, and changes can be made to the functions and arrangements of the elements discussed without departing from the scope of protection of the content of this specification. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described in some examples can also be combined in other examples.

[0033] As Figure 1 , Figure 2 , Figure 4 shown, the present embodiment discloses a full-automatic assembling machine for deep groove ball bearings, including: a bearing table 100, a feeding unit 200 disposed on the bearing table 100, the feeding unit 200 including an outer ring feeding pipe 201 and an inner ring feeding pipe 202 fixedly installed on the bearing table 100. The inner diameter of the outer ring feeding pipe 201 is equal to the outer diameter of the bearing outer ring, and the inner diameter of the inner ring feeding pipe 202 is equal to the outer diameter of the bearing inner ring. An assembling mechanism 300 is disposed on the bearing table 100. The assembling mechanism 300 includes a large disk 301 and a small disk 302 rotatably disposed on the bearing table 100, and the small disk 302 is located above the large disk 301. The discharging end of the outer ring feeding pipe 201 is disposed above the large disk 301, and the discharging end of the inner ring feeding pipe 202 is disposed above the small disk 302. A first feeding hole 303 is formed through the large disk 301, and second feeding holes 304 are formed through both the large disk 301 and the small disk 302. A discharging hole 305 is formed through the bearing table 100. A moving component 400 is disposed on the bearing table 100 for driving the large disk 301 and the small disk 302 to rotate in the same direction.

[0034] The working principle and beneficial effects of the above technical solution are as follows: First, the bearing outer ring and the bearing inner ring are respectively placed into the outer ring feeding pipe 201 and the inner ring feeding pipe 202 in a stacked manner. The bearing outer ring at the lowermost side abuts against the upper surface of the large disk 301, and the bearing inner ring at the lowermost side abuts against the upper surface of the small disk 302.

[0035] Next, the large disc 301 and the small disc 302 are driven by the moving device to rotate in the same direction. The first feeding hole 303 on the large disc 301 first rotates to a position directly opposite to the outer ring feeding pipe 201. The bearing outer ring at the lowermost side falls into this feeding hole. Finally, the second feeding hole 304 on the small disc 302 rotates to a position directly opposite to the inner ring feeding pipe 202, and the bearing inner ring at the lowermost side falls into this feeding hole. At this time, the second feeding hole 304 on the large disc 301 also rotates to a position directly opposite to the outer ring feeding pipe 201. However, since the diameter of the second feeding hole 304 is smaller than the outer diameter of the bearing outer ring, the bearing outer ring does not fall into this feeding hole. The large disc 301 continues to rotate, driving the bearing outer ring in the first feeding hole 303 to move to a position directly opposite to the discharging hole 305. The bearing outer ring first falls into the discharging hole 305. Then, the two second feeding holes 304 rotate synchronously to a position directly opposite to the discharging hole 305, and the bearing inner ring also falls into the discharging hole 305 under the action of gravity, thus successfully completing the assembly process of the bearing inner ring and the bearing outer ring.

[0036] The present invention adopts the technical means of the cooperation between the feeding unit 200 and the assembling mechanism 300. By using the same-direction rotation of the large disc 301 and the small disc 302, the bearing outer ring and the bearing inner ring are successively pushed into the discharging hole 305 to complete the combination process of the bearing outer ring and the bearing inner ring, overcoming the deficiencies of the prior art and improving the practicability of the device.

[0037] As Figure 3 shown, in a specific embodiment: The moving assembly 400 includes two rotating shafts 401 rotatably connected to the bearing platform 100. The two rotating shafts 401 are respectively fixedly connected to the large disc 301 or the small disc 302, and synchronous wheels 402 are fixedly connected to the upper ends of the two rotating shafts 401. The two synchronous wheels 402 are in transmission cooperation through a synchronous belt 403. A driving device for driving one of the rotating shafts 401 to rotate is fixedly installed on the lower surface of the bearing platform 100.

[0038] The working principle and beneficial effects of the above technical solution are: Start the driving device. The driving device drives one of the rotating shafts 401 to rotate, and then the synchronous wheel 402 thereon rotates. Under the transmission action of the synchronous belt 403, the two synchronous wheels 402 rotate synchronously, thereby driving the large disc 301 and the small disc 302 to rotate synchronously to complete the feeding work of the bearing outer ring and the bearing inner ring.

[0039] As Figure 3 shown, in a specific embodiment: The driving device is set as a servo motor 404, and the output shaft of the servo motor 404 is fixedly connected to one of the rotating shafts 401.

[0040] The working principle and beneficial effects of the above technical solution are as follows: Start the servo motor 404, and the output shaft of the servo motor 404 rotates, driving the rotating shaft 401 to rotate synchronously.

[0041] As Figure 4 shown, in a specific embodiment: A positioning unit 500 is provided on the carrier table 100. The positioning unit 500 includes a slideway 501 fixedly installed on the carrier table 100. The slideway 501 is arranged directly below the discharge hole 305. A positioning block 502 is fixedly connected to the side of the slideway 501 away from the carrier table 100. A positioning groove is provided on the positioning block 502. The slideway 501 is inclined at a first set angle, and the positioning block 502 is inclined at a second set angle, and the first set angle is greater than the second set angle.

[0042] The working principle and beneficial effects of the above technical solution are as follows: The outer ring and inner ring of the bearing enter the slideway 501 through the discharge hole 305 successively. Since the slideway 501 is inclined, the outer ring and inner ring of the bearing slide down the slideway 501 to the positioning groove in the positioning block 502 successively. And because the positioning block 502 is also inclined, under the action of gravity, the inner ring of the bearing abuts against the inner ring part on the lower side of the outer ring of the bearing, so that a gap convenient for filling the bearing balls is formed between the outer side of the inner ring of the bearing and the inner side of the outer ring of the bearing.

[0043] As Figure 4 shown, in a specific embodiment: A ball supply unit 600 is provided on the carrier table 100. The ball supply unit 600 includes an automatic ball separator 601 fixedly installed on the carrier table 100. The discharge end of the automatic ball separator 601 is located directly above the positioning block 502.

[0044] The working principle and beneficial effects of the above technical solution are as follows: Whenever the inner ring and outer ring of the bearing fall into the positioning groove on the positioning block 502, the automatic ball separator 601 ejects a set number of bearing balls, and the bearing balls just fall into the gap formed between the inner ring and outer ring of the bearing.

[0045] As Figure 5 shown, in a specific embodiment: A reset assembly 700 is provided on the slideway 501. The reset assembly 700 includes a mounting frame 701 fixedly connected to the lower side of the slideway 501. A pressing rod 702 is rotatably connected to the mounting frame 701. One end of the pressing rod 702 close to the positioning block 502 has a protrusion. A through groove for the protrusion to pass through is provided through the positioning block 502. A triangular block 703 is fixedly connected to the end of the pressing rod 702 away from the positioning block 502. A spring 704 is arranged between the mounting frame 701 and the pressing rod 702. One end of the spring 704 is fixedly connected to the mounting frame 701, and the other end of the spring 704 is fixedly connected to the pressing rod 702. A push rod 705 is fixedly connected to the rotating shaft 401 away from the servo motor 404.

[0046] The working principle and beneficial effects of the above technical solution are as follows: After both the inner bearing ring and the outer bearing ring slide down into the positioning grooves on the positioning block 502 and the bearing balls are filled, the rotating shaft 401 continues to rotate, driving the extrusion rod 702 at its lower end to contact and press the inclined surface of the triangular block 703, thereby driving the extrusion rod 702 to rotate. The spring 704 is compressed, and the protruding part on the extrusion rod 702 passes through and pushes the inner bearing ring, causing it to move to the central position of the inner bearing ring. Multiple bearing balls are distributed in a ring between the outer bearing ring and the inner bearing ring. At this time, the extrusion rod 702 just disengages from the triangular block 703, and the extrusion rod 702 resets under the elastic force of the spring 704. By repeating this cycle, the positioning of the inner bearing ring can be intermittently completed through the rotation of the rotating shaft 401.

[0047] As Figure 2 shown, in a specific embodiment: A buffer pad 503 is fixedly connected to the inner side of the positioning block 502, and the buffer pad 503 is made of rubber material.

[0048] The working principle and beneficial effects of the above technical solution are as follows: The setting of the buffer pad 503 can prevent the direct collision between the outer bearing ring and the positioning block 502.

[0049] As Figure 2 shown, in a specific embodiment: Two extraction slots 504 are penetrated through the positioning block 502, and the two extraction slots 504 are symmetrically arranged.

[0050] The working principle and beneficial effects of the above technical solution are as follows: The setting of the extraction slots 504 facilitates the staff to take out the bearings that have been assembled together by hand or fixture, further improving the practicality of this device.

[0051] As Figure 4 shown, in a specific embodiment: An infrared scanner 602 is installed on the lower side of the automatic ball separator 601.

[0052] The working principle and beneficial effects of the above technical solution are as follows: When the infrared scanner 602 scans that the inner bearing ring stays within its scanning range, it will control the automatic ball separator 601 to eject a set number of bearing balls through a pre-set control program, and the bearing balls just fall into the gap formed between the inner bearing ring and the outer bearing ring.

[0053] As Figure 2 shown, in a specific embodiment: A plurality of support feet 101 are fixedly connected to the lower side of the carrier 100, and the plurality of support feet 101 are symmetrically arranged.

[0054] The working principle and beneficial effects of the above technical solution are as follows: The setting of the support feet 101 can improve the stability of this device.

[0055] Working principle:

[0056] First, the outer ring and inner ring of the bearing are respectively placed into the outer ring feeding pipe 201 and the inner ring feeding pipe 202 in a stacked manner. The bottommost outer ring of the bearing abuts against the upper surface of the large disc 301, and the bottommost inner ring of the bearing abuts against the upper surface of the small disc 302.

[0057] Next, start the driving device. The driving device drives one of the rotating shafts 401 to rotate, and then the synchronous pulley 402 thereon rotates. Under the driving action of the synchronous belt 403, the two synchronous pulleys 402 rotate synchronously, thereby driving the large disc 301 and the small disc 302 to rotate synchronously.

[0058] The first feeding hole 303 on the large disc 301 first rotates to a position directly opposite to the outer ring feeding pipe 201, and the bottommost outer ring of the bearing falls into this feeding hole. Finally, the second feeding hole 304 on the small disc 302 rotates to a position directly opposite to the inner ring feeding pipe 202, and the bottommost inner ring of the bearing falls into this feeding hole. At this time, the second feeding hole 304 on the large disc 301 also rotates to a position directly opposite to the outer ring feeding pipe 201. However, since the diameter of the second feeding hole 304 is smaller than the outer diameter of the bearing outer ring, the bearing outer ring does not fall into this feeding hole. The large disc 301 continues to rotate, driving the bearing outer ring in the first feeding hole 303 to move to a position directly opposite to the discharge hole 305. The bearing outer ring first falls into the discharge hole 305. Then, the two second feeding holes 304 rotate synchronously to a position directly opposite to the discharge hole 305, and the bearing inner ring also falls into the discharge hole 305 under the action of gravity.

[0059] The bearing outer ring and the bearing inner ring successively enter the slideway 501 through the discharge hole 305. Since the slideway 501 is inclined, the bearing outer ring and the bearing inner ring successively slide down along the slideway 501 into the positioning grooves in the positioning block 502. And since the positioning block 502 is also inclined, the bearing inner ring abuts against the inner ring part on the lower side of the bearing outer ring under the action of gravity, forming a gap convenient for filling the bearing balls between the outer side of the bearing inner ring and the inner side of the bearing outer ring.

[0060] Whenever a bearing inner ring and a bearing outer ring fall into the positioning grooves on the positioning block 502, the automatic ball separator 601 ejects a set number of bearing balls, and the bearing balls just fall into the gap formed between the bearing inner ring and the bearing outer ring.

[0061] After both the inner bearing ring and the outer bearing ring slide down into the positioning grooves on the positioning blocks 502 and the bearing beads are filled, the rotating shaft 401 continues to rotate, driving the extrusion rod 702 at its lower end to contact and squeeze the inclined surface portion of the triangular block 703, thereby driving the extrusion rod 702 to rotate. The spring 704 is compressed, and the protruding portion on the extrusion rod 702 passes through and pushes the inner bearing ring, causing it to move to the central position of the inner bearing ring. Multiple bearing beads are annularly distributed between the outer bearing ring and the inner bearing ring. At this time, the extrusion rod 702 just disengages from the triangular block 703, and the extrusion rod 702 resets under the elastic force of the spring 704. By repeating this cycle, the positioning of the inner bearing ring can be intermittently completed through the rotation of the rotating shaft 401.

[0062] The embodiments of the present invention have been described above, but these embodiments are not limited to the above specific implementation manners. The above specific implementation manners are merely illustrative and not restrictive. Under the inspiration of this embodiment, those of ordinary skill in the art can also make many forms, all of which fall within the protection scope of this embodiment.

Claims

1. A fully automatic deep groove ball bearing assembly machine, characterized in that: include: Loading platform; A feeding unit is arranged on the bearing platform; the feeding unit comprises an outer ring feeding pipe and an inner ring feeding pipe fixedly mounted on the bearing platform, the inner diameter of the outer ring feeding pipe is equal to the outer diameter of the bearing outer ring, and the inner diameter of the inner ring feeding pipe is equal to the outer diameter of the bearing inner ring; A sleeve-fitting mechanism is arranged on the bearing platform; the sleeve-fitting mechanism comprises a large disc and a small disc rotatably arranged on the bearing platform, and the small disc is located on the upper side of the large disc, the discharge end of the outer ring feed pipe is arranged on the upper side of the large disc, the discharge end of the inner ring feed pipe is arranged on the upper side of the small disc, a first feed hole is penetrated on the large disc, a second feed hole is penetrated on both the large disc and the small disc, and a discharge hole is penetrated on the bearing platform; A moving assembly, arranged on the bearing platform, for driving the large disc and the small disc to rotate in the same direction; When the large disc and the small disc rotate in the same direction to a position where the first feed hole on the large disc and the outer ring feed pipe are directly opposite, the outer ring of the bearing located at the lowermost side falls into the first feed hole; When the second feed hole on the small disc rotates to a position directly opposite to the inner ring feed tube, the bearing inner ring at the bottom falls into the second feed hole on the small disc. At this time, the second feed hole on the large disc also rotates to a position directly opposite to the outer ring feed tube. The diameter of the second feed hole is smaller than the outer diameter of the bearing outer ring. The bearing outer ring does not fall into the second feed hole on the large disc. The large disc drives the bearing outer ring in the first feed hole to move to a position directly opposite to the discharge hole. The bearing outer ring first falls into the discharge hole. Then, when the two second feed holes rotate synchronously to a position directly opposite to the discharge hole, the bearing inner ring falls into the discharge hole under the action of gravity, completing the fitting process of the bearing inner ring and the bearing outer ring.

2. The fully automatic deep groove ball bearing assembly machine according to claim 1, characterized in that: The moving assembly includes two rotating shafts rotatably connected to the supporting platform, the two rotating shafts are respectively fixedly connected to the large disc or the small disc, and the upper ends of the two rotating shafts are fixedly connected with synchronous wheels, and the two synchronous wheels are matched through a synchronous belt transmission. A driving device for driving one of the rotating shafts to rotate is fixedly installed on the lower surface of the supporting platform.

3. The fully automatic deep groove ball bearing assembly machine according to claim 2, characterized in that: The driving device is configured as a servo motor, and an output shaft of the servo motor is fixedly connected to one of the rotating shafts.

4. The fully automatic deep groove ball bearing assembly machine according to claim 3, characterized in that: A positioning unit is provided on the supporting platform, and the positioning unit includes a slide fixedly installed on the supporting platform, the slide is provided directly below the discharge hole, a positioning block is fixedly connected to a side of the slide away from the supporting platform, a positioning groove is provided on the positioning block, the slide is inclined at a first set angle, the positioning block is inclined at a second set angle, and the first set angle is greater than the second set angle.

5. The fully automatic deep groove ball bearing assembly machine according to claim 4, characterized in that: The support platform is provided with a bead supply unit, and the bead supply unit comprises an automatic bead separator fixedly mounted on the support platform, and a discharge end of the automatic bead separator is located directly above the positioning block.

6. The fully automatic deep groove ball bearing assembly machine according to claim 5, characterized in that: The slide is provided with a reset assembly, and the reset assembly includes a mounting bracket fixedly connected to the lower side of the slide, an extrusion rod is rotatably connected to the mounting bracket, the extrusion rod has a protrusion at one end close to the positioning block, a through slot is penetrated through the positioning block for the protrusion to pass through, the extrusion rod is fixedly connected to the end away from the positioning block with a triangular block, a spring is provided between the mounting bracket and the extrusion rod, one end of the spring is fixedly connected to the mounting bracket, and the other end of the spring is fixedly connected to the extrusion rod, and a push rod is fixedly connected to the rotating shaft away from the servo motor.

7. The fully automatic deep groove ball bearing assembly machine according to claim 6, characterized in that: A buffer pad is fixedly connected to the inner side of the positioning block, and the buffer pad is made of rubber material.

8. The fully automatic deep groove ball bearing assembly machine according to claim 7, characterized in that: The positioning block is provided with two extraction grooves, and the two extraction grooves are symmetrically arranged.

9. The fully automatic deep groove ball bearing assembly machine according to claim 8, characterized in that: An infrared scanner is installed on the lower side of the automatic bead separator.

10. The fully automatic deep groove ball bearing assembly machine according to claim 9, characterized in that: A plurality of supporting legs are fixedly connected to the lower side of the bearing platform, and the plurality of supporting legs are symmetrically arranged.

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