Motor direct-drive horizontal rotary table

Abstract

A motor direct-drive horizontal rotary table, comprising: a housing, comprising a main housing (21), a front cover plate (22) and a rear cover plate (23); a spindle, comprising a first spindle (31), a second spindle (32) and a third spindle (33) which are coaxially connected in sequence in the horizontal direction; a bearing (6), sleeved on the first spindle (31); a direct drive motor, comprising a motor rotor (41) and a motor stator (42); a table plate (5), connected to a connection end (312) of the first spindle (31); a first protective structure, provided between the table plate (5), the front cover plate (22) and the connection end (312), the front cover plate (22) being internally provided with a first air inlet channel (221) communicated with the first protective structure; and a main control center, used for controlling the direct drive motor and controlling a protective airflow provided by the first air inlet channel (221) for the first protective structure. The motor rotor (41) is spaced apart from the bearing (6), and the motor rotor (41) is fixed at a fixed connection position between a driving end (311) and the second spindle (32). The horizontal rotary table has the advantages of high rotation accuracy and stable and reliable structure.

Description

Motor direct drive horizontal rotary table TECHNICAL FIELD

[0001] The present application relates to the technical field of numerical control machine tools, in particular to a motor direct drive horizontal rotary table. BACKGROUND

[0002] Horizontal rotary tables are widely used in various numerical control machine tools, mainly in numerical control machining machine tools such as milling machines and drilling machines, for fixing and rotating workpieces. The horizontal rotary tables in the prior art are basically driven by servo motors through gear transmission or worm gear to drive the mandrel to rotate the table top. The workpiece is fixed on the table top, and a protective structure is arranged between the table top and the end face of the shell to prevent foreign matters such as condensed water, hydraulic oil, cutting fluid or dust from entering the interior. However, the existing horizontal rotary table still has at least the following disadvantages:

[0003] 1. Low rotation accuracy. Since the motor drives the mandrel through mechanical transmission structures such as gear transmission or worm gear transmission, the accuracy is low, which is difficult to meet the current high-precision machining requirements.

[0004] 2. Poor reliability of the protective structure. The existing horizontal rotary table adopts a relatively simple protective structure, which has poor protection capability, resulting in foreign matters such as condensed water, hydraulic oil and cutting fluid entering the interior of the rotary table during use, thereby affecting the accuracy and service life. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art, and proposes a motor direct drive horizontal rotary table, which has the advantages of high accuracy and stable and reliable structure.

[0006] The present application proposes a motor direct drive horizontal rotary table, which comprises:

[0007] A shell comprising a main shell and a front cover plate and a rear cover plate respectively assembled on both end sides of the main shell;

[0008] A mandrel in a hollow cylindrical structure, comprising a first mandrel, a second mandrel and a third mandrel connected coaxially in sequence in the transverse direction, both ends of the first mandrel being a driving end and a connecting end respectively, the connecting end extending out of the front cover plate, and the driving end being fixedly connected with the second mandrel;

[0009] A bearing is sleeved on the first mandrel and arranged close to the connecting end;

[0010] A direct drive motor comprising a motor rotor sleeved on the first mandrel and a motor stator for driving the motor rotor, the motor stator being fixed to the inner wall of the main shell;

[0011] A disc-shaped table top located on the outer side of the front cover plate and connected with the connecting end of the first mandrel;

[0012] A first protection structure is arranged between the table top, the front cover plate and the connecting end to form an air curtain seal to prevent foreign matter from entering;

[0013] A master control center is configured to control the direct drive motor and control the first air inlet to provide protection air flow to the first protection structure;

[0014] The motor rotor is arranged at a distance from the bearing, and the motor rotor is fixed at the fixed connection between the driving end and the second mandrel.

[0015] In some preferred embodiments, one end side of the motor rotor is at a first distance from the bearing, the other end side of the motor rotor is at a second distance from the rear cover plate, the motor rotor, the motor stator and the mandrel are coaxially arranged, and the motor rotor and the motor stator are at a third distance, which connects the first distance and the second distance.

[0016] In some preferred embodiments, the first distance L1, the second distance L2 and the third distance L3 are in the order of L3 < L2 < L1.

[0017] In some preferred embodiments, the first protection structure comprises:

[0018] A first air equalization ring groove is formed between the outlet of the first air inlet and the connecting end.

[0019] A first drainage channel is axially arranged in the front cover plate and connected to the first air equalization ring groove.

[0020] A first air outlet is formed by the gap between the table top and the front cover plate, and the first air outlet comprises a flow-increasing sub-air channel with a bending structure and an exhaust sub-air channel with a straight structure, and the lateral spacing of the flow-increasing sub-air channel is smaller than that of the exhaust sub-air channel.

[0021] A first water prevention groove is connected between the flow-increasing sub-air channel and the exhaust sub-air channel, and a first water guide slope is arranged between the inner wall of the first water prevention groove and the exhaust sub-air channel.

[0022] The flow-increasing sub-air channel accelerates the air from the first air equalization ring groove to blow out, so that the foreign matter entering the first water prevention groove is accelerated to blow out through the exhaust sub-air channel.

[0023] In some preferred embodiments, a first water-blocking ring coaxial with the mandrel is protruded on the inner side of the deck, and a second water-blocking ring is protruded on the side of the front cover plate, the first water-blocking ring and the second water-blocking ring are oppositely arranged in staggered and spaced manner, so that the air passage of the flow multiplier is formed between the deck and the front cover plate.

[0024] A second water-preventing groove is arranged on the horizontal side of the second water-blocking ring, the second water-preventing groove and the first water-preventing groove are communicated by a first vertical air passage, the first vertical air passage is part of the air passage of the flow multiplier, and the first vertical air passage is located in the projection range of the air exhaust passage.

[0025] In some preferred embodiments, a third water-blocking ring located inside the second water-blocking ring is further protruded on the inner side of the deck, the third water-blocking ring abuts against the connecting end, and the first air equalizing ring groove is located between the second water-blocking ring and the third water-blocking ring.

[0026] A third water-preventing groove is arranged on the connecting end, the first air inlet passage is located in the third water-preventing groove in the projection of the connecting end, the third water-preventing groove and the third water-blocking ring have a second water-guiding inclined surface therebetween, and one end of the first water outlet passage is located in the third water-preventing groove.

[0027] In some preferred embodiments, the first protection structure further comprises:

[0028] A second air outlet passage is formed by the gap between the front cover plate and the connecting end.

[0029] A fourth water-preventing groove is arranged on the side of the front cover plate facing the connecting end, and the fourth water-preventing groove and the third water-preventing groove are oppositely arranged in staggered and spaced manner.

[0030] In some preferred embodiments, the third mandrel is exposed outside the rear cover plate, the second mandrel is provided with a stepped position, the stepped position is fixed with a disc grating, and the inner side of the rear cover plate is provided with a reading head matched with the disc grating.

[0031] In some preferred embodiments, the third mandrel and the rear cover plate have a second protection structure, and a second air inlet passage is arranged in the rear cover plate and communicated with the second protection structure.

[0032] In some preferred embodiments, the main control center controls the first air inlet passage to provide a protection gas flow with a preset pressure P1 before starting the direct drive motor.

[0033] After the direct drive motor is started, the main control center generates a random jitter control signal in each preset period T, and based on the random jitter control signal, the protective air flow provided to the first air inlet is randomly increased or decreased to generate a protective air pressure fluctuation, so that the foreign matter that has entered the first protective structure changes position based on the protective air pressure fluctuation to promote the foreign matter to be discharged from the first protective structure.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] 1. The direct drive motor directly drives the mandrel installed inside the shell, so that the overall structure of the horizontal rotary table is compact, and there is no mechanical transmission structure when the traditional servo motor is driven, and there is no cogging effect, thereby greatly improving the rotation accuracy of the horizontal rotation.

[0036] 2. The mandrel adopts a segmented structure to facilitate assembly and later disassembly and maintenance of the horizontal rotary table; the bearing sleeve is arranged on the first mandrel and close to the connecting end, and the motor rotor of the direct drive motor is fixed at the fixed connection between the driving end and the second mandrel, so that the motor rotor and the bearing cooperate to reduce the runout error of the table during rotation to improve the rotation accuracy, and the second mandrel is directly driven by the direct drive motor to enable the disc grating to accurately detect the rotation of the table.

[0037] 3. The first protective structure forms a reliable air curtain sealing structure, which can completely avoid the entry of foreign matter such as condensed water, hydraulic oil and cutting fluid generated during processing from the rotation avoidance gap between the table and the front cover plate into the rotary table, thereby affecting the working accuracy of the horizontal rotary table, and also preventing the foreign matter from entering and damaging the direct drive motor, thereby protecting the horizontal rotary table and improving the working stability and service life of the horizontal rotary table. BRIEF DESCRIPTION OF DRAWINGS

[0038] Fig. 1 is a schematic view of the horizontal rotary table according to the present application.

[0039] Fig. 2 is a schematic view of the internal structure of the horizontal rotary table according to the present application.

[0040] Fig. 3 is an enlarged view of part A in Fig. 2.

[0041] Fig. 4 is an enlarged view of part B in Fig. 2. DETAILED DESCRIPTION

[0042] For further illustrating the technical means and effects taken by the present application to achieve the predetermined purposes, the specific embodiments, structures, features and effects thereof according to the present application are described in detail as follows in combination with the drawings and preferred embodiments. In the following description, different "an embodiment" or "embodiments" refer to different embodiments, which are not necessarily the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0043] In combination with the drawings shown in FIG. 1-4, the present application discloses a motor direct drive horizontal rotary table, comprising: a support seat 1; a shell fixed on the support seat 1, the shell specifically comprising a main shell 21 and a front cover plate 22 and a rear cover plate 23 respectively assembled at both ends of the main shell 21; a core shaft transversely arranged in the main shell 21, which is a hollow cylindrical structure, can reduce the mass to reduce the rotational inertia of the core shaft to improve the rotation accuracy of the horizontal rotary table; a bearing 6 arranged between the core shaft and the main shell 21; a direct drive motor coaxially arranged with the core shaft, driven by the direct drive motor to rotate the core shaft relative to the main shell 21 according to the bearing 6; a table top 5 fixed at one end of the core shaft, which is a disc-shaped structure for fixing the workpiece to be processed, the table top 5 is located on the outer side of the front cover plate 22 and drives the table top 5 to rotate by the core shaft, so that the workpiece fixed on the table top 5 rotates as needed to meet the processing needs; a first protection structure arranged between the table top 5, the front cover plate 22 and the end of the core shaft, which prevents foreign matter such as condensed water, hydraulic oil and cutting fluid from entering the rotary table during the processing process from the rotating gap between the table top 5 and the front cover plate 22; a master control center for controlling the direct drive motor and controlling the protection airflow provided to the first protection structure.

[0044] The core shaft adopts a segmented structure to facilitate the assembly and later disassembly and maintenance of the horizontal rotary table. The core shaft specifically comprises a first core shaft 31, a second core shaft 32 and a third core shaft 33 which are transversely and coaxially connected in sequence, both ends of the first core shaft 31 are respectively a driving end 311 and a connecting end 312, the connecting end 312 extends out of the front cover plate 22 and is fixedly connected with the table top 5, the driving end 311 is fixedly connected with the second core shaft 32, and the direct drive motor is connected with the driving end 311 of the first core shaft 31.

[0045] Specifically, the bearing 6 is sleeved on the first core shaft 31 to support the rotation of the core shaft relative to the main shell 21; and the bearing 6 is arranged close to the connecting end 312 of the first core shaft 31. Since the direct drive motor is connected with the driving end 311 of the first core shaft 31, and the bearing 6 is arranged close to the connecting end 312 of the first core shaft 31, the bearing 6 provides rotational support for the connecting end 312, which can reduce the axial jump of the connecting end 312 of the first core shaft 31 during rotation relative to the driving end 311, so as to reduce the jump amplitude of the table top 5 and improve the rotation accuracy of the horizontal rotary table.

[0046] Specifically, the direct drive motor comprises a motor rotor 41 sleeved on the first shaft 31 and a motor stator 42 for driving the motor rotor 41, the motor stator 42 is fixed on the inner wall of the main housing 21, and the motor rotor 41 is fixed on the driving end 311 of the first shaft 31. By adopting the direct drive motor to directly drive the shaft and installing the direct drive motor inside the housing, the overall structure of the horizontal rotary table is compact, and there is no mechanical transmission structure and no cogging effect when the traditional servo motor is driven, so that the rotation accuracy of the horizontal rotary table is greatly improved.

[0047] In addition, the motor rotor 41 is spaced apart from the bearing 6, and the motor rotor 41 is fixed at the fixed connection between the driving end 311 and the second shaft 32. This structure reduces the axial runout amplitude of the connecting end 312 of the first shaft 31 by spacing the motor rotor 41 and the bearing 6 to cooperate to improve the rotation accuracy, and directly drives the second shaft 32 by the motor rotor 41 to make the second shaft 32 have no runout error relative to the first shaft 31, which provides the implementation condition for the disc grating 91 to accurately detect the rotation of the table top 5 when the disc grating 91 is installed on the second shaft 32.

[0048] Specifically, the second shaft 32 is provided with a stepped position, and the disc grating is fixed on the stepped position of the second shaft 32. In addition, the third shaft 33 is exposed outside the rear cover plate 23, so that the horizontal rotary table can be connected to other parts of the numerical control machine tool as needed through the third shaft 33 to meet the actual machining needs. The inner side of the rear cover plate 23 is provided with a reading head 92 matched with the disc grating 91.

[0049] Specifically, as shown in FIG. 3, one end side of the motor rotor 41 has a first interval with the bearing 6, the transverse dimension of the first interval is L1; the other end side of the motor rotor 41 has a second interval with the rear cover plate 23, the transverse dimension of the second interval is L2; the motor rotor 41, the motor stator 42 and the first shaft 31 are coaxially arranged, and the motor rotor 41 and the motor stator 42 have a third interval, the third interval is arranged to communicate the first interval and the second interval to form a heat dissipation channel of the motor stator 42; the axial dimension of the third interval is L3, L3 < L2 < L1, so that the heat dissipation channel formed on the side of the motor stator 42 is large, and the heat dissipation effect of the motor stator 42 installed inside the housing is good to ensure the stable and reliable operation of the direct drive motor.

[0050] In addition, by setting L3 to be small so that the motor rotor 41 and the motor stator 42 have a reasonable rotation gap, the direct drive motor can be ensured to have stable and reliable operation and better working efficiency; by setting L1 to be maximum so that the motor rotor 41 is arranged as far away from the bearing 6 as possible, the motor rotor 41 and the bearing 6 are cooperated to reduce the runout error of the rotating table 5 to improve the rotation accuracy of the horizontal rotary table; by setting L2 to be relatively small compared with L1 but larger than L3, the second shaft 32 and the third shaft 33 are designed to have a relatively short axial length so that the overall structure of the rotary table is more compact.

[0051] The first protection structure is arranged to form an air curtain seal between the table 5, the front cover plate 22 and the connecting end 312 of the first shaft 31 to prevent foreign matters from entering from the rotation gap between the table 5 and the front cover plate 22. The first air inlet 221 is arranged in the front cover plate 22 and communicates with the first protection structure. Of course, an outer extension section 211 of the first air inlet can also be arranged on the main housing 21 to communicate with the first air inlet 221. An external air source is injected into the first protection structure through the outer extension section 211 and the first air inlet 221 as needed to form an air curtain seal in the first protection structure, thereby preventing foreign matters from entering the main housing 21 to affect the working accuracy of the horizontal rotary table and preventing damage to the direct drive motor.

[0052] Especially in combination with FIGS. 2 and 4. The first protection structure comprises a first air equalizing ring groove 71 formed between the outlet of the first air inlet and the connecting end 312 of the first shaft 31. Since the shaft is a hollow cylinder, the first air equalizing ring groove 71 is arranged in a ring around the connecting end 312. At least one first drainage channel 72 is axially arranged in the front cover plate 22 and communicates with the first air equalizing ring groove 71. When the shaft rotates to a position where the first drainage channel 72 is downward from the first air equalizing ring groove 71, foreign matters entering the first air equalizing ring groove 71 can be discharged from the first drainage channel 72. A first air outlet is formed by the gap between the table 5 and the front cover plate 22. The first air outlet comprises a flow-increasing sub-air channel 731 having a bending structure and an air exhaust sub-air channel 732 having a straight line structure. The lateral spacing of the flow-increasing sub-air channel 731 is smaller than that of the air exhaust sub-air channel 732. A first water-proof groove 74 is arranged in communication between the flow-increasing sub-air channel 731 and the air exhaust sub-air channel 732. A first water guide slope 741 is arranged between the inner wall of the first water-proof groove 74 and the air exhaust sub-air channel 732. The flow-increasing sub-air channel 731 forms a narrow tube effect relative to the air exhaust sub-air channel 732. The flow-increasing sub-air channel 732 accelerates the blowing of the gas in the first air equalizing ring groove 71 to accelerate the blowing of foreign matters in the first water-proof groove 74 through the air exhaust sub-air channel 732.

[0053] The protection air flow with preset pressure P1 is provided to the first air inlet 221 controlled by the master control center, the protection air flow fills the first air equalizing ring groove 71 through the first air inlet 221, and diffuses into the flow-increasing sub-air channel 731 through the first air equalizing ring groove 71 in the circumferential direction to be accelerated and blown out from the air outlet sub-air channel 732 to form a sealed air curtain in the rotation avoiding gap between the table top 5 and the front cover plate 22.

[0054] During the working process of the horizontal rotary table, if foreign matters such as condensed water, hydraulic oil, cutting fluid or dust fall into the air outlet sub-air channel 732, they will be blown away by the air flow accelerated and blown out from the air outlet sub-air channel 732, and it is difficult for them to fall into the air outlet sub-air channel 732. If the foreign matters have a large mass, they will first enter the first water-proof groove 74 after falling into the air outlet sub-air channel 732 against the protection air flow. With the continuous rotation of the rotary table, the foreign matters stay in the first water-proof groove 74. When the first water-proof groove 74 is located above the air outlet sub-air channel 732, the air flow can easily blow the foreign matters in the first water-proof groove 74 out, so that the first water-proof groove 74 forms the first level protection of the first protection structure against the foreign matters.

[0055] In some preferred embodiments, a first water-blocking ring 51 coaxial with the mandrel is protruded on the inner side of the table top 5, and a second water-blocking ring 222 is protruded on the side of the front cover plate 22. The first water-blocking ring 51 and the second water-blocking ring 222 are oppositely arranged in a staggered and spaced manner, so that the flow-increasing sub-air channel 731 with a bending structure and a small transverse size is formed between the table top 5 and the front cover plate 22, so that the flow-increasing sub-air channel 731 can form a narrow tube effect relative to the air outlet sub-air channel 732.

[0056] Further, a second water-proof groove 75 is arranged on the horizontal side of the second water-blocking ring 222, and the second water-proof groove 75 is in communication with the first water-proof groove 74 through a first vertical air channel 7311. The first vertical air channel 7311 is part of the flow-increasing sub-air channel 731, and the first vertical air channel 7311 is located in the range of the orthographic projection of the air outlet sub-air channel 732.

[0057] If the foreign matters with a large mass further fall down from the first water-proof groove 74 under the action of their own weight, they will enter the second water-proof groove 75. Similarly, when the second water-proof groove 75 is located above the first water-proof groove 74 during the rotation of the rotary table, the foreign matters will be blown out from the second water-proof groove 75 through the first vertical air channel 7311 and the air outlet sub-air channel 732 directly and quickly under the action of their own weight and the protection air flow, so that the second water-proof groove 75 forms the second level protection of the first protection structure.

[0058] In some preferred embodiments, a third water-blocking ring 52 is further provided on the inner side of the table top 5 and located inside the second water-blocking ring 222, the third water-blocking ring 52 abuts against the connecting end 312, and the first air equalizing ring groove 71 is located between the second water-blocking ring 222 and the third water-blocking ring 52; and a third waterproof groove 76 is provided on the connecting end 312, the orthographic projection of the first air inlet 221 on the connecting end 312 is located in the third waterproof groove 76, and the third waterproof groove 76 and the third water-blocking ring 52 have a second water guide slope 761, and one end of the first water outlet passage 72 is located in the third waterproof groove 76.

[0059] If the foreign matter with a larger mass can further fall into the first air equalizing ring groove 71 against the protective air flow in the first air outlet under the action of its own weight, it will fall into the third waterproof groove 76; at the same time, since the orthographic projection of the first air inlet 221 on the connecting end 312 is located in the third waterproof groove 76, the first air inlet 221 blows the protective air flow directly into the third waterproof groove 76, and when the horizontal rotary table is rotated to the position where the first water outlet passage 72 faces downward, the foreign matter falling into the third waterproof groove 76 can be blown out of the first water outlet passage 72 to the outside by the protective air flow, so that the third waterproof groove 76 and the first water outlet passage 72 cooperatively form the third level of protection of the first protective structure to prevent foreign matter from entering.

[0060] Further, the first protective structure further comprises a second air outlet 733 formed by the gap between the front cover plate 22 and the connecting end 312; and a fourth waterproof groove 77 is provided on the side of the front cover plate 22 facing the connecting end 312, and the fourth waterproof groove 77 is located opposite to the third waterproof groove 76.

[0061] If the foreign matter such as condensed water, hydraulic oil and cutting fluid enters the third waterproof groove 76, in order to prevent the foreign matter from entering the inside through the gap between the front cover plate 22 and the connecting end 312, a fourth waterproof groove 77 located opposite to the third waterproof groove 76 is provided, so that part of the foreign matter entering the second air outlet 733 is thrown into the fourth waterproof groove 77 under the centrifugal force during the rotation of the horizontal rotary table, and when the horizontal rotary table is further rotated to the position where the fourth waterproof groove 77 is located above the third waterproof groove 76, the foreign matter can fall into the third waterproof groove 76 and be discharged from the first water outlet passage 72. Therefore, the fourth waterproof groove 77 and the third waterproof groove 76 cooperatively form the fourth level of protection of the first protective structure to prevent foreign matter from entering.

[0062] In addition, the third core shaft 33 and the rear cover plate 23 have a second protective structure, and a second air inlet 231 is provided in the rear cover plate 23 and communicates with the second protective structure.

[0063] The second protection structure is completely identical to the first protection structure, or the second protection structure is partially identical to the first protection structure, for example, the second protection structure only has the first level of protection of the first protection structure, or has the first and second levels of protection of the first protection structure, or has the first, second and third levels of protection of the first protection structure, and the detailed description is not repeated here.

[0064] The protection gas flow provided for the first air inlet 221 can be realized by an external air pump or an electrically controlled valve and an external air source, and the air pump or the electrically controlled valve is controlled by the master control center.

[0065] The master control center controls the direct drive motor and the protection gas pressure provided by the first air inlet for the first protection structure. Specifically, before the master control center controls the direct drive motor to start, the master control center controls the first air inlet to provide a protection gas flow with a preset pressure P1, to ensure that the horizontal rotary table has formed a gas curtain sealing protection with good sealing performance before starting to rotate.

[0066] After the direct drive motor starts, the master control center generates a random jitter control signal (for example, the length of the control signal is 3s, 5s) in each preset period T (for example, T is 30s, 60s, 120s), and based on the random jitter control signal, the protection gas flow provided for the first air inlet is randomly increased or decreased to generate a protection gas pressure fluctuation, so that the foreign matter entering the first protection structure changes position based on the protection gas pressure fluctuation to promote the foreign matter to be discharged from the first protection structure.

[0067] When the master control center generates a random jitter control signal to randomly increase or decrease the protection gas flow of the first air inlet, the gas flow pressure in the first air inlet and the first air outlet will correspondingly increase or decrease, thereby generating a protection gas pressure fluctuation; based on the protection gas pressure fluctuation, the foreign matter entering the first protection structure will break the force balance before the protection gas pressure fluctuation, thereby the foreign matter will change position based on the protection gas pressure fluctuation, so that the foreign matter which is not easily blown out by the protection gas flow before the position change can increase the probability of being blown out by the protection gas flow, to promote the foreign matter to be discharged from the first protection structure.

[0068] For example, if the cutting fluid remains in the first water tank 74 far away from the first vertical air duct 7311 under the action of the centrifugal force of the rotary table for a long time and is difficult to be blown out by the protection gas flow, when the protection gas pressure fluctuation is switched, the air pressure in the first water tank 74 will increase or decrease, and especially when the air pressure changes, the foreign matter in the first water tank 74 will change position towards the first vertical air duct 7311, thereby increasing the opportunity of the foreign matter being taken out through the first vertical air duct 7311 or further falling into the first air ring groove 71 and finally being discharged from the first drainage passage 72.

[0069] Therefore, by generating the protective air pressure fluctuation, not only the sealing performance of the first protective structure in preventing foreign matters from entering the inside of the rotary table during the rotation of the horizontal rotary table can be improved, but also it can be ensured that no foreign matters remain in the first protective structure before the horizontal rotary table stops rotating, so as to avoid that the remaining foreign matters enter the inside of the rotary table after the motor stops working.

[0070] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A motor direct drive horizontal rotary table, characterized in that, The application relates to a kind of direct drive motor and its control method, including: Shell, including main shell (21) and front cover plate (22) and rear cover plate (23) respectively assembled in both end sides of the main shell (21); Spindle, hollow cylindrical structure, including transverse sequentially coaxial first spindle (31), second spindle (32) and third spindle (33), both ends of the first spindle (31) are driving end (311) and connecting end (312) respectively, the connecting end (312) extends out of the front cover plate (22), the driving end (311) is fixedly connected with the second spindle (32); Bearing (6), sleeve set on the first spindle (31) and close to the connecting end (312) is arranged; Direct drive motor, including motor rotor (41) and motor stator (42) for driving the motor rotor (41) sleeve set on the first spindle (31), the motor stator (42) is fixed on the inner wall of the main shell (21); Disc-shaped table (5), located on the outer side of the front cover plate (22) and connected with the connecting end (312); First protective structure, arranged between the table (5), the front cover plate (22) and the connecting end (312) to form air curtain seal to prevent foreign matter from entering, the first air inlet (221) is arranged in the front cover plate (22) and communicated with the first protective structure; Master control center, for controlling the direct drive motor and controlling the first air inlet (221) to provide protective airflow for the first protective structure; Wherein, the motor rotor (41) is arranged with the bearing (6) interval, and the motor rotor (41) is fixed at the fixed connection of the driving end (311) and the second spindle (32).

2. The motor direct drive horizontal rotary table according to claim 1, wherein, One end side of the motor rotor (41) and the bearing (6) have first interval; the other end side of the motor rotor (41) and the rear cover plate (23) have second interval; the motor rotor (41), the motor stator (42) and the spindle are coaxially arranged, and the third interval is arranged between the motor rotor (41) and the motor stator (42), the third interval is communicated with the first interval and the second interval.

3. The motor direct drive horizontal rotary table according to claim 2, wherein, The transverse dimension L1 of the first interval, the transverse dimension L2 of the second interval, the axial dimension L3 of the third interval, L3 < L2 < L1.

4. The motor direct drive horizontal rotary table according to claim 1, wherein, The first protective structure includes: First air equalizing ring groove (71), formed between the outlet of the first air inlet (221) and the connecting end (312); First drainage channel (72), axially arranged in the front cover plate (22) and connected with the first air equalizing ring groove (71); First air outlet, formed by the gap between the table (5) and the front cover plate (22), the first air outlet includes flow-increasing sub-air channel (731) with bending structure and exhaust sub-air channel (732) with straight line structure, the transverse spacing of the flow-increasing sub-air channel (731) is less than the transverse spacing of the exhaust sub-air channel (732). A first waterproof groove (74) is communicated between the flow-increasing sub-air channel (731) and the exhaust sub-air channel (732), and a first water guide slope (741) is arranged between the inner wall of the first waterproof groove (74) and the exhaust sub-air channel (732); The flow-increasing sub-air channel (731) accelerates the gas in the first gas equalizing ring groove (71) to blow out, so that foreign matters entering the first waterproof groove (74) are accelerated to blow out through the exhaust sub-air channel (732).

5. The motor direct drive horizontal rotary table according to claim 4, wherein, A first water blocking ring (51) coaxial with the core shaft is protruded on the inner side of the table top (5), and a second water blocking ring (222) is protruded on the side of the front cover plate (22), the first water blocking ring (51) and the second water blocking ring (222) are oppositely arranged in a staggered and spaced manner, so that the flow-increasing sub-air channel (731) is formed between the table top (5) and the front cover plate (22). A second waterproof groove (75) is arranged on the horizontal side of the second water blocking ring (222), the second waterproof groove (75) and the first waterproof groove (74) are communicated by a first vertical air channel (7311), the first vertical air channel (7311) is part of the flow-increasing sub-air channel (731), and the first vertical air channel (7311) is located in the projection range of the exhaust sub-air channel (732).

6. The motor direct drive horizontal rotary table according to claim 5, wherein, A third water blocking ring (52) located inside the second water blocking ring (222) is further protruded on the inner side of the table top (5), the third water blocking ring (52) abuts against the connecting end (312), and the first gas equalizing ring groove (71) is located between the second water blocking ring (222) and the third water blocking ring (52). A third waterproof groove (76) is arranged on the connecting end (312), the first air inlet channel (221) is projected on the connecting end (312) and located in the third waterproof groove (76), and a second water guide slope (761) is arranged between the third waterproof groove (76) and the third water blocking ring (52), and one end of the first water outlet channel (72) is located in the third waterproof groove (76).

7. The motor direct drive horizontal rotary table according to claim 6, wherein, The first protection structure further comprises: A second air outlet channel (733) is formed by the gap between the front cover plate (22) and the connecting end (312); A fourth waterproof groove (77) is arranged on the side of the front cover plate (22) facing the connecting end (312), and the fourth waterproof groove (77) and the third waterproof groove (76) are oppositely arranged in a staggered and spaced manner.

8. The motor direct drive horizontal rotary table according to claim 1, wherein, The third core shaft (33) is arranged outside the rear cover plate (23), the second core shaft (32) is provided with a stepped position, and a disc grating (91) is fixed to the stepped position; and the inner side of the rear cover plate (23) is provided with a reading head (92) matched with the disc grating (91).

9. The motor direct drive horizontal rotary table according to claim 8, wherein, The third core shaft (33) and the rear cover plate (23) have a second protection structure, and a second air inlet channel is arranged in the rear cover plate (23) and communicated with the second protection structure.

10. The motor direct drive horizontal rotary table according to any one of claims 1-9, characterized in that, The master control center controls the first air inlet (221) to provide a protection air flow with a preset pressure P1 before controlling the direct drive motor to start; After the direct drive motor starts, the master control center generates a random jitter control signal in each preset period T, and based on the random jitter control signal, the protection air flow provided to the first air inlet (221) is randomly increased or decreased to generate a protection air pressure fluctuation, so that the foreign matter that has entered the first protection structure changes its position based on the protection air pressure fluctuation to facilitate the foreign matter to be discharged from the first protection structure.

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