阅读说明：本技术 数控机床竖直轴的高精度快速驱动机构 (High-precision quick driving mechanism of vertical shaft of numerical control machine tool ) 是由 肖飞 高峰 白旭 张广为 张扬 孔令友 严昊明 李享 陈帅 徐吉存 戴漫一 陈 于 2021-10-28 设计创作，主要内容包括：本发明涉及一种数控机床竖直轴的高精度快速驱动机构,包括滑板和滑枕,滑枕沿滑板外表面竖直滑动,滑枕的底部连接刀具,在滑枕的左右两侧对称设有直线导轨,直线导轨与滑板滑动连接；在滑枕的顶部左右两侧对称设置丝杠上支撑座,滑枕的中部左右两侧对称设置丝杠下支撑座,在同侧的丝杠上支撑座与丝杠下支撑座之间连接丝杠,每个丝杠上同轴配合直驱电机,直驱电机的电机座连接在滑板上。该高精度快速驱动机构规避了齿轮驱动产生的传动间隙,保证了传动链的高精度及动态响应速度,易于实现大行程高精度驱动。(The invention relates to a high-precision quick driving mechanism of a vertical shaft of a numerical control machine tool, which comprises a sliding plate and a ram, wherein the ram vertically slides along the outer surface of the sliding plate; the left side and the right side of the top of the ram are symmetrically provided with screw rod upper supporting seats, the left side and the right side of the middle of the ram are symmetrically provided with screw rod lower supporting seats, a screw rod is connected between the screw rod upper supporting seat and the screw rod lower supporting seat on the same side, a motor is directly driven by coaxial matching on each screw rod, and a motor seat of the direct drive motor is connected to the sliding plate. The high-precision quick driving mechanism avoids a transmission gap generated by gear driving, ensures the high precision and the dynamic response speed of a transmission chain, and is easy to realize large-stroke high-precision driving.)

1. The utility model provides a quick actuating mechanism of high accuracy of digit control machine tool vertical axis, includes slide (22) and ram (20), and ram (20) are followed slide (22) surface vertical slip, and cutter (19), its characterized in that are connected to the bottom of ram (20): the left side and the right side of the ram (20) are symmetrically provided with linear guide rails (25), and the linear guide rails (25) are connected with the sliding plate (22) in a sliding manner; the screw upper supporting seats (14) are symmetrically arranged on the left side and the right side of the top of the ram (20), the screw lower supporting seats (2) are symmetrically arranged on the left side and the right side of the middle of the ram (20), a screw (3) is connected between the screw upper supporting seats (14) and the screw lower supporting seats (2) on the same side, a motor (12) is directly driven by coaxial matching on each screw (3), and a motor seat of the direct drive motor (12) is connected to the sliding plate (22).

2. High-precision rapid driving mechanism of a vertical shaft of numerically controlled machine tools according to claim 1, characterized in that: the direct-drive motor (12) structurally comprises a screw (13) in threaded fit with a lead screw (3), the upper end of the screw (13) is connected with an inner rotor sleeve (8) through a flange, the middle part of the outer circumference of the inner rotor sleeve (8) is connected with an inner rotor (9) through a connecting table, the upper end and the lower end of the outer circumference of the inner rotor sleeve (8) are respectively provided with an angular contact ball bearing (7), the outer rings of the angular contact ball bearings (7) at the upper end and the lower end are respectively in coaxial fit with a bearing outer ring sleeve (5), an outer stator (10) is arranged between the two bearing outer ring sleeves (5), and the outer stator (10) is in coaxial fit with the inner rotor (9); the outer circumference of the outer stator (10) is coaxially matched with a motor base of a direct drive motor (12), and the upper end and the lower end of the motor base of the direct drive motor (12) are connected with a bearing outer ring sleeve (5) at a corresponding position; the outer end parts of the upper end bearing outer ring sleeve (5) and the lower end bearing outer ring sleeve (5) are respectively connected with an annular locking nut (6) through bolts (4), the upper end of the upper angular contact ball bearing (7) is limited on the bottom surface of the upper end locking nut (6), the bottom surface of the upper angular contact ball bearing (7) is provided with an inner spacer sleeve (11), and the lower end of the inner spacer sleeve (11) is limited on the connecting table; the top surface of the angular contact ball bearing (7) at the lower part is limited on the limiting table of the inner rotor sleeve (8), and the lower end of the angular contact ball bearing (7) at the lower part is limited on the top surface of the locking nut (6) at the lower end.

3. High-precision rapid driving mechanism of a vertical shaft of numerically controlled machine tools according to claim 1, characterized in that: the linear guide rail (25) is connected with a band-type brake sliding block (24) in a matching mode, and the band-type brake sliding block (24) is connected with the top surface of the sliding plate (22) through a band-type brake sliding block seat (23).

4. High-precision rapid driving mechanism of a vertical shaft of numerically controlled machine tools according to claim 1, characterized in that: the bottom surface of the lower screw supporting seat (2) is provided with a groove, and a lower screw end fixing tensioning sleeve (1) is arranged in the groove; the upper surface of a support seat (14) on the screw rod is provided with a groove, a spacer bush (15) on the screw rod is arranged in the groove, a disc spring (16) is coaxially arranged on the spacer bush (15) on the screw rod, the bottom of the disc spring (16) is limited on a limiting table of the spacer bush (15) on the screw rod, the top end of the screw rod (3) is provided with a compression nut (18), and the compression nut (18) is compressed on the top surface of the disc spring (16) through a gasket (17).

5. High-precision rapid driving mechanism of a vertical shaft of numerically controlled machine tools according to claim 4, characterized in that: the screw rod (3) is prestretched when being installed, and the prestretching amount is 11.6 multiplied by 10^-6And multiplying by L and multiplying by delta T, wherein L is the supporting distance of the lead screw, and delta T is the temperature rise change value of the lead screw.

Technical Field

The invention relates to a high-precision quick driving mechanism for a vertical shaft of a numerical control machine tool, belonging to the technical field of numerical control machine tool manufacturing.

Background

With the continuous development of science and technology, the requirements of large-scale high-precision bridge type five-axis numerical control machine tools in the fields of aerospace, rail transit, military industry and the like are continuously improved. The latest requirement of a high-grade large high-precision five-axis machine tool is that the machine tool has the characteristics of high precision, high dynamic characteristics and the like, the main equipment applied to the shaping and processing of large parts in the aviation industry is a high-precision bridge five-axis machine tool, the stroke of a vertical shaft is generally required to be more than 2m, the repeated positioning precision is less than 3 micrometers, a spindle box of the conventional large-scale gantry five-axis machine tool mostly adopts a motor to be connected with a lead screw to drive a ram to move, and a balance oil cylinder balances the gravity form of the ram.

Disclosure of Invention

The invention aims to solve the technical problem of providing a high-precision quick driving mechanism of a vertical shaft of a numerical control machine tool, which avoids a transmission gap generated by gear driving, ensures high precision and dynamic response speed of a transmission chain and is easy to realize large-stroke high-precision driving.

In order to solve the above problems, the specific technical scheme of the invention is as follows: a high-precision quick driving mechanism of a vertical shaft of a numerical control machine tool comprises a sliding plate and a ram, wherein the ram vertically slides along the outer surface of the sliding plate, the bottom of the ram is connected with a cutter, linear guide rails are symmetrically arranged on the left side and the right side of the ram, and the linear guide rails are in sliding connection with the sliding plate; the left side and the right side of the top of the ram are symmetrically provided with screw rod upper supporting seats, the left side and the right side of the middle of the ram are symmetrically provided with screw rod lower supporting seats, a screw rod is connected between the screw rod upper supporting seat and the screw rod lower supporting seat on the same side, a motor is directly driven by coaxial matching on each screw rod, and a motor seat of the direct drive motor is connected to the sliding plate.

The direct-drive motor structure comprises a screw rod, a nut, an inner rotor sleeve, an inner rotor, an outer stator, an outer rotor sleeve, a connecting platform, an inner rotor, an outer rotor sleeve, an inner rotor sleeve, an outer stator and an outer rotor sleeve, wherein the screw rod is in threaded fit with the nut; the outer circumference of the outer stator is coaxially matched with a motor base of the direct drive motor, and the upper end and the lower end of the motor base of the direct drive motor are connected with bearing outer ring sleeves at corresponding positions; the outer end parts of the upper end bearing outer ring sleeve and the lower end bearing outer ring sleeve are respectively connected with an annular locking nut through bolts, the upper end of the upper angular contact ball bearing is limited on the bottom surface of the upper end locking nut, the bottom surface of the upper angular contact ball bearing is provided with an inner spacer, and the lower end of the inner spacer is limited on the connecting table; the top surface of the angular contact ball bearing at the lower part is limited on the limiting table of the inner rotor sleeve, and the lower end of the angular contact ball bearing at the lower part is limited on the top surface of the locking nut at the lower end.

The linear guide rail is connected with a band-type brake sliding block in a matching mode, and the band-type brake sliding block is connected with the top surface of the sliding plate through a band-type brake sliding block seat.

The bottom surface of the lower screw supporting seat is provided with a groove, and a lower screw end fixing tensioning sleeve is arranged in the groove; the upper surface of the support seat on the screw rod is provided with a groove, the groove is internally provided with a spacer bush on the screw rod, the spacer bush on the screw rod is coaxially provided with a disc spring, the bottom of the disc spring is limited on a limiting table of the spacer bush on the screw rod, the top end of the screw rod is provided with a compression nut, and the compression nut is compressed on the top surface of the disc spring through a gasket.

The screw rod is pre-stretched when being installed, and the pre-stretching amount is 11.6 multiplied by 10^-6And multiplying by L and multiplying by delta T, wherein L is the supporting distance of the lead screw, and delta T is the temperature rise change value of the lead screw.

The invention has the following innovation points:

1. according to the invention, the transmission clearance can be effectively reduced through the direct-drive nut structure, the transmission efficiency is high, and the high-precision transmission and high dynamic response of a high-precision five-axis machining center can be ensured;

2. both ends of the lead screw are fixed after being pre-stretched, and one end of the lead screw is pre-tensioned through a disc spring structure to realize clearance elimination and eliminate expansion caused by self thermal deformation of the lead screw body in the transmission process;

3. compared with the screw rotation driving mode, the direct-drive screw nut structure driving mode can realize large-stroke driving, optimize the specification of the screw, avoid the increase of the diameter specification of the screw due to the fact that the screw is too long in stroke and the limit rotating speed of the screw is not enough, and meanwhile compared with the screw rotation mode, the load inertia can be effectively reduced, and better inertia matching is realized;

4. two sets of direct-drive structures are arranged at the driving end, so that large-load driving is easy to realize, and compared with the traditional balancing oil cylinder which balances the load weight, the configuration can effectively avoid the disturbance of pressure change on the processing precision;

5. the double-brake can reduce the probability of the risk of falling of the vertical shaft caused by sudden stop or sudden power failure of the machine tool;

in conclusion, compared with the traditional lead screw rotation, the high-precision quick driving mechanism of the vertical shaft of the numerical control machine tool can reduce the load inertia, is suitable for large-stroke high-speed driving, reduces the disturbance of pressure change to the processing precision compared with a structure with a balance oil cylinder, and can realize the high-precision high-dynamic characteristic movement of the ram on the vertical shaft.

Drawings

Fig. 1 is an axonometric view of a high precision quick drive mechanism of a vertical shaft of a numerically controlled machine tool.

FIG. 2 is a cross-sectional view of the lead screw connected with the direct drive motor and the upper and lower lead screw supporting seats.

Detailed Description

As shown in fig. 1, a high-precision fast driving mechanism for a vertical shaft of a numerical control machine tool comprises a sliding plate 22 and a sliding rail 20, wherein a ram 20 vertically slides along the outer surface of the sliding plate 22, a cutter 19 is connected to the bottom of the ram 20, linear guide rails 25 are symmetrically arranged on the left side and the right side of the ram 20, and the linear guide rails 25 are slidably connected with the sliding plate 22; the left and right sides of the top of the ram 20 are symmetrically provided with the upper screw supporting seats 14, the left and right sides of the middle of the ram 20 are symmetrically provided with the lower screw supporting seats 2, the upper screw supporting seats 14 and the lower screw supporting seats 2 on the same side are connected with the screw 3, the screw 3 is of a hollow structure and used for cooling water circulation, the upper screw 3 is coaxially matched with the direct-drive motor 12, and the motor base of the direct-drive motor 12 is connected to the sliding plate 22. The linear guide rail 25 is matched and connected with a band-type brake slider 24, and the band-type brake slider 24 is connected with the top surface of the sliding plate 22 through a band-type brake slider seat 23.

As shown in fig. 2, the direct drive motor 12 structurally comprises a screw nut 13 in threaded fit on a lead screw 3, an inner rotor sleeve 8 is connected to the upper end of the screw nut 13 through a flange, the middle part of the outer circumference of the inner rotor sleeve 8 is connected with an inner rotor 9 through a connecting table, angular contact ball bearings 7 are respectively arranged at the upper end and the lower end of the outer circumference of the inner rotor sleeve 8, the outer rings of the angular contact ball bearings 7 at the upper end and the lower end are respectively in coaxial fit with a bearing outer ring sleeve 5, an outer stator 10 is arranged between the two bearing outer ring sleeves 5, and the outer stator 10 is in coaxial fit with the inner rotor 9; the outer circumference of the outer stator 10 is coaxially matched with a motor base of a direct drive motor 12, and the upper end and the lower end of the motor base of the direct drive motor 12 are connected with the bearing outer ring sleeves 5 at corresponding positions; the outer end parts of the upper end bearing outer ring sleeve 5 and the lower end bearing outer ring sleeve 5 are respectively connected with an annular locking nut 6 through bolts 4, the upper end of an upper angular contact ball bearing 7 is limited on the bottom surface of the upper end locking nut 6, an inner spacer 11 is arranged on the bottom surface of the upper angular contact ball bearing 7, and the lower end of the inner spacer 11 is limited on a connecting table; the top surface of the lower angular contact ball bearing 7 is limited on the limiting table of the inner rotor sleeve 8, and the lower end of the lower angular contact ball bearing 7 is limited on the top surface of the locking nut 6 at the lower end. When the axis moves, the screw 13 only rotates but does not move linearly, the outer stator 10 and the inner rotor 9 drive the screw 13 to rotate through electromagnetic induction, the outer stator 10 and the inner rotor 9 are cooled through a water cooler by an annular cooling groove arranged on the periphery of the outer stator 10, the electromagnetic drive heating transmission is reduced, the cooling groove is also arranged on the outer cylindrical surface of the bearing outer ring sleeve 5, the two lead screws 3 and the ram 20 are driven by the balls in the screw 13 to linearly and vertically move, the left linear guide rail 25 and the right linear guide rail 25 are additionally provided with the band-type brake sliding blocks 24, the ram 20 is firmly locked on the sliding plate 22 by the locking force provided by the band-type brake sliding blocks 24 through the disc springs, and the probability of the risk of vertical shaft falling caused by emergency stop or sudden power failure of a machine tool can be reduced.

The bottom surface of the lower screw supporting seat 2 is provided with a groove, and a lower screw end fixing tensioning sleeve 1 is arranged in the groove; the upper surface of the support seat 14 on the screw rod is provided with a groove, the groove is internally provided with a spacer bush 15 on the screw rod, the spacer bush 15 on the screw rod is coaxially provided with a disc spring 16, the bottom of the disc spring 16 is limited on a limiting table of the spacer bush 15 on the screw rod, the top end of the screw rod 3 is provided with a compression nut 18, and the compression nut 18 is compressed on the top surface of the disc spring 16 through a gasket 17. The mechanism avoids a transmission gap generated by gear driving, ensures high precision and dynamic response speed of a transmission chain, is easy to realize large-stroke high-precision driving, and can effectively avoid disturbance of pressure change to processing precision compared with the balance of a traditional balance oil cylinder; the screw supporting end is pre-tightened through a disc spring structure to achieve clearance elimination, expansion caused by self thermal deformation of the screw body in the transmission process is eliminated through pre-stretching, thermal deformation influence generated by high-speed rotation of the screw pair can be effectively controlled, and the circulating cooling system can effectively control influence of a temperature field on transmission precision, so that the machining precision and the surface quality of a high-precision five-axis machine tool are improved.

The screw rod 3 is pre-stretched when being installed, and the pre-stretching amount is 11.6 multiplied by 10^-6And multiplying by L and multiplying by delta T, wherein L is the supporting distance of the lead screw, and delta T is the temperature rise change value of the lead screw. The screw supporting end is pre-tightened through a disc spring structure to achieve clearance elimination, expansion caused by self thermal deformation of the screw body in the transmission process is eliminated through pre-stretching, thermal deformation influence generated by high-speed rotation of the screw pair can be effectively controlled, and therefore machining precision and surface quality of a machine tool are improved.