KR101374464B1 - Linear motor - Google Patents

Abstract

As a small gap between the bearing and the shaft member provided in the movable part, which was a problem of the conventional linear motor, rattling or fluctuation occurs between the bearing and the shaft member, and as a result, the positioning accuracy of the shaft tip portion that transmits the driving force to the machine The linear motor is fixed part (1) and movable part (2) in order to solve the deterioration point, and to obtain a linear motor capable of eliminating rattling and fluctuation between the bearing and the shaft member and increasing the positioning accuracy of the movable part. The movable part 2 includes a permanent member 21 and a sliding member 32 made of a magnetic material disposed at one end of the permanent magnet 21 and sliding in the axial direction of the fixed part 1. 1) is provided with a sliding bearing 31 in contact with the inner surface of the fixed part (1) for slidably supporting the sliding member (32), and provided inside the fixed part (1) to move the inner space of the movable part (2). A relative displacement coil (11) is provided, and the sliding member (32) is eccentrically arranged toward the sliding bearing (31) side from the central axis of the inner space formed by the coil (11) and the sliding bearing ( 31).

Description

Linear Motor {LINEAR MOTOR}

The present invention relates to a linear motor having a sliding bearing disposed between a movable portion and a fixed portion, and a sliding member disposed eccentrically from a central axis of the fixed portion.

In the conventional linear motor, the shaft member (the first sleeve) is formed with alternating permanent magnets of the N pole and the S pole in the axial direction, and for improving the driving force between the permanent magnets. The structure in which a magnetic body (yoke) was provided is employ | adopted. A coil surrounding the outer circumference of the shaft member is provided in the movable portion, and a bearing for guiding the linear movement of the shaft member relative to the movable portion in the axial direction relative to the movable portion is provided inside the movable portion located on the outer circumferential side of the shaft member. It is prepared. The linear motor having such a configuration has a structure in which a cylindrical or quadrilateral bearing and movable portion are arranged around the shaft member, and a minute gap is provided in order to facilitate relative movement between the bearing and the shaft member. (For example, refer patent document 1).

[Patent Document 1] Japanese Unexamined Patent Publication No. 9-182408 (Page 4, FIG. 1)

Since the conventional linear motor is constituted as described above, a small gap provided between the bearing and the shaft member causes rattling or fluctuation between the bearing and the shaft member, and as a result, for example, a driving force is applied to the machine. In a shaft type linear motor in which a shaft to be transmitted is provided in the movable portion, there is a problem that the positioning accuracy of the shaft tip portion is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to eliminate rattling or fluctuation between the bearing and the shaft member, and to increase the positioning accuracy of the shaft tip of the shaft-type linear motor, for example. .

In the linear motor according to the present invention, a linear motor having a fixed part and a movable part located inside the fixed part and provided relative to the fixed part in the axial direction, the movable part being a plurality of permanent magnets stacked in the axial direction. And a first sliding part made of a magnetic material disposed at one end of the magnet part and guiding sliding of the inside of the fixed part in the axial direction, wherein the fixed part is provided on an inner surface of the fixed part that slidably supports the first sliding part. A first bearing made of abutted non-magnetic material, and a plurality of coils provided inside the fixed part and generating magnetic flux in its inner space, and acting on the magnet part to relatively displace the movable part; The first sliding part includes a first sliding part having a first axis from a cross-sectional center axis of an inner space in which a central axis of the first sliding part is formed by a coil. By being eccentrically arranged on the bearing side and contacting the first bearing, the magnetic attraction force from the permanent magnet acts in the eccentric direction.

According to the present invention, the positioning accuracy of the shaft tip portion of the shaft linear motor can be increased, and the shaft linear motor can be applied to precision electronic devices such as a surface mounter and a board inspection machine.

1 is a sectional view of a shaft linear motor according to a first embodiment of the present invention.
2 is an exploded perspective view of the shaft-type linear motor according to the first embodiment of the present invention.
3 is a configuration diagram of a control unit of the shaft-type linear motor according to the first embodiment of the present invention.
4 is a structural diagram of a sliding bearing of a shaft-type linear motor according to the first embodiment of the present invention.
5 is a cross-sectional view of a shaft linear motor according to a second embodiment of the present invention.
6 is a cross-sectional view of a shaft linear motor according to a third embodiment of the present invention.
7 is a structural diagram of a sliding bearing of the shaft-type linear motor according to the fourth embodiment of the present invention.
Fig. 8 is a sectional view of a shaft linear motor showing a fifth embodiment of the present invention.
9 is a sectional view of a shaft-type linear motor showing a sixth embodiment of the present invention.

Example 1.

1 is a cross-sectional view of a shaft linear motor according to a first embodiment of the present invention, and FIG. 2 is an exploded perspective view of the shaft linear motor according to a first embodiment of the present invention. 1 and 2, 1 is a fixed portion of the shaft-type linear motor, 2 is a movable portion of the shaft-type linear motor, and relative displacement is possible in the axial direction with respect to the fixed portion 1. 31 is a sliding bearing having an L-shape in cross section along the axial direction, serving as the first bearing, 51 is a lead wire for power supply, 11 is a current flowing from the power lead wire 51 for the magnetic flux. A plurality of coils for generating, 12 is a bobbin made of resin insulating the plurality of coils 11, 13 is an upper frame that is a magnetic circuit of the magnetic flux generated, 14 is an magnetic circuit of the magnetic flux generated, axial direction The lower frame is U-shaped in cross section, 15 is a base for increasing mechanical rigidity, 16 is a bearing for supporting the shaft (shaft), 17 is a bracket for holding the bearing 16, 18 is a foreign material The cover which prevents intrusion, 41 is a position detector, and the fixing part 1 is a sliding bearing 31, the coil 11, the bobbin 12, the upper frame 13, the lower frame 14, the base 15, It is composed of a bearing 16, a bracket 17, a cover 18, a position detector 41.

On the other hand, 32 is a sliding member for slidingly guiding the surface of the sliding bearing 31, which functions as a first sliding part, 21 is a magnet part, and generates a propulsion force by interaction with the magnetic flux of the plurality of coils 11. It is a plurality of permanent magnets laminated in order to. 22 is made of a magnetic material or a nonmagnetic material, and disposed between the plurality of permanent magnets 21 so that the magnetic poles of the N poles and the S poles of the plurality of stacked permanent magnets 21 are alternately formed in the axial direction. Spacer, 23 is a shaft coupling member, 24 is a shaft (shaft) for transmitting the generated propulsion force to the machine, the movable part 2 is a sliding member 32, permanent magnet 21, spacer 22, shaft coupling member ( 23, the movable portion 2 is connected to the end of the shaft 24. One end of the shaft 24 extends out of the fixing part 1 and is used for position detection. The central axis of the plurality of permanent magnets 21, the central axis of the spacer 22, and the central axis of the shaft coupling member 23 coincide with the central axis of the shaft 24, respectively. The movable part 2 is arrange | positioned inside the fixing | fixed part 1, and has a structure which is movable to Z direction in FIG. The plurality of coils 11 and the plurality of bobbins 12 are arranged concentrically on the outside of the plurality of permanent magnets 21, and the central axes of the plurality of coils 11 and the plurality of bobbins 12 The central axis coincides with the central axis of the shaft 24, respectively.

Reference numeral 42 is a scale, 25 is a shaft tip of the shaft 24, 26 is a scale coupling member, and 52 is a lead for position detector. The scale 42 is coupled to the shaft tip portion 25 by the scale coupling member 26 and has a structure that moves in accordance with the movement of the shaft 24. In addition, the scale 42 has optical or magnetic position information recorded therein, and the position detector 41 coupled to the fixing part 1 adjusts the position of the shaft 24 in the Z direction in FIG. It detects and transmits a position signal from the position detector lead wire 52 to a control part.

In addition, A-A 'cross section and B-B' cross section show the cross section along the X-Y surface of the shaft type linear motor shown in FIG.

3 is a configuration diagram of a control unit of the shaft-type linear motor according to the first embodiment of the present invention. In FIG. 3, 90 is a control part, 100 is a shaft type linear motor. 91 is a position control circuit, 92 is a speed control circuit, 93 is a current control circuit, 99 is a current detector, and the control unit 90 is a position control circuit 91, a speed control circuit 92, a current control circuit 93, It consists of a current detector 99.

The positional information detected by the scale 42 and the position detector 41 is fed back to the control unit 90 of the shaft-type linear motor 100. The position control circuit 91 performs position control by comparing the position feedback value from the position detector 41 and the command value, and the speed control circuit 92 differentiates the output value from the position control circuit 91 and the position feedback value. The speed is controlled by comparing the speed feedback value, and the current control circuit 93 can control the driving force by comparing the output value from the speed control circuit 92 and the current feedback value from the current detector 99, respectively.

4 is a structural diagram of a sliding bearing of a shaft-type linear motor according to the first embodiment of the present invention. 61 is a magnetic flux, 62a and 62b is a magnetic attraction force generated by the influence of the magnetic flux 61 produced by the permanent magnet (21).

The sliding bearing 31 is made of resin (nonmagnetic material), and has a cross-section along the axial direction in the form of an 'L' shape as shown in the cross section A-A 'in FIG. On the other hand, the sliding member 32 is S50C material, the upper frame 13, and the lower frame 14, for example, are SPCC materials, and all are magnetic materials. Here, the sliding member 32 is provided so as not to be concentric with respect to the central axis of the inner space of the coil 11 arranged concentrically with respect to the central axis of the shaft 24, but eccentrically toward the sliding bearing 31 side. As a result, the gap between the sliding member 32 and the upper frame 13 and the gap between the sliding member 32 and the lower frame 14 are each a sliding bearing 31 having an L-shaped cross section. The sliding member 32 does not exist on the intervening side (from the A-A 'cross section in FIG. 4, on the left side and the lower surface of the sliding member 32 in the cross section). At the right side and the upper side of the), they exist at a predetermined distance.

In section A-A 'of FIG. 4, the magnetic flux 61 is between the upper frame 13, which is a magnetic material, and the permanent magnet 21, and both sides and the permanent magnets of the' U 'shaped lower frame 14, which is a magnetic material. Between the 21, the cross section, which is a magnetic material, is formed between the lower surface of the 'U'-shaped lower frame 14 and the permanent magnet 21, respectively. Under the influence of the formed magnetic flux 61, magnetic attraction forces 62a and 62b are generated between the sliding member 32 which is a magnetic material, the upper frame 13 which is a magnetic material, and the lower frame 14 having a 'U' shape. Since the sliding member 32 is provided with the cross section of the lower frame 14 biased toward the intervening side of the sliding bearing 31 having an 'L' shape, the sliding member 32 is biased due to the bias of the sliding member 32. 62a) acts strongly on the side ('A' cross section of Fig. 4, the left surface and the lower surface of the sliding member 32) in which the sliding bearing 31 having an 'L' shape is interposed, and the magnetic attraction force ( 62b) hardly acts on the side ("A-A" cross section of FIG. 4, the right side and upper surface of the sliding member 32) which is not interposed of the "L" shape sliding bearing 31. As shown in FIG.

In the shaft-type linear motor configured as described above, since the sliding member 32 and the sliding bearing 31 having an 'L' shape in cross section are always in contact with the constant magnetic attraction force 62a, the sliding member 32 There is no gap between and the sliding bearing 31, and as a result, there is no rattling or fluctuation due to the gap that occurred in the conventional shaft type linear motor configuration, and the positioning accuracy of the shaft tip portion 25 is improved. It becomes possible to make high. In addition, in the case where the gap of the conventional shaft type linear motor was intended to be small, it was necessary to process the dimensions of the sliding member 32 and the sliding bearing 31 with high accuracy. In the configuration of the linear motor, no machining is required.

As described above, according to the configuration of the shaft-type linear motor described in the first embodiment, since the positioning accuracy of the shaft tip portion of the shaft-type linear motor can be increased, it is possible to apply the shaft-type linear motor to a surface mounter or a board inspection machine. For example, the density of components mounted on an electromagnetic plate can be increased.

Example 2.

In Example 1 of this invention, although the case where only the one end of the movable part 2 was made into the sliding bearing 31 was demonstrated, as shown in FIG. 5, the both ends of the movable part 2 are sliding bearings which are 1st bearings ( It is good also as 31a) and the sliding bearing 31b which is a 2nd bearing, and the same effect can be acquired also by such a structure. In correspondence with making the both ends of the movable part 2 into the sliding bearings 31a and 31b, the sliding member 32a which is a 1st sliding part, and both sides which slide with the sliding bearings 31a and 31b of the fixed part 1, The sliding member 32b which is 2 sliding parts is provided.

Example 3.

In Example 1 and Example 2 of this invention, although the case where the position precision of the X and Y direction was secured using the two surfaces of the "L" shaped sliding bearing 31 was demonstrated, position accuracy is required. In the case where only one direction is used, for example, only the X direction, the sliding bearing 35 may have a flat plate shape parallel to the lower surface of the lower frame 14 along the axial direction. Also in this case, the same effects as in Example 1 and Example 2 can be obtained.

Example 4.

7 is a structural diagram of a sliding bearing of the shaft-type linear motor according to the fourth embodiment of the present invention. 71 is a first intermediate member, and in FIG. 7 is an intermediate member.

The sliding bearing 31 is made of resin (nonmagnetic material), and has a cross-sectional shape in the 'L' shape along the axial direction as shown in the cross section A-A 'of FIG. 7, and the right and upper surfaces of the intermediate member 71. Abuts on The intermediate member 71 is, for example, a magnetic material such as an SPCC material, and has a 'L' shape in cross section along the axial direction as shown in cross section A-A 'in FIG. 14) is in contact with the left side and the lower surface. That is, the intermediate member 71 is a central axis of the fixing part 1 (see FIG. 1) including the upper frame 13 and the lower frame 14 as shown in FIG. 7 (the central axis of the permanent magnet 21). It is non-rotationally symmetric type. On the other hand, the sliding member 32 is S50C material, the upper frame 13, and the lower frame 14, for example, are SPCC materials, and all are magnetic materials. Here, the sliding member 32 is provided coincident with the central axis of the inner space of the coil 11 which is arranged concentrically with respect to the central axis of the shaft 24. As a result, the gap between the sliding member 32 and the upper frame 13, and the gap between the sliding member 32 and the lower frame 14, each have a sliding bearing 31 having an L-shaped cross section. ) And the side where the intermediate member 71 is interposed (in the A-A 'cross section of FIG. 7, the left side and the lower surface of the sliding member 32 in the cross section), and do not exist (A-A' in FIG. 7). In the cross section, the right side and the top surface of the sliding member 32) exist at a predetermined distance.

In section A-A 'of FIG. 7, the magnetic flux 61 is between the upper frame 13, which is a magnetic material, and the permanent magnet 21, and the right side of the lower frame 14, which is a magnetic material, and the permanent magnet. Between (21) and the lower surface of the intermediate member 71 of the 'L' shape of the magnetic material and between the permanent magnet 21 and the right surface of the intermediate member 71 of the 'L' shape of the magnetic material It is formed between the permanent magnets 21, respectively. Under the influence of the formed magnetic flux 61, the sliding member 32 of magnetic material, the upper frame 13 of magnetic material, the lower frame 14 of 'U' shape, and the intermediate member 71 of 'L' shape The magnetic attraction force 62a and 62b generate | occur | produced between them, but the magnetic attraction force 62a is the side through which the sliding bearing 31 and the intermediate member 71 of the L-shaped cross section intervene (A-A of FIG. 7). 'In the cross section, it acts strongly on the left side and the bottom side of the sliding member 32, and the magnetic attraction force 62b is the side (not shown) between the sliding bearing 31 and the intermediate member 71 having an' L 'shape. In A-A 'cross section of 7, it hardly acts in the right side and upper surface of the sliding member 32).

In the shaft-type linear motor configured as described above, the sliding member 32 and the sliding bearing 31 having the 'L' shape in cross section are always in contact with the constant magnetic attraction force 62a. ), And there is no gap between the sliding bearing 31, and as a result, there is no rattling or fluctuation due to the gap that occurred in the conventional shaft type linear motor configuration, and the positioning accuracy of the shaft tip portion 25 It becomes possible to make high. In addition, in the case where the gap of the conventional shaft type linear motor was intended to be small, it was necessary to process the dimensions of the sliding member 32 and the sliding bearing 31 with high accuracy. In the configuration of the linear motor, no machining is required.

As mentioned above, according to the structure of the shaft type linear motor demonstrated in Example 4, since the positioning accuracy of the shaft tip part of a shaft type linear motor can be made high, it is possible to apply a shaft linear motor to a surface mounter or a board | substrate tester. For example, the density of components mounted on an electromagnetic plate can be increased.

Example 5.

In Example 4 of this invention, although the case where the intermediate member 71 was applied only to the one end of the movable part 2 was demonstrated, as shown in FIG. 8, the intermediate | middle which is a 1st intermediate member in the both ends of the movable part 2 is shown. The member 71a and the intermediate member 71b which is a 2nd intermediate member may be applied, and the same effect can also be acquired by such a structure.

Example 6.

In Example 4 and Example 5 of this invention, although the case where the positional precision of the X and Y direction was secured using the two surfaces of the "L" shape intermediate member 71 was demonstrated, the positional precision is required. In the case where only one direction is used, for example, only the X direction, as shown in FIG. 9, the intermediate member 75 may have a flat plate shape parallel to the lower surface of the lower frame 14 along the axial direction. Also in this case, the same effects as in Example 4 and Example 5 can be obtained.

In the configuration of the shaft-type linear motor described in the fourth to sixth embodiments, the case where the intermediate members 71, 71a, 71b and the lower frame 14 are respectively handled as separate members has been described. The same effect can be obtained even with the configuration of the new lower frame 14 having the structure of the intermediate members 71, 71a, and 71b.

In addition, in Example 1 to Example 6 of this invention, although the case where this invention was applied to the shaft type linear motor was demonstrated, it is not limited to this, The same effect can be acquired even if it applies to another linear motor.

1 fixed part, 2 movable parts,
11 coils, 12 bobbins,
13 upper frame, 14 lower frame,
15 bases, 16 bearings,
17 brackets, 18 covers,
21 permanent magnets, 22 spacers,
23 shaft coupling member, 24 shaft,
25 shaft tip, 26 scale coupling member,
31 plain bearing, 31a plain bearing,
31b sliding bearing, 32 sliding members,
32a sliding member, 32b sliding member,
35 sliding bearings, 41 position detectors,
42 scale, 51 power lead,
52 lead wire for position detector, 61 flux,
62a magnetic attraction force, 62b magnetic attraction force,
71 intermediate member, 71a intermediate member,
71b intermediate member, 75 intermediate member,
90 controller, 91 position control circuit,
92 speed control circuit, 93 current control circuit,
99 current detector, 100 shaft linear motor.

Claims (12)

A linear motor having a fixed part and a movable part located inside the fixed part and provided with a relative displacement in the axial direction with respect to the fixed part,
The movable part includes a magnet part made up of a plurality of permanent magnets stacked in the axial direction, and a first sliding part made of a magnetic material disposed at one end of the magnet part to guide the inside of the fixed part in the axial direction.
The fixing part is provided with a first bearing made of a nonmagnetic material in contact with an inner surface of the fixing part for slidably supporting the first sliding part, and is provided inside the fixing part to generate magnetic flux in its inner space. And a plurality of coils acting on the magnet part to relatively displace the movable part.
The first sliding part is disposed eccentrically toward the first bearing side from the cross-sectional central axis of the inner space formed by the coil and the first sliding part central axis is in contact with the first bearing, so that the permanent A linear motor, characterized in that the magnetic attraction force from the magnet acts in the eccentric direction. The method according to claim 1,
The inner end surface of the fixing portion is a rectangular shape, the first sliding portion is a rectangular shape, the cross section of the first bearing is a linear motor, characterized in that the 'L' shape. The method according to claim 2,
The cross section of the first bearing is a linear motor, characterized in that the flat shape. A linear motor having a fixed part and a movable part located inside the fixed part and provided with a relative displacement in the axial direction with respect to the fixed part,
The movable part includes a magnet part made up of a plurality of permanent magnets stacked in the axial direction, and first and second sliding parts made of magnetic materials disposed at both ends of the magnet part and guiding sliding of the inside of the fixed part in the axial direction. Equipped,
The fixing part is provided with first and second bearings made of a nonmagnetic material in contact with an inner surface of the fixing part that slidably supports the first and second sliding parts, and is provided inside the fixing part and has magnetic flux in its inner space. And a plurality of coils acting on the magnet part to relatively displace the movable part,
The first and second sliding parts are disposed eccentrically to the first and second bearing sides from the cross-sectional center axis of the inner space in which the central axes of the first and second sliding parts are formed by the coil. 2. A linear motor, wherein the magnetic attraction force from the permanent magnet acts in an eccentric direction by contacting a bearing. The method of claim 4,
The inner end surface of the fixing portion is a rectangular shape, the first and second sliding portion is a rectangular shape, the cross-section of the first and second bearing is a linear motor, characterized in that the 'L' shape. The method according to claim 5,
The cross-section of the first and second bearing is a linear motor, characterized in that the flat shape. A linear motor having a fixed part and a movable part located inside the fixed part and provided with a relative displacement in the axial direction with respect to the fixed part,
The movable part includes a magnet part made up of a plurality of permanent magnets stacked in the axial direction, and a first sliding part made of a magnetic material disposed at one end of the magnet part and guiding sliding of the inside of the fixed part in the axial direction.
The fixing part is in contact with a first intermediate member made of a magnetic material fixed to the inner surface of the fixing part in a non-rotationally symmetrical manner with respect to the central axis of the magnet part, and the first intermediate member slidably supporting the first sliding part. A first bearing made of a non-magnetic material, and a plurality of coils provided inside the fixing part and generating magnetic flux in its inner space and acting on the magnet part to relatively displace the movable part,
And the first sliding portion is in contact with the first bearing to exert a magnetic attraction force from the permanent magnet on the side of the first intermediate member. The method of claim 7,
The inner end surface of the fixing part is a rectangular shape, the first sliding part is a rectangular shape, the cross-section of the first bearing and the first intermediate member is a linear motor, characterized in that the 'L' shape. The method according to claim 8,
The cross section of the first bearing and the first intermediate member is a linear motor, characterized in that the flat plate shape. A linear motor having a fixed part and a movable part located inside the fixed part and provided with a relative displacement in the axial direction with respect to the fixed part,
The movable part includes a magnet part made up of a plurality of permanent magnets stacked in the axial direction, and first and second sliding parts made of magnetic materials disposed at both ends of the magnet part and guiding sliding of the inside of the fixed part in the axial direction. Equipped,
The fixing part may include first and second intermediate members made of a magnetic material fixed to an inner surface of the fixing part in a non-rotating symmetrical manner with respect to a central axis of the magnet part, and the first and second sliding parts slidably supporting the first and second sliding parts. And first and second bearings made of a nonmagnetic material in contact with the second intermediate member, and provided inside the fixing part to generate magnetic flux in its inner space, and act on the magnet part to displace the movable part. With a plurality of coils to make
And the first and second sliding parts contact the first and second bearings to exert a magnetic attraction force from the permanent magnet on the first and second intermediate members. The method of claim 10,
The inner end face of the fixing part is rectangular in shape, the first and second sliding parts are rectangular in shape, and the cross-sections of the first and second bearings and the first and second intermediate members are 'L' shaped. Linear motor made. The method of claim 11,
And the cross-section of the first and second bearings and the first and second intermediate members has a flat plate shape.

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