JP4461213B2 - motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small motor used in FA equipment such as a pump for medical equipment that handles drugs such as serum and a parts feeder, and more particularly, to realize a circulation cycle of lubricating grease at a contact point between a brush and a commutator. The present invention also relates to a motor that improves the contactability of the contact portion.
[0002]
[Prior art]
FIG. 6 is an explanatory diagram showing a configuration of a conventional coreless motor. In FIG. 6, reference numeral 1 is a motor case, reference numeral 2 is a rotor portion, 2a is a coil, and 2b is a coil holder. Reference numeral 3 is a permanent magnet, reference numeral 4 is a motor shaft (shaft), reference numeral 5 is a bearing, reference numeral 6 is a sleeve, reference numeral 7 is a commutator (commutator) for switching the current supplied via the brush 8 one after another, reference numeral Reference numeral 8 denotes a brush that contacts the commutator 7 and supplies current, and reference numeral 9 denotes a brush base to which the brush 8 is attached. In addition, the code | symbol G of illustration is the lubrication grease apply | coated to the sliding contact part of the commutator 7 and the brush 9. FIG.
[0003]
The motor has a cup-shaped hollow at one end (left part in FIG. 6 (a)) of the motor case 1, and the rotor is supported by a bearing 5 and a sleeve 6 and set at a predetermined position. After that, the brush base 9 to which the brush 8 is attached is inserted as a lid. The brush 8 has a substantially U-shaped shape as shown in FIG. 6 (b), one is fixed to the brush base 9, and the other tip is in contact with the commutator 7 surface. 9 is attached. At this time, the tip of the brush 8 is pressed against the commutator 7 and is in contact with the commutator 7 by its own bending force.
[0004]
[Problems to be solved by the invention]
However, in the conventional motor as shown above, when the motor continues to rotate, the lubricating grease applied to the contact portion between the brush and the commutator is moved in the space in the motor along with the rotational motion. There was a problem of being scattered.
[0005]
In addition, since the conventional brush is in contact with the commutator by utilizing the amount of deflection (pressing force) due to the bending shape, the accuracy of parts such as brushes and brush bases and the variation in stacking tolerances during assembly increase. The desired contact pressure of the contact portion is not ensured accurately, sparking of the contact portion due to brush jumping or vibration occurs, and as a result, the contact portion reduces the contact life due to electrical wear. There was a problem.
[0006]
The present invention has been made in view of the above, and by sealing the space in the brush case where the brush and the commutator are installed to realize a grease circulation cycle to the brush contact, mechanical wear of the brush contact is achieved. The first object is to reduce the contact life and improve the contact life.
[0007]
In addition, by contacting the plate brush with a commutator via a pressure spring, a reliable contact pressure that does not depend on the component accuracy is ensured, and the occurrence of brush jumping or vibration is suppressed. A second object is to reduce the occurrence of electrical wear and improve the contact life of the motor.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the motor according to claim 1, the brush is brought into contact with the commutator while being lubricated with lubricating grease or lubricating oil, and current is supplied from the brush to each commutator. In the rotationally driven motor, the brush and the commutator are installed inside, a brush case for preventing leakage of the lubricating grease or lubricating oil, and installed so as to surround a contact portion between the brush and the commutator, And an oil retaining member capable of retaining the scattered lubricating grease or lubricating oil, and a brush holder portion and a brush formed by a part of the oil retaining member for supplying the retained lubricating grease or lubricating oil to the brush again. The plate portion is provided with a gap.
[0009]
According to the present invention, the lubrication grease that has flowed around due to the rotation of the motor and the temperature rise in the machine is retained in the oil retaining member, and the lubrication grease retained through the gap is returned to the brush contact. Grease retention and supply circulation cycle is realized to make the contact portion oil rich, thereby suppressing deterioration due to mechanical wear due to lack of lubricating grease at the brush contact. This motor can be applied to a motor having a brush contact, such as a DC motor, a coreless motor, and a universal motor.
[0010]
In the motor according to claim 2, the oil retaining member is formed of a porous body that obtains a capillary phenomenon.
[0011]
According to the present invention, by forming the oil retaining member and the gap with a porous body, the lubricating grease that has been dispersed due to a decrease in viscosity due to temperature rise in the machine is effectively retained inside the porous body, and the porous body The grease that has been held at the brush contact part is returned again to eliminate the brush contact grease shortage.
[0012]
In the motor according to the third aspect of the present invention, a multi-layer coil spring is provided on the back surface of the brush contact to press the brush contact surface against the commutator to obtain a capillary phenomenon.
[0013]
According to the present invention, by adopting a mechanism that pressurizes the commutator from the back of the brush with a coil spring, the tolerance of related parts and the stacking tolerance at the time of assembly are tightened as compared to the conventional mechanism that relied on the shape accuracy of the brush. This eliminates the need for this, and a stable spring constant is obtained by pressurization by the coil spring, so that the contact pressure of the brush with respect to the commutator is stabilized.
In addition, since the coil spring is a multi-layer winding, naturally a capillary action of grease may occur here.
[0014]
In the motor according to claim 4, a contact member having a predetermined thickness is provided on the brush contact surface.
[0015]
According to the present invention, a contact life having a predetermined thickness is provided on the brush contact surface, so that the contact life depends on the thickness of the contact portion even when contact deterioration due to contact with the commutator progresses. Can be extended. For this contact member, for example, gold, silver, or an alloy containing these metals can be used.
[0016]
The motor according to claim 5 has a coil spring holder that is L-shaped and has one end inserted into the coil spring, and the oil retaining member includes a locking groove for locking the coil spring holder, A pressurizing groove that pressurizes the coiled spring by fitting the coiled spring, and a porous body that surrounds at least the contact point.
[0017]
According to the present invention, by inserting a coil spring into one end of an L-shaped coil spring holder, inserting it into the retaining groove of the oil retaining member, and setting it in the pressurizing groove, it is possible to press the brush with a coil spring with a simple configuration. The mechanism is realized.
[0018]
According to a sixth aspect of the present invention, a pair of brushes that contact the commutator are opposed in parallel, and the ends of the brushes are fixed.
[0019]
According to the present invention, the ends of the brushes are fixed in a state in which the pair of brushes in contact with the commutator face each other in parallel, that is, in a state where the two brushes are arranged with the center of the motor shaft as a point symmetry. As a result, when the other end is pressurized, it moves in one direction, so that it is possible to avoid the vibration of the brush from being multi-directional as in the prior art, and it is possible to suppress the behavior of brush jumping.
[0020]
In the motor according to claim 7, a plurality of the positions of the locking grooves are provided by changing the positions in the pressurizing direction, and the applied pressure of the coil spring is adjusted.
[0021]
According to the present invention, the coil spring holder in which the coil spring is sub-assembled is set by selecting a desired pressure groove from the plurality of pressure grooves, and thereby depending on the position of the pressure groove (the amount of deflection of the coil spring). It is possible to perform pressure adjustment.
[0022]
In the motor according to claim 8, the periphery of the commutator is surrounded by the oil retaining member, and lubricating grease is supplied from the oil retaining member to the contact portion via the brush.
[0023]
According to this invention, the commutator is disposed so as to surround the seal and the oil retaining member, oil leakage is prevented by the seal, and the lubricating grease retained on the oil retaining member is transmitted to the contact portion through the brush. And improve the grease lubricity of the brush contacts.
[0024]
In the motor according to claim 9, a seal plate is attached to the open side of the oil retaining member to prevent oil leakage between the seal plate and the motor shaft and between the seal plate and the motor case. A sealing material is provided.
[0025]
According to the present invention, by setting the seal plate on which the sealing material for sealing both sides of the motor shaft and the motor case is set on the open side of the oil retaining member, a sealed structure is realized, the seal plate and the motor case, and Prevent oil leakage from the seal plate and motor shaft.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of a motor according to the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the structure of a DC coreless motor will be described as an example, but the present invention is not limited to this embodiment as long as it does not depart from the gist of the present invention.
[0027]
The present invention is particularly characterized by an oil retaining mechanism and a brush contact pressure mechanism in a brush contact structure of a motor. In other words, in order to maintain the slidability of the contact portion between the commutator and the brush, lubrication grease is applied to the contact portion, the applied lubrication grease is retained, and the retained lubrication grease is circulated for rectification. The contact life of the child and the brush is remarkably improved. Further, the pressurizing mechanism is improved as will be described later in order to eliminate chattering and vibration caused by brush jumping with respect to the commutator. Hereinafter, a specific example will be described.
[0028]
FIG. 1 is an explanatory diagram showing an enlarged configuration of a motor according to an embodiment of the present invention. In addition, the same code | symbol as FIG. 6 is attached | subjected about the same element as the component of the motor shown in the prior art example (FIG. 6), and description here is abbreviate | omitted. In FIG. 1, reference numeral 10 denotes a motor, reference numeral 11 denotes a motor case, reference numeral 12 denotes a brush portion, reference numeral 13 denotes a commutator, reference numeral 14 denotes an oil retaining member, reference numeral 15 denotes a brush case, and reference numeral 16 denotes a pressure spring ( (Coil spring), numeral 17 is an O-ring, numeral 18 is an oil seal plate, numeral 19 is an oil seal, numeral 20 is an end cap, and numeral 25 is a lead wire.
[0029]
The motor 10 is, for example, a DC motor having a diameter of about 30 mm and a length of about 40 mm. Basically, in the motor case 11, a coil 2a, a coil holder 2b, and a commutator (fixed integrally with the shaft 4). A rotor portion 2 composed of a commutator 13, a permanent magnet 3, a brush 12, and a motor shaft (shaft) 4 that is integrated with the rotor portion 2 and serves as an output shaft.
[0030]
As shown in the figure, the motor case 11 is designed so that one end thereof fits the brush case 15 and the outer diameter of the end cap 20. The brush case 15 has a U-shaped cross-sectional shape, and an oil retaining member 14 formed of a porous resin is inserted therein, and a pressure spring is inserted into a groove portion of the oil retaining member 14. 16 or the like is set.
[0031]
The material of the oil retaining member 14 retains the lubricating grease by capillary action, retains the lubricating grease whose fluidity increases as the commutator 13 rotates, and uses the retained grease as the contact portion of the brush 12. In order to realize a so-called lubricating grease circulation cycle function, a porous resin is used. As this porous resin, for example, a polymer sintered porous body or the like is used.
[0032]
In addition, the polymer sintered porous body means that a polymer particle having a predetermined particle size is fused with an area between adjacent particles in a molding die and weaves a three-dimensional network structure. A porous material having certain pores. In addition to this polymer sintered porous body, a configuration in which a felt material is used in combination with another porous material or a felt material is partially mixed may be used.
[0033]
The oil seal plate 18 is provided with an O-ring 17 on the outer side and an oil seal 19 on the inner side (motor shaft side) in order to prevent oil leakage. The oil seal plate 18 is inserted in close contact with the open side of the oil retaining member 14 after the oil retaining member 14 is set in the motor case 11 to form a sealed structure. That is, oil leakage from the motor shaft 4 is prevented by the oil seal 19 and oil leakage from the outside of the motor case 11 and the brush case 15 is prevented by the O-ring 17.
[0034]
Of course, the brush plate 12a has a plate shape, one end of which is in contact with the commutator 13, and a mechanism that pressurizes each of the brush plates 12a with the pressure spring 16 in this contacted state. Thereby, compared with the pressurization using the spring property of the plate-shaped bending brush as in the prior art, the brush shape is simple, so that it is easy to ensure the accuracy of component manufacture and attachment. Therefore, reliable pressurization can be performed without considering pressurization variations due to variations in component accuracy and stacking tolerances. That is, since the pressurized state is stabilized, it is possible to suppress the occurrence of brush jumping.
[0035]
As described above, by providing the plate-like brush 12 and pressurizing with the pressure spring 16 from the vertical direction, a stable spring constant can be obtained and the degree of freedom of the set pressure with respect to the contact portion is increased. Further, by suppressing the jumping and chatter vibration of the brush contact portion by this pressurizing mechanism, the spark occurrence rate of the contact can be lowered, and electrical wear can be reduced.
[0036]
Next, the configuration and subassembly of the brush case 15 will be described with reference to FIGS. 2 and 3. 2A is a view of the brush case 15 as viewed from the end cap side, and FIG. 2B is a side sectional view of FIG. 2A. FIG. 3 is a perspective view in FIG. In FIG. 3, for example, the pressure spring 16 is provided with a spring base 21 that supports the whole by fitting the pressing member 22 to the spring inner diameter on the tip side and also fitting the spring inner diameter on the opposite side. Prepare these as a sub-assembly.
[0037]
First, the brush 12 is attached to the inner protrusion of the brush case 15 inside the brush case 15 having a U-shaped cross section (see FIG. 1), and the oil retaining member 14 is further fitted into the sub-assembly pressure spring 16. Then, by inserting the spring groove 24a (or 24b) from the front in FIG. 3 (in the direction (1)) and rotating it in the direction (2), the pair of pressure springs 16 are set at predetermined positions. Then, the state shown in FIG. 2 is obtained. That is, the pressure spring 16 pressurizes each brush plate 12 a via the pressing member 22 in a state of being opposed to each other via the commutator portion 13. At this time, the applied pressure can be adjusted by selecting the grooves 24a and 24b (horizontal positions). In addition, adjustment (change) of pressurization is performed by changing the height of the presser member 22, changing the height of the brim of the presser member 22, or changing the linearity or number of turns of the pressurization spring. Can do.
[0038]
After this assembly, a donut-shaped space is formed around the sliding contact portion of the brush 12 and commutator portion 13 as shown in FIGS. After applying an appropriate amount of grease centering on the contact portion of the brush plate 12a, the oil seal plate 18 in which the O-ring 17 and the oil seal 19 are set is fitted, and a gap 30 having a sealed structure is formed in the gap with the brush case 15. . Then, the end cap 20 is inserted from above the oil seal plate 18.
[0039]
The state after the end cap 20 is inserted is shown in FIG. A groove for distributing a power supply lead wire 25 is formed inside the end cap 20, and the lead wire 25 is fixed at a predetermined position by inserting the end cap 20 as shown in the figure. Yes.
[0040]
By the way, although the L-shaped brush has been described as an example as described above, a configuration may be adopted in which a thick contact member is provided at the tip of the brush so as to take into account the progress of wear over time at the brush contact. An example of this configuration is shown in FIG. As shown in FIG. 5, a sintered contact 26a using a rivet-shaped noble metal sintered material is projected at the tip of a brush 12a by a fastening method such as caulking or crimping. As the precious metal sintered material, gold, silver-based metal, or an alloy thereof is used. By bringing the sintered contact 26 a into contact with the commutator 13, the contact portion wears out and can be sufficiently handled, so that the contact life can be further improved. As described above, the thickness and shape of the contact portion and the material can be easily changed, and variations thereof can be increased, and the life of the contact can be extended.
[0041]
Next, the circulation cycle of the lubricating grease at the contact portion between the brush 12 and the commutator 13 will be described. At the time of assembly, an appropriate amount of lubricating grease is applied to the contact portion before setting the oil sheet plate 18. As the lubricating grease, for example, grease having a consistency of about 2 is used, and the base oil viscosity is 11.5 mm 2 / s. The lubrication grease applied at the time of assembly increases the temperature in the gap 30 inside the motor due to the drive rotation of the motor, and the lubricating grease softens as the temperature rises, and the oil retaining material molded with porous resin Grease is retained by soaking into the member 14 by capillary action. This oil-retained grease flows in the gap 30 by the rotation of the motor and is replenished to the contact portion.
[0042]
In this way, even if the lubricating grease scatters from the contact portion, it is held by the oil retaining member 14 made of a porous body, so that the base oil of the lubricating grease is one of the oil retaining member 14 and the oil retaining member 14. By continuously circulating and recycling from the brush holder part formed by the part, the gap 30 and the contact part, and maintaining lubricity, mechanical wear of the contact part can be reduced.
[0043]
【The invention's effect】
As described above, according to the motor according to the present invention (Claim 1), the lubricating grease that has flowed around due to the rotation of the motor and the temperature rise in the machine and is scattered around is held in the oil retaining member, and the gap The lubrication grease held through the brush contact is returned to the brush contact again, realizing the so-called grease retention and supply circulation cycle, and making the contact portion oil rich, resulting in mechanical failure due to the lack of lubrication grease on the brush contact In order to suppress deterioration due to wear, the mechanical wear of the brush contact can be reduced and the contact life can be improved.
[0044]
According to the motor of the present invention (Claim 2), the lubrication grease that has been dispersed due to a decrease in viscosity due to an increase in temperature is formed inside the porous body by forming the oil retaining member and the gap with the porous body. Thus, the lubricating grease scattered by the rotation of the motor can always be replenished from the porous body by returning the grease held on the brush contact portion from the porous body again.
[0045]
Further, according to the motor according to the present invention (Claim 3), a mechanism that pressurizes the commutator from the back surface of the brush with a coil spring allows the related parts to be compared to the conventional mechanism that has depended on the shape accuracy of the brush. It is not necessary to tighten tolerances and stacking tolerances during assembly, and a stable spring constant is obtained by pressurization with a coil spring, and the contact pressure of the brush against the commutator is stabilized. Therefore, a reliable contact pressure that does not depend on the component accuracy is ensured, and the occurrence of brush jumping or vibration is suppressed, so that electrical wear of the brush contact is reduced and the contact life of the motor can be improved.
[0046]
Further, according to the motor according to the present invention (Claim 4), when contact wear with low wear and low friction is provided on the brush contact surface, contact wear deterioration due to contact with the commutator proceeds. In addition, since the contact life can be extended by the thickness of the contact portion, the reliability of the contact portion is improved.
[0047]
According to the motor of the present invention (Claim 5), the coil spring is inserted into one end of the L-shaped coil spring holder, and is inserted into the locking groove of the oil retaining member, and further set in the pressure groove. Since a brush pressurizing mechanism using a coil spring is realized with a simple configuration, a desired contact pressure of the brush can be secured, and as a result, occurrence of brush jumping and the like is reduced.
[0048]
According to the motor of the present invention (Claim 6), the pair of brushes that contact the commutator face each other in parallel, that is, the two brushes are arranged with the center of the motor shaft as point symmetry. By fixing the end of each brush with the other end, it moves in one direction when the other end is pressurized, so it is possible to avoid brush vibration from being multi-directional as in the past, and the behavior of brush jumping It becomes possible to suppress. Therefore, it is possible to position and fix the brush with a simple configuration compared to the conventional bending brush (R brush), and in particular, the contact life is increased by increasing the thickness of the contact portion in a high-speed rotating motor or the like. Greatly improved.
[0049]
According to the motor of the present invention (Claim 7), the position of the pressure groove is determined by selecting and setting one of the plurality of pressure grooves provided on the coil spring holder in which the coil spring is sub-assembled. Therefore, it is possible to respond quickly when the pressure adjustment or change of the contact occurs during manufacturing or over time.
[0050]
According to the motor of the present invention (Claim 8), the lubricating grease is disposed around the commutator so as to surround the seal and the oil retaining member, prevents oil leakage by the seal, and is held by the oil retaining member. By supplying the brush to the contact part and improving the grease lubricity of the brush contact, it is possible to replenish the contact with grease without oil leakage, so that the contact can be lubricated well regardless of the motor installation state. Is realized.
[0051]
Further, according to the motor of the present invention (Claim 9), the sealing structure is set by setting the seal plate on which the sealing material for sealing both sides of the motor shaft and the motor case is set on the open side of the oil retaining member. In order to prevent the oil leakage from the seal plate and the motor case, and the seal plate and the motor shaft, respectively, it can be used in a wide range of motor mounting conditions and usage environments.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of a motor according to an embodiment of the present invention.
2 shows the configuration of the brush case in FIG. 1, (a) is a view of the brush case as viewed from the end cap side, and (b) is a side sectional view of (a).
FIG. 3 is a perspective view in FIG.
FIG. 4 is an explanatory view showing a state after joining the end cap portion.
FIG. 5 is an explanatory diagram showing a configuration example in which a contact member is attached to the tip of a brush. FIG. 6 is an explanatory diagram showing a configuration of a conventional motor.
2 Rotor part 2a Coil 2b Coil holder 4 Motor shaft 10 Motor 11 Motor case 12 Brush part 12a Brush plate 12b Brush holder 12c Brush holder part gap 12d Brush holder attaching part 13 Commutator 14 Oil retaining member 15 Brush case 16 Pressure spring 17 O-ring 18 Oil seal plate 19 Oil seal 21 Spring base 22 Holding members 24a and 24b Groove 26a Sintered contact 30 Gap

Claims (9)

In a motor that rotates by bringing a brush into contact with a commutator while lubricating with lubricating grease or lubricating oil and supplying current to each commutator from the brush,
A brush case in which the brush and the commutator are installed, and preventing leakage of the lubricating grease or lubricating oil;
An oil retaining member installed so as to surround a contact portion between the brush and the commutator and capable of retaining the scattered lubricating grease or lubricating oil;
A gap between the brush holder part and the brush plate part formed by a part of the oil retaining member to supply the retained lubricating grease or lubricating oil to the brush again,
A motor characterized by comprising. The motor according to claim 1, wherein the oil retaining member is formed of a porous body that obtains a capillary phenomenon. The motor according to claim 1 or 2, further comprising a multi-layer coil spring arranged on the back surface of the brush contact to press the brush contact surface against the commutator to obtain a capillary phenomenon. The motor according to claim 3, wherein a contact member having a predetermined thickness is provided on the brush contact surface. An L-shaped coil spring holder having one end inserted into the coil spring;
The oil retaining member is
A locking groove for locking the coil spring holder;
A pressurizing groove that pressurizes the coil spring by fitting the coil spring;
A porous body surrounding at least the contact point;
The motor according to claim 3, wherein the motor is provided. The motor according to any one of claims 3 to 5, wherein a pair of brushes in contact with the commutator are opposed in parallel, and ends of the brushes are fixed. The motor according to any one of claims 3 to 6, wherein a plurality of positions of the locking grooves are provided by changing positions in a pressurizing direction, and a pressing force of the coil spring is adjusted. The periphery of the commutator is surrounded by the oil retaining member, and lubricating grease is supplied from the oil retaining member to the contact portion via the brush. Motor. 2. A seal plate is attached to an open side of the oil retaining member, and a seal material for preventing oil leakage is provided between the seal plate and the motor shaft and between the seal plate and the motor case. The motor as described in any one of -8.

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