JP2001309617A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a lifetime of a contact reducing a mechanical abrasion of a brush contact by materializing a grease-lubrication cycle to the brush contact. SOLUTION: In a motor driven by feeding a current to a commutator 13 from a brush plate 12a contacting a brush 12 to the commutator 13 with lubricating a lubricant grease, an oil-holding member 14, which is so mounted as to surround a contact of the brush plate 12a and a commutator 30 to hold a dispersed grease, feeds the lubricant grease on holding to the brush plate 12a again by a phenomenon of a capillarity through a gap of a brush-holder section and a gap of a brush plate section and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor for use in FA equipment such as a pump for medical equipment or a part feeder which handles a drug such as a serum, and more particularly, to a small motor in a contact point between a brush and a commutator. The present invention relates to a motor that realizes a circulation cycle of lubricating grease and improves contact properties of a contact portion.

[0002]

2. Description of the Related Art FIG. 6 is an explanatory view showing the structure of a conventional coreless motor. 6, reference numeral 1 denotes a motor case, reference numeral 2 denotes a rotor unit, 2a denotes a coil, 2
b is a coil holder. 3 is a permanent magnet, 4 is a motor shaft, 5 is a bearing, 6 is a sleeve,
Reference numeral 7 denotes a commutator for switching the current supplied through the brush 8 one after another, reference numeral 8 denotes a brush that contacts the commutator 7 and supplies the current, and reference numeral 9 denotes a brush stand on which the brush 8 is mounted. is there. It should be noted that the reference symbol G
Is a lubricating grease applied to a sliding contact portion between the commutator 7 and the brush 9.

[0003] In the motor, one end of the motor case 1 (the left part in Fig. 6 (a)) has a cup-shaped hollow shape, and the rotor is supported by a bearing 5 and a sleeve 6, and is positioned at a predetermined position. After that, the brush stand 9 to which the brush 8 is attached is inserted as a lid. The brush 8 is shown in FIG.
(B) is formed into a substantially U-shaped shape, one of which is fixed to the brush stand 9 and the other end of which is attached to the brush stand 9 so as to contact the commutator 7 surface. .
At this time, the tip of the brush 8 is pressed against the commutator 7 and is in contact with the commutator 7 with its own bending force.

[0004]

However, in the conventional motor as described above, when the rotation of the motor is continuously performed, the lubricating grease applied to the contact portion between the brush and the commutator does not work. There was a problem in that it was scattered in the space inside the motor due to the rotational movement.

[0005] Further, since the conventional brush is in contact with the commutator using the amount of bending (pressing force) due to the bending shape, the accuracy of parts such as the brush and the brush base and the variation in the stacking tolerance during assembly are large. As a result, the desired contact pressure of the contact portion is not ensured with high accuracy, and spark of the contact portion occurs due to jumping or vibration of the brush. As a result, the contact portion shortens the contact life due to electrical wear. There was a problem that would.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has been made in consideration of the above. By enclosing a space in a brush case in which a brush and a commutator are installed and realizing a grease circulation cycle to the brush contact, the present invention provides a brush contact. A first object is to reduce mechanical wear and improve contact life.

Further, by contacting the plate brush with the commutator via a pressure spring, a reliable contact pressure independent of component accuracy is secured, and the occurrence of brush jumping and vibration is suppressed. It is a second object of the present invention to reduce the occurrence of electrical wear of the brush contacts and to improve the contact life of the motor.

[0008]

In order to achieve the above object, in the motor according to the first aspect, the brush is brought into contact with the commutator while lubricating with lubricating grease or lubricating oil. In a motor that is driven to rotate by supplying current to a commutator, the brush and the commutator are installed inside, and a brush case that prevents leakage of the lubricating grease or lubricating oil, and the brush and the commutator An oil retaining member installed to surround the contact portion and capable of retaining the scattered lubricating grease or lubricating oil; and a brush of the lubricating member for supplying the retained lubricating grease or lubricating oil to the brush again A gap is provided between the holder portion and the brush plate portion.

According to the present invention, the lubricating grease scattered around due to the increase in fluidity due to the rotation of the motor and the temperature rise in the machine is held by the oil retaining member, and the lubricating grease held through the gap is applied to the brush contact. Return, so-called grease holding and supply circulation cycle,
By making the contact portion oil-rich, deterioration due to mechanical abrasion due to lack of lubricating grease at the brush contact is suppressed. This motor can be applied to a motor having brush contacts, such as a DC motor, a coreless motor, and a universal motor.

[0010] In the motor according to the second aspect, the oil retaining member is formed of a porous body that obtains a capillary phenomenon.

According to the present invention, by forming the oil retaining member and the gap with a porous body, the lubricating grease that has become less viscous due to a rise in temperature inside the machine and scattered is effectively held inside the porous body. By returning the grease held in the brush contact portion from the porous body again, the grease running out of the brush contact is eliminated.

In the motor according to a third aspect of the present invention, a multi-layer coil spring for obtaining a capillary phenomenon by pressing a brush contact surface against a commutator is disposed on a back surface of the brush contact.

According to the present invention, by providing a mechanism for pressing the commutator from the back of the brush by the coil spring,
Compared to the conventional mechanism that relied on the brush shape accuracy, it is no longer necessary to tighten the tolerances of the related parts and the stacking tolerance during assembly, and a stable spring constant is obtained by applying pressure by the coil spring. Stabilizes the contact pressure. In addition, since the coil spring has a multilayer winding, a grease capillary phenomenon can naturally occur here.

Further, in the motor according to the fourth aspect, a contact member having a predetermined thickness is projected from the brush contact surface.

According to the present invention, the contact member having a predetermined thickness is protruded from the brush contact surface, so that the contact portion can be reduced in thickness even when the contact is deteriorated due to contact with the commutator. As a result, the contact life can be extended.
For this contact member, for example, gold, silver, or an alloy containing these metals can be used.

According to a fifth aspect of the present invention, there is provided a motor having an L-shape, a coil spring holder having one end inserted into the coil spring, and the oil retaining member engaging the coil spring holder. It has a stop groove, a pressurizing groove that presses the coil spring by fitting the coil spring, and a porous body surrounding at least the contact point.

According to the present invention, the coil spring is inserted into one end of the L-shaped coil spring holder, fitted into the locking groove of the oil retaining member, and set in the pressurizing groove. A brush pressure mechanism is realized.

Further, in the motor according to the present invention, a pair of brushes contacting the commutator are opposed in parallel, and the ends of the brushes are fixed.

According to the present invention, in a state where a pair of brushes contacting the commutator are opposed to each other in parallel, that is, in a state where two brushes are arranged with the center of the motor shaft being point-symmetrical, the end portions of each brush are arranged. Is fixed, the brush moves in one direction when the other end is pressurized, so that the vibration of the brush can be prevented from becoming multidirectional as in the related art, and the behavior of the brush jumping can be suppressed. .

Further, in the motor according to the present invention, a plurality of the locking grooves are provided in different positions in the pressing direction to adjust the pressing force of the coil spring.

According to the present invention, the position of the pressing groove (the deflection of the coil spring) is set by selecting and setting a desired pressing groove from a plurality of pressing grooves provided in the coil spring holder in which the coil spring is sub-assembled. Volume) can be adjusted.

Further, in the motor according to claim 8, 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. It is.

According to the present invention, the seal and the oil retaining member are arranged around the commutator so as to prevent oil leakage by the seal and to transmit the lubricating grease held by the oil retaining member through the brush to make contact with the brush. To improve the grease lubrication of the brush contacts.

Further, in the motor according to the ninth aspect, a seal plate is attached to an open side of the oil retaining member, and oil leakage occurs between the seal plate and the motor shaft and between the seal plate and the motor case. This is provided with a sealing material for preventing the occurrence of the above.

According to the present invention, a sealing structure is realized by setting the seal plate on which the seal material for sealing both sides of the motor shaft and the motor case is set on the open side of the oil retaining member. Prevents oil leakage from the case, seal plate and motor shaft.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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.

The present invention is particularly characterized by an oil retaining mechanism and a brush pressure mechanism in a brush contact structure of a motor. That is, in order to maintain the slidability of the contact portion between the commutator and the brush, lubricating grease is applied to the contact portion, and the applied lubricating grease is kept oily. This significantly improves the contact life between the brush and the brush. Also,
In order to eliminate the occurrence of chatter caused by the jumping and vibration of the brush with respect to the commutator, the pressing mechanism is improved as described later. Hereinafter, a specific example will be described.

FIG. 1 is an explanatory diagram showing an enlarged configuration of a motor according to an embodiment of the present invention. Note that the same components as those of the motor shown in the conventional example (FIG. 6) are denoted by the same reference numerals as in FIG. 6, and description thereof will be 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 (commutator), reference numeral 14 denotes an oil retaining member, reference numeral 15 denotes a brush case, and reference numeral 16 denotes a pressure spring ( Reference numeral 17 denotes an O-ring, reference numeral 18 denotes an oil seal plate, reference numeral 19 denotes an oil seal, reference numeral 20 denotes an end cap, and reference numeral 25 denotes a lead wire.

The motor 10 has, for example, a diameter of 30 mm.
× Take a DC motor of about 40mm in length as an example,
Basically, in a motor case 11, a rotor portion 2, a permanent magnet 3, a brush 12, and a rotor portion 2 each including a coil 2a, a coil holder 2b, and a commutator 13 fixed integrally to a shaft 4 are provided. And a motor shaft (shaft) 4 which is integrally formed as an output shaft.

The motor case 11 is, as shown in FIG.
One side end is designed such that the outer diameters of the brush case 15 and the end cap 20 are fitted. Brush case 15
Has a U-shaped cross-section, in which an oil retaining member 14 molded of a porous resin is inserted, and a pressure spring 16 or the like is inserted into a groove portion of the oil retaining member 14. It is set.

The material of the oil retaining member 14 is to retain the lubricating grease by capillary action, to retain the lubricating grease whose fluidity has increased with the rotation of the commutator 13, and to apply the retained grease to the brush 12. The porous resin is used to realize a so-called lubricating grease circulation cycle function that returns to the contact portion of the lubricating grease. As the porous resin, for example, a polymer sintered porous body or the like is used.

The porous sintered polymer is a result of polymer particles having a predetermined particle size fused in a molding die with a certain area between adjacent particles to form a three-dimensional network structure. A porous body having a certain average pore. Further, the present invention is not limited to this porous polymer sintered body, and may be configured to be used in combination with another porous material or to partially mix a felt material.

The oil seal plate 18 is provided with an O-ring 17 on the outside and an oil seal 19 on the inside (motor shaft side) to prevent oil leakage. After the oil retaining member 14 is set in the motor case 11, the oil seal plate 18 is inserted in close contact with the open side of the oil retaining member 14 to form a sealed structure. That is, oil leakage from the motor shaft 4 is
The O-ring 17 prevents oil leakage from the outside of the motor case 11 and the brush case 15.

The brush plate 12a is, of course, plate-shaped, and one end thereof is in contact with the commutator 13, and a pressure spring 16 presses each of the brushes 12a in this state. Accordingly, the brush shape is simpler than in the conventional pressurization using the spring property of the plate-shaped bending brush, so that the accuracy of component production and attachment is easily ensured. Therefore, reliable pressurization can be performed without considering the pressurization variation due to variations in component accuracy, stacking tolerance, and the like. That is, since the pressurized state is stabilized, it is possible to suppress the occurrence of brush jumping.

As described above, by providing the plate-shaped brush 12 and applying pressure by the pressing spring 16 from the vertical direction, a stable spring constant is obtained and the degree of freedom of the set pressure with respect to the contact portion is increased. spread. In addition, by suppressing the jumping and chattering of the brush contact portion by this pressurizing mechanism, the spark generation rate of the contact is reduced, and the electrical abrasion can be reduced.

Next, the structure and subassembly of the brush case 15 will be described with reference to FIGS. FIG. 2A is a view of the brush case 15 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, the pressurizing spring 16 is provided with, for example, a spring base 21 in which the pressing member 22 is fitted to the inner diameter of the spring on the distal end side, and is similarly fitted to the inner diameter of the spring on the opposite side to support the whole. These are subassembled and prepared.

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. The spring 16 is inserted into the spring groove 24a (or 24b) from the front in FIG. 3 and lifted (in the direction of FIG. 3), and is rotated in the direction of FIG. The state shown in FIG. That is, the pressing springs 16 press the respective brush plates 12 a in a state where the brush plates 12 a face each other with the commutator portions 13 interposed therebetween.
Pressurized through 2. At this time, the pressing force can be adjusted by selecting the grooves 24a and 24b (positions in the horizontal direction). In addition, the adjustment (change) of the pressurization may be performed by changing the height of the presser member 22, changing the height of the collar of the presser member 22, or changing the linearity or the number of turns of the pressurizing spring. Can be.

After this assembling, a donut-shaped space is formed around the sliding portion of the brush 12 and the commutator portion 13 as shown in FIGS. After applying an appropriate amount of grease around the contact portion of the brush plate 12a, the oil seal plate 18 on which the O-ring 17 and the oil seal 19 are set is fitted to form a gap 30 having a closed structure in the gap with the brush case 15. . Then, the end cap 20 is inserted from above the oil seal plate 18.

FIG. 4 shows a state after the end cap 20 is inserted. A groove for distributing the power supply lead wire 25 is formed inside the end cap 20. As shown in the figure, the insertion of the end cap 20 fixes the lead wire 25 in a predetermined position. I have.

As described above, the L-shaped brush is taken as an example. However, a thick contact member is protruded at the tip of the brush, and the brush contact at the brush contact point takes into account the progress of wear over time. Is also good. FIG. 5 shows an example of this configuration.
As shown in FIG. 5, a sintered contact 26 a using a rivet-shaped noble metal sintered material is provided at the tip of the brush 12 a by a fastening method such as caulking or crimping. As the noble metal sintered material, gold, silver-based metal, or an alloy thereof is used. By bringing the sintered contact 26a into contact with the commutator 13, the wear of the contact portion progresses and it is possible to sufficiently cope with it, so that the contact life can be further improved. As described above, it is possible to easily change the thickness and the shape of the contact portion and the material of the contact portion, to increase the variation, and to prolong the service life of the contact.

Next, the circulation cycle of the lubricating grease at the contact point between the brush 12 and the commutator 13 will be described. At the time of assembly, before setting the oil sheet plate 18, an appropriate amount of lubricating grease is applied to the contact portion. As the lubricating grease, for example, a grease having a consistency of about 2 is used, and the base oil viscosity is 11.5 mm 2 / s. The lubricating grease applied to the contacts at the time of assembly increases the temperature inside the gap 30 inside the motor due to the driving rotation of the motor, and the lubricating grease softens as the temperature rises, and the lubricating oil molded from the porous resin The grease is oil-retained by penetrating the member 14 by capillary action. The oil-retained grease flows in the gap 30 by the rotation of the motor, and is supplied to the contact portion.

As described above, even if the lubricating grease scatters from the contact portion, the lubricating grease is held in the brush holder 14 made of a porous material, so that the base oil of the lubricating grease is constantly circulated from the brush holder 14 and the contact portion. By being recyclable and maintaining lubricity, the mechanical wear of the contact portion can be reduced.

[0043]

As described above, according to the motor according to the present invention (claim 1), the lubricating grease scattered around by increasing the fluidity due to the rotation of the motor and the temperature inside the machine increases to the oil retaining member. Insufficient lubrication grease on brush contacts by realizing a so-called circulating cycle of grease retention and supply, while maintaining and returning the lubricating grease held through the gap to the brush contacts, and making the contact portions oil-rich Therefore, the mechanical wear of the brush contacts can be reduced, and the contact life can be improved.

Further, according to the motor according to the present invention (claim 2), the oil retaining member and the gap are formed of a porous body, so that the lubricating grease whose viscosity has been reduced due to a rise in temperature and which has scattered is used as the porous body. By effectively holding the grease held inside and returning the grease held on the brush contact portion from the porous body again, lubricating grease scattered by the rotation of the motor can always be supplied from the porous body.

Further, according to the motor according to the present invention (claim 3), the mechanism for pressing the commutator by the coil spring from the back of the brush makes it possible to reduce the conventional mechanism which depends on the accuracy of the shape of the brush. It is not necessary to tighten the tolerance of the related parts and the stacking tolerance at the time of assembly, and a stable spring constant is obtained by pressurization by the coil spring, and the contact pressure of the brush with the commutator is stabilized. Therefore, a reliable contact pressure that does not depend on component accuracy is secured, and the occurrence of brush jumping and vibration is suppressed, so that electrical wear of the brush contacts is reduced, and the contact life of the motor can be improved.

According to the motor of the present invention (claim 4), a contact member with low abrasion and low friction is provided on the brush contact surface so that abrasion deterioration of the contact due to contact with the commutator is prevented. Even in the case of progress, the contact life can be extended by the thickness of the contact portion, so that the reliability of the contact portion is improved.

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, this is fitted into the locking groove of the oil retaining member, and further set in the pressurizing groove. By doing so, it is possible to secure a desired brush contact pressure in order to realize a brush pressing mechanism using a coil spring with a simple configuration,
As a result, the occurrence of brush jumping or the like is reduced.

Further, according to the motor of the present invention (claim 6), a state in which a pair of brushes in contact with the commutator are opposed to each other in parallel, that is, the two brushes are set with the center of the motor shaft being point-symmetrical. By fixing the end of each brush in the arranged state, it moves in one direction when the other end is pressed, so that the brush vibration can be prevented from becoming multi-directional as in the past, and the brush jumping Can be suppressed. Accordingly, the brush can be positioned and fixed with a simpler structure than the conventional bending brush (R brush), and the life of the contact is increased particularly by increasing the thickness of the contact portion in a high-speed rotating motor or the like. Significantly improved.

According to the motor according to the present invention, the coil spring holder in which the coil spring is sub-assembled is selected and set by selecting one of a plurality of pressure grooves. Since it is possible to adjust the pressure by the position of the groove, it is possible to quickly cope with a case where the pressure of the contact is adjusted or changed during manufacturing or over time.

According to the motor according to the present invention, the seal and the oil retaining member are arranged around the commutator to prevent oil leakage by the seal.
In addition, the lubricating grease held by the oil retaining member is transmitted to the brush by the brush and supplied to the contacts to improve the grease lubrication of the brush contacts, so that grease can be supplied to the contacts without oil leakage. Good contact lubrication is realized regardless of the state.

According to the motor of the present invention (claim 9), by setting the seal plate on which the seal material for sealing both sides of the motor shaft and the motor case is set on the open side of the oil retaining member, It realizes a sealed structure and prevents oil leakage from the seal plate and the motor case, and from the seal plate and the motor shaft.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a motor according to an embodiment of the present invention.

FIG. 2 shows a configuration of a brush case in FIG. 1,
(A) is the figure which looked at the brush case from the end cap side, (b) is the sectional side view of (a).

FIG. 3 is a perspective view of FIG.

FIG. 4 is an explanatory view showing a state after joining of an 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 view showing a configuration of a conventional motor.

[Explanation of symbols]

 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 gap 12d Brush holder mounting 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 Pressing member 24a, 24b Groove 26a Sintered contact 30 Gap

Claims (9)

[Claims] 1. A motor that rotates a brush by bringing a brush into contact with a commutator while lubricating with a lubricating grease or a lubricating oil and supplying current to each commutator from the brush, wherein the brush and the commutator are internally provided. A brush case that is installed and that prevents leakage of the lubricating grease or lubricating oil; and a brush case that is installed so as to surround a contact portion between the brush and the commutator and that can hold the scattered lubricating grease or lubricating oil. A motor comprising: an oil retaining member; and a gap between a brush holder portion and a brush plate portion of the oil retaining member for supplying the held lubricating grease or lubricating oil to the brush again. 2. The motor according to claim 1, wherein the oil retaining member is formed of a porous body that obtains a capillary phenomenon. 3. A multi-layer coil spring for obtaining a capillary phenomenon by bringing a brush contact surface into contact with a commutator on a back surface of the brush contact.
Motor as described in. 4. The motor according to claim 3, wherein a contact member having a predetermined thickness is protruded on the brush contact surface. 5. An oil retaining member having an L-shape, one end of which is inserted into the coil spring, wherein the oil retaining member includes a locking groove for locking the coil spring holder, and the coil spring being fitted therein. The motor according to claim 3, further comprising: a pressurizing groove for pressing the coil spring in a pressurized state; and a porous body surrounding at least the contact. 6. The motor according to claim 3, wherein a pair of brushes in contact with the commutator are opposed to each other in parallel, and an end of the brush is fixed. 7. The method according to claim 3, wherein a plurality of the locking grooves are provided in different positions in the pressing direction to adjust the pressing force of the coil spring. motor. 8. 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.
A motor according to any one of the preceding claims. 9. A seal plate is mounted on an open side of the oil retaining member, and a seal member for preventing oil leakage is provided between the seal plate and the motor shaft and between the seal plate and the motor case. Claim 1
A motor according to any one of claims 1 to 8.