JPH11355999A - Bearing equipment of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent foreign matter like dust from permeating into a bearing case from a penetrating hole of a bracket. SOLUTION: Outside a bracket 6 from which a rotor shaft 4a protrudes, a sealing member 16 composed of material excellent in elasticity like rubber is installed surrounding a penetrating hole a1 from which the rotary shaft 4a protrudes, in the range where rotation of the rotor shaft 4a is not obstructed. In the bearing equipment constituted like this, recessed trenches b4 , b5 are filled with semisolid viscous lubricant. By the heat generated at the time of rotation of the rotor, the lubricant is softened, and oil films of the lubricant are formed between the rotor shaft 4a corresponding to the recessed trenches b4 , b5 and the back of the bracket 6 and the side surface of a ball bearing 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a bearing device for an electric motor, and more particularly to a bearing device for preventing entry of dust and moisture containing salt.

[0002]

2. Description of the Related Art Conventionally, various electric motors have been used as a drive source for a blower or the like used for many home electric appliances such as heating / cooling equipment. Most of the electric motors use ball bearings in their bearings.
That is, a rotor rotatably mounted on a stator core of an electric motor includes a ball bearing mounted on both ends of a rotor shaft, a housing in which the stator core is fitted, and a cover for closing an open end of the housing. By being inserted into the bearing housings formed respectively, the rotor is rotatably supported and held on the stator core. The rotor is rotated in a predetermined direction via the ball bearing by energizing a coil wound around the stator core.

[0003]

However, in a configuration in which the rotor is rotatably supported by using a ball bearing, the bearing housing on the housing side is normally closed because the rotor shaft does not protrude to the outside. Because of this, it is possible to prevent dust and foreign substances that adversely affect the ball bearings from entering the bearing housing, but on the cover side of the bearing housing, a rotor of a rotor on which a fan of a blower is mounted. A through-hole for projecting the shaft to the outside is provided, and the rotor shaft projects through the through-hole to the outside with a small gap. For this reason, when an electric motor is used as a drive source of a blower that supplies air to a combustion section (burner section) of a heating device to improve combustion efficiency, for example, a ball bearing that rotatably supports a rotor is used. Since it is sealed only by the shield plate, it has been difficult to properly prevent the intrusion of dust or foreign matter that flows when air is introduced into the blower.

That is, since the ball bearing itself generally has only a shield plate for protecting the ball inserted between the inner and outer races from dust and the like, the air is introduced when the blower is operated. At the same time, dust including salt, moisture containing salt, etc. can easily enter the bearing housing from the gap of the through hole of the cover from which the rotor shaft projects,
It accumulates in the bearing housing over time, or enters the ball bearing through a narrow gap between the shield plate of the ball bearing and the inner and outer races. As a result, the outer race surface of the ball bearing and the outer race is roughened, or the ball and the inside of the bearing housing are rusted, thereby lowering the rotation function of the ball bearing and generating a noise generating factor.
There is a problem that the life of the ball bearing is shortened, the operation of the motor becomes difficult, and the reliability of equipment using the motor is impaired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. By providing a highly elastic sealing member made of rubber or synthetic resin on the back surface of a ball bearing constituting a bearing, An object of the present invention is to provide a bearing device for an electric motor in which the infiltration of air containing dust, salt, and the like is satisfactorily improved, and the function of a ball bearing is surely improved.

[0006]

According to the first aspect of the present invention, a rotor provided on a rotor shaft and a stator core arranged opposite to the rotor are sandwiched from both sides, and a bearing housing is provided at a center position. And a ball bearing attached to both ends of a rotor shaft, wherein the rotor is rotatably inserted into a stator core, and ball bearings at both ends of the rotor shaft are mounted on both sides of the rotor. A pair of brackets that rotatably support the rotor while fitted to
In a motor configured to be mounted on a stator core with a rotor shaft protruding from a through hole of one bracket, a range in which rotation of the rotor shaft is not hindered outside the bracket from which the rotor shaft protrudes. And a sealing member made of a member having excellent elasticity such as rubber is mounted so as to surround the through hole from which the rotor shaft projects.

According to a second aspect of the present invention, there is provided a sealing member having a first concave groove in an insertion hole through which a rotor shaft is inserted, and a second concave groove in an inner surface corresponding to an outer surface of the bearing housing. Each formed,
Each of the grooves is filled with a semi-solid viscous lubricant, and an oil film of the lubricant is provided between the rotor shaft and the grooves.

According to a third aspect of the present invention, there is provided a pair of brackets which hold a rotor mounted on a rotor shaft and a stator core opposed to the rotor from both sides, and have a bearing housing formed at a center position. And ball bearings mounted on both ends of a rotor shaft, wherein the rotor is rotatably inserted into a stator core, and ball bearings at both ends of the rotor shaft are fitted into bearing housings from both sides thereof. A motor in which a pair of brackets rotatably supporting the rotor are mounted on a stator core with the rotor shaft protruding from a through hole of one of the brackets, wherein the bracket protrudes from the rotor shaft. A large-diameter through-hole is drilled in the rear part of the sealing member, and a sealing member made of a member having a high elasticity such as rubber in a range that does not hinder the rotation of the rotor shaft is closed in the through-hole. That you have And butterflies.

According to a fourth aspect of the present invention, there is provided a sealing member integrally including a body inserted into the through hole and a flange connected to the body and held between the bearing housing and the ball bearing. The first and second concave grooves are respectively formed in the body and the side surface corresponding to the insertion hole for inserting the rotor shaft of the body and the ball bearing, and semi-solid grooves are formed in these grooves. The viscous lubricant is filled to form an oil film of the lubricant between the rotor shaft and the groove.

According to a fifth aspect of the present invention, a thin plate-like collar having a small coefficient of friction is loosely fitted to a rotor shaft between the sealing member and the bracket or between the sealing member and the ball bearing. An oil film of a lubricant is formed between the sealing member and the collar with a semi-solid viscous lubricant filled in a concave groove at a position corresponding to the collar of the sealing member. I do.

According to the present invention, a sealing member made of rubber or synthetic resin and having excellent elasticity is mounted on a bracket from which the rotor shaft protrudes, with the rotor shaft penetrating the center of the sealing member. A groove is formed around the insertion hole through which the rotor shaft of the sealing member penetrates, and a portion corresponding to the back surface of the bracket or the side surface of the ball bearing, and a semi-solid viscous lubricant is filled in these grooves. The lubricant is softened by the heat generated during the rotation of the rotor when the rotor rotates, so that an oil film of the lubricant is formed between the concave groove, the corresponding rotor shaft, the back surface of the bracket, and the side surface of the ball bearing. So
During operation of the motor, the oil film can effectively shield the intrusion of dusty or salty air from the through hole of the bracket from which the rotor shaft protrudes, so that the life of the ball bearing decreases due to intrusion of dust and the like. This makes it possible to reliably solve the problem that the motor is driven, and the motor can be driven in a stable state for a long time, which is convenient.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which an embodiment of the present invention is applied to an electric motor used for a blower will be described below with reference to FIGS. FIG. 1 is a cutaway sectional view of a main part of a blower generally used in the related art.
For example, denotes a shading coil type electric motor. This electric motor 1 is rotatable in a stator core 3 having a coil bobbin 2 wound with a coil (not shown) mounted on one side and an insertion hole provided in the other of the stator core 3. And a bracket 6, 6a provided with ball bearings 5, 5a rotatably supporting a rotor shaft 4a axially mounted on the rotor 4 and mounted on the stator core 3. Have been.

The electric motor 1 is provided with, for example, a blower 7 for blowing air to a burner section of a hot water supply device (not shown) or for discharging combustion gas. As shown in FIG. 2, turbofans 8, 9 arranged in two stages on the rotor shaft 4a, and first and second fan covers 1 for individually accommodating the turbofans 8, 9 are provided.
0 and 11 are schematically configured.

The blower means 7 fastens the bottom plate 12 to a mounting bolt (not shown) screwed to the stator core 3 by using a nut, and then the first turbo fan 8 to the rotor shaft 4a. Is fixed to the bottom plate 12 with fixing means such as screws, and then the first fan cover 10 is opened. The second turbofan 9 is fixed to the tip of the rotor shaft 4a protruding from the hole 13, and thereafter, the first turbofan 9 is fixed.
A second fan cover 11 opened around a suction port 14 is attached to the fan cover 10 using screws or the like, and the blowing means 7 and the electric motor 1 are connected via the bottom plate 12. They are integrally connected and fixed. In addition, 15 shown in FIG. 1 is a discharge port provided in the bottom plate 12.

Next, reference numeral 16 shown in FIG. 1 denotes a bracket 6 on which the rotor shaft 4a protrudes.
a is a cap-shaped sealing member attached near the protruding portion of FIG.

The structure of the sealing member 16 is shown in FIGS.
This will be described below. In Figure 2, through the sealing member 16 is drilled outer surface of the bearing housing a that accommodates the ball bearing 5 of the bracket 6 and the large-diameter large ring portion b ₁ encapsulating, the back wall of the bearing housing a rotor shaft 4a penetrating, protruded from the holes a ₁
It is configured cap-shaped and an insertion hole b ₃ the annular portion b ₁ integrally with bridge-shaped small-diameter small ring portion b ₂ a for inserting the. The sealing member 16 is formed by molding rubber or a synthetic resin (for example, polytetrafluoroethylene).

[0017] Then, the in the recess of the inner surface corresponding to the large ring portion b ₁ of bracket 6 back wall of the sealing member 16, the second groove b ₅ is recessed at the position of the insertion hole b ₃ nearer And
The first groove b ₄ is circumferentially provided along the outer periphery of the rotor shaft 4a is in the insertion hole b ₃ of the small ring portion b _2.

When the sealing member 16 is attached to the bracket 6, the semi-solid viscous lubricant (a semi-solid viscous lubricant) is added to the concave grooves b ₄ and b ₅ of the large and small ring portions b ₁ and b ₂ respectively. For example, grease) O ₁ and O ₂ are filled in an overflowing state, and a collar 17 made of synthetic resin having excellent oil resistance, heat resistance, and abrasion resistance is fitted to the rotor shaft 4a, and then the same as the collar 17 described above. an insertion hole b ₃ of the small ring portion b ₂ fitted large ring portion b ₁ as shown in FIG. 1, by utilizing the elasticity of Daiwa unit b ₁ to the bearing housing a bracket 6 fitted to By doing so, the sealing member 16 is attached to the back of the bracket 6. As described above, the sealing member 16
After mounting the motor 1, the mounting holes 12a provided in the center of the bottom plate 12 as shown in FIG. 1 the small ring portion b ₂ the outer periphery of the sealing member 16
The blower A is configured by integrally connecting and fixing the blower means 7 and the electric motor 1 with mounting bolts and nuts (not shown) in this state.

Next, the operation will be described. When current is supplied to a coil (not shown) wound around the coil bobbin 2 of the electric motor 1 to rotate the rotor 4, the first
The second turbo fans 8 and 9 rotate, and supply the outside air to the blowing means 7.
The air is sucked from a suction port 14 provided in the second fan cover 11, and the sucked outside air is pressure-fed in the blowing means 7, while passing from a discharge port 15 provided in the bottom plate 12 through a flow hole 13 through a feeding pipe (not shown). The outside air is pressure-fed to, for example, a burner of a water heater (not shown). When the outside air is pressure-fed in the blowing means 7, the bottom plate 12 of the blowing means 7 is hermetically sealed by a sealing member 16 attached to the outer periphery of the bearing housing a of the bracket 6 of the electric motor 1 so that no gap is formed. Since it is stopped, the outside air does not leak to the outside at all, and the outside air can be satisfactorily pumped and fed to the burner portion of the water heater.

When foreign matter such as powdered snow or dust flows into the outside air at the time of pressurizing and feeding the outside air, or when the outside air itself contains salt (the blower A is generally installed outdoors). , And these foreign substances and salts are not
Then, the air flows into the blowing means 7 and is supplied from the discharge port 15 to the burner together with the outside air. However, there is no particular problem if all the foreign matter and the like flowing into the blowing means 7 is discharged from the discharge port 15, but the outside air is pressure-fed by the blowing means 7 by the turbo fans 9, 8, and a part of the air is fed during the pressure-fed. The outside air tends to flow out of the mounting hole 12a of the bottom plate 12 to the outside.

Since the mounting hole 12a is closed by the sealing member 16 attached to the outer periphery of the bearing housing a of the bracket 6, as shown in FIG. entering from the gap between the insertion hole b ₃ parts b ₂ in the bearing housing a. In this case, the rotor shaft 4a is heated during the rotation of the rotor 4, that is, by the heat generated by the operation of the electric motor 1 within a range that does not hinder the operation of the electric motor 1, and the sealing member is heated by this heat. The lubricants O ₁ and O ₂ filled in the sixteen grooves b ₄ and b ₅ are softened, and the outer circumference of the rotor shaft 4a corresponding to the groove b ₄ and the collar 17 corresponding to the groove b ₅ correspond. An oil film is formed in the minute voids.

[0022] That is, the sealing the through-holes a ₁ of the rotor shaft 4a drilled to the bearing housing a by an oil film of the lubricant O _1, O ₂ to the outside. Therefore, dust or the like from entering together with the outside air is blocked by the oil film of the lubricant can be prevented from the through hole a ₁ reliably from entering the bearing housing a. As a result, the environmental resistance to the bearing housing a and the ball bearing 5 can be maintained well, the operation of the motor can be smoothly maintained for a long time, and the reliability of the motor 1 can be significantly improved.

Next, a second embodiment of the present invention will be described with reference to FIGS.
An example will be described. The same parts as those described in the first embodiment are denoted by the same reference numerals. The difference from the bearing device described in the first embodiment is the structure of the sealing member 16a. That is, as shown in FIGS. 6 to 8, the sealing member 16 a shown in the second embodiment is a large-diameter flange sandwiched between the side surface of the ball bearing 5 and the back wall of the bearing housing a of the bracket 6. and parts b _11, and b ₂₂ (a smaller diameter than the collar section b ₁₁₎ barrel that is loosely fitted in the large diameter through hole a ₁₁ drilled in the rear wall of the bearing housing a,
Has an insertion hole b ₃ of the rotor shaft 4a in the center, a rubber Toka synthetic resin (e.g., polytetrafluoroethylene) is formed by molding in a convex shape in such elasticity superior member.

[0024] Then, a body portion b ₂₂ side of the insertion hole b ₃ of the sealing member 16a, the inner surface of the flange portion b ₁₁ side, similarly to the sealing member 16 described in the first embodiment, respectively Concave grooves b ₄ and b ₅ for filling lubricants O ₁ and O ₂ are provided. When mounting the sealing member 16a is initially fitted to the body portion b ₂₂ of the sealing member 16a from the inside of the bearing housing a the through hole a ₁₁ in the bracket 6, a portion of which is shown in FIG. 6 Then, the ball bearing 5 which is projected on the outer side of the bracket 6 and is mounted on the rotor shaft 4a is moved to the rotor shaft 4a.
Is inserted into the bearing housing a via a collar 17 made of synthetic resin having excellent heat resistance, oil resistance, and wear resistance which has been fitted in advance.

[0025] As a result, the collar portion b ₁₁ of the sealing member 16a is
As shown in FIG. 6, the outer peripheral edge of the collar 17 is firmly held between the side surface of the outer race of the ball bearing 5 and the back wall of the bearing housing a in a state in which the collar 17 is loosely fitted in the inner concave portion. Thus, the mounting of the sealing member 16a is completed. As described above, in the second embodiment, the sealing member 16a is sandwiched by using the bearing housing a.
Dust and the like that enter from the air blowing means 7 during the operation can be satisfactorily prevented from entering by the oil films of the lubricants O ₁ and O ₂ , as described by the sealing member 16 shown in the first embodiment. Thus, the reliability of the electric motor 1 can be significantly improved. In FIG. 5, reference numeral 20 denotes a rubber ring for sealing a gap between the bracket 6 and the bottom plate 12, for example.

[0026]

As described above, according to the present invention, a sealing member made of a material having excellent elasticity, such as rubber or synthetic resin, is provided on the bracket side from which the rotor shaft projects, and the center of the sealing member is inserted through the rotor shaft. The sealing member is mounted, and a groove is provided around the insertion hole through which the rotor shaft of the sealing member penetrates, and a portion corresponding to the back surface of the bracket or the side surface of the ball bearing. Is filled with a viscous lubricant, and the heat generated when the rotor rotates causes the lubricant to be softened, so that the lubricant is formed between the groove and the corresponding rotor shaft, the back surface of the bracket, and the side surface of the ball bearing. Since the bearing device is formed so as to form an oil film, the infiltration of air containing dust and salt from the through hole or through hole of the bracket from which the rotor shaft protrudes during operation of the motor is effectively blocked by the oil film. It is possible Ri, as a result, the ball bearings can be its life by dust or other foreign matter intrusion reliably eliminate the problem of decreased, the electric motor can be driven in a stable state for a long time.

In addition, the sealing member can be easily manufactured by injection molding or molding, and can be easily assembled, so that the bearing device for the electric motor can be manufactured easily and inexpensively. .

[Brief description of the drawings]

FIG. 1 is a cutaway side view of a main part of a blower showing a use state of an electric motor provided with a bearing device of the present invention.

FIG. 2 is a longitudinal sectional view showing the bearing device of the present invention.

FIG. 3 is a perspective view of a sealing member.

FIG. 4 is a perspective view showing the sealing member in a longitudinal section.

FIG. 5 is a cutaway side view of a main part of a blower provided with an electric motor according to a second embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing the bearing device of the second embodiment.

FIG. 7 is a perspective view showing a sealing member used for the bearing device of the second embodiment.

FIG. 8 is a perspective view showing a state where the sealing member is longitudinally cut.

[Explanation of symbols]

1 motor 4 rotor 4a rotor shaft 5,5a ball bearing 6,6a bracket 16,16a sealing member a bearing housing b _4, b ₅ first, second groove O _1, O ₂ lubricant

Claims (5)

[Claims] 1. A pair of brackets having a rotor attached to a rotor shaft, a stator core opposed to the rotor and sandwiched from both sides, and a bearing housing formed at a center position.
Ball bearings mounted on both ends of a rotor shaft, wherein the rotor is rotatably inserted into a stator core, and ball bearings at both ends of the rotor shaft are fitted into bearing housings from both sides thereof. In a motor configured by attaching a pair of brackets rotatably supporting a rotor to a stator core with a rotor shaft protruding from a through hole of one of the brackets, a bracket having the rotor shaft protruding is provided. An electric motor, wherein a sealing member made of a member having excellent elasticity, such as rubber, is mounted outwardly so as not to hinder rotation of the rotor shaft so as to surround a through hole from which the rotor shaft projects. Bearing device. 2. The sealing member has a first groove formed in an insertion hole through which a rotor shaft is inserted, and a second groove formed on an inner surface corresponding to an outer surface of the bearing housing. 2. The method according to claim 1, wherein the first groove is filled with a semi-solid viscous lubricant, and an oil film of the lubricant is provided between the rotor shaft and the groove. Electric motor bearing device. 3. A pair of brackets having a rotor mounted on a rotor shaft, a stator core opposed to the rotor and sandwiched from both sides, and a bearing housing formed at a center position;
Ball bearings mounted on both ends of a rotor shaft, wherein the rotor is rotatably inserted into a stator core, and ball bearings at both ends of the rotor shaft are fitted into bearing housings from both sides thereof. In a motor configured by attaching a pair of brackets rotatably supporting a rotor to a stator core with a rotor shaft protruding from a through hole of one of the brackets, after a bracket from which the rotor shaft protrudes. A large-diameter through-hole was bored in the back, and a sealing member made of a highly elastic member such as rubber was attached to the through-hole so as not to hinder the rotation of the rotor shaft so as to close the through-hole. A bearing device for an electric motor, characterized in that: 4. The sealing member integrally forms a trunk inserted into the through-hole and a flange connected to the trunk and sandwiched between a bearing housing and a ball bearing, and First and second grooves are respectively formed in the body and the side surface corresponding to the insertion hole for inserting the rotor shaft of the body and the ball bearing, and semi-solid grooves are formed in the first and second grooves. 2. The bearing device for an electric motor according to claim 1, wherein a viscous lubricant having a shape is filled to form an oil film of the lubricant between the rotor shaft and the groove. 5. The sealing member and a bracket, or
Between the sealing member and the ball bearing, a thin plate-like collar having a small coefficient of friction is loosely fitted to the rotor shaft, and a semi-solid viscous material is filled in a groove corresponding to the collar of the sealing member. The bearing device for an electric motor according to claim 2, wherein an oil film of the lubricant is formed between the sealing member and the collar with a suitable lubricant.