JP2022177344A - Motor, and electrical machine including the same - Google Patents

Abstract

To provide a highly reliable motor capable of ensuring airtightness against the intrusion of moisture and the like.SOLUTION: A motor 100 includes: a frame 20; a stator 60 and a rotor 50 housed in the frame 20; a resin end plate 30 covering an opening 21 of the frame 20; and a seal ring 80 constituted of an annular elastic body. Between a step 36 formed on the end plate 30 and the inner peripheral surface of the frame 20, an annular open space S is formed for accommodating the seal ring 80. The seal ring 80 with an X-shaped cross-section has first to fourth lips 80a to 80d. The fourth lip 80d abuts on the corner of the step 36. The cross-sectional area of the first to third lips 80a to 80c is greater than that of the fourth lip 80d.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a motor and an electric device having the same, and more particularly to a motor having a structure that prevents entry of moisture, oil, etc. from the outside.

2. Description of the Related Art In recent years, motors have been widely used in electrical equipment, power tools, and in-vehicle applications. For example, small motors are used to drive hydraulic pumps used in antilock braking systems (ABS). Motors used in these applications are required to be more compact and lightweight, and are also required to have high reliability. In addition, since the motor used for the ABS is installed in the engine room of the vehicle, the motor may be exposed to moisture from the outside during rainy weather, etc., and sufficient waterproof measures must be taken.

Therefore, conventionally, in an end plate that is press-fitted into and covers the opening of the frame, which is the outer shell of the motor, a certain gap is formed between the commutator and the bearing along the rotation shaft that is rotatably supported by the bearing. A technique has been proposed to solve the above-described problem by forming a wall with a ridge (see, for example, Patent Literature 1). In order to electrically insulate the motor from the rotor, stator, etc., the end plate is generally made of a resin material.

Japanese Unexamined Patent Application Publication No. 2002-204548

By the way, the above-mentioned water and the like enter the interior of the frame mainly from the connecting portion between the end plate and the frame. For this reason, a seal ring such as an O-ring or an X-ring is provided at this connecting portion to prevent moisture or the like from entering the frame. On the other hand, when the motor and the load are assembled, the end plates are assembled with axial pressure applied from the load side, and this state is maintained.

However, it is generally known that when the temperature rises while pressure is applied to the resin material, the resin material undergoes deformation due to thermal creep. When thermal creep deformation of the end plate occurs, the contact surface pressure of the seal ring on the end plate, frame and load side decreases, creating a gap between the seal ring and their contact parts, making it impossible to maintain sufficient airtightness. Gone. In this state, if water is splashed into the gap from the outside, the water may enter the motor and significantly reduce the reliability and insulation of the motor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide a highly reliable motor in which airtightness is maintained at the connecting portion between the end plate and the frame, and an electric device using the same.

In order to achieve the above object, the motor according to the present invention comprises a bottomed cylindrical frame with one end open, a stator housed in the frame, a stator housed in the frame, and the stator and a rotor arranged at a predetermined interval, and an end plate which is a plate-shaped member disposed in the opening of the frame so as to cover the opening and having a through hole provided at the center through which the rotating shaft is inserted. and a seal ring made of an annular elastic body for keeping the inside of the frame airtight, between a step formed on the outer peripheral portion of the outer surface of the end plate and the inner peripheral surface of the frame. An annular open space is defined in the open space, the seal ring is accommodated in the open space, the seal ring has an X-shaped cross section and has first to fourth lips, and the fourth lip is At least one of the first to third lips is in contact with the corner of the step, and has a cross-sectional area larger than that of the fourth lip.

According to this configuration, it is possible to increase the contact surface pressure of the seal ring at the corner portion of the open space including the inner peripheral surface of the frame. In addition, when a load is connected to the rotating shaft of the motor, it is possible to increase the contact surface pressure of the seal ring at the corner formed by the load and the inner peripheral surface of the frame. As a result, even if the end plate is deformed due to heat or pressure, airtightness is maintained at the corner, preventing moisture from entering the frame, and realizing a highly reliable motor. can.

The electric device according to the present invention includes the motor and a driven shaft that is connected to the motor and protrudes from the through hole to the outside of the end plate and is driven by the rotation of the motor. and a load having a driving portion, wherein the seal ring is pressed from the surface of the load toward the bottom side of the frame so that the first lip contacts the bottom surface of the step and the inner peripheral surface of the frame. The second corner portion is formed by the surface of the load and the inner peripheral surface of the frame, and the third lip is formed between the surface of the load and the stepped portion. and the fourth lip is in contact with the fourth corner, which is the corner of the step.

According to this configuration, by forming the cross section of the seal ring into an X shape, the first to third lips are in predetermined contact with respect to the first to third corner portions corresponding to the entry path of moisture or the like from the outside. By contacting with surface pressure, it is possible to reliably prevent entry of moisture or the like into the interior of the frame or the interior of the load. Thereby, a highly reliable electric device can be realized.

As described above, according to the present invention, it is possible to prevent moisture from entering the frame even when the end plate is deformed due to heat or pressure, thereby realizing a highly reliable motor.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram of the principal part of the electric equipment which concerns on Embodiment 1 of this invention. FIG. 5 is a schematic diagram for explaining temporal deformation of an end plate and a seal ring for comparison; It is a cross-sectional schematic diagram of a seal ring. It is a cross-sectional schematic diagram of the connection part of an end plate and a flame|frame before and after assembly of an electric device. 4A and 4B are schematic diagrams illustrating temporal deformation of the end plate and the seal ring according to the first embodiment; FIG. 5 is a schematic cross-sectional view of a seal ring according to Modification 1. FIG. 8 is a schematic cross-sectional view of a connecting portion between an end plate and a frame according to Modification 1; FIG. 8 is a schematic cross-sectional view of another seal ring according to Modification 1. FIG. 8 is a schematic cross-sectional view of another connecting portion between the end plate and the frame according to Modification 1. FIG. It is a cross-sectional schematic diagram of the connection part of the end plate and frame which concern on Embodiment 2 of this invention. FIG. 10 is a schematic diagram illustrating temporal deformation of an end plate and a seal ring according to Embodiment 2; FIG. 11 is a schematic cross-sectional view of a connecting portion between an end plate and a frame according to Modification 2; FIG. 12 is another schematic cross-sectional view of the connecting portion between the end plate and the frame according to Modification 2;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following description of preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its applicability or its uses.

(Embodiment 1)
[Configuration of motor and electrical equipment]
FIG. 1 shows a schematic cross-sectional view of a main part of an electrical device according to this embodiment.

As shown in FIG. 1, the motor 100 includes a frame 20, an end plate 30, bearings 40 and 41, a rotor 50, a stator 60, brushes 70 and a seal ring 80. Also, the electric device 300 includes a load 200 and a motor 100 . In the following description, the longitudinal direction of the rotating shaft 54 forming part of the rotor 50 is called the axial direction, the radial direction of the end plates 30 is called the radial direction, and the circumferential direction of the end plates 30 is called the circumferential direction. I may call In addition, in the axial direction, the side of the frame 20 on which the end plate 30 is arranged may be called "upper", and the opposite side, the bottom side of the frame 20, may be called "lower". For convenience of explanation, details of the load 200 are omitted.

The frame 20 is a semi-cylindrical metal member with a bottom having a flange around an opening 21 provided at the top. A bearing holding portion 22 is formed on the bottom surface of the frame 20 so that one end of the rotating shaft 54 is inserted therethrough. A plurality of plate support portions 24 (see FIGS. 4 to 9) are provided at intervals in the circumferential direction. In order to press-fit the end plate 30 into the opening 21 , an annular flange 25 bent radially outward is formed at the upper end of the frame 20 , that is, near the opening 21 .

The end plate 30 is a plate-shaped member formed by molding a resin material, and includes a substantially disc-shaped base 31, a through hole 32 provided in the center of the base 31, and a brush holding member formed on the inner surface of the base 31. a portion 33 , a bearing holding portion 34 formed on the outer surface of the base portion 31 , an electric wire outlet (not shown) through which an electric wire for supplying power to the motor 100 from the outside is drawn, and the outer surface of the base portion 31 . and a step 36 formed on its outer periphery. Details of the shape of the end plate 30, particularly the shape of the step 36 will be described later. For convenience of explanation, the illustration of the electric wire pulled out from the electric wire outlet is omitted. Further, as described above, the surface of the end plate 30 facing the inside of the frame 20 is called the "inner surface" of the end plate 30, and the surface of the end plate 30 opposite to the inner surface is called the "outer surface" of the end plate 30. sometimes called

After being positioned with respect to the frame 20 , the end plate 30 is press-fitted into the opening 21 of the frame 20 , and the inner surface of the end plate 30 is brought into contact with the plate supporting portion 24 provided on the frame 20 and covers the opening 21 . It is arranged on the frame 20 as follows. A rotor 50 is housed in a space defined by the frame 20 and the end plate 30 . Further, the rotating shaft 54 is inserted through the through hole 32 of the end plate 30 and protrudes outward from the end plate 30 . The rotary shaft 54 is rotatably supported by a bearing 40 held by the bearing holding portion 22 of the frame 20 and a bearing 41 provided to close the through hole 32 . Further, a step 36 is formed on the outer peripheral portion of the outer surface of the end plate 30 (see FIG. 2). A bottom surface 38 of the step 36 is a flat surface and formed so as to be perpendicular to the side surface 37 of the step 36 . The term "perpendicular" means "perpendicular" including the machining tolerance of the step 36, and does not mean that the two to be compared are strictly perpendicular to each other.

The rotor 50 has an armature core 51 , a plurality of salient poles 52 , an armature winding 53 , a rotating shaft 54 , a commutator 55 and an insulator 56 . The armature core 51 has a plurality of salient poles 52 protruding radially outwardly arranged at predetermined intervals in the circumferential direction. An armature winding 53 is wound therethrough, and a lead wire of the armature winding 53 drawn out from the armature core 51 is connected to the commutator 55 . A rotating shaft 54 is provided at the axial center of the rotor 50, passes through the centers of the armature core 51 and the commutator 55, and is connected to them.

The stator 60 is composed of a frame 20 and a plurality of permanent magnets 61 arranged on the inner peripheral surface 23 of the frame 20 at predetermined intervals in the circumferential direction. They are arranged with different polarities. The frame 20 also functions as a yoke forming a magnetic circuit together with the permanent magnet 61 .

The pair of brushes 70 are composed of a carbon brush material such as graphite and a composition containing a solid lubricant, are held in a brush holding portion 33 provided on the inner surface of the end plate 30, and are supported by brush springs (not shown). ) onto the commutator 55 .

The seal ring 80 is made of an annular elastic body such as EPDM (ethylene-propylene-diene rubber), nitrile rubber, fluorinated rubber, or the like, and has an X-shaped cross section and four lips 80a to 80d. . The shape of the seal ring 80 will be detailed later.

The seal ring 80 is accommodated in an annular open space S defined between the step 36 and the inner peripheral surface 23 of the frame 20 facing the side surface 37 of the step 36. The connecting portion with the plate 30 is sealed to prevent moisture from entering the frame 20 from the outside. The annular open space S is an open space with an open top.

The operation of the motor 100 configured as above will be described.

Electric power is supplied to the motor 100 from the outside through a wire (not shown) drawn out from a wire outlet provided in the end plate 30 . Armature current thus flows through the armature winding 53 via the brushes 70 and the commutator 55 . The magnetic flux generated by the stator 60 and the magnetic field generated by the armature current flowing through the armature winding 53 interact to generate torque, and the rotating shaft 54 is supported by the bearings 40 and 41 to rotate. do. Further, the contact and separation between the brush 70 and the commutator 55 are periodically repeated according to the rotation of the rotating shaft 54, and the direction of the armature current flowing through the armature winding 53 is changed corresponding to this cycle. be.

In the electric device 300 , the load 200 is arranged above the motor 100 , and the driven portion 210 is drivingly connected to the rotary shaft 54 protruding from the through hole 32 outside the end plate 30 . The driven part 210 has a mechanical element (not shown) that rotates in the same direction or in the opposite direction in accordance with the rotation of the rotating shaft 54, or converts rotary motion into linear motion. Load 200 is, for example, a hydraulic pump. However, it is not limited to this.

Further, the outer shell 220 of the load 200 is assembled to the motor 100 with its surface 221 in contact with the frame 20 and the second and third lips 80b, 80c of the seal ring 80. As shown in FIG. The motor 100 and the load 200 are arranged such that the surface 221 of the outer shell 220 and the outer surface of the end plate 30 are separated from each other while maintaining a predetermined clearance. The shell 220 is, for example, a block made of aluminum. However, it is not limited to this. Also, in the following description, the surface 221 of the outer shell 220 may be called the surface 221 of the load 200 .

When pressed downward from the surface 221 of the load 200, that is, toward the bottom of the frame 20, the seal ring 80 is compressed and deformed so that the four lips 80a to 80d form an annular open space S and the surface of the load 200. 221 and four corners C1 to C4 (see FIGS. 2 to 4).

The first lip 80 a contacts the first corner portion C 1 formed by the bottom surface 38 of the step 36 formed on the end plate 30 and the inner peripheral surface 23 of the frame 20 , and the second lip 80 b contacts the inner surface of the frame 20 . It abuts on the second corner portion C<b>2 formed by the peripheral surface 23 and the surface 221 of the load 200 . As described above, the upper end portion of the frame 20 is formed with the flange 25 bent radially outward. Therefore, at the second corner portion C2, the second lip 80b may not fully contact the inner peripheral surface 23 of the frame 20, and may mainly contact only the surface 221 of the load 200. . Also, the third lip 80c abuts on a third corner portion C3 formed by the surface 221 of the load 200 and the side surface 37 of the step 36, and the fourth lip 80d contacts the fourth corner corresponding to the corner of the step 36. It abuts on the portion C4. The first lip 80a is positioned diagonally to the third lip 80c when viewed in cross section, and the second lip 80d is positioned diagonally to the fourth lip 80d when viewed in cross section.

In this way, the seal ring 80 and the load 200, the frame 20 and the end plate 30 come into contact with each other, and pressure is applied to the contact surfaces, thereby is sealed to prevent moisture from entering from the outside into the frame 20 from the load 200 side. Also, by sealing between the end plate 30 and the load 200, it is possible to prevent moisture from adhering to the bearing 41 and the rotary shaft 54. FIG.

[Knowledge leading to the present invention]
FIG. 2 shows a schematic diagram for explaining the temporal deformation of the end plate and the seal ring for comparison. For convenience of explanation, constituent members of the motor 100 other than the frame 20, the end plate 30, the seal ring 80, and the bearing 41 are omitted from the illustration. Also, in load 200, only a portion of shell 220, including surface 221, is shown.

In FIG. 2, the upper diagram shows the state immediately after the motor 100 and the load 200 are assembled. In this state, each member maintains the layout relationship as designed within the range of assembly tolerance. . However, in this state, pressure is applied from the load 200 side to the motor 100 side. For example, in the case shown in FIG. has been added. Even when the bearing 41 is arranged inside the frame 20 , pressure is applied to the central portion of the end plate 30 from the load 200 side.

On the other hand, when the electric device 300 starts to be used, the temperature of the motor 100 and the load 200 starts to rise due to the driving of the motor 100, the operation of the load 200, and the temperature of the environment in which the electric device 300 is arranged. . As described above, when the temperature rises while pressure is applied to the resin material, the resin material deforms due to thermal creep. , and, accordingly, the outer peripheral side is deformed so as to be lifted upward.

As a result, as shown in the lower side of FIG. 2, between the outer peripheral surface of the end plate 30 and the inner peripheral surface 23 of the frame 20, and between the inner peripheral surface 23 of the frame 20 and the surface 221 of the load 200. will open. In particular, the gap between the inner peripheral surface 23 of the frame 20 and the surface 221 of the load 200 becomes large at the second corner portion C2. Moreover, the contact surface pressure of the second lip 80b at the second corner portion C2 is weakened. Further, the gap between the side surface 37 of the step 36 and the inner peripheral surface 23 of the frame 20 weakens the contact surface pressure of the first lip 80a at the first corner portion C1.

Moreover, the deformation of the end plate 30 due to thermal creep weakens the contact pressure of the third lip 80c at the third corner portion C3 and the contact pressure of the fourth lip 80d at the fourth corner portion C4.

On the other hand, as is clear from FIG. 2, among the first to fourth corner portions C1 to C4, the first to third corner portions C1 to C3 correspond to entry paths for moisture and the like from the outside. Among the four corner portions C1 to C4, the second corner portion C2 is most likely to be exposed to moisture and the like from the outside. What is needed is the first corner portion C1. In addition, if moisture or the like enters from the third corner portion C3, the damage to the bearing 41 and the rotating shaft 54 is increased, and the performance of the motor 100 and, in turn, the electric device 300 may be degraded.

In this way, the inventors of the present application have found that the sealing performance of the seal ring 80 at the first to third corner portions C1 to C3 is lowered, and fluid such as water is likely to enter the interior of the frame 20. rice field.

Therefore, the inventors of the present application focused on the shape of the seal ring 80 and found that the airtightness inside the frame 20 can be maintained by changing the shape as described later.

[Configuration of connecting portion between end plate and frame]
3 is a schematic cross-sectional view of a seal ring, FIG. 4 is a schematic cross-sectional view of a connecting portion between an end plate and a frame before and after assembly of an electrical device, and FIG. 5 is an end plate and a seal according to this embodiment. Schematic diagrams for explaining deformation over time with a ring are shown, respectively. 4A shows a cross section of the connecting portion between the end plate 30 and the frame 20 before the load 200 is attached, and FIG. 4B shows the end plate 30 after the load 200 is attached. A cross-section of a connecting portion with the frame 20 is shown. 4 and 5 also show partial cross-sections of the load 200, the frame 20 and the end plates 30, respectively.

As shown in FIG. 3, the three lips 80a to 80c of the seal ring 80 are formed to have a larger cross-sectional area, in other words, a larger volume than the fourth lip 80d.

As shown in FIG. 4A, the annular open space S accommodates the seal ring 80 . At this time, the first lip 80a and the fourth lip 80d are pressed against the first corner portion C1 and the fourth corner portion C4, respectively, and are deformed. Further, the second and third lips 80b and 80c each protrude above the upper surface of the annular open space S, that is, toward the load 200 by a length A. As shown in FIG.

4B, when the load 200 is assembled to the motor 100, the surface 221 of the load 200 abuts against the second and third lips 80b and 80c, respectively. downwards. As a result, the second and third lips 80b and 80c are deformed so as to be pushed into the annular open space S. As shown in FIG. At this time, a restoring force is generated in the first to fourth lips 80a to 80d to return them to their original shapes. Due to this restoring force, the first to fourth lips 80a to 80d that are in contact with the first to fourth corner portions C1 to C4 press the first to fourth corner portions C1 to C4, respectively. The connecting portion with the plate 30, the connecting portion between the frame 20 and the surface 221 of the load 200, and the like are sealed.

By doing so, it is possible to reliably prevent entry of moisture or the like into the interior of the frame 20 . Further description will be made with reference to FIG.

As shown in the upper part of FIG. 5, the surface 221 of the load 200 contacts the second and third lips 80b, 80c of the seal ring 80 respectively to press the seal ring 80 downward. 5, due to thermal creep, the load 200 presses the central portion of the end plate 30 further downward via the bearing 41 accommodated in the bearing holding portion 34. As shown in FIG.

From this state, when the outer peripheral side of the end plate 30 is deformed by thermal creep so as to be lifted upward, the contact surface pressures of the first to fourth lips 80a to 80d at the first to fourth corner portions C1 to C4 are lowered. Coming is similar to the case shown in FIG.

On the other hand, the first to third lips 80a to 80c are formed to have a larger cross-sectional area than the fourth lip 80d. That is, the contact surface pressure of the seal ring 80 at the first to third corner portions C1 to C3 is higher than the contact surface pressure at the fourth corner portion C4. Therefore, the decrease in contact surface pressure of the seal ring 80 at the first to third corners C1 to C3 due to thermal creep is offset, and the airtightness at the first to third corners C1 to C3 is maintained. As a result, entry of moisture or the like into the interior of the frame 20 can be prevented. Since the fourth corner portion C4 is composed only of the end plate 30, it does not directly contribute to the airtightness between the frame 20 and the endplate 30 and the airtightness between the frame 20 and the load 200. Therefore, even if the contact surface pressure of the seal ring 80 is reduced at the fourth corner portion C4, the influence of moisture or the like entering the inside of the frame 20 is small.

[Effects, etc.]
As described above, the motor 100 according to the present embodiment includes a cylindrical frame 20 with an open end, a stator 60 housed in the frame 20, and a stator 60 housed in the frame 20. 60 and a rotor 50 arranged at a predetermined interval, and an end plate 30, which is a plate-like member made of resin, disposed in the opening 21 of the frame 20 so as to cover the opening 21. there is A through hole 32 through which the rotating shaft 54 is inserted is provided in the center of the end plate 30 .

The motor 100 is made of an annular elastic body and includes a seal ring 80 for keeping the inside of the frame 20 airtight. An annular open space S is defined between the peripheral surface 23 and the seal ring 80 is accommodated in the annular open space S.

The seal ring 80 has an X-shaped cross section and has four lips 80a to 80d. In other words, the fourth lip 80d abuts only the end plate 30. As shown in FIG. The first to third lips 80a to 80c have a larger cross-sectional area than the fourth lip 80d.

By configuring the motor 100 in this manner, the contact surface pressure of the first to third lips 80a to 80c is increased with respect to the first to third corner portions C1 to C3, which are paths for water or the like from the outside to enter. Thus, entry of moisture into the frame 20 and the load 200 can be reliably prevented.

In addition, by forming the cross section of the seal ring 80 into an X shape, the seal ring 80 is placed at two locations on the bottom surface 38 of the step 36 on which the seal ring 80 is installed. Since the lip 80d abuts, the position of the seal ring 80 within the annular open space S can be stabilized.

In addition, by making the cross section of the seal ring 80 X-shaped, the twist when the seal ring 80 is accommodated in the annular open space S can be reduced, and the contact pressure is dispersed over the entire cross section of the seal ring 80. Therefore, good airtightness with little leakage can be obtained.

Further, by making the cross-sectional area of the fourth lip 80d smaller than that of the other lips 80a to 80c, it is possible to prevent the volume of the seal ring 80 itself from becoming too large. If the volume of the seal ring 80 becomes too large, the seal ring 80 may be deformed abnormally when the load 200 is attached to the motor 100, and airtightness may not be maintained. By using the seal ring 80 of this embodiment, such problems can be avoided.

An electric device 300 according to the present embodiment is connected to a motor 100 and a rotary shaft 54 that projects from a through hole 32 to the outside of an end plate 30, and is driven according to the rotation of the motor 100. and a load 200 having a driven portion 210 to be driven.

The seal ring 80 is pressed from the surface 221 of the load 200 toward the bottom side of the frame 20 , so that the first lip 80 a is a first corner portion formed by the bottom surface 38 of the step 36 and the inner peripheral surface 23 of the frame 20 . C1, the second lip 80b is formed between the surface 221 of the load 200 and the inner peripheral surface 23 of the frame 20 at the second corner C2, and the third lip 80c is formed between the surface 221 of the load 200 and the side surface 37 of the step 36. , and the fourth lip 80d contacts the fourth corner portion C4, which is the corner portion of the step 36, respectively.

By configuring the electric device 300 in this way, the end plate 100 is caused by the heat continuously generated when the motor 100 is driven and the driven portion 210 of the load 200 is operated, and the pressure applied to the end plate 30 . Even when the frame 30 is deformed, it is possible to prevent moisture or the like from entering the frame 20 and the load 200, so that a highly reliable electric device 300 can be realized. In particular, the cross section of the seal ring 80 is X-shaped, and the cross-sectional area of each of the first to third lips 80a to 80c is larger than the cross-sectional area of the fourth lip 80d. The contact surface pressure of the first to third lips 80a to 80c can be increased with respect to the first to third corner portions C1 to C3 corresponding to the approach path, and moisture and the like can enter the interior of the frame 20 and the interior of the load 200. can be reliably prevented.

Moreover, the electric device 300 of the present embodiment is useful because it can ensure high reliability when it is installed in an external environment and continuously used in a state where the environmental temperature reaches several tens of degrees or more.

<Modification 1>
FIG. 6 shows a schematic cross-sectional view of a seal ring according to this modification, and FIG. 7 shows a schematic cross-sectional view of a connecting portion between an end plate and a frame. FIG. 8 shows a schematic cross-sectional view of another seal ring, and FIG. 9 shows a schematic cross-sectional view of another connecting portion between the end plate and the frame. In FIGS. 6 to 9, the same reference numerals are assigned to the same parts as in the first embodiment, and detailed description thereof will be omitted.

The seal ring 81 shown in FIG. 6 is formed such that the cross-sectional areas of the first and second lips 81a and 81b are larger than the cross-sectional area of the fourth lip 81d. Further, as described above, the first and second lips 81a and 81b abut on the first and second corner portions C1 and C2, respectively, and the first and second corner portions C1 and C2 contact the inner peripheral surface of the frame 20. 23, respectively.

By configuring the seal ring 81 in this way, the contact surface pressure of the seal ring 81 at the first and second corner portions C1 and C2 can be increased.

As described above, thermal deformation of the end plate 30 increases the gap between the inner peripheral surface 23 of the frame 20 and the surface 221 of the load 200 at the second corner portion C2. For this reason, it is the second corner portion C2 that is most likely to receive moisture or the like from the outside. On the other hand, the path through which moisture or the like directly enters the interior of the frame 20 is the first corner portion C1. Therefore, it is necessary to improve the airtightness at the first corner portion C1.

By using the seal ring 81 shown in FIG. 6, the contact surface pressure of the seal ring 81 at the first and second corner portions C1 and C2 shown in FIG. It is possible to reliably prevent the entry of moisture etc. into the By making the cross-sectional area of the third lip 81c equal to the cross-sectional area of the fourth lip 81d, the volume of the seal ring 81 itself can be reduced, and abnormal deformation of the seal ring 81 can be suppressed. As a result, the airtightness of the inside of the frame 20 and the inside of the load 200 can be improved.

Further, as described above, the upper end portion of the frame 20 is the flange 25 bent radially outward. Therefore, simply enlarging the cross-sectional area of the second lip 81b may not allow the second lip 81b to seal the second corner portion C2 enough to maintain airtightness at the second corner portion C2.

Therefore, as shown in FIG. 8, by forming the shape of the second lip 82b along the inner peripheral surface 23 of the flange 25 of the frame 20, the airtightness at the second corner portion C2 shown in FIG. This can be reliably maintained, and the intrusion of moisture or the like into the interior of the frame 20 and the interior of the load 200 can be reliably prevented.

The cross-sectional area of at least one of the first to third lips 81a-81c and 82a-82c may be made larger than the cross-sectional area of the fourth lips 81d and 82d. Depending on the size of the motor 100 and the load 200 and the degree of deformation of the end plate 30, one or more of the first to third lips 81a to 81c and 82a to 82c may be arranged more than the fourth lips 81d and 82d. By increasing the cross-sectional area, it is also possible to prevent moisture from entering the interior of the frame 20 and the interior of the load 200 .

(Embodiment 2)
FIG. 10 shows a schematic cross-sectional view of the connecting portion between the end plate and the frame according to this embodiment, and FIG. 11 shows a schematic diagram for explaining the deformation of the end plate and the seal ring over time according to this embodiment. 10A shows a state in which the seal ring 80 is not accommodated in the annular open space S, and FIG. 10B shows a state in which the seal ring 80 is accommodated.

In the end plate 30 shown in FIGS. 1 to 4, the bottom surface 38 of the step 36 is a flat surface and is perpendicular to the side surface 37 of the step 36. includes a first bottom surface 38a positioned radially outward and a second bottom surface 38b positioned radially inward and continuous with the side surface 37 of the step 36 and the first bottom surface 38a. The first bottom surface 38a and the second bottom surface 38b are inclined in different directions with respect to the axial direction. The first bottom surface 38 a extends to the radial outer edge of the outer surface of the end plate 30 and is inclined radially outward downward, that is, toward the bottom side of the frame 20 . In other words, the outer peripheral portion of the outer surface of the end plate 30 has a downwardly tapered shape. Also, the side surface 37 of the step 36 and the second bottom surface 38b are orthogonal to each other. In addition, in the present embodiment, the first bottom surface 38a is inclined at a predetermined angle with respect to the second bottom surface 38b when viewed in cross section in the axial direction, but the present invention is not particularly limited to this. This angle of inclination depends on the width of the bottom surface 38 in the radial direction, the height of the annular open space S in the axial direction, the filling rate of the seal ring 80 with respect to the annular open space S, the material of the seal ring 80, or the shape of the seal ring 80. The radius of curvature of the first lip 80a can be changed as appropriate.

In the case shown in FIG. 10, the first bottom surface 38a is formed by linearly notching the radial outer edge of the outer surface of the end plate 30 in an axial cross-sectional view. In other words, the first bottom surface 38a is an inclined surface whose radial outer edge linearly extends to the extension of the radial inner portion. Therefore, in a cross-sectional view in the axial direction, the first corner portion C1 is configured to form an acute angle. It should be noted that the end plate 30 is actually a member made of resin that is integrally molded using a mold, and the corners are not notched. Further, the first bottom surface 38a is formed such that the radial width L1 is less than half the radial width L of the bottom surface 38a.

As shown in FIG. 10(b), when the load 200 does not press the lower motor 100, the axial projection height A of the seal ring 80 is greater than that of the first bottom surface 38a in the axial direction. is accommodated in the annular open space S so as to be larger than the height B of the .

When the load 200 is assembled to the motor 100 having the seal ring 80 in this way, the surface 221 of the load 200 presses the seal ring 80 downward as shown in the upper side of FIG. The first to fourth lips 80a to 80d abut on the first to fourth corner portions C1 to C4, respectively. As described above, this seals the connecting portion between the frame 20 and the end plate 30, the connecting portion between the frame 20 and the surface 221 of the load 200, and the like.

Here, while the first bottom surface 38a of the step 36 is the inclined surface described above, the second bottom surface 38b is inclined in a direction different from that of the first bottom surface 38a and is perpendicular to the side surface 37 of the step 36. As shown in FIG. When the seal ring 80 in contact with the surface 221 of the load 200 is pressed downward, the amount of deformation and contact pressure of the fourth lip 80d at the fourth corner portion C4 are the same as those shown in FIG. On the other hand, the first corner portion C1 has a larger spatial volume extending downward, that is, toward the bottom side of the frame 20 than in the case shown in FIG. can be displaced along As a result, as shown in FIG. 10(b), the first lip 80a of the seal ring 80 is deformed to enter the first corner portion C1 by a greater amount than in the case shown in FIG. 4(b). Become. As the penetration amount increases, the contact surface pressure of the seal ring 80 at the first corner portion C1 becomes higher than in the case shown in FIG. 4(b). From this state, when the outer peripheral side of the end plate 30 is deformed by thermal creep so as to be lifted upward, the contact surface pressure with which the first lip 80a presses the inner peripheral surface 23 of the frame 20 at the first corner portion C1 decreases. Coming is similar to the case shown in FIG. However, in the present embodiment, as described above, the contact surface pressure of the seal ring 80 at the first corner portion C1 is already in a high state, so the contact surface pressure of the seal ring 80 at the first corner portion C1 can be sufficiently covered to prevent entry of moisture or the like into the interior of the frame 20 .

As described above, in the motor 100 according to the present embodiment, the step 36 is formed on the outer peripheral portion of the outer surface of the resin end plate 30 covering the opening 21 of the frame 20. The first bottom surface 38 a positioned radially outward extends to the radial outer edge of the outer surface of the end plate 30 and slopes radially outward downward, that is, toward the bottom side of the frame 20 .

With such a configuration, when a downward pressing force is applied to the seal ring 80, the amount of penetration of the seal ring 80 increases at the first corner portion C1, and the contact surface of the seal ring 80 increases. Pressure can be increased. As a result, airtightness is maintained at the first corner portion C1, which is a path through which moisture or the like directly enters the interior of the frame 20, and a highly reliable motor 100 can be realized.

Further, by setting the radial width L1 of the first bottom surface 38a to be half or less of the radial width L of the bottom surface 38, compression deformation in the radial direction of the first lip 80a at the first corner portion C1 is prevented. It is possible to suppress the decrease in the amount and maintain the contact surface pressure to the inner peripheral surface 23 of the frame 20 at a desired value or higher. As a result, airtightness at the first corner portion C1 can be maintained even when the end plate 30 undergoes thermal creep deformation.

Further, when the seal ring 80 is accommodated in the annular open space S, the axial protrusion height A of the seal ring 80 is made larger than the axial height B of the first bottom surface 38a, thereby forming an annular open space. Sufficient airtightness due to the seal ring 80 can be ensured by suppressing a decrease in the filling rate of the seal ring 80 with respect to the space S.

In addition, by making the cross section of the seal ring 80 X-shaped, the position of the seal ring 80 in the annular open space S can be stabilized, and the torsion can be reduced so that the contact surface pressure can be reduced to the cross section of the seal ring 80. Distributed throughout is the same as shown in the first embodiment.

<Modification 2>
FIG. 12 shows a schematic cross-sectional view of the connecting portion between the end plate and the frame according to this modification, and FIG. 13 shows another schematic cross-sectional view of the connecting portion between the end plate and the frame. In addition, in FIGS. 12 and 13, the same reference numerals are assigned to the same parts as in Embodiments 1 and 2, and detailed description thereof will be omitted. Also, for convenience of explanation, the illustration of the seal ring 80 is omitted.

10 and 11 show an example in which the first bottom surface 38a is formed by linearly notching the radial outer edge of the outer surface of the end plate 30 in a cross-sectional view in the axial direction. As described above, at the first corner portion C1, the first bottom surface 38a and the second bottom surface 38b are inclined in different directions with respect to the axial direction so as to increase the space volume extending downward. It is sufficient to determine the shape of Therefore, as shown in FIG. 12, the radially outer edge portion of the outer surface of the end plate 30 may be formed in a fillet shape curved radially outward toward the bottom side of the frame 20, that is, in an R-chamfered shape. good. Further, as shown in FIG. 13, the second bottom surface 38b may be inclined on the side opposite to the first bottom surface 38a so that the bottom surface 38 is formed with a convex portion. Also, in the case shown in FIG. 13, the shape of the first bottom surface 38a may be the shape shown in FIG. In either case, the airtightness at the first corner portion C1 can be maintained to prevent entry of moisture or the like into the frame 20, and highly reliable motor 100 and electric device 300 can be realized.

(Other embodiments)
A new embodiment can be made by appropriately combining each component shown in each modified example and the first and second embodiments. For example, the seal rings 81 and 82 shown in Modification 1 can also be applied to the motor 100 shown in Embodiment 2.

In the second embodiment, the bottom surface 38 of the step 36 formed on the end plate 30 may be an inclined surface linearly extending from the side surface 37 of the step 36 to the radial outer edge of the outer surface of the end plate 30 . Further, in Embodiments 1 and 2 including Modifications 1 to 3, the case where the motor 100 is a motor with a brush was exemplified, but the motor 100 is not particularly limited to this. It may be a motor of any kind. Further, the motor 100 according to the present embodiment will be described as being used in a so-called inner rotor type motor in which the stator 60 is arranged radially outside the rotor 50. However, another type of motor, for example Needless to say, the present invention can also be applied to a so-called outer rotor type motor in which the rotor 50 is arranged radially outwardly of the stator 60 with a predetermined spacing.

Further, the bearing 41 arranged on the through hole 32 side of the end plate 30 is accommodated in the bearing holding portion 34 and is in contact with the outer surface of the end plate 30 , but is arranged on the inner surface side of the end plate 30 . and may be housed inside the frame 20 .

In addition, although the brush holding portion 33 provided integrally with the end plate 30 accommodates the brush 70, the brush holding portion 33 is provided inside the frame 20 separately from the end plate 30 to accommodate the brush 70. You may do so.

In addition, in the present embodiment, the stator 60 is composed of the frame 20 and a plurality of permanent magnets 61, but other structures such as a plurality of field magnets arranged at predetermined intervals in the circumferential direction may be used. A field winding may be wound around each of the magnetic poles to form the stator 60 .

INDUSTRIAL APPLICABILITY The motor according to the present invention can prevent water, oil, and the like from entering from the outside, and is therefore useful for application to electrical equipment including fluid pumps such as hydraulic pumps, and electrical equipment installed in a high-temperature external environment. be.

20 Frame 21 Opening 22 Bearing Holding Part 23 Inner Peripheral Surface 24 Plate Supporting Part 25 Flange 30 End Plate 31 Base 32 Through Hole 33 Brush Holding Part 34 Bearing Holding Part 36 Step 37 Side of Step 38 Bottom of Step 38a First Bottom 38b Second 2 bottom 40, 41 bearing (bearing)
50 rotor 51 armature core 52 salient pole 53 armature winding 54 rotating shaft 55 commutator 56 insulator 60 stator 61 permanent magnet 70 brush 80 seal ring 80a to 80d first to fourth lip 81 seal ring 81a to 81d 1st to 4th lips 82 seal rings 82a to 82d 1st to 4th lips 100 motor 200 load 210 driven part 220 outer shell 221 surface of load (surface of outer shell)
300 Electrical equipment C1 to C4 1st to 4th corners A Protruding height of seal ring B Axial height of first bottom surface S Annular open space

Claims (12)

a bottomed cylindrical frame with one end open;
a stator housed within the frame;
a rotor housed in the frame and spaced apart from the stator;
an end plate, which is a plate-shaped member disposed in the opening of the frame so as to cover the opening, and having a through hole in the center through which the rotating shaft is inserted;
at least a seal ring made of an annular elastic body for keeping the inside of the frame airtight,
An annular open space is defined between a step formed on the outer peripheral portion of the outer surface of the end plate and the inner peripheral surface of the frame, and the seal ring is accommodated in the open space,
The seal ring has an X-shaped cross section and has first to fourth lips,
The fourth lip is in contact with the corner of the step,
A motor, wherein at least one of the first to third lips has a cross-sectional area larger than that of the fourth lip. 2. The motor of claim 1, wherein
The first and second lips are in contact with the inner peripheral surface of the frame,
A motor according to claim 1, wherein each of said first and second lips has a larger cross-sectional area than said fourth lip. 3. The motor according to claim 1 or 2,
a flange bent radially outward of the motor is formed near the opening in the frame,
The second lip is positioned diagonally to the fourth lip in a cross-sectional view,
A motor, wherein the shape of the second lip is defined so as to follow the inner peripheral surface of the flange. The motor according to any one of claims 1 to 3,
a side surface of the step radially faces an inner peripheral surface of the frame;
A motor according to claim 1, wherein the bottom surface of the step has a portion extending to a radial outer edge of the outer surface of the end plate and inclined radially outward toward the bottom side of the frame. 5. The motor of claim 4,
A motor according to claim 1, wherein the bottom surface of the stepped portion is an inclined surface extending linearly from the side surface of the stepped portion to the radial outer edge of the outer surface of the end plate. 5. The motor of claim 4,
The bottom surface of the step includes a first bottom surface positioned radially outward and a second bottom surface continuously positioned radially inward from the first bottom surface, and the first bottom surface is located on the outer surface of the end plate. Extending to a radially outer edge and sloping radially outward toward the bottom side of the frame, the second bottom surface is slanted in a different axial direction from the first bottom surface. motor. A motor according to claim 6, wherein
A motor, wherein the second bottom surface is perpendicular to the side surface of the step. A motor according to claim 6, wherein
The motor, wherein the second bottom surface is an inclined surface that is inclined in a direction opposite to the first bottom surface. The motor according to any one of claims 6 to 8,
A motor, wherein the first bottom surface is an inclined surface linearly extending from a radially outer edge portion to a radially inner portion. The motor according to any one of claims 6 to 8,
A motor according to claim 1, wherein a radially outer edge portion of the first bottom surface has a fillet shape curved radially outward toward a bottom portion side of the frame. The motor according to any one of claims 6 to 10,
The motor according to claim 1, wherein the first bottom surface has a radial width that is less than half the radial width of the bottom surface of the step. a motor according to any one of claims 1 to 11;
a load connected to the motor, drivingly connected to the rotating shaft protruding from the through hole to the outside of the end plate, and having a driven portion driven according to the rotation of the motor;
The seal ring is pressed from the surface of the load to the bottom side of the frame, so that the first lip is positioned at the first corner portion formed by the bottom surface of the step and the inner peripheral surface of the frame. The second lip is located at the second corner portion formed by the surface of the load and the inner peripheral surface of the frame, and the third lip is located at the third corner portion formed by the surface of the load and the side surface of the step. , wherein the fourth lip is in contact with a fourth corner that is a corner of the step, respectively.

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