JPS61112545A - Motor - Google Patents

Abstract

PURPOSE:To inexpensively increase the output of a motor having longer length as compared with a radius by holding a bearing piece in the slot of a stator of the motor to form an auxiliary bearing, and forming a journal supported to the auxiliary bearing on the outer periphery of the rotor. CONSTITUTION:A stator 2 of a motor having a longer length as compared with a radius is engaged within the inside of a frame 1. The rotary shaft 15 of the rotor is rotatably supported by upper and lower radial metals 13, 20, and a thrust bearing is formed of members of thrust housing 31. Further, a bearing piece is held in the central slot of the stator 2 in the longitudinal direc tion to form an auxiliary bearing 49, a journal 48 is formed on the outer periph ery of the rotor corresponding to the bearing to be supported to the bearing 49. Thus, a motor having a longer length as compared with the radius is inexpen sively increased in the output. This is adapted for an underwater pump in a deep well.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] "Industrial Application Field" The present invention relates to electric motors that require a long rotor, such as submersible motors for deep wells.

``Prior Art'' Conventionally, in this type of motor, the length of the motor shaft has been limited depending on the well size due to the rigidity and strength of the rotor, especially the motor shaft.Therefore, the length of the rotor has also been limited, and the length of the motor to be applied to each well size has been limited. Maximum output was regulated. This is because the difference between the operating torque of the induction motor and the torque at the time of starting reaches several times to more than ten times, and the unbalanced magnetic attraction force is particularly concentrated at the time of starting, so in long motors that aim to obtain high output. The reason is that even if the stiffness of the motor shaft is satisfactory during operation, it becomes unsatisfactory during startup. Therefore, in order to obtain even higher output, some electric motors are connected vertically.

Also, although the motor is not necessarily for use in deep wells, in long motors, in addition to bearings at both ends of the motor shaft, a part without a rotor is created in the middle of the motor, exposing the motor shaft. There are bearings that support the motor shaft.

Furthermore, some canned motors have a journal formed on the outer periphery of the rotor and supported by a bearing formed on the inner periphery of the stator can.

``Problems to be solved by the invention'' When electric motors are connected vertically, each individual electric motor has its own bearing, shaft sealing device, rotor, stator, connector,
It requires wiring, making the structure complicated and expensive, the output is low considering the long external shape, the weight is heavy, and the rigidity of the joints when connecting vertically becomes a problem.

Motor shafts in which the middle of the motor shaft is directly supported by an intermediate bearing have the disadvantage that the rotor and stator must be separated in the middle, making it difficult to manufacture, making it difficult to maintain the intermediate bearing, and making it almost impossible to replace the intermediate bearing. be.

A canned motor in which the rotor is supported between both bearings is an excellent proposal because the bearing can be arranged inside the stator can. However, since the present invention is directed to an electric motor that is not a canned motor, and is not a special electric motor having a stator can, a problem must be solved on the bearing side of the intermediate bearing.

An object of the present invention is to solve the above-mentioned problems in electric motors having a large length to diameter (slenderness ratio) and to obtain a high-output electric motor that is not a canned motor.

[Structure of the invention]

"Means for Solving the Problems" The present invention provides a stator coil housed in a slot of a stator, which is held by a wedge fitted into the slot, and a slot of the stator that opens on the inner periphery of the stator. In an electric motor in which the rotor and the rotor are arranged with a direct gap between them, and the motor shaft is supported on both sides of the rotor, a bearing piece is held in the slot of the stator to constitute an auxiliary bearing, and the auxiliary bearing is This electric motor is provided with a journal part on the outer circumference of the rotor, which is supported by the shaft.

"Function" At least when a transient magnetic unbalance force is applied at the time of starting the electric motor, and at subsequent critical speeds, the eccentricity of the rotor is supported by the sliding of the auxiliary support and the rotor journal, and the rotor The rotation is kept within a certain range.

"Embodiments" Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a submersible motor for deep wells. A stator is fixed inside the cylindrical frame made of sheet metal, and on both sides there are ring-shaped upper frame side plates and lower frame side plates! is press-fitted and fixed. Reference numeral 6 denotes a coil end support member made of rubber, which is located between the stator coil and the lower frame side plate 5 and supports the stator. The paper is a coil end insulating paper of the stator coil and is placed between the frame l and the stator coil 7 around the entire inner circumference of the frame.

An upper bracket t is fitted into the upper end of the frame via a packing, and has a hexagonal part that passes through the bolt hole of the flange of the upper bracket d and engages with a tool in the middle via a seal washer. Attach the pump connecting bolt 12, which has a threaded shaft on both sides, to the upper bracket)? Insert the bolt hole and screw it into the upper frame side plate. Upper radial metal 13 is attached to upper bracket 9)? It is fitted in through a detent pin/41 which is fitted in the radial direction cross-fittingly between the two.

The upper radial metal of the upper bracket (the end where the J is fitted and the upper bracket)? A hole is formed in the radial direction so that the space between the oil seals/6 for sealing the motor shaft 15 fitted in the motor shaft 15 passes through the upper part 17 of the motor inner space on the outer peripheral side of the upper bracket. A is provided.

The lower bracket/Ir is fitted into the lower end of the frame l via the packing, and the bolt/te is inserted through the bolt hole of the flange of the lower bracket/j through the spring washer to the lower frame side plate! is screwed into. The lower radial metal λO is fitted into the lower bracket lt, and the lower bracket i
A detent pin λ/ is fitted in the radial direction of the fitting surface of the lower radial metal λO.

A motor shaft 15 is slid into the upper radial metal 13 and the lower radial metal O, to which the rotor is press-fitted and fixed with a slight gap from the stator.Jf is the motor shaft/! This is a balance ring that adjusts the dynamic balance of the rotating body that is press-fitted into the body.

A thrust disk core is fitted and fixed to the lower end of the motor shaft /j via a keyco j. An annular flat thrust carbon plate xi is fitted into the thrust disk body, and a dowel for preventing rotation in the axial direction is press-fitted into the thrust disk body across the abutting end surfaces of the thrust disk 7 and the thrust carbon plate t. Bin-9 is loosely fitted into the thrust carbon plate Jf.

A thrust housing 31 having the same outer diameter as the frame / is fitted into the lower bracket TT via a sealant, and three bolts inserted through seal washers to seal the bolt holes of the thrust housing 31 are inserted into the bolt holes of the lower bracket lr. Insert the lower frame side plate! The thrust housing 31 is fixed to the lower frame side plate.

A collar 3 with a flange and a female thread cut on the inner diameter is fitted and fixed into a round hole at the center of the bottom of the bearing chamber 3J of the thrust housing Jl. An adjustment screw 35 with a hemispherical tip is screwed into the collar, 7tI, and the adjustment screw 3! The leveling disk J Todoroki is held by the leveling disk No. 36, supported so as to be freely tiltable, and carries a thrust pad 31 which is arranged on the circumference and rubs against the thrust carbon plate -t. and the thrust carbon plate λt are tilted so as to be in close contact with each other when the thrust disk λ7 is tilted in all directions.

A cylindrical diaphragm chamber is provided in the lower part of the thrust housing 3/, partitioned by the bottom surface of the bearing chamber, and a cylindrical container-shaped diaphragm 3d is fitted into the chamber so as to press the outer flange of the diaphragm 3q. The presser plate tI/ is fitted into the cylindrical hole at the lower end of the thrust housing 31, and the presser plate l
A bolt is inserted into the bolt hole of the flange of the diaphragm 3D and screwed into the 2-stroke housing 31.

Following the oil seal/6, there is a cylindrical sealing force bar at the cross section Lm shown in the upper bracket.
? A sand sling gark 3 is press-fitted into the upper end and fixed to the motor shaft 15 on the cylindrical outer periphery of the seal cover 112.
lips are approaching.

The lead wire of the stator coil 7 is connected to the end of a three-core flat cable PP, and the cable ep is watertightly penetrated by a rubber gasket aS that fits into a stepped circular hole provided in the axial direction of the flange of the upper bracket 9. Rubber packing lI
& is pressed by a rounded lock screw at which is screwed into the female thread of the stepped circular hole through the washer of the packing holder.

The flange of the upper bracket is provided with an inlet for filling liquid from the top of the motor interior space toward the outside, into which a hexagon socket plug duct is screwed, and the liquid is sealed inside the motor.

A journal part lIt is provided on the central outer circumference of the rotor 22 with a constant width and covered with a material suitable for a journal over the entire circumference so that the diameter is slightly larger than the outer diameter of the other parts of the rotor 2. be. When the journal portion at is formed by metal spraying, it is made of molybdenum or tribaloy, but it may also be formed by hard chrome plating or carbon coating.

Alternatively, a cylindrical thin plate may be fitted around the outer diameter of the rotor, or the thin plate may be wound around the rotor and the ends may be welded. No matter which coating is used, the journal part 4t is ground.
Perform lapping or super finishing.

A stator is provided with 21 bearing portions at for bearing the journal portions 4tj.

Figure 1 is an axis-perpendicular cross-sectional view of the stator. Five axial slots provided on the inner periphery of the stator core t/ have narrow openings jJ. A stator coil 7 is disposed in this slot 5.2, and a wedge 50 is fitted into the mouth j3 over the entire length of the stator coil 7 to hold the stator coil 7.

3 is a side view of the wedge, FIG. 7 is a front view of FIG. 3, and FIG. 5 is a plan view of the wedge. The bearing portion 4t9 of the wedge 50 facing the journal portion of the rotor is provided with a recess 59, and both sides of the bearing portion 4t9 are inserted under the mouth portion 53 of the slot 5 to press the stator coil 7, as in a normal electric motor. This is the rectangular cross section shown in Figure S.

The bearing piece 51I is fitted into the recess 5D.

Adhesive and integrally molded. As shown in FIG. 6, which is a sectional view taken along the line AA in FIG. 3, the bearing piece ip has an engineering shape. Its base 55 has a thickness equal to the depth of the recess j9 and a width equal to the wedge 50. The width of the base portion 5B following the base portion j5 is equal to the width of the mouth portion jJ of the five slots of the stator core, and the height of the base portion 56 is equal to the height of the mouth portion j3. However, when inserting the wedge 50 and the bearing piece jtI into the mouth part j3 of the slot 5U, the insulating paper that wraps the stator coil 7 is interposed, so the wedge go and the bearing piece are sized to accommodate the insulating paper! The cross section of Da is determined. At the tip of the main body 56 is a bearing surface material part j.
7 is formed. The width of the bearing face material portion 57 is within a range that does not interfere with the wide ends of the adjacent bearing pieces 5 as shown in Figure 1.The bearing pieces are preferably made of nylon mixed with carbon. Instead, an appropriate bearing material is selected.

The bearing surface sr of the bearing piece rp is typically a plane parallel to the tangential direction of the outer periphery of the rotor or stator, or a concave surface with a larger curvature than the radius of the journal portion at.

The radial gap between the bearing surface sr and the journal part at is selected to be 0.3 mm, assuming that the gap between the stator and the rotor is o, g to l mm. This is due to the motor shaft/S deflection due to the unbalanced force applied to the rotor 22 caused by the magnetic field at the time of starting the motor, or when the critical speed is exceeded at the time of starting, this limit is 117. ．． At 7 mm 1, the rotor 2.2 is supported by the intermediate bearing with limited runout, and as the critical speed is exceeded and the speed increases, the journal part at no longer moves, and the bearing surface 5g and the journal part tIt become non-contact. This is because it is better to rotate at However, in the bearing clearance between the bearing surface 5g and the journal portion ttr, it is possible to always support the journal portion≠g by the bearing surface 5g as in a normal bearing.

When the electric motor is started, the electric motor shaft 15 is supported by the upper radial metal /J and the lower radial metal 20#, and rotates with thrust being carried by the lower thrust bearing 1. The starting torque at the time of starting reaches several to several times the rated torque, and the unbalanced force acts, causing the rotor-1 to whirl around. At that time, the journal part at is limited to a certain range of deflection and the bearing part 4? Supported by Next, depending on the motor, if the motor shaft /j is long and causes deflection vibration when passing through the critical speed, the journal section a should be
Is t the bearing part U? supported by the vehicle to pass the critical speed without causing any obstruction. Electric motor shaft! When deflection occurs, the motor shaft 15 tilts, and the so-called full-floating thrust bearing accommodates the thrust and carries the thrust. However, since the deflection of the center of the rotor is limited, the motor shaft 15 The inclination angle of No. 15 is small, and the amount by which the thrust bearing follows the whirling of the carbon plate AI is small.

In the above explanation, the journal part tIt and the bearing part at are arranged at the center of the rotor 1 and the stator 1 in the axial direction, but the center part in the tm direction is suitable, but they can also be arranged one behind the other. good.

If the motor shaft is made extremely long, the above-mentioned auxiliary bearings can be provided at two locations in the axial direction: the rotor knee and the stator co. This results in a magnetic unbalance force of 1 when starting the motor shaft/! The deflection of the motor is restricted to a smaller value, and even the nodal deflection vibration of the motor shaft /j when passing through a critical speed can be safely passed through.

In the embodiment, bearing pieces are provided in all of the slots of the stator, but bearing pieces may be provided in some of the slots. In this case, a conventional wedge without a bearing piece is used, which has the same cross section over its entire length.

Although the embodiment uses a vertical motor (for deep wells), it is also possible to use a horizontal motor.

〔Effect of the invention〕

(1) The present invention makes it possible to configure an auxiliary bearing between the stator and the rotor between both bearings in an electric motor, so it is longer in the axial direction than conventional electric motors in electric motors with limited outer diameter dimensions. By equipping it with a rotor and stator, it became possible to create a high-output electric motor.

As an example, the output of electric motors used in pumps for deep wells with a well diameter of t inch was until now limited to 75 kW.
KW or more is now possible.

(2) It becomes possible to provide a submersible motor for use in small-diameter wells with high head and deep wells.

(3) Low cost because it is not a vertically connected motor.

(4) Since the bearing piece is held in the slot of the stator, the bearing piece can be inserted from the end of the stator core, and no matter how long the stator is, the assembly force S of the bearing can be applied.

(5) In a horizontal electric motor, even if there is a diameter restriction, the length of the stator and rotor can be increased, so a high output can be obtained.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 2 is a sectional view perpendicular to the axis of the stator, Fig. 3 is a side view of the wedge, and Fig. q is a vertical sectional view of the stator.
FIG. 5 is a plan view of FIG. 5, and FIG. 6 is a sectional view taken along line A-A of FIG. 3. L...Frame Co...Stator G...Upper frame side plate Y/Lower frame side plate 6...Coil end support material R...Stator coil T...Coil end insulation paper D...Upper bracket) 9A... Hole/λ...Pump connection hole/L/) 13...Top radial metal /Hiroshi...Stopping pin /j...Motor shaft 16...Oil seal /7...Top of outer motor inner space ll:-・Lower bracket /9・・Bolt λO・・Lower radial metal −／・・Rotator pin here・・Rotor Kohiro・・Balance ring = 5・・Key Core・・Thrust disk Coj・・Thrust carbon plate Cob・・Rotation stopper
31. Thrust housing 3 pieces, fist bolt 33.
・Bearing chamber 3g・・Collar J5・・Adjustment screw 36・・Leveling disc 3Ir・・Thrust pad 39・・Diaphragm Hiroshi/・・W work board Hiroshi J・e
Seal cover qJ...Sandslinger-tI Hiro...Cable Hiro!・・Rubber seal 6・・Lock screw ・・Hexagon socket head plug at・・・Journal part data・・
Bearing part 50...＜Scis/・Φcore! r2--Slot jJ-φ Lo part 5a--Bearing piece! r! @-Base! 6...Basic part 57...Bearing face material part 5t...Bearing surface! Ri... recess. Figure 2 Group Figure 3 Figure 4

Claims (1)

[Claims] 1. The stator coil housed in the slot of the stator is held by a wedge fitted into the slot, and the slot of the stator opens on the inner periphery of the stator, so that the stator and rotor are directly connected. In an electric motor in which a motor shaft is supported on both sides of a rotor with a gap in between, a bearing piece is held in a slot of a stator to constitute an auxiliary bearing, and a journal part is supported on the auxiliary bearing. An electric motor with a rotor installed on the outer periphery of the rotor. 2. The electric motor according to claim 1, wherein the journal portion of the rotor is coated with a sliding material by thermal spraying, welding, or fitting. 3. Claim 1 in which the clearance between the auxiliary bearing and the journal portion of the rotor is such that the auxiliary bearing and the journal portion of the rotor come into contact only at the transient rotational speed of the electric motor.
Electric motor described in section.