KR200450619Y1 - Motor having thrust system - Google Patents

Abstract

The electric motor includes a stator, a rotor including a rotor shaft having a positioning groove formed therein, and a locator disposed in the groove for positioning the thrust system at a predetermined position.

Electric motor, stator, rotor, thrust system, locator

Description

Motor with Thrust System {MOTOR HAVING THRUST SYSTEM}

The present invention relates to a motor with a thrust system.

Conventional motors with a thrust system are mostly assembled using epoxy. While such a motor is satisfactory, there are several disadvantages to such a motor. First, the use of epoxy is not suitable for "lean" manufacturing techniques. Epoxy requires several hours for curing and virtually another few hours for the assembly process, increasing the number of "processes" of the motor at a given time. Epoxy tends to have sharp edges after curing, which makes handling more difficult.

Therefore, there is a need for a highly reliable and effective motor structure that can eliminate the need for epoxy in the manufacturing process.

In one aspect, the electric motor includes a rotor including a stator, a rotor shaft having a positioning groove therein, a thrust system mounted to the rotor shaft, and a thrust system at a predetermined position. And a locator disposed in the groove to make it.

In another aspect, the electric motor includes a thrust system mounted to the rotor shaft and including a bearing, a thrust collar, and a compression ring. The thrust collar includes a space for receiving the ring. The space is sized and shaped such that the ring extends axially from the surface of the thrust collar in the relaxed position and does not extend axially from the surface in the compressed position.

In another aspect, the rotor includes a rotor shaft having a protrusion and a locator spaced apart from the protrusion. The thrust system is generally mounted to the rotor shaft between the locator and the protrusion, the thrust system comprising a component having a deformable portion. The deformable portion receives the protrusion and has a depth corresponding to the fluctuation of the thrust system so that the thrust system is precisely positioned relative to the locator regardless of the fluctuation.

Various improvements exist in the features mentioned in connection with the aforementioned aspects of the present invention. In addition, the features may be incorporated in the aforementioned aspects of the present invention. These improvements and additional features may be present individually or in any combination. For example, the various features described below in connection with any of the illustrated embodiments of the present invention may be incorporated individually or in any combination to any of the aforementioned aspects of the present invention. have.

The present invention can provide a highly reliable and effective motor structure that can eliminate the need for epoxy in the manufacturing process.

1 and 2, the motor of one embodiment of the present invention is indicated generally by reference numeral 11. The motor typically comprises a stator 12 with a winding 13 and a stator core (generally indicated by reference numeral 14) comprising a lamination 14a. The rotor, indicated generally at 15, is in magnetic coupling with the stator and has a rotor core 16 and a rotor shaft 17. The motor also includes an endshield 19 secured to the stator core 14. The motor 11 can be suitably used as a motor for a dryer. In the dryer field, one end of the shaft has a pulley 21 in which a belt mounting groove is formed so as to rotate the dryer drum (not shown). Many other applications for motors fall within the scope of the present invention.

2 and 3, the first thrust system 25 is mounted to the rotor shaft 17. The thrust system 25 includes a sleeve bearing 27 mounted to one of the end shields 19 and received over the rotor shaft 17. The end shield 19 has a rib 29 (also referred to as a "bearing land") in contact with the outer peripheral surface 27a of the bearing and an inner surface opposite the outer peripheral surface such that the bearing is trapped between the rib and the arm. And arm 31 of the retainer in contact with 27b. The rib 29 and the arm 31 together hold the bearing 27 on the end shield 19. Terms such as "inner" and "outer" are used herein to facilitate the description of the drawings, but such related terms do not limit the scope of the present invention. The end shield 19 is a suitable metal casting, for example aluminum, but may be molded from plastic as another option. The retainer is optionally made detachable from the casting.

The inner and outer washers 35a, 35b of the thrust system 25 are disposed on opposite sides of the bearing 27. In this embodiment, the washer is a thin steel washer, for example hardened steel.

The spacer 37 is disposed outside from the outer washer 35b. In this embodiment, the spacer is made of nylon and has a thickness of about 0.125 inches (0.318 millimeters). The inner diameter is sized to slide over the shaft 17 and the outer diameter is sized larger than the outer washer 35b to move inwardly of the bearing relative to the shaft by impacting the shaft or by force in another inward direction, etc. The inner side of the spacer is supported against the ribs 29 of the endshield so that force is “acted” or transmitted through the end shield 19 rather than the bearing 27.

The outer O-ring 41 (specifically a locator or ring) is disposed outwardly from the spacer 37. This o-ring 41 is housed in a positioning groove 43 (see Fig. 3A) which is integrally molded to the shaft 17. The o-ring is suitably made of an elastic material such as rubber. The inner diameter of the o-ring is sized significantly smaller than the overall diameter of the shaft so that the o-ring is received in the groove 43. The o-ring may have a cross section of a shape other than a circular cross section.

Referring to Fig. 3, the groove 43 of this embodiment is formed in the shaft at a precise distance from the outer end 45 of the shaft 17. The thrust system 25 is then precisely positioned relative to the groove (and the o-ring inside the groove) as further described below. Alternatively, the groove 43 can be formed in the shaft irrespective of the distance to the end of the shaft 17, and the thrust system can be simply and precisely positioned relative to the groove, but not both the end and the groove of the shaft. Alternatively, the end of the shaft may be provided as a locator. The locator may also have other structures and include other features instead of or in addition to the ends or o-rings of the shaft.

The groove 43 extends substantially continuously around the shaft 17 and has a constant shape. The groove has a radius of the cross section corresponding to the radius of the cross section of the o-ring so that the o-ring is not trapped in the groove and released. In one embodiment, the depth of the groove is such that at least about 33%, for example about 40%, of the periphery of the o-ring can be received in the groove. The groove 43 includes a chamfered inner edge portion 43a (FIG. 3A shows a groove with the o-ring omitted), and in this embodiment the inner edge portion is chamfered at an angle A of about 10 °. do. The outer edge portion 43b is chamfered at a larger angle B, for example an angle of about 20 °. The o-ring 41 excludes the depth of the chamfer and at least about 33% is received in the groove. Alternatively, the edge portion can have a radius or other structure that flattens the edge portion. Chamfers (or similar structures) are useful, among other reasons, in that they can prevent damage when various components are assembled on the shaft. In particular, the outer chamfer prevents damage to the o-rings when they are against axial forces.

In addition, the bearing cap 51 and the hub ring 53 are located outside the o-ring. The outer end 45 of the shaft 17 may or may not be attached with other elements, but threads are formed to receive the blower for the dryer (not shown).

The thrust collar 57 and the inner o-ring 59 are disposed inward from the bearing opposite the inner washer 35a. The thrust collar of the present embodiment is annular and includes a space 61 extending inwardly from its inner side 63 to receive the inner o-ring 59. The space 61 is sized and shaped such that the o-ring 59 extends inwardly from the inner surface 63 of the thrust collar 57 for the reasons described below. In addition, the space 61 is sized and shaped such that the o-ring 59 is completely or substantially completely received in the space as the o-ring 59 is compressed so that it does not extend outwardly from the inner side during assembly of the embodiments described below. In this embodiment, the thrust collar is made of nylon and the o-ring is made of an elastic material such as rubber.

3, 3A, 3B and 4, the thrust system 25 also includes a tolerance system 71 for absorbing variations or tolerances of the thrust system inward from the thrust collar. Tolerance system 71 includes a portion of fan 67 (more specifically the innermost component) for cooling motor 11. The fan 67 is mounted to the rotor shaft 17 and fixed in position by the tolerance system 71. The tolerance system includes a changeable portion or recess 73 extending in the circumferential direction at the hub 74 of the fan 67. This recess 73 is formed during assembly of the motor (ie, not previously formed in the hub) and its depth D is used to absorb variations or tolerances of the system in the exemplary assembly method as described below. Can be changed. The hub may include a chamfered edge 75 formed in advance in the hub to facilitate assembly. The tolerance system 71 further includes a protrusion 79 extending from the shaft 17. In this embodiment, the protrusion 79 is the outer edge of the rolled collar 80 formed integrally with the shaft 17. However, many other structures are contemplated. The recess 73 of the hub is generally formed by the protrusion 79 during assembly and then rests on the plastically deformed hub 74.

Referring to Figure 4, the hub 74 of the fan includes a notch 83 (specifically a "relief") for ease of assembly and cracking of the hub. Solid continuous hubs may crack when fixed across the roll collar. Thus, as shown, the hub 74 includes two notches 83, although other numbers of notches (eg, three and four notches) may be used. This design is superior to conventional designs in which the hub has several ribs that function to hold the fan from the shaft to the roll collar or other protrusion. However, fan 67 is optional. Instead, the thrust collar 57 may comprise part of the tolerance system 71 described as being formed in the fan 67.

In one embodiment, first, the thrust system 25 is assembled to the shaft 17 by sliding by the hub 74 of the fan 67 across the shaft. Next, the thrust collar 57, the inner o-ring 59, the inner washer 35a, and the endshield assembly 19 (including the bearing 27) are the outer washer 35b and the spacer 37. Previously located on the shaft. An axial inner pressure is applied to the spacer 37 to compress the inner o-ring 59 into the space 61 in the thrust collar 57.

In addition, the pressure may pressurize the fan hub 74 to a position on the protrusion 79 of the roll collar 80, whereby a recess 73 is formed. (Note: If the tolerance system is part of the thrust collar 57 instead of the fan 67 as shown, the thrust collar is coupled to the roll collar.) The pressure causes the output system 25 to be precise with respect to the groove 43. Is released when it is positioned so that the recess has a depth D as shown in Fig. 3B. The depth D is determined by the position of the projection 79, the thrust collar 57, the inner o-ring 59, the washers 35a and 35b, the endshield assembly 19 (including the bearing 27), It varies depending on the thickness of the spacer 37 and the fan 67. In other words, the tolerance system 71 absorbs both tolerances and fluctuations of each of the above-described components of the motor 11, so that the thrust system 25 is precisely positioned even if each component is varied.

After the pressure is released, the outer o-ring 41 is positioned over the outer end of the shaft 17 (the o-ring needs to be extended or extended) to move inward until it seats in the groove 43. do. Once the outer o-ring 41 is disposed, the thrust system 25 is arranged as shown in FIG. The thrust system 25 of this embodiment allows a certain amount of free endplay on the shaft, for example, about 0.020 inches (0.508 millimeters) or less, or about 0.002 inches to 0.015 inches (0.051 millimeters to 0.381 millimeters). Is allowed. Thereafter, the rest of the parts to be mounted at the outer end of the shaft 17 (eg a blower for a dryer) can be mounted. Before assembling the thrust system 25 to the shaft 17, the shaft is pressed into the rotor core 16, and the centrifugal actuator 87 (see FIG. 2) also moves from the thrust system to the core on the opposite side of the rotor core. Is pressurized. In this embodiment, the thrust system 25 is disposed on the opposite side of the stator core 14 from the end of the shaft which supports the load (the grooved pulley 21 for the belt (see Fig. 1)). This arrangement reduces the temperature of the bearing and generally improves the reliability and service life of the motor.

5, each end shield 19 has an open end slot 91 for receiving a fastener 93. As shown in FIG. In this embodiment, the fastener is a screw, which slightly pulls the lamination 14a into the slot to ensure a good connection during assembly. By using slots 91 rather than holes, the endshield 19 does not extend outwardly from the stator core. When an impact force is applied to the stator core 14, the end shield 19 is not impacted, thereby preventing damage to the end shield and preventing damage to the motor. Conventional end shields simply have holes, which means that the end shields extend outward from the stator core. When an impact force is applied to the conventional end shield, this can negatively affect the operation of the motor since it can change the air gap between the stator and the rotor.

Another advantage is that the endshield of this embodiment is an easier part to cast. That is, the closed hole used in the conventional end shield is more difficult to cast than the open end slot of this embodiment.

Embodiments of the present invention may be more suitable for the liner manufacturing process than the conventional motor. For example, manufacturing embodiments of the motor can be completed without epoxy, thus allowing for faster manufacturing process, efficient cost and precision. In addition, the new motors allow better control over the extension tolerance of the shaft. In addition, since the thrust added to the bearing face is weaker or the same as the thrust added to the conventional motor, the temperature of the bearing is maintained at an acceptable level. The free end play enabled by the thrust system ensures no heat on both bearing sides. In other words, the added thrust occurs only on one of the bearing faces at a given time. Thrust assemblies are less expensive than thrust assemblies employing ball bearings, and are more precise and easier to remove than thrust assemblies employing PAL nuts.

In addition, the thrust assembly of some embodiments resists shock in either cross section of the shaft. The spacer described above transmits an impact force to the end shield so that the bearing seats. The o-ring of the groove is provided to hold the assembly in position. In addition, the two o-rings function to reduce the noise of the motor.

Another advantage of the o-ring of the groove structure is that it reduces the stacking of tolerances. The groove is precisely dimensioned from the end of the shaft and the assembly is positioned away from the groove and the o-ring. All thrust in the shaft acts through one thrust system rather than two thrust systems like most conventional motors. The inner thrust acts through the end shield by the spacers, and the outer thrust acts through the end shield. In this way, the thrust system operates to prevent damage to the bearings and the motor under impact loads or forces directed in the direction along or parallel to the axis of the shaft. In addition, only the tolerances of the shaft grooves, the o-rings and the assembly affect the free end play. The tolerance stacking is remarkably low since there is no need to support thrust on the other side of the stator / rotor. This allows for a more efficient manufacturing process and enables precise free end play in the thrust system. In one embodiment, the tolerance is about 0.020 inches (0.508 millimeters) or less or even about 0.002 inches to 0.015 inches (0.051 millimeters to 0.381 millimeters).

In describing the elements of the present invention or the preferred embodiment (s) of the present invention, it is intended to mean one or more elements, even if described in the singular. The term "comprising" is intended to mean the addition of other elements in addition to the elements described in a generic sense.

Various modifications may be made in the above-described structure, manufacture and method without departing from the spirit of the present invention, and all details contained in the description and the appended drawings are to be interpreted as illustrative and not restrictive.

1 is a perspective view of one embodiment of a motor;

2 is a cross-sectional view of the motor.

Fig. 3 is a partially enlarged view of Fig. 2 showing the thrust system of this embodiment, Figs. 3A and 3B are further enlarged views, and Fig. 3C is a view showing a fan hub before assembly.

4 is a perspective view of a fan of the thrust system.

FIG. 5 is an enlarged fragmentary view of FIG. 1 showing the area of the fastener connecting the end shield and stator; FIG.

Claims (31)

With the stator, A rotor including a rotating shaft having a positioning groove formed therein and having a protrusion spaced from the positioning groove; A thrust system mounted to the rotating shaft, A locator disposed in the groove for positioning the thrust system at a predetermined position; A tolerance system comprising a deformable portion of a component mounted on the shaft between the locator and the protrusion, The deformable portion is configured to be deformed by the protrusion to absorb dimensional variations in the thrust system, thereby helping the thrust system to be accurately positioned by the locator regardless of dimensional variation. The electric motor of claim 1, wherein the groove and locator are configured to maintain the thrust system when a load is applied. The electric motor of claim 1, wherein the locator comprises an elastic ring. The method of claim 3, wherein the groove extends continuously around the shaft, An electric motor having a generally constant cross-sectional shape comprising a bottom having a generally constant radius of curvature. The electric motor of claim 4, wherein the cross-sectional shape of the ring includes a periphery, and the groove has a size and shape in which at least 33% of the periphery of the ring is accommodated in the groove. 5. The electric motor of claim 4, wherein the edge portion of the groove is curbed to facilitate assembly and to prevent damage to the ring. The electric motor of claim 1, wherein the thrust system includes an end shield disposed at an end of the stator and the rotor, the end shield comprising an open end slot for receiving the fastener to secure the end shield to the stator. . 8. The electric motor of claim 7, wherein the stator has an outer perimeter and the endshield does not extend outwardly from the outer perimeter of the stator. The electric motor of claim 1, wherein the thrust system comprises an end shield, a sleeve bearing held in the end shield, and a spacer disposed between the bearing and the locator. 10. The apparatus of claim 9, wherein the spacer has a size and position for contacting the end shield and transferring the force to the end shield when a force is applied on the shaft to move the spacer towards the end shield. Electric motor. The electric motor of claim 1, wherein the component mounted adjacent to the protrusion includes a fan. The device of claim 1, wherein the protrusion comprises a collar having an outer edge, Within the deformable portion there is a recess extending inwardly from the outer edge of the collar, And the size of the recess varies with the amount of deformation of the deformable portion. The electric motor of claim 1, wherein the component mounted adjacent to the protrusion further comprises a plurality of notches that facilitate engagement with the protrusion to prevent damage to the component. The device of claim 1, wherein the component mounted adjacent to the protrusion includes a fan with a fan hub, the fan hub having a plurality of notches to prevent cracking of the hub when engaged with the protrusion. Electric motor. With the stator, With a rotor comprising a rotor shaft, A thrust system mounted to the rotor shaft, the thrust system having a bearing, a thrust collar and a compressible ring, The thrust collar includes a space for receiving the ring, the space having a size and shape such that the ring extends axially from the surface of the thrust collar in the relaxed position and not axially from the surface in the compressed position. Equipped with an electric motor. 16. The electric motor of claim 15 further comprising a washer disposed between the bearing and the thrust collar to compress the ring. 16. The electric motor of claim 15, further comprising a second compressible ring disposed outward from the bearing, wherein the bearing is disposed between the first reference ring and the second ring to mitigate noise of the motor. 18. The groove of claim 17, further comprising a positioning groove disposed relative to the outer end of the shaft for positioning the thrust system relative to the outer end of the shaft, wherein the second ring is a groove for positioning and maintaining the thrust system. Electric motor placed in the. 19. The system of claim 18, wherein the thrust system comprises an end shield for holding a bearing and the end shield for transmitting the force to the end shield when a force in an inward direction adjacent the bearing is applied on the shaft. An electric motor comprising a spacer configured to be in contact. 20. The electric motor of claim 19, wherein the thrust system is free to move on the shaft such that thrust load on the bearing occurs only on one side of the bearing. With the stator, A rotor including a locator and a rotor shaft having protrusions spaced apart from the locator, A thrust system mounted to the rotor shaft between the locator and the protrusion, The thrust system comprises a component having a deformable portion, The deformable portion is configured to be deformed by the protrusion to accommodate a variation in the thrust system, the thrust system being precisely positioned relative to the locator irrespective of the variation. The electric motor of claim 21, wherein the deformable portion includes a recess extending in the peripheral direction, and the protrusion also extends in the peripheral direction. The electric motor of claim 21, wherein the locator comprises a ring. With the stator, A rotor including a rotating shaft having a positioning groove formed therein, A thrust system mounted on a rotating shaft, A locator disposed in the groove for positioning the thrust system at a predetermined position, The groove extends continuously around the shaft and has a constant cross-sectional shape, Wherein the cross-sectional shape comprises a bottom having a generally constant radius of curvature. The electric motor of claim 24, wherein the groove has a curved edge portion to facilitate assembly and to prevent damage to the locator. 26. The electric motor of claim 25, wherein the groove has a chamfered inner edge portion and a chamfered outer edge portion, the chamfering angle of the outer edge portion being greater than the chamfering angle of the inner edge portion. With the stator, A rotor including a rotating shaft having a positioning groove formed therein, A thrust system mounted on a rotating shaft, A locator disposed in the groove for positioning the thrust system at a predetermined position, The thrust system includes an end shield disposed at the end of the stator and including an open end slot for receiving a fastener for securing the end shield to the stator. 28. The electric motor of claim 27, wherein the stator has an outer perimeter and the end shield does not extend outwardly from the outer perimeter of the stator. With the stator, A rotor including a rotating shaft having a positioning groove formed therein, A thrust system mounted on a rotating shaft, A locator disposed in the groove for positioning the thrust system at a predetermined position, The thrust system comprises an end shield disposed at an end of the stator and a sleeve bearing held at the end shield, The thrust system includes a spacer between the bearing and the locator, And said spacer is sized and positioned to contact said end shield and transfer said force to said end shield when a force to move the spacer towards said end shield is exerted on said shaft. 30. The electric motor of claim 29, wherein the thrust system is configured to receive a axially directed thrust load along the rotating shaft. 31. The electric motor of claim 30, wherein the thrust system is free to move on the shaft such that thrust load on the bearing occurs only on one side of the bearing.

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