Abstract:
A centrifugal actuator of an electric motor is modified to reduce noise produced by torque pulses of the motor. The centrifugal actuator comprises a damper sleeve that is mounted in a tight friction fit on the motor shaft. The main body of the centrifugal actuator is mounted on the damper sleeve by a friction fit which permits limited rotational movement of the actuator main body relative to the actuator damper sleeve. In addition, pairs of tabs are provided on both the actuator main body and the actuator damper sleeve and are positioned in circumferentially overlapping relationships whereby engagement of the main body and damper sleeve tabs provides a positive driving connection between the main body and damper sleeve.

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention pertains to a centrifugal actuator of an electric motor that has been modified to reduce noise produced by the operation of the actuator. More specifically, the present invention pertains to a centrifugal actuator comprising a damper sleeve that mounts the actuator to the shaft of an electric motor and permits limited rotational movement of the actuator relative to the shaft to reduce the transmission of acceleration pulses from the shaft to the actuator and thereby reduce chattering of the centrifugal actuator. 
     (2) Description of the Related Art 
     Electric motors having stators with separate start windings and run windings typically employ centrifugal actuators to control the energization of the two windings. The start windings are energized during startup of the motor, or when the speed of the motor falls below a specified operating speed, so as to create a rotating magnetic field in the motor stator and to apply sufficient torque to the motor rotor for starting purposes. However, once the motor has accelerated to a desired operating speed, or to a predetermined percentage of the desired operating speed, the rotor is able to follow the alternations of the magnetic field created by the run windings and the start windings are no longer needed. At this point In the motor&#39;s operation the centrifugal actuator automatically switches over energization of the start windings to the run windings. 
     Usually, the start windings are not intended for continuous use and may fail if not de-energized during normal operation of the motor. Conventionally, a switch referred to as a motor starting switch is provided on the motor for energizing the start windings only during startup of the motor and for de-energizing the start windings once the motor has attained its desired operating speed. A centrifugal actuator is typically employed in switching the motor windings between their start windings and run windings. The centrifugal actuator is mounted on the motor shaft for rotation with the shaft, and is responsive to the speed of the motor shaft for switching the motor start switch between the start windings and the run windings, and visa versa. 
     A typical centrifugal actuator is disclosed in the U.S. Patent of Hildebrandt, U.S. Pat. No. 3,609,421, which issued on Sep. 28, 1971, and is incorporated herein by reference. Basically, the centrifugal actuator includes a main body that is mounted on the electric motor shaft for rotation with the shaft. An actuator sleeve is mounted on the main body for axially reciprocating movement of the actuator sleeve over the main body between first and second positions of the actuator sleeve relative to the motor shaft. The sleeve has an annular flange that projects radially outwardly from the sleeve. The centrifugal actuator is positioned on the shaft so that the annular flange of the actuator sleeve is positioned adjacented to the start switch of the motor that completes the circuits through the start windings and the run windings of the motor. In the operation of the actuator sleeve to be explained, the switch completes a circuit through the start windings or the run windings of the motor in response to the actuator sleeve moving between its respective first and second axially displaced positions on the motor shaft 
     The actuator sleeve and its annular flange are biased by a pair of springs on the actuator toward the first position of the sleeve relative to the shaft. The springs extend transversely across opposite sides of the motor shaft and the actuator body and are connected between a pair of levers mounted on the actuator body on opposite sides of the motor shaft. The levers are mounted on the actuator body for pivoting movement of the levers relative to the body. Each of the levers is formed as a bell crank having one end connected to the actuator sleeve and the opposite end connected to a weight. Each of the levers has an intermediate portion that is mounted for pivoting movement on the actuator body. The pair of springs exert a biasing force on the levers pulling the weighted ends of the levers radially inwardly, and thereby bias the actuator sleeve toward its first position relative to the actuator body and the motor shaft. 
     On startup of the electric motor the switch of the motor is in position to complete a circuit through the start windings of the motor. The run windings circuit is open. Thus, the circuit through the start windings causes initial rotation of the motor shaft. When rotation of the shaft and the centrifugal actuator reaches a predetermined speed, the centrifugal force exerted on the weighted ends of the actuator levers causes the weighted ends to move radially outwardly against the bias of the pair of springs. This in turn causes the opposite ends of the levers that engage with the actuator sleeve to move the sleeve from its first axial position relative to the shaft to its second axial position relative to the shaft. This movement of the sleeve causes the sleeve annular flange to switch the motor switch from its position closing the circuit through the start windings to its position closing the circuit through the run windings where the start windings circuit is opened. When the speed of rotation of the shaft falls below the predetermined speed the pair of springs pull the weighted ends of the levers radially Inwardly, thereby causing the opposite ends of the levers to move the actuator sleeve from its second position relative to the shaft to its first position relative to the shaft. This in turn causes the sleeve annular flange to switch the motor switch from its position closing the circuit of the run windings back to its position closing the circuit of the start windings. 
     The construction of the centrifugal actuator described above is typical among prior art centrifugal actuators. Most actuators basically employ an actuator sleeve and a pair of lever arms mounted on the main body of the actuator for movement relative to the main body and the motor shaft However, this simplified and inexpensive construction of the typical centrifugal actuator has its disadvantages. The actuator main body has a center bore that is mounted in tight engagement around the motor shaft. Because the motor rotor on the shaft is basically rotated by rotating magnetic fields created in the windings of the motor stator, the rotor and the motor shaft are continuously subjected to a series of torque pulses that rotate the rotor and the motor shaft. These torque pulses are transmitted from the motor shaft through the tight engagement of the actuator main body on the shaft to the component parts of the actuator, i.e., the actuator sleeve and the actuator weighted levers. The series of torque pulses often produce a clicking or chattering noise in the component parts of the centrifugal actuator that is very undesirable in certain applications of the electric motors, in particular where the electric motors are used In home appliances. 
     The prior art solution to reducing the vibration-induced clicking or chattering, noise of the centrifugal actuator was to mount the centrifugal actuator in a friction fit on the motor shaft that allowed some relative movement between the actuator and shaft. This would reduce the transmitted vibration due to the torque pulses of the motor that would produce the noise in the component parts of the actuator. However, it was still necessary for the centrifugal actuator to rotate with the motor shaft in order for it to function properly in switching between the start and run windings of the motor. Therefore, a pair of annular grooves were machined in the motor shaft adjacent to the opposite ends of the centrifugal actuator. A lubricated caring was assembled into one of the grooves at one side of the actuator and the actuator was provided with serrations that extended radially inwardly into the other groove on the opposite side of the actuator. The centrifugal actuator would be mounted on the motor shaft between the pair of groves with the c-ring and serrations mounted in the grooves. The positioning of the grooves on the shaft and the positioning of the c-ring and serrations mounted in the grooves provided limited axial movement of the centrifugal actuator on the shaft between the grooves. The engagement of the actuator serrations in one of the grooves locates the actuator axially on the shaft relative to the switch. An axial projection on the actuator extended into the gap of the c-ring and would engage against one end of the c-ring to transmit rotation of the shaft to the actuator. As described in the earlier referenced patent of Hildebrandt U.S. Pat. No. 3,609,421, with this construction of the actuator, the torque pulses transmitted from the motor shaft to the centrifugal actuator were attenuated and the clicking or chattering noise of the actuator was reduced. However, because the c-ring would move under the acceleration and deceleration loads of the centrifugal actuator, it was necessary that the c-ring be lubricated to prevent shaft wear requiring an additional manufacturing step. In addition, providing the annular grooves in the motor shaft adjacent to the centrifugal actuator and the assembly of the c-ring into one of the annular grooves also required additional manufacturing steps that increased the cost associated with assembly of the motor. 
     SUMMARY OF THE INVENTION 
     The centrifugal actuator of the present invention overcomes the disadvantages associated with prior art centrifugal actuators by providing a centrifugal actuator construction that employs a damping sleeve that mounts the actuator to a motor shaft and dampens the clicking or chattering noise of the actuator components due to vibration from torque pulses transmitted from the motor shaft to the actuator. The damper of the invention also eliminates the additional expense of machining a pair of annular grooves in the motor shaft and assembling a pair of lubricated c-rings into the annular grooves. 
     The centrifugal actuator of the invention is comprised of many of the component parts of a typical, prior art centrifugal actuator such as that disclosed in the earlier referenced U.S. Pat. No. 3,609,421. The actuator of the invention includes the main body having an interior bore that is mounted on the motor shaft. An actuator sleeve with an annular flange is mounted on the exterior surface of the main body for axially reciprocating movement of the sleeve over the main body. A pair of weighted levers are mounted on the main body for pivoting movement of the levers relative to the main body that cause the axial movement of the actuator sleeve. A pair of springs interconnect the pair of levers and bias the levers radially inwardly, thereby biasing the actuator sleeve to its first position relative to the main body. 
     The actuator of the present invention differs from the prior art actuator in that the main body interior bore is dimensioned slightly larger than the exterior diameter of the motor shaft, providing a clearance between the main body interior bore and the motor shaft. A damper sleeve is mounted on the motor shaft in a tight, friction engagement of the sleeve on the shaft. The main body interior bore is mounted on an exterior surface of the damper sleeve. The main body interior bore fits in tight engagement on the damper sleeve exterior surface but permits rotational, sliding movement of the actuator main body over the damper sleeve. In addition, the damper sleeve has an axial length that is slightly larger than the axial length of the actuator main body and prevents the main body from becoming trapped or wedged between the rotor and thrust washer on the opposite side of the main body when the actuator is assembled to the motor shaft. 
     A pair of diametrically opposite main body tabs project radially outwardly and axially from the actuator main body. A pair of diametrically opposite damper sleeve tabs project radially outwardly and axially from the damper sleeve. The main body tabs project into an arcuate spacing between the damper sleeve tabs and the damper sleeves tabs project into an arcuate spacing between the main body tabs. The sliding friction engagement of the actuator main body center bore on the damper sleeve exterior surface allows limited rotational movement between the main body and the damper during operation of the motor that reduces the clicking or chattering noise generated in the component parts of the actuator due to the torque pulses of the motor delivered to the actuator. The positioning of the main body tabs in the arcuate space between the damper sleeve tabs and the positioning of the damper sleeve tabs in the arcuate space between the main body tabs provides a positive driving connection between the damper sleeve and the main body when their respective tabs are rotated relative to each other into engagement. Thus, the construction of the centrifugal actuator of the invention with the damper sleeve that allows limited rotational movement of the main body relative to the sleeve reduces the clicking or chattering noise of the actuator components due to torque pulses transmitted to the actuator while providing a positive driving engagement between the motor shaft, damper sleeve and actuator main body without requiring the additional expense of machining annular grooves in the motor shaft and assembling c-rings into the grooves. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features of the invention are revealed in the following detailed descriptions of the preferred embodiments of the invention and in the drawing figures wherein: 
     FIG. 1 is a side view of a first embodiment of the centrifugal actuator of the invention mounted on an electric motor shaft; 
     FIG. 2 is a partially sectioned view of the actuator of FIG. 1 shown removed from the motor shaft; 
     FIG. 3 is a cross section view in the plane of line  3 — 3  of FIG. 1; 
     FIG. 4 is a side view of a second embodiment of the centrifugal actuator of the invention mounted on an electric motor shaft; 
     FIG. 5 is a partially sectioned view of the centrifugal actuator of FIG. 4 shown removed from the motor shaft; and, 
     FIG. 6 is a cross section view in the plane of line  6 — 6  of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows the centrifugal actuator  10  of the invention mounted on an electric motor shaft  12 . FIG. 2 shows the centrifugal actuator  10  of FIG. 1 removed from the motor shaft and with a portion of the actuator components cut away to better illustrate the novel features of the invention. As explained earlier, the centrifugal actuator  10  of the Invention is comprised of many of the component parts of a typical, prior art centrifugal actuator such as that disclosed in the earlier referenced U.S. Pat. No. 3,609,421. Because these component parts of the actuator are known in the prior art, they are described only generally herein. 
     The actuator includes a main body  14  of the actuator that has a tube or sleeve portion  16 . The main body tube  16  has a cylindrical interior surface  18  that surrounds a center bore  20  of the tube. The main body tube center bore  20  has a center axis  22  that is coaxial with an axis  24  of the motor shaft when the centrifugal actuator is mounted on the motor shaft. Unlike the prior art centrifugal actuator, the cylindrical interior surface  18  of the main body tube  16  is dimensioned slightly larger than the exterior diameter of the motor shaft  12 , providing a clearance between the main body cylindrical interior surface  18  and the exterior surface of the motor shaft  12 . The main body tubular portion  16  has a generally cylindrical exterior surface  26  with a pair of support flanges  28  projecting radially outwardly from diametrically opposite sides of the exterior surface  26 . A pair of circular end surfaces  30 ,  32  at the axially opposite ends of the main body extend between the main body interior surface  18  and the main body exterior surface  26 . 
     The construction of the centrifugal actuator main body  14  described to this point is substantially the same as that of prior art centrifugal actuators except for the larger interior bore dimension. However, the actuator main body  14  of the invention also differs from prior art actuator main bodies in that it is provided with a pair of ridges  34 ,  36  that extend axially along a portion of the main body exterior surface  26  on diametrically opposite sides of the main body. Each ridge  36 ,  38  has a rectangular cross section and projects radially outwardly from the main body exterior surface  26 . Each ridge  36 ,  38  extends axially from one of the main body support flanges  28  across the exterior surface  26  to one of the main body circular end surfaces  32 . As seen in FIGS. 1 and 2, the ridges  38 ,  38  each terminate at a tab  40 ,  42  that projects axially beyond the main body circular end surface  32  for a short distance. The main body tabs  40 ,  42  have the same cross section configuration as the ridges  36 ,  38  and therefore project radially outwardly from the main body circular end surface  32  as they extend axially beyond the main body circular end surface  32 . Like the main body ridges  36 ,  38  the tabs  40 ,  42  are positioned on diametrically opposite sides of the main body  14  and define a pair of arcuate spaces or notches  44 ,  46  that extend around the motor shaft  12  between opposed surfaces  48 ,  50  of the respective tabs  40 ,  42 . 
     A pair of lever arms  54  are mounted on the distal ends of the pair of main body support flanges  28  for pivoting movement of the lever arms in the same manner as in the prior art. As is done in the prior art, each of the lever arms  54  is formed as a bell crank with a weight  56  at one end of the arm and a pronged portion  58  at the opposite end of the arm. As is conventional, an intermediate portion of each lever arm  54  is mounted to the distal end of one of the main body support flanges  28  for a pivoting movement of the lever arm in response to rotation of the motor shaft  12 . 
     An actuator sleeve  62  is mounted on the main body exterior surface  26  for axial sliding movement over the exterior surface. The actuator sleeve  62  has a generally cylindrical interior surface  64  that is dimensioned to slide axially over the main body exterior surface  26  between first and second positions of the actuator sleeve relative to the main body. The actuator sleeve interior surface  64  is provided with a pair of axial grooves  66 ,  68  on diametrically opposite sides of the interior surface. The pair of axial grooves  66 ,  68  receive the main body ridges  36 ,  38  for sliding movement of the ridges through the grooves. Thus, the pair of grooves  66 ,  68  will permit the actuator sleeve  62  to reciprocate axially over the main body exterior surface  26  between the first and second positions of the actuator sleeve relative to the main body while preventing relative rotation between the actuator sleeve and the main body. 
     An annular flange  70  projects radially outwardly from an exterior surface  72  of the actuator sleeve. The annular flange  70  of the actuator sleeve is constructed and functions in basically the same manner as that of the prior art centrifugal actuator. In addition, the actuator sleeve is operatively connected to the pronged portions  58  of the actuator lever arms  54  to move the actuator sleeve  62  axially between its first and second positions relative to the main body  14  in response to the movement of the lever arms  54 . Again, apart from the presence of the pair of grooves  66 ,  68  in the interior surface of the actuator sleeve  62 , its construction and functioning is basically the same as that as the prior art actuator sleeve. 
     The centrifugal actuator  10  of the present invention differs from the prior art centrifugal actuator in that it also includes a damper sleeve  76  as one of its component parts. The damper sleeve  76  has an axial length that Is slightly longer than that of the actuator main body  14 . The sleeve has a cylindrical interior surface  78  that surrounds a center bore  80  of the sleeve. The center bore  80  has a center axis  82  that is coaxial with the shaft center axis  24  when the actuator is mounted on the shaft. The interior diameter of the sleeve interior surface  78  is dimensioned so that the sleeve will fit in a tight friction engagement on the exterior of the motor shaft  12  when the actuator is, mounted on the shaft. 
     The damper sleeve has a generally cylindrical exterior surface  84  that has an exterior diameter dimension that allows the damper sleeve to be mounted in a sliding engagement in the interior bore  20  of the actuator main body  14 . The sliding engagement between the main body bore Interior surface  18  and the damper sleeve exterior surface  84  permits the main body to rotate slightly on the damper sleeve exterior surface  84  in response to torque pulses of the electric motor transmitted through the motor shaft  12  and the damper sleeve  76  to the actuator main body  14 . Despite this limited slip permitted between the main body  14  and the damper sleeve  76 , the sliding engagement between the main body and damper sleeve causes them to rotate with each other and causes the centrifugal actuator  10  to operate in the same manner as prior art centrifugal actuators in switching between two windings of an electric motor. 
     As best seen in FIG. 2, the damper sleeve has one circular end surface  86  that is positioned in substantially the same plane as one of the circular end surfaces  30  of the main body. The axially opposite end of the damper sleeve has an annular thrust washer  88  formed integrally with the sleeve. As seen in FIGS. 1 and 2, the thrust washer  88  is positioned axially relative to the projecting tabs  40 ,  42  of the actuator main body so that there is a small axial tolerance or spacing between the thrust washer  88  and the distal ends of the main body tabs  40 , 42 . Thus, the axial length of the damper sleeve exterior surface  84  is slightly larger than the axial length of the main body interior bore surface  18 . Because the axial length of the damper sleeve exterior surface  84  is slightly larger than the axial length of the main body interior bore surface  18 , the damper sleeve will prevent the main body from becoming trapped between the rotor and the thrust washer  88  at opposite ends of the actuator when the actuator is mounted on the motor shaft The distal ends of the main body tabs  40 ,  42  engage in sliding engagement with the thrust washer  88  to maintain the proper axial positioning between the actuator main body  14  and the actuator damper sleeve  76 . A pair of damper tabs  92 ,  94  project radially outwardly from the damper sleeve exterior surface  84  adjacent the thrust washer  88 . The damper tabs  92 ,  94  extend axially from the thrust-washer  88  toward the actuator main body  14 . The damper tabs  92 ,  94  are positioned on diametrically opposite sides of the damper sleeve and define a pair of arcuate spacings or notches  96 ,  98  that extend around the damper sleeve between the pairs of damper tabs. Opposite surfaces  100 ,  102  of the respective damper tabs  92 ,  94  define the lengths of the arcuate spaces or notches  96 ,  98  between the tabs. As seen in the drawing figures, with the relative positioning of the actuator main body  14  on the actuator damper sleeve  76 , the main body tabs  40 ,  41  extend Into the arcuate spaces or notches  96 ,  98  between the damper tabs  92 ,  94 , and the damper tabs  92 ,  94  extend Into the arcuate spaces or notches  44 ,  46  between the main body tabs. When the main body tabs  40 ,  42  engage against the damper tabs  92 ,  94  a positive driving engagement is established between the main body  14  and the damper sleeve  76 . Thus, the ability of the main body tabs and the damper tabs to move through the arcuate spacings or notches between the respective tabs allows the limited rotational movement between the actuator main body,  14  and the actuator damper sleeve  76 . This limited rotational movement is slightly less than one-half of a rotation of the actuator main body  14  on the actuator sleeve  76 , due to the circumferential thicknesses of the respective main body tabs and damper sleeve tabs. 
     In the operation of the embodiment of the centrifugal actuator  10  of FIGS. 1 through 3, as the electric motor (not shown) is started, rotation of the motor shaft  12  is transmitted to the centrifugal actuator  10  through the friction engagement of the damper sleeve  76  on the motor shaft  12  and the friction engagement of the actuator main body  14  on the damper sleeve. Any relative slip between the actuator main body  14  and the damper sleeve  76  will be eliminated by positive engagement of the main body tabs  40 ,  42  with the damper sleeve tabs  92 ,  94 . When the motor has attained a relatively constant speed with the run windings of the motor actuated, the torque pulses created by power source current reversals in the stator run windings will be transmitted from the centrifugal actuator damper sleeve  76  to the actuator main body  14 . However, due to the friction engagement between the main body  14  and the damper sleeve  76 , the main body will be allowed to rotate to a limited extent relative to the damper sleeve, thus reducing or attenuating the torque pulses. In this manner, the dicing or chattering of prior art centrifugal actuators due to torque pulses of the motor is reduced or eliminated. The relative slipping between the main body  14  and damper sleeve  76  will constantly continue as the torque pulses of the motor tend to accelerate and then decelerate the rotation of the motor shaft  12  and the centrifugal actuator  10 . However, as the main body  14  may be caused to rotate to a limited extent relative to the damper sleeve  76 , a positive driving engagement will always be maintained between the main body  14  and the damper sleeve  76  due to the circumferential overlapping positioning of the main body tabs  40 ,  42  and the damper sleeve tabs  92 ,  94 . 
     Thus, the construction of the centrifugal actuator of the invention with the damper sleeve that allows limited rotational movement between the main body relative to the damper sleeve reduces the clicking or chattering noise of the actuator components due to torque pulses transmitted to the actuator while providing a positive driving engagement between the motor shaft, the damper sleeve and the actuator main body without requiring the additional expense of machining annular grooves in the motor shaft and assembling c-rings into the grooves. 
     FIGS. 4 through 6 show an alternate embodiment of the centrifugal actuator  10  of FIGS. 1 through 3. Many of the component parts of the centrifugal actuator  110  of the FIGS. 4 through 6 are the same as those of the previously described embodiment of the actuator and are labeled with the same reference numbers. Because the centrifugal actuator  110  of FIGS. 4 through 6 is very similar to that of FIGS. 1 through 3, only the differences between the actuator assemblies will be described. 
     The second embodiment of the centrifugal actuator  110  also has an actuator main body  112 . The actuator sleeve  62  is mounted on the main body  112  in the same manner as the previous embodiment. In addition, the lever arms  54  are mounted on the main body in the same manner as the previously described embodiment However, the tubular portion  114  of the second embodiment of the actuator main body  112  has a shorter axial length than the previously described embodiment As seen in FIGS. 4 and 5, the main body tubular portion  114  has a cylindrical interior surface  118  and a generally cylindrical exterior surface  118  that are similar to those of the previously described embodiment. However, the axial length of the main body tubular portion  114  is less than that of the previously described embodiment. The tubular portion  114  has a circular end surface  120  at one end of the main body that is adjacent to the pair of support flanges  122  of the main body. The tubular portion extends to a circular end surface  124  at the opposite end of the main body. A pair of diametrically opposite ridges  126  extend across the main body exterior surface  116 , but do not project axially beyond the second circular end surface  124  of the main body, as they did in the first embodiment. Instead, the second embodiment of the centrifugal actuator  110  has a pair of main body tabs  128  that project axially from the one end surface  120  of the main body that is adjacent the support flanges  122 . With the pair of main body tabs  128 ,  130  projecting from diametrically opposite sides of the main body  112 , they define a pair of arcuate spacings or notches  132 ,  134  that extend around the centrifugal actuator between opposing surfaces  136 ,  138  of the respective main body tabs  128 ,  136 . 
     The damper sleeve  140  of the second embodiment has a cylindrical interior surface  142  that surrounds a center bore  144  of the damper sleeve. As in the first embodiment, the cylindrical interior surface  142  is dimensioned for a tight friction fit on the motor shaft The damper sleeve center bore  144  has a center axis  146  that is coaxial with the center axis of the motor shaft  12  when the centrifugal actuator is mounted on the motor shaft. The damper sleeve  140  also has a generally cylindrical exterior surface  148  that extends between a first circular end surface  150  and an opposite second circular end surface  152  of the sleeve. However, there is no thrust washer provided at the second end surface of the damper sleeve as there was with the first described embodiment. The second embodiment of the centrifugal actuator  110  is employed with a separate thrust washer (not shown) positioned on the motor shaft  12  adjacent the second end surface  152  of the damper sleeve. The thrust washer may be configured as the thrust washer  80  of the first described embodiment without the damper tabs  92 ,  94  projecting from the thrush washer, or may be a conventional thrust washer. A pair of damper tabs  154 ,  156  are provided on the damper sleeve exterior surface  148  at the first end surface  150  of the damper sleeve. The axial length of the damper sleeve exterior surface  148  between the damper tabs  154 , 156  and the second end surface  152  of the sleeve is slightly larger than the axial length of the main body interior bore surface  116  to prevent the main body of the actuator from becoming trapped or wedged between the rotor and a thrust washer when the actuator is mounted on the shaft just as in the first embodiment. As seen in FIG. 5, an annular collar  158  projects radially outwardly from the damper sleeve exterior surface  148  adjacent the sleeve second end  152 , and the pair of damper tabs  154 ,  156  project radially outwardly from the sleeve exterior surface  148  and axially from the annular collar  158 . The damper sleeve collar  158  properly positions the damper sleeve tabs  154 ,  156  in axially overlapping, positions with the main body tabs  128 ,  130 . The damper sleeve tabs  154 ,  156  also have arcuate spacings or notches  160 ,  162  that extend between opposing surfaces  164 ,  166  of the respective tabs. 
     The main body tabs  128 ,  130  and the damper sleeve tabs  154 ,  156  of the second embodiment of the centrifugal actuator  110  function in the same manner as the tabs of the previously described actuator. Thus, the respective tabs of the main body  112  and the damper sleeve  140  allow limited rotational movement of the main body relative to the damper sleeve and reduce the clicking or chattering noise of the actuator components due to torque pulses transmitted to the actuator while providing a positive driving engagement between the motor shaft, the damper sleeve and actuator main body without requiring the additional expense of machining annular grooves in the motor shaft and assembling c-rings into the grooves. 
     While the present invention has been described by reference to specific embodiments, it should be understood that modifications and variations of the invention may be constructed without department from the scope of the invention defined in the following claims.