United States Patent [19]
`United States P3116111; [19]
`Viskochi]
`Viskochil
`
`I1I1I
`
`IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII~ 111111111111111
`US005672927 A
`USOO5672927A
`5,672,927
`[11] Patent Number:
`[11] Patent Number:
`5,672,927
`Sep.30, 1997
`[45] Date of Patent:
`[45] Date of Patent:
`Sep. 30, 1997
`
`[54] MOTOR WITH OVERMOLD COIL SUPPORT
`[54] MOTOR WITH OVERMOLD COIL SUPPORT
`
`[75]
`
`Inventor: Stephen Viskocbil, Los Gatos, Calif.
`
`Inventor: Stephen ‘fiskocllila L05 Gatosq
`
`t- ‘Mil 1a ,Ca?f'
`I mm C
`3 A -
`[73] Assignee: Quantum Corporation, Milpitas. Calif.
`[7 ]
`sslgnee Q“
`orpom Ion
`pl 5
`
`[21] Appl. No.: 490,962
`[21] Appl. No.: 490,962
`_
`Jon. 15, 1995
`[22] Filed:
`[22] Filed:
`Jun’ 15’ 1995
`Int. CI.6
`[51] 1111. c1.6 .......................... .. H02K 1/00; H02K 11/00;
`[51]
`•••••••••••••••••••••••••••• H02K UOO; H02K 11100;
`H02K 1112
`1102K 1/12
`[52] U.S. CI .............................. 310/194; 310nl; 3101254
`[52] US. Cl. ........................... .. 310/194; 310/71; 310/254
`[5 8] Field of Search .............................. .. 3101194. 51, 71.
`[58] Field of Search ................................ 310/194.51.71,
`310/39~ 254_ 67 R; 360/9903
`310/89.254.67 R; 360/99.08
`
`[56]
`[56]
`
`References Cited
`References Cited
`
`U.S. PATENT DOCUMENTS
`U.S. PATENT DOCUMENfS
`
`3,780,323 1211973 Swain ........................................ 310/43
`3,780,323 12/1973 Swain
`310/43
`1/1979 Laumer et aI ........................ 310/68 C
`4,132,913
`4,132,913
`1/1979 Lautner et a]
`. 310/68 C
`8/1989 Lessig, III ............................... 3101171
`4,853,575
`4,853,575
`8/1989 Lessig, III ............................. .. 310/171
`
`4,975,611 12/1990 Rochester . . . . . .
`
`. . . . .. 310/194
`
`211990 Feigel et aI ............................. 3101260
`4,900,968
`2/1990 Felgel et a1. ..
`.... .. 310/260
`4,900,968
`1211990 Rochester ................................ 310/194
`4,975,611
`1211991 Takagi ....................................... 310m
`5,073,735
`3/1992 Takekoshi et aI ...................... 3101254
`5,097,168
`5,097,168
`411993 Fruge et aI .......................... 360/99.08
`5,200,866
`4/1993 Fruge et a1.
`360/9908
`5,200,866
`8/1993 Cap et a1.
`360/9701
`5,237,471
`811993 Cap et aI ............................. 360/97.01
`5,237,471
`1011993 Bosman et aI ........................ 310/49 R
`5,254,892
`5,254,892 10/1993 Bosman et a]. ..................... .. 310/49 R
`
`
`
`. . . . . . . . . . . . . . . 3/1992 Takekoshi et a1.
`
`
`
`. . . . . . .. .... .. 310/254
`
`Primary Examiner-Steven L. Stephan
`Primary Examiner—Steven L. Stephan
`Assistant Examiner-Michael Wallace, Jr.
`Assistant Examiner-Michael Wallace. Jr.
`Attorney, Agent, or Finn-John C. Chen
`Attorney- Age'", 0’ Fi""—J°hl1 0 Chan
`[57]
`ABSTRACT
`ABSTRACT
`[57]
`
`A motor assembly integrates a motor mounting structure and
`Amotor assembly imcsIar?s a motor mounting Structurc and
`electrical connection parts achieving reduced motor compo(cid:173)
`electrical connection parts achieving reduced motor compo
`nent count and assembly cost. The motor assembly includes
`nent count and assembly cost. The motor assembly includes
`a mounting structure integrally formed into a motor coil
`a mounting strucmre integrally formed into a motor coil
`support with plastic overmold. Aplurality of connector pins
`support with plastic overmold. A plurality of connector pins
`are molded into the coil support for electrically coupling the
`are molded into the coil support for electrically coupling the
`motor to a printed circuit board (PCB).
`motor to a printed circuit board (PCB).
`
`10 Claims, 7 Drawing Sheets
`10 Claims, 7 Drawing Sheets
`
`47
`
`NIDEC and HONDA - Ex. 1014
`Nidec Corporation and American Honda
`Motor Co., Inc. - Petitioners
`
`1
`
`

`

`u.s. Patent
`US. Patent
`
`Sep. 30, 1997
`Sep. 30, 1997
`
`Sheet 1 0f 7
`Sheet 1 of 7
`
`5,672,927
`5,672,927
`
`2
`
`

`

`u.s. Patent
`US. Patent
`
`Sep. 30, 1997
`Sep. 30, 1997
`
`Sheet 2 of 7
`Sheet 2 of 7
`
`5,672,927
`5,672,927
`
`
`
`FIG. -— 2 (PRIOR ART)
`
`3
`
`

`

`u.s. Patent
`US. Patent
`
`Sep. 30, 1991
`Sep.30, 1997
`
`Sheet 3 of 7
`Sheet 3 of 7
`
`5,672,927
`5,672,927
`
`
`
`FIG. -— 3 (PRIOR ART)
`
`4
`
`

`

`u.s. Patent
`U.S. Patent
`
`Sep. 30, 1997
`Sep.30, 1997
`
`Sheet 4 of7
`Sheet 4 of 7
`
`5,672,927
`5,672,927
`
`)
`
`42
`
`55
`
`86
`
`40
`
`86
`
`... --so
`
`46
`
`FIG.-4
`
`5
`
`

`

`u.s. Patent
`US. Patent
`
`Sep. 30, 1997
`Sep. 30, 1997
`
`Sheet 5 of 7
`Sheet 5 of 7
`
`5,672,927
`5,672,927
`
`60
`
`~
`
`83
`
`46
`
`FIG.-5
`FIG-5
`
`6
`
`

`

`u.s. Patent
`US. Patent
`
`Sep. 30, 1997
`Sep.30, 1997
`
`Sheet 6 of 7
`Sheet 6 of 7
`
`5,672,927
`5,672,927
`
`7
`
`

`

`u.s. Patent
`US. Patent
`
`Sep. 30, 1997
`Sep.30, 1997
`
`Sheet 7 of 7
`Sheet 7 of 7
`
`5,672,927
`5,672,927
`
`05
`Q
`
`l'(cid:173)
`I
`
`FIG-7
`
`8
`
`

`

`1
`1
`MOTOR wr'rn OVERMOLD COIL SUPPORT
`MOTOR WITH OVERMOLD COIL SUPPORT
`
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`
`The present invention relates to the ?eld of electrical
`The present invention relates to the field of electrical
`motors. More particularly, the present invention relates to an 5
`motors. More particularly. the present invention relates to an
`improved motor stator coil support including mounting legs
`improved motor stator coil support including mounting legs
`and a plurality of straight through-pin connectors as an
`and a plurality of straight through-pin connectors as an
`integal part thereof for reducing the overall cost of and
`integral part thereof for reducing the overall cost of and
`component count in mounting an electrical motor assembly
`component count in mounting an electrical motor assembly
`onto a baseplate.
`onto a baseplate.
`
`10
`10
`
`30
`30
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`DC motors, particularly of the brushless variety, are used
`DC motors, particularly of the brushless variety, are used
`in a number of applications requiring precisely constant
`in a number of applications requiring precisely constant
`15
`rotation, for example, in magnetic disk drives. In a disk drive
`rotation. for example, in magnetic disk drives. In a disk drive
`application, an electronically-commutated brushless DC
`application, an electronically-commutated brushless DC
`motor includes a stator coil assembly commonly mounted
`motor includes a stator coil assembly commonly mounted
`inside of a rotating hub of a spindle motor-disk hub assem(cid:173)
`inside of a rotating hub of a spindle motor-disk hub assem
`bly. The rotating hub includes an outer rotor permanent
`bly. The rotating hub includes an outer rotor permanent
`20
`magnet ring having alternate permanently magnetized seg
`magnet ring having alternate permanently magnetized seg- 20
`ments outside of the central stator coil assembly. The stator
`ments outside of the central stator coil assembly. The stator
`coil assembly typically includes a stationary circular array of
`coil assembly typically includes a stationary circular array of
`slotted laminar pole pieces carrying a plurality of electrical
`slotted laminar pole pieces carrying a plurality of electrical
`coils usually wound about radial axes. and electrically
`coils usually wound about radial axes, and electrically
`25
`connected in a multi-phase circuit arrangement. In some 25
`connected in a multi-phase circuit arrangement. In some
`spindles, a shaft and hub are axially mounted on and rotate
`spindles. a shaft and hub are axially mounted on and rotate
`together about a stationary tubed bearing sleeve carrying
`together about a stationary tubed bearing sleeve carrying
`bearings and integral with or secured to the base of the disk
`bearings and integral with or secured to the base of the disk
`drive, known as the "baseplate". In other spindle shaft
`drive, lmown as the “baseplate". In other spindle shaft
`assemblies, the shaft is a stationary member secured to the
`assemblies, the shaft is a stationary member secured to the
`baseplate, and the hub is mounted by bearings to the shaft.
`baseplate, and the hub is mounted by bearings to the shaft.
`In the continuing demand for a lower cost disk drive,
`In the continuing demand for a lower cost disk drive,
`manufacturers have had to constantly find ways to decrease
`manufacturers have had to constantly ?nd ways to decrease
`manufacturing costs within the various sub-systems of the
`manufacturing costs within the various sub-systems of the 35
`35
`disk drive. For example, within the spindle motor-disk hub
`disk drive. For example, within the spindle motor-disk hub
`assembly, the trend has been to integrate parts such as the
`assembly, the trend has been to integrate parts such as the
`stator mounting in the brushless DC motor, to reduce the
`stator mounting in the brushless DC motor, to reduce the
`overall disk drive component count and cost.
`overall disk drive component count and cost.
`In a disk drive spindle motor of the prior art. shown in 40
`In a disk drive spindle motor of the prior art, shown in
`FlG. 1, the motor stator mounting assembly includes a stator
`FIG. 1, the motor stator mounting assembly includes a stator
`mounting cup 70, (shown in a partial cross sectional view),
`mounting cup 70, (shown in a partial cross sectional view),
`which is typically press fit into a mounting hole 60 in a tub
`which is typically press ?t into a mounting hole 60 in a tub
`style baseplate 20, and the stator 68 which is epoxy-mounted
`style baseplate 20, and the stator 68 which is epoxy-mounted
`to the mounting cup 70. The disadvantage of this assembly
`to the mounting cup 70. The disadvantage of this assembly 45
`45
`is that it requires an extraneous number of assembly parts
`is that it requires an extraneous number of assembly parts
`and steps in mounting the motor into the baseplate.
`and steps in mounting the motor into the baseplate.
`Commonly owned U.S. Pat. No. 5,200,866 discloses a
`Commonly owned US. Pat. No. 5,200,866 discloses a
`similar example using the above described mounting cup
`similar example using the above described mounting cup
`arrangement of mounting the motor to the baseplate.
`arrangement of mounting the motor to the baseplate.
`In another prior art motor mounting arrangement shown
`In another prior art motor mounting arrangement shown
`in FlG. 2, a motor mounting cup 2S is fonned integrally into
`in FIG. 2, a motor mounting cup 25 is formed integrally into
`the baseplate 2D and concentric with a recessed stator
`the baseplate 20 and concentric with a recessed stator
`mounting area 27 and a mounting hole 23 for a spindle shaft.
`mounting area 27 and a mounting hole 23 for a spindle shaft.
`The stator mounting area 1:1 is lined with an insulation layer 55
`The stator mounting area 27 is lined with an insulation layer
`SS
`which protects the coils from scraping against the baseplate
`which protects the coils from scraping against the baseplate
`and prevents possible damage to the wires. Stator 84 is
`and prevents possible damage to the wires. Stator 84 is
`epoxy-mounted to mounting cup 25 then electrically con
`epoxy-mounted to mounting cup 2S then electrically con(cid:173)
`nected to the electronic circuit subassembly. The advantage
`nected to the electronic circuit subassembly. The advantage
`of this arrangement is that the mounting cup 25 is formed
`of this arrangement is that the mounting cup 2S is formed 60
`into the baseplate, reducing the overall assembly component
`into the baseplate, reducing the overall assembly component
`count. The disadvantages are the added costs of forming the
`count. The disadvantages are the added costs of forming the
`mounting cup 25 into the baseplate and the assembly steps
`mounting cup 2S into the baseplate and the assembly steps
`in electrically connecting the DC motor to the electronic
`in electrically connecting the DC motor to the electronic
`circuitry sub-assembly. Typically, these steps include hand
`circuitry sub-assembly. TYpically, these steps include hand 65
`65
`soldering the wires from each motor coil 86 to a small motor
`soldering the wires from each motor coil 86 to a small motor
`PCB 29 epoxy-mounted within stator mounting area 27.
`PCB 29 epoxy-mounted within stator mounting area 27.
`
`50
`
`5,672,927
`5,672,927
`
`2
`2
`Then, as shown in FlG. 3, an elastomeric connector 23 is
`Then, as shown in FIG. 3, an elastomeric connector 23 is
`placed into connector hole 21. on the backside of baseplate
`placed into connector hole 21. on the backside of baseplate
`20, to electronically connect the motor PCB 23 to a main
`20, to electronically connect the motor PCB 23 to a main
`removable PCB (not shown).
`removable PCB (not shown).
`Thus, a hitherto unsolved need has remained for a motor
`Thus, a hitherto unsolved need has remained for a motor
`mounting assembly which combines the functions of the
`mounting assembly which combines the functions of the
`motor mounting cup and the motor PCB in a cooperative,
`motor mounting cup and the motor PCB in a cooperative,
`synergistic manner and to reduce overall motor mounting
`synergistic manner and to reduce overall motor mounting
`components count, prime cost. assembly costs and overall
`components count, prime cost, assembly costs and overall
`complexity.
`complexity.
`SUMMARY OF THE INVENTION WITH
`SUMMARY OF THE INVENTION WIIH
`OBJECTS
`OBJECTS
`A general object of the present invention is to provide a
`A general object of the present invention is to provide a
`simpli?ed and uni?ed motor stator coil mounting structure
`simplified and unified motor stator coil mounting structure
`in a manner overcoming limitations and drawbacks of the
`in a manner overcoming limitations and drawbacks of the
`prior art.
`prior art.
`Another object of the present invention is to provide a
`Another object of the present invention is to provide a
`disk drive spindle motor coil support having an overmold
`disk drive spindle motor coil support having an overmold
`which integrates a motor stator assembly mounting
`which integrates a motor stator assembly mounting
`structure, thereby eliminating the need for a separate motor
`structure, thereby eliminating the need for a separate motor
`mounting portion and reducing the overall disk drive assem
`mounting portion and reducing the overall disk drive assem(cid:173)
`bly component count, assembly complexity. and cost of
`bly component count, assembly complexity, and cost of
`assembly.
`assembly.
`Another object of the present invention is to provide a
`Another object of the present invention is to provide a
`motor coil support having an overmold which integrates a
`motor coil support having an overmold which integrates a
`motor stator assembly mounting structure, thereby eliminat
`motor stator assembly mounting structure, thereby eliminat(cid:173)
`ing the need for a separate motor mounting portion and
`ing the need for a separate motor mounting portion and
`reducing the overall assembly component count, assembly
`reducing the overall assembly component count, assembly
`complexity, and cost of assembly.
`complexity, and cost of assembly.
`A further object of the present invention is to provide a
`A further object of the present invention is to provide a
`motor coil support having an overmold which integrates
`motor coil support having an overmold which integrates
`electrical connecting parts into the overmold thereby elimi
`electrical connecting parts into the overmold thereby elimi(cid:173)
`nating the need for hand soldering motor coil wires to a
`nating the need for hand soldering motor coil wires to a
`motor PCB and further reducing the overall motor mounting
`motor PCB and further reducing the overall motor mounting
`component count and cost.
`component count and cost.
`Another object of the present invention is to provide a
`Another object of the present invention is to provide a
`motor coil support having an overmold which eliminates the
`motor coil support having an overmold which eliminates the
`need for an elastomeric connector to electrically connect the
`need for an elastomeric connector to electrically connect the
`motor PCB, thereby further reducing the overall assembly
`motor PCB, thereby further reducing the overall assembly
`component count and cost of assembly.
`component count and cost of assembly.
`In accordance with a feature of this invention, a plurality
`In accordance with a feature of this invention, a plurality
`of mounting legs is integrally formed into the motor coil
`of mounting legs is integrally formed into the motor coil
`support for mounting the motor onto a baseplate.
`support for mounting the motor onto a baseplate.
`In accordance with another feature of this invention, a
`In accordance with another feature of this invention, a
`plurality of connector pins extends from the motor coil
`plurality of connector pins extends from the motor coil
`support overmold for electrically coupling the spindle motor
`support overmold for electrically coupling the spindle motor
`with a main PCB.
`with a main PCB.
`In accordance with yet another feature of this invention,
`In accordance with yet another feature of this invention,
`the motor is mounted on a baseplate essentially comprising
`the motor is mounted on a baseplate essentially comprising
`a fiat sheet metal plate.
`a ?at sheet metal plate.
`These and other objects, advantages, aspects and features
`These and other objects, advantages, aspects and features
`of the present invention will be more fully understood and
`of the present invention will be more fully understood and
`appreciated upon consideration of the following detailed
`appreciated upon consideration of the following detailed
`description of a preferred embodimen~ presented in con(cid:173)
`description of a preferred embodiment, presented in con
`junction with the accompanying drawings.
`junction with the accompanying drawings.
`
`. BRIEF DESCRIPI10N OF THE DRAWINGS
`BRIEF DESCRIPTION OF THE DRAWINGS
`In the Drawings:
`In the Drawings:
`FIG. 1 is an exploded isometric view of a first prior art
`FIG. 1 is an exploded isometric view of a ?rst prior art
`motor stator coil mounting arrangement, shown with a
`motor stator coil mounting arrangement, shown with a
`baseplate.
`baseplate.
`FIG. 2 is an exploded isometric view of a second prior art
`FIG. 2 is an exploded isometric view of a second prior art
`motor stator coil mounting arrangement, shown with a
`motor stator coil mounting arrangement, shown with a
`baseplate,
`baseplate.
`
`9
`
`

`

`5,672,927
`5,672,927
`
`3
`3
`FIG. 3 is an isometric view of the back side of the
`FIG. 3 is an isometric view of the back side of the
`baseplate of FIG. 2.
`baseplate of FIG. 2.
`FIG. 4 is an enlarged and exploded isometric view of the
`FIG. 4 is an enlarged and exploded isometric view of the
`motor of the present invention.
`motor of the present invention.
`FIG. 5 is a cross sectional view of the stator shown in FIG.
`FIG. 5 is a cross sectional view of the stator shown in FIG.
`4.
`4.
`FIG. 6 is an exploded isometric view of the motor stator
`FIG. 6 is an exploded isometric view of the motor stator
`coil mounting arrangement of FIG. 4.
`coil mounting arrangement of FIG. 4.
`FIG. 7 is a cross sectional view of the FIG. 4 motor,
`FIG. 7 is a cross sectional view of the FIG. 4 motor.
`shown mounted into a baseplate.
`shown mounted into a baseplate.
`
`4
`4
`Four connector pins 82 are molded into coil support 46 in
`Four connector pins 82 are molded into coil support 46 in
`an arrangement which enables the motor coils 86 to be
`an arrangement which enables the motor coils 86 to be
`connected at one end of the pins 82, thereby eliminating an
`connected at one end of the pins 82. thereby eliminating an
`extraneous step of hand soldering the motor coils 86 to a
`extraneous step of hand soldering the motor coils 86 to a
`motor PCB (shown in FIG. 2). also as taught by the prior art.
`5 motor PCB (shown in FIG. 2), also as taught by the prior art.
`Coil support 46 also includes a connector pin support
`Coil support 46 also includes a connector pin support
`portion 89 which enables coil support 46 to be mounted to
`portion 89 which enables coil support 46 to be mounted to
`a baseplate 50 (FIG. 6) in the same relative orientation.
`a baseplate 50 (FIG. 6) in the same relative orientation.
`While in the preferred example of FIG. 5 the coil support 46
`While in the preferred example of FIG. 5 the coil support 46
`is preferably overmolded by plastic injection molding
`10 is preferably overmolded by plastic injection molding
`10
`process, those skilled in the art will appreciate that embodi(cid:173)
`process. those skilled in the art will appreciate that embodi
`ments of the present invention may be provided for use
`ments of the present invention may be provided for use
`employing other methods of plastic molding.
`employing other methods of plastic molding.
`FIG. 6 shows the mounting arrangement of stator coil
`FIG. 6 shows the mounting arrangement of stator coil
`assembly 60 in baseplate 50. Mounting leg holes 85 are
`15 assembly 60 in baseplate SO. Mounting leg holes 85 are
`de?ned in baseplate 50 and arranged in a pattern aligned
`defined in baseplate 50 and arranged in a pattern aligned
`with the tripod arrangement of the legs 83. enabling the
`with the tripod arrangement of the legs 83, enabling the
`stator coil assembly 60 to be easily inserted into baseplate 50
`stator coil assembly 60 to be easily inserted into baseplate 50
`in a consistent relative orientation. Baseplate 50 also
`in a consistent relative orientation. Baseplate 50 also
`20 includes a connector pin hole 87 aligned with connector pin
`includes a connector pin hole 87 aligned with connector pin
`support portion 89 enabling the support portion 89 to be
`support portion 89 enabling the support portion 89 to be
`inserted in the same relative orientation. Thus, the mounting
`inserted in the same relative orientation. Thus. the mounting
`legs 83 and connector pin support portion 89 eliminate the
`legs 83 and connector pin support portion 89 eliminate the
`need for a stator coil mounting cup or other special mounting
`need for a stator coil mounting cup or other special mounting
`features in the baseplate as required by the prior art. The
`25
`25 features in the baseplate as required by the prior art. The
`baseplate 50 further includes a sheet of insulation film
`baseplate 50 further includes a sheet of insulation ?lm
`material 47. which protects the coils 86 from scraping
`material 47, which protects the coils 86 from scraping
`against the baseplate 50 and possibly breaking or shorting
`against the baseplate 50 and possibly breaking or shorting
`the wires to the baseplate SO. The insulation film 47 is
`the wires to the baseplate 50. The insulation ?lm 47 is
`30 epoxied to the baseplate 50 in an area where the coil
`30
`epoxied to the baseplate 50 in an area where the coil
`assembly is to be mounted and is provided with mounting
`assembly is to be mounted and is provided with mounting
`leg holes 85 and connector pin hole 87 aligned with those on
`leg holes 85 and connector pin hole 87 aligned with those on
`baseplate 50. Alternatively, the insluation film may be
`baseplate 50. Alternatively. the insluation ?lm may be
`formed as a ring or annulus and placed under the coil wire
`formed as a ring or annulus and placed under the coil wire
`35 portion of the stator coil assembly 60.
`portion of the stator coil assembly 60.
`This arrangement further enables the other end of the pins
`This arrangement further enables the other end of the pins
`82 to be inserted through connector pin hole 87, into a main
`82 to be inserted through connector pin hole 87. into a main
`PCB (not shown), thereby eliminating the use of the elas-
`PCB (not shown). thereby eliminating the use of the elas
`tomeric connector (shown in FIG. 3). as taught by the prior
`40 tomeric connector (shown in FIG. 3), as taught by the prior
`art. While in the preferred example of FIG. 5 the connector
`art. While in the preferred example of FIG. 5 the connector
`pins 82 are molded into overmold 84, those skilled in the art
`pins 82 are molded into overrnold 84. those skilled in the art
`will appreciate that embodiments of the present invention
`will appreciate that embodiments of the present invention
`may be provided for use employing other methods of
`may be provided for use employing other methods of
`extending connector pins 82 from coil support 46, such as
`extending connector pins 82 from coil support 46, such as
`45 soldering or epoxy-mounting pins 82 to coil support 46.
`45
`soldering or epoxy-mounting pins 82 to coil support 46.
`While in the preferred example of FIG. 6 the ?at baseplate
`While in the preferred example of FIG. 6 the llat baseplate
`is preferably formed of sheet metal, those skilled in the art
`is preferably formed of sheet metal. those skilled in the art
`will appreciate that embodiments of the present invention
`will appreciate that embodiments of the present invention
`may be provided for use employing bases formed by casting
`50 may be provided for use employing bases formed by casting
`50
`stamping, extrusion or any other suitable base fabrication
`stamping. extrusion or any other suitable base fabrication
`method.
`method.
`FIG. 7 shows the motor 40 of the present invention
`FIG. 7 shows the motor 40 of the present invention
`mounted into baseplate 50. The assembly procedure consists
`mounted into baseplate SO. The assembly procedure consists
`of inserting the connector pins 82 and the mounting legs 83
`of inserting the connector pins 82 and the mounting legs 83
`through their respective mounting holes, 87 and 85, in
`through their respective mounting holes, 87 and 85. in
`baseplate 50. ‘The stator coil assembly 60 is then epoxied.
`baseplate SO. The stator coil assembly 60 is then epoxied,
`screwed or heat-staked to the baseplate, on the insulation
`screwed or heat-staked to the baseplate, on the insulation
`film 47. The hub assembly 42 is then mounted over the stator
`?lm 47. The hub assembly 42 is then mounted over the stator
`assembly 60 by press ?tting shaft 46 into shaft mounting
`assembly 60 by press fitting shaft 46 into shaft mounting
`hole 64. This arrangement enables the motor assembly to be
`hole 64. This arrangement enables the motor assembly to be
`assembled in a simpli?ed procedure which is less labor cost
`assembled in a simplified procedure which is less labor cost
`intensive and preferred over those taught by the prior art.
`intensive and preferred over those taught by the prior art.
`Having thus described an embodiment of the invention, it
`Having thus described an embodiment of the invention. it
`will now be appreciated that the objects of the invention
`will now be appreciated that the objects of the invention
`have been fully achieved. and it will be understood by those
`have been fully achieved. and it will be understood by those
`skilled in the art that many changes in construction and
`skilled in the art that many changes in construction and
`
`DErAILED DESCRIPTION OF A PREFERRED
`DETAILED DESCRIPTION OF A PREFERRED
`EMBODMENT
`EMBODIMENT
`
`The details of construction of disk drives in which the
`The details of construction of disk drives in which the
`invention ?nds utility. including the assembly of the read!
`invention finds utility, including the assembly of the read!
`write head subsystem. disk stack assembly. electronic
`write head subsystem, disk stack assembly, electronic
`circuitry. and the rotary voice coil head positioning servo
`circuitry, and the rotary voice coil head positioning servo(cid:173)
`mechanism are well known to those skilled in the art, and
`mechanism are well known to those skilled in the art, and
`thus. are not included herein. The following description
`thus, are not included herein. The following description
`provides only such detail as is necessary to teach the best
`provides only such detail as is necessary to teach the best
`mode of the present invention, and is necessary to enable
`mode of the present invention. and is necessary to enable
`those skilled in the art to practice the invention.
`those skilled in the art to practice the invention.
`With reference to FIG. 4, a motor 40 of the present
`With reference to FIG. 4. a motor 40 of the present
`invention is shown in an exploded view. The motor 40
`invention is shown in an exploded view. The motor 40
`includes a hub assembly 42 and a stator coil assembly 60.
`includes a hub assembly 42 and a stator coil assembly 60.
`The partial cross sectional view of disk hub 42 shows the
`The partial cross sectional view of disk hub 42 shows the
`hub assembly 42 mounted to a bearing sleeve 43 which is
`hub assembly 42 mounted to a bearing sleeve 43 which is
`rotatably mounted by two ball bearing assemblies 45 to a
`rotatably mounted by two ball bearing assemblies 45 to a
`stationary shaft 55. Flux return ring 49 is attached along
`stationary shaft 55. Flux return ring 49 is attached along
`circumferential lower lip 41 of hub assembly 42 and is
`circumferential lower lip 41 of hub assembly 42 and is
`preferably formed of a ferromagnetic material. A permanent
`preferably formed of a ferromagnetic material. A permanent
`magnet ring 44 of a ceramic or bonded composite material
`magnet ring 44 of a ceramic or bonded composite material
`having hard magnetic properties (e.g. a bonded neodymium.
`having hard magnetic properties (e.g. a bonded neodymium.
`iron, boron magnet) is attached to the inner circumferential
`iron. boron magnet) is attached to the inner circumferential
`wall of the llux return ring 49 by e.g. a suitable adhesive.
`wall of the ?ux return ring 49 by e.g. a suitable adhesive.
`The integral arrangement of disk hub 42 enables a simple
`The integral arrangement of disk hub 42 enables a simple
`and e?cient assembly.
`and efficient assembly.
`Permanent magnet ring 44 is magnetized with alternating
`Permanent magnet ring 44 is magnetized with alternating
`discrete regions of oppositely polarized magnetic domains
`discrete regions of oppositely polarized magnetic domains
`having a predetermined even integer number of polar faces
`having a predetermined even integer number of polar faces
`oppositely confronting poles and slots of the stator coil
`oppositely confronting poles and slots of the stator coil
`assembly 60. In one preferred arrangement said to reduce
`assembly 60. In one preferred arrangement said to reduce
`cogging torque. there are eight polar faces of the magnet ring
`cogging torque, there are eight polar faces of the magnet ring
`44, and nine slots between coils 86 of the stator coil
`44, and nine slots between coils 86 of the stator coil
`assembly 60.
`assembly 60.
`Stator coil assembly 60 includes nine motor coils 86 that
`Stator coil assembly 60 includes nine motor coils 86 that
`are wound about the magnetic poles of an overmolded coil
`are wound about the magnetic poles of an ova-molded coil
`support 46. connector pins 82 and a series of mounting legs
`support 46, connector pins 82 and a series of mounting legs
`83 (shown in FIG. 5) which are integrally formed with coil
`83 (shown in FIG. 5) which are integrally formed with coil
`support 46.
`support 46.
`In the FIG. 5 cross sectional view of stator 60, coil support
`In the FIG. 5 cross sectional view of stator 60. coil support
`46 comprises a magnetically soft lamination stack 88 over(cid:173)
`46 comprises a magnetically soft lamination stack 88 over
`molded with plastic overmold 84. The ferromagnetic lami- 55
`molded with plastic overrnold 84. The ferromagnetic lami
`55
`nation stack 88 is generally formed of insulated layers of
`nation stack 88 is generally formed of insulated layers of
`steel sheets. Plastic overmold 84 is preferably made of a
`steel sheets. Plastic overrnold 84 is prefmably made of a
`liquid crystal polymer which provides the desired proper1ies
`liquid crystal polymer which provides the desired properties
`to enable proper molding and electrical insulation. Mounting
`to enable proper molding and electrical insulation. Mounting
`legs 83 are integrally formed with plastic overmold 84. In 60
`legs 83 are integrally formed with plastic overrnold 84. In
`the preferred embodiment. three mounting legs 83 are
`the preferred embodiment, three mounting legs 83 are
`spaced apart in a tripod arrangement which provides mount
`spaced apart in a tripod arrangement which provides mount(cid:173)
`ing stability. Each of the legs 83 also defines a recessed area
`ing stability. Each of the legs 83 also defines a recessed area
`81 for receiving a mounting peg, post, screw, etc., (not
`81 for receiving a mounting peg. post. screw. etc.. (not
`shown) to securely mount the stator coil assembly 60 to the 65
`shown) to securely mount the stator coil assembly 60 to the
`65
`base