Patent Publication Number: US-2023133502-A1

Title: Drive unit for automotive vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a bypass continuation of International Patent Application No. PCT/IB2021/052581 filed Mar. 29, 2021, which claims the benefit of U.S. Provisional Patent Application No. 63/004,427 filed Apr. 2, 2020. The disclosure of each of the above-referenced applications is incorporated by reference as if fully set forth in detail herein. 
    
    
     FIELD 
     The present disclosure relates to a drive unit for an automotive vehicle. 
     BACKGROUND 
     There is increasing interest on the part of vehicle manufacturers to incorporate an electrically-operated vehicle drive unit into a vehicle drivetrain to provide a vehicle with a hybrid and/or fully electrically-powered propulsion system. There remains a need in the art for an improved vehicle drive unit. There also remains a need in the art for a manner for connecting high-power electric leads to the motor of the electrically-operated vehicle drive unit. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     In one form, the present disclosure provides a vehicle drive unit that includes a housing, an input pinion mounted in the housing for rotation about a first axis, a first shaft, a ring gear, a final reduction input gear, a final reduction output gear, a differential assembly and a pair of output shafts. The first shaft is mounted in the housing for rotation about a second axis that is transverse to the first axis. The ring gear is meshingly engaged to the input pinion and is rotationally coupled to the first shaft. The final reduction input gear is rotationally coupled to the first shaft. The final reduction output gear is housed in the housing and is rotatable about an output axis. The differential assembly has a differential input, and a pair of differential outputs. The differential input receives rotary power from the final reduction output gear. Each of the output shafts is rotatably coupled to a corresponding one of the differential outputs. 
     In another form, the present disclosure provides a vehicle drive unit that includes a housing, an electric motor, a differential assembly, and a transmission. The electric motor is coupled to the housing and has a hollow motor output shaft that is rotatable about an output axis. The differential assembly has a differential input member and a pair of differential output members that are rotatable about the output axis. The transmission is configured to transmit rotary power between the motor output shaft and the transmission input member. The transmission has a first intermediate reduction, a second intermediate reduction, a final reduction, and a transmission coupling. The first intermediate reduction has a first intermediate gear, which is coupled to the motor output shaft, and a second intermediate gear. The second intermediate reduction has a third intermediate gear, which is coupled to the motor output shaft, and a fourth intermediate gear. The final reduction has a drive gear and a driven gear. The driven gear is rotatable about the output axis. The transmission coupling is operable in a first mode in which the third intermediate gear is rotatably coupled to the drive gear and the fourth intermediate gear is rotatably decoupled from the drive gear, and a second mode in which the third intermediate gear is rotatably decoupled from the drive gear and the fourth intermediate gear is rotatably coupled to the drive gear. The driven gear is configured to drive the differential input member. 
     In yet another form, the present disclosure provides a vehicle drive unit that includes a housing, an electric motor, a power terminal, a cover, an electric lead and a blocking member. The housing has a motor portion that defines a channel and a mounting flange. The electric motor is coupled to the motor portion of the housing. The power terminal is disposed in the channel in the motor portion. The cover is removably coupled to the motor portion to cover at least a portion of the channel to inhibit access to the power terminal. The cover is configured to seat against or proximate the mounting flange when coupled to the motor portion. The electric lead is received in the channel and is electrically coupled to the power terminal. The blocking member is coupled to the motor portion and is movable relative to the motor portion between a first position, which at least partially blocks access of the electric lead to the power terminal through the channel and projects from the motor portion to inhibit the cover from is coupled to the motor portion, and a second position which permits access of the electric lead to the power terminal through the channel and is oriented to permit the cover to be coupled to the motor portion. 
     Optionally, the vehicle drive unit can further comprise a differential assembly, a pair of shafts and a transmission. The differential assembly is received in the housing and has a differential input member and a pair of differential output members. Each of the shafts is driven by a respective one of the differential output members. The transmission is disposed in the housing and transmits rotary power between the electric motor and the differential input member. 
     In still another form, the present disclosure provides a method for assembling a vehicle drive unit. The vehicle drive unit has a housing, an electric motor, and a power terminal. The housing has a motor portion that defines a channel and a mounting flange. The electric motor is coupled to the motor portion of the housing. The power terminal is disposed in the channel in the motor portion. The method includes: providing a blocking member that is coupled to the motor portion of the housing. The blocking member is movable between a first position, which inhibits access to the power terminal through the channel and projects into a location that inhibits installation of a cover to the motor portion of the housing, and a second position that permits access to the power terminal through the channel and which clears the location to permit installation of the cover to the motor portion of the housing. The blocking member is biased into the first position; moving the blocking member from the first position to the second position while inserting an electric lead through the channel to route the electric lead through the channel and to the power terminal; coupling the electric lead to the power terminal, wherein retention of the electric lead in the channel inhibits movement of the blocking member from the second position to the first position; and with the blocking member in the second position, installing the cover to the motor portion of the housing. 
     Optionally, the vehicle drive unit can include a differential assembly, a pair of shafts and a transmission. The differential assembly is received in the housing and has a differential input member and a pair of differential output members. Each of the shafts is driven by a respective one of the differential output members. The transmission is disposed in the housing and transmits rotary power between the electric motor and the differential input member. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG.  1    is a cross-sectional view of an exemplary vehicle drive unit constructed in accordance with the teachings of the present disclosure; 
         FIGS.  2  and  3    are enlarged portions of  FIG.  1   ; 
         FIG.  4    is a section view of a portion of the vehicle drive unit of  FIG.  1   , the view illustrating a portion of the differential assembly including a limited slip mechanism and an actuator for operating the limited slip mechanism; 
         FIG.  5    is an enlarged portion of  FIG.  1   ; 
         FIG.  6    is a section view of a portion of the vehicle drive unit of  FIG.  1   , the view illustrating a portion of an interlock that requires the meeting of a set of predetermined conditions before electrical power is provided to a set of electric leads from a source of electrical power; 
         FIGS.  7  and  8    are perspective views that depict a blocking member of the interlock that moves to provide access within a channel for the electric lead and to also permit the assembly of a cover to a housing of the vehicle drive unit; 
         FIG.  9    is a perspective view of an alternately configured blocking member; 
         FIG.  10    is a section view of a portion of the vehicle drive unit of  FIG.  1   , the view illustrating another portion of the interlock; 
         FIG.  11    is an exploded perspective view of a portion of the vehicle drive unit of  FIG.  1    illustrating portions of the interlock in a condition that inhibits the installation of the cover to the housing when the electric leads are not first coupled to respective power terminals; and 
         FIG.  12    is an exploded perspective view of the drive unit of  FIG.  1    illustrating the interlock in a condition that permits the installation of the cover to the housing. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     With reference to  FIG.  1   , an exemplary vehicle drive unit is generally indicated by reference numeral  10 . The vehicle drive unit  10  can include a housing assembly  12 , an input shaft  14 , a first fixed reduction  16 , a first shaft  18 , a second fixed reduction (final reduction)  20 , a differential assembly  22 , an auxiliary power source  24 , a multi-speed transmission  26 , a third fixed reduction  28  and a pair of output shafts  30   a,    30   b.    
     The housing assembly  12  can include a gearbox portion  40  and a motor portion  42  that can fixedly coupled to one another. The gearbox portion  40  can be formed of one or more components and defines a gearbox cavity  46 , an input bore  48  and a first output bore  50 . The input bore  48  is disposed about a first axis  52 . The first output bore  50  intersects the gearbox cavity  46  and extends through an exterior lateral side of the gearbox portion  40 . The motor portion  42  can likewise be formed of one or more components and defines a motor cavity  54  and a second output bore  56 , which intersects the motor cavity  54  and extends through an exterior lateral side of the motor portion  42 . An interior annular wall  58  of the motor portion  42  segregates the motor cavity  54  from the gearbox cavity  46 . The first and second output bores  50  and  56  are disposed about a second axis (output axis)  60 . 
     With reference to  FIG.  2   , the input shaft  14  is received into the input bore  48  and is supported for rotation relative to the gearbox portion  40  for rotation about the first axis  52  via a set of input shaft bearings  64 . The input shaft bearings  64  are depicted as being tapered roller bearings, but it will be appreciated that various other types of bearings, such as one or more angular contact bearings, could be employed in the alternative to support the input shaft  14  for rotation relative to the housing assembly  12 . A flange  66  is fixedly coupled to the input shaft  14  and is configured to be coupled to a propshaft (not shown). It will be appreciated that the propshaft could receive rotary power from a conventional powertrain (i.e., an assembly of an internal combustion engine, a transmission and optionally a torque converter). 
     The first fixed reduction  16 , the first shaft  18  and the second fixed reduction  20  are received in the gearbox cavity  46  and cooperate to transmit rotary power from the input shaft  14  to the differential assembly  22 . The first fixed reduction  16  could be configured with any type of gears, such as spur or helical gears, but in the example provided the first fixed reduction  16  comprises a bevel pinion (input pinion)  70  and a bevel ring gear (ring gear)  72  that are formed as spiral bevel gears. It will be appreciated that the bevel pinion  70  and the bevel ring gear  72  could be formed as straight bevel gears or as a hypoid gearset in the alternative. The bevel pinion  70  is fixedly coupled to (e.g., integrally and unitarily formed with) the input shaft  14  and as such, rotates with the input shaft  14  about the first axis  52 . The bevel ring gear  72  is meshingly engaged with the bevel pinion  70  and is rotationally coupled to the first shaft  18 . 
     The first shaft  18  is supported by a set of first shaft bearings  76  for rotation about a first intermediate axis  78  relative to the housing assembly  12 . The first intermediate axis  78  is parallel to but offset from the second axis  60  ( FIG.  1   ). 
     The second fixed reduction  20  can include an intermediate output gear  80  (final reduction input gear) and a differential input gear (final reduction output gear)  82  that is meshingly engaged to the intermediate output gear  80 . In the example provided, the intermediate output gear  80  is a helical gear that is fixedly coupled to (e.g., integrally and unitarily formed with) the first shaft  18  for rotation about the first intermediate axis  78 , while the differential input gear  82  is a helical gear that is rotatable about the second axis  60  ( FIG.  1   ). 
     In  FIG.  3   , the differential assembly  22  is received in the gearbox cavity  46  and can include a differential input member  90 , a pair of differential output members  92   a,    92   b  and any desired means for transmitting rotary power from the differential input member  90  and the differential output members  92   a,    92   b,  such as one or more friction clutches or a differential gearset. In the example provided, the differential assembly  22  comprises a differential gearset  94  having a pair of differential pinions  96  and a pair of side gears, and the side gears are the differential output members  92   a,    92   b.  The differential input member  90  is coupled to the differential input gear  82  for common rotation about the second axis  60 . A set of differential bearings  98  support the differential input member  90  for rotation relative to the housing assembly  12 . In the example shown, the set of differential bearings  98  is mounted directly to the differential input member  90  and the housing assembly  12 , but it will be appreciated that the set of differential bearings  98  could be directly mounted to the differential input gear  82  and the housing assembly  12 . The differential input member  90  defines a gearset cavity  100  into which the differential gearset  94  is received. Each of the differential pinions  96  is coupled to the differential input member  90  for rotation therewith about the second axis  60 , and are rotatable relative to the differential input member  90  about respective differential pinion axes. For example, the differential pinions  96  could be rotatably mounted on one or more pins  102 , and each of the pins  102  can have a first end, which is coupled to the differential input member  90 , and a second end that is either connected to the differential input member  90  or to another one of the pins  102 . Alternatively, each of the differential pinions  96  could include a journal portion (not shown) that is rotatably mounted to the differential input member  90 . The side gears (differential output members  92   a,    92   b ) are received in the gearset cavity  100  and are meshingly engaged to the differential pinions  96 . The side gears are rotatable relative to the differential input member  90  about the second axis  60 . 
     Optionally, the differential assembly  22  can be configured with a limited slip mechanism  110  that is operable for inhibiting or limiting a speed differential between the differential output members  92   a,    92   b.  In the example provided, the limited slip mechanism  110  includes a friction clutch  112  and an actuator  114 . The friction clutch  112  can have a clutch pack  116  that can include a plurality of first clutch plates  118 , which can be non-rotatably but axially slidably coupled to the differential input member  90 , and a plurality of second clutch plates  120  that are interleaved with the first clutch plates  118  and non-rotatably but axially slidably coupled to the differential output member  92   b.  Alternatively, the limited slip mechanism  110  could comprise a dog clutch (not shown) that is selectively operable for non-rotatably coupling one of the differential output members  92   a,    92   b  to the differential input member  90 . Additionally, or alternatively, a disconnect clutch (not shown) for selectively inhibiting the transmission of rotary power between the differential input gear  82  and one or both of the output shafts  30   a,    30   b.  The disconnect clutch could be any type of clutch or coupling and can be operable for selectively rotationally de-coupling various torque-transmitting elements, such as the differential input gear  82  and the differential input member  90 , or one of the differential output members  92   a,    92   b  and a respective one of the output shafts  30   a,    30   b,  from one another. 
     With reference to  FIGS.  3  and  4   , the actuator  114  is configured to compress the clutch pack  116  to frictionally engage the first and second clutch plates  118  and  120  to one another by an amount that varies with the force that is applied by the actuator  114  to compress the clutch pack  116 . In the example provided, the actuator comprises a ball-ramp mechanism  124  that is driven by an actuator motor  130 . The actuator motor  130  can be employed to transmit rotary motion through an actuator transmission  132  having a sector gear  134  that is rotationally coupled to a rotatable ball-ramp ring  136  of the ball-ramp mechanism  124 . Rotation of the rotatable ball-ramp ring  136  relative to a rotationally stationary ball-ramp ring  138  of the ball-ramp mechanism  124  causes movement of balls (not specifically shown) in the ball-ramp mechanism  124  in a grooved track (not specifically shown) to selectively expand or contract the axial width of the ball-ramp mechanism  124 . When the axial width of the ball-ramp mechanism  124  is expanded, pins  140  that extend through the differential input member  90  axially between the ball-ramp mechanism  124  and the clutch pack  116  transmit a force that tends to compress the clutch pack  116 , which has the effect of tending to inhibit speed differentiation between the differential output members  92   a,    92   b.  It will be appreciated that limited slip mechanisms and actuators for operating limited slip mechanisms are well known in the art and as such, the limited slip mechanism  110  and/or the actuator  114  could be constructed differently from what is depicted herein. 
     Returning to  FIG.  1   , the auxiliary power source  24  is an electric motor and is housed in the motor portion  42  of the housing assembly  12 . The auxiliary power source  24  can include a stator  141 , which can be fixedly coupled to the housing assembly  12 , a rotor  142 , which is received in the stator  141  and which is rotatable relative to the stator  141  about the second axis  60 , and a motor output shaft  144  that is hollow and coupled to the rotor  142  for rotation therewith about the second axis  60 . A set of motor bearings  148  can be employed to support the motor output shaft  144  for rotation relative to the housing assembly  12 . The motor output shaft  144  can extend through the interior annular wall  58  into the gearbox cavity  46  and can have a toothed or splined segment, such as an internally splined segment  150 . 
     With reference to  FIG.  5   , the multi-speed transmission  26  is received in the gearbox cavity  46  and can include a second shaft  170 , a third shaft  172 , a first intermediate gear reduction  174 , a second intermediate gear reduction  176 , a coupling  178 , and an actuator  180 . The second shaft  170  is a hollow structure that is mounted on a set of second shaft bearings  182  to support the first shaft  18  for rotation about the second axis  60  relative to the housing assembly  12 . The second shaft  170  can be coupled to the motor output shaft  144  for rotation therewith about the second axis  60 . In the example provided, the second shaft  170  includes an externally splined segment  186  that is received into and rotationally engaged with the internally splined segment  150  in the motor output shaft  144 . A set of third shaft bearings  190  supports the third shaft  172  for rotation relative to the housing assembly  12  about a second intermediate axis  192 . The second intermediate axis  192  is parallel to but offset from both the first axis  52  and the second axis  60 . Groups of two or more of the first axis  52 , the first intermediate axis  78 , the second axis  60  and the second intermediate axis  192  can be disposed in a plane with one another. For example, the first axis  52  and the first intermediate axis  78  can be disposed in one plane, and the second axis  60  and the second intermediate axis  192  can be disposed in another plane. 
     The first intermediate gear reduction  174  comprises a first intermediate gear  200 , which is fixedly coupled to (e.g., unitarily and integrally formed with) the second shaft  170 , and a second intermediate gear  202  that is meshingly engaged to the first intermediate gear  200  and which is rotatably disposed on the third shaft  172 . In the example provided, the first and second intermediate gears  200  and  202  are helical gears and a bearing  204  is disposed between the second intermediate gear  202  and the third shaft  172 . The second intermediate gear reduction  176  comprises a third intermediate gear  206 , which is fixedly coupled to (e.g., unitarily and integrally formed with) the second shaft  170 , and a fourth intermediate gear  208  that is meshingly engaged to the second intermediate gear  202  and which is rotatably disposed on the third shaft  172 . In the example provided, the third and fourth intermediate gears  206  and  208  are helical gears and a bearing  210  is disposed between the fourth intermediate gear  208  and the third shaft  172 . The first intermediate gear reduction  174  has a first gear ratio, while the second intermediate gear reduction  176  has a second gear ratio that is different from the first gear ratio. 
     The coupling  178  is configured to selectively couple one of the second and fourth intermediate gears  202  and  208  to the third shaft  172  for common rotation about the second intermediate axis  192 . The coupling  178  could be configured in any desired manner, but in the example provided, the coupling  178  comprises a set of first coupling teeth  211 , which are formed on the second intermediate gear  202 , a set of second coupling teeth  212 , which are formed on the fourth intermediate gear  208 , a coupling lug  214 , which is fixedly coupled to the third shaft  172  and which has a set of third coupling teeth (not specifically shown), and a coupling collar  218  having a set of internal coupling teeth (not specifically shown) that are non-rotatably but axially slidably engaged with the third coupling teeth on the coupling lug  214 . The coupling collar  218  is movable along the second intermediate axis  192  between a low-speed position, in which the internal coupling teeth on the coupling collar  218  are meshingly engaged to the first coupling teeth  211  on the second intermediate gear  202  and the third coupling teeth on the coupling lug  214 , a high-speed position in which the internal coupling teeth on the coupling collar  218  are meshingly engaged to the second coupling teeth  212  on the fourth intermediate gear  208  and the third coupling teeth on the coupling lug  214 , and a neutral position, in which the internal coupling teeth are meshingly engaged to only the third coupling teeth on the coupling lug  214  but are not engaged to either the first coupling teeth  211  on the second intermediate gear  202  or the second coupling teeth  212  on the fourth intermediate gear  208 . It will be appreciated that placement of the coupling collar  218  in the low-speed position rotationally couples the second intermediate gear  202  to the third shaft  172  so that the first intermediate gear reduction  174  is active in transmitting rotary power between the second and third shafts  170  and  172 , that placement of the coupling collar  218  in the high-speed position rotationally couples the fourth intermediate gear  208  to the third shaft  172  so that the second intermediate gear reduction  176  is active in transmitting rotary power between the second and third shafts  170  and  172 , and that placement of the coupling collar  218  in the neutral position couples neither of the second and fourth intermediate gears  202  and  208  to the third shaft  172  so that neither of the first and second intermediate gear reductions  174  and  176  is active. 
     The actuator  180  can comprise any desired means for selectively translating the coupling collar  218  along the second intermediate axis  192  between the low-speed position, the neutral position and the high-speed position. In the example provided, the actuator  180  is of a type that includes a motor driven fork and is well known in the art. As such, a detailed discussion of the actuator  180  need not be provided herein. Briefly, the actuator  180  includes a fork  230 , which is received into a circumferentially extending groove formed in the coupling collar  218  so that the fork  230  is axially but non-rotationally coupled to coupling collar  218 , and a rotary electric motor (not specifically shown) is employed to drive a cam (not specifically shown) that cooperates with a cam follower (not specifically shown) to cause translation of the fork  230  along the second intermediate axis  192 . 
     With reference to  FIGS.  2  and  5   , the third fixed reduction  28  can include a fifth intermediate gear  250  that can be fixedly coupled to (e.g., unitarily and integrally formed with) the third shaft  172 , and a sixth intermediate gear  252  that can be meshed with the fifth intermediate gear  250  and rotationally coupled to the first shaft  18 . In the example provided, the fifth and sixth intermediate gears  250  and  252  are helical gears. 
     The auxiliary power source  24  ( FIG.  1   ) can be operated to provide rotary power that drives the differential input member  90  about the second axis  60 . Power output from the auxiliary power source  24  ( FIG.  1   ) through the motor output shaft  144  is transmitted through the multi-speed transmission  26  and the third fixed reduction  28  to the first shaft  18  to drive the differential input member  90  through the second fixed reduction  20 . 
     In  FIG.  1   , each of the output shafts  30   a,    30   b  can be rotationally coupled to an associated one of the differential output members  92   a,    92   b.  The output shaft  30   a  can exit the housing through the first output bore  50 , while the output shaft  30   b  can extend through the second shaft  170  and the motor output shaft  144  and can exit the housing assembly  12  through the second output bore  56   
     With reference to  FIG.  6   , the vehicle drive unit  10  can be coupled to a relatively high-voltage, high-current electrical power source  280  via a plurality of high-power battery leads (electric leads)  282  (only one shown). The vehicle drive unit  10  can include an interlock that is configured to inhibit the supply of electrical power from the auxiliary power source  24  if certain predetermined conditions are not met. For example, the interlock can be configured to require a battery lead  282  that couples the auxiliary power source  24  to a desired electrical ground be present in a channel  290  in the motor portion  42  of the housing assembly  12 , and that a cover  292  can be installed to the motor portion  42 . 
     With reference to  FIGS.  6  and  7   , a movable blocking member can be employed to both block entry into one or more of the channels  290  from a location outside the motor portion  42 , and b) can be disposed in a location that inhibits the seating of the cover  292  against the motor portion  42  when a battery lead or leads  288  is/are not present in the channels  290 . In the example provided, the blocking member comprises a lever  294  can be pivotally coupled to the motor portion  42  of the housing assembly  12  and a torsion spring  296  biases the lever  294  into a position that a) blocks entry into a single one of the channels  290  from a location outside the motor portion  42 , and b) is disposed in a location that inhibits the seating of the cover  292  against the motor portion  42  when the respective battery lead  282  is not present in the single one of the channels  290 . 
     The lever  294  can be formed of an appropriate plastic material and can be formed in various different ways depending upon a variety of factors, including the volume that is available to package the lever  294  into the vehicle drive unit  10 . In the example shown, the lever  294  includes first and second lever portions  300  and  302 , respectively, that are disposed on opposite sides of a pivot hub  304 . The pivot hub  304  is hollow and receives a pivot pin  306  therethrough. The pivot pin  306  extends into pin holes that are formed into the sidewalls  310  of the channel  290  in the motor portion  42  when the lever  294  is disposed between the sidewalls  310 . The pivot pin  306  can be secured to the motor portion  42  in any desired manner. In the example of  FIG.  8    for example, the pivot pin  306  could be configured as an axle and can have circumferential grooves  316  in one or both ends that receive external snap rings  318 . The snap rings  318  can abut the sidewalls  310  to inhibit or limit axial sliding movement of the pivot pin  306  in the holes in the sidewalls  310 . Returning to  FIGS.  6  and  7   , the pivot pins  306  could additionally or alternative be formed with heads  320  that are relatively larger in diameter than the hole in an associated one of the sidewalls  310 . In the particular example provided, the pivot pin  306  has a head  320  on one end and a plurality of threads (not specifically shown) on an opposite end. The threaded end of the pin  306  is inserted through the hole in one sidewall  310 , through the pivot hub  304  and is threaded into the hole in the opposite sidewall  310 . 
     The torsion spring  296  is configured to bias the lever  294  about the pivot pin  306  into an interlock position that is shown in  FIG.  7   . When the lever  294  is in the interlock position, the first lever portion  300  closes the exterior side of the channel  290 , while the second lever portion  302  is in an elevated position that inhibits the abutment of the cover  292  to a mounting flange  330  on the motor portion  42 . In the example provided, the channel  290  is formed by an inner housing assembly  336  that is part of the motor portion  42  and shrouds a power terminal  338  to which the battery lead  282  is to be coupled. 
     The lever  294  can be pivoted manually about the pivot pin  306  to uncover the channel  290  and permit the battery lead  282  to be inserted through the channel  290  and mounted to the power terminal  338  as is shown in  FIGS.  6  and  12   . Prior to the installation of the cover  292  to the motor portion  42 , the first lever portion  300  can contact the battery lead  282 , to inhibit the torsion spring  296  from returning the lever  294  to the interlock position. 
     While the lever  294  has been described as including a pair of lever portions that are disposed on opposite sides of a pivot hub  304 , it will be appreciated that the lever could be formed somewhat differently. With reference to  FIG.  9   , the lever  294 ′ could include a single lever portion that extends from the pivot hub  304 . In this example, the pivot hub  304 ′ is formed as a yoke, the torsion spring  296  is mounted between the ears of the yoke, and the pivot hub  304 ′ and pivot pin  306  are disposed relative to the channel  290  so that the lever  294  is biased upwards to not only block the channel  290  but also to inhibit the cover  292  ( FIG.  6   ) from being secured to the mounting flange  330  ( FIG.  6   ). 
     While a single lever  294  has been illustrated and described, it will be appreciated that additional levers  294  could be incorporated into the interlock. In the particular example provided, a seal boot that sealingly engages the motor portion  42  of the housing  12  fixedly couples the several battery leads  282  to one another, which essentially necessitates the simultaneous insertion of all of the battery leads  282  into respective channels  290  at the same time. Consequently, a single lever  294  can optionally be employed (rather than a lever  294  for each battery lead  282 ) because the presence of a single battery lead  282  through a channel  290  to pivot the lever  294  infers the presence of all battery leads  282  in their respective channels  290 . Alternatively, multiple levers  294  or other blocking members could be employed. 
     It will also be appreciated that while various pivoting levers  294 ,  294 ′ have been illustrated and described, the blocking member need not pivot relative to the motor portion  42  of the housing  12 . In this regard, the blocking member could translate relative to the motor portion  42  between a first position, which provides access for a battery lead  282  through the channel  290 , and a second position that blocks access through the channel  290  for the battery lead  282 . 
     With reference to  FIGS.  6 ,  10  and  11   , the cover  292  has a lever engagement  350  and a magnet  352 . With the first lever portion  300  contacting the battery lead  282  so that the lever  294  is pivoted substantially from the interlock position, the cover  292  can be disposed against the mounting flange  330  on the motor portion  42  and can be removably coupled to the motor portion  42  via a plurality of threaded fasteners  360 . A gasket  362  can be disposed between the cover  292  and the mounting flange  330  on the motor portion  42  to seal the interface between the cover  292  and the mounting flange  330 . With the cover  292  secured to the mounting flange  330  in this manner, the lever engagement  350  can be in contact with the second lever portion  302  to position the lever  294  about the pivot pin  306  such that the first lever portion  300  does not touch or engage the battery lead  282 . The magnet  352  on the cover  292  is positioned proximate a sensor  370  that is mounted to the motor portion  42 . The sensor  370  is configured to sense the presence of the magnet  352  and to responsively generate a sensor signal that is transmitted to a controller  372 . The controller  372  can be configured to inhibit the supply of electrical power unless the sensor signal is transmitted by the sensor  370  to the controller  372 . 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.