Abstract:
The invention provides a hub motor for a wheeled conveyance having a stationary electric motor encased in a rotating, multi-part housing, at least one of the parts of the housing constituting a wheel disk and a wheel rim, and a reduction gear internal or external to the motor, the output member of which is adapted to drive at least one part of the multi-part housing, wherein the rim portion of the multi-part housing carries, and is in direct contact with, a wheel tire.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a hub motor for a wheeled conveyance.  
         BACKGROUND OF THE INVENTION  
         [0002]    Hub motors, per se, are known. Certain types of bicycles are equipped with hub motors that carry, via spokes, a wheel rim in which a tire is seated. These motors, however, are not reversible, nor are they provided with a brake. Some wheelchairs, on the other hand, do have reversible, braked hub motors that are connected, again via spokes, to a wheel rim provided with a tire.  
         DISCLOSURE OF THE INVENTION  
         [0003]    It is thus one of the objects of the present invention to provide a hub motor having a housing that constitutes both a wheel disk and a wheel rim carrying a tire.  
           [0004]    According to the invention, the above object is achieved by providing a hub motor for a wheeled conveyance, comprising a stationary electric motor encased in a rotating, multi-part housing, at least one of the parts of the housing constituting a wheel disk and a wheel rim, and a reduction gear internal or external to the motor, the output member of which is adapted to drive at least one part of the multi-part housing; wherein the rim portion of the multi-part housing carries, and is in direct contact with, a wheel tire. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]    The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures, so that it may be more fully understood.  
         [0006]    With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.  
         [0007]    In the drawings:  
         [0008]    [0008]FIG. 1 is a partial cross-sectional view of the hub motor assembly according to the present invention;  
         [0009]    [0009]FIG. 2 is a cross-sectional view of a first part of the split housing of the motor;  
         [0010]    [0010]FIG. 3 is a similar view of the second part of the split housing;  
         [0011]    [0011]FIG. 4 is a cross-sectional view of the solenoid brake of the hub motor;  
         [0012]    [0012]FIG. 5 represents a partial top view of the solenoid brake of FIG. 4;  
         [0013]    [0013]FIG. 6 is a front view of the solenoid brake enclosure;  
         [0014]    [0014]FIG. 7 is an elevational view of the bearing enclosure, seen from its inside;  
         [0015]    [0015]FIG. 8 is a cross-sectional view along plane VIII-VIII of FIG. 7;  
         [0016]    [0016]FIG. 9 illustrates the way the hub motor is attachable to a member of a conveyance;  
         [0017]    [0017]FIG. 10 is a side view of the arrangement according to FIG. 9, and  
         [0018]    [0018]FIG. 11 is a block diagram of the electric and electronic systems associated with the hub motor according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0019]    Referring now to the drawings, FIG. 1 illustrates, encased in a multi-part or split housing  2 ,  4 , an electric motor  6 , in this particular embodiment a DC, permanent magnet, flat motor of the type ZYP-6N, having an output shaft  8  extending beyond an end plate  9  to the other side of the motor as brake shaft  10 . Brake shaft  10  is designed to be acted upon by a solenoid brake  12 , represented in detail in FIGS. 4 and 5. Also shown is brake enclosure  14 , fixedly attached to motor  6  by means of screws (not shown), and seen to better advantage in FIG. 6. Shown emerging from stationary brake enclosure  14  are two pairs of cables: a first pair  16  supplying motor  6 , and a second pair  18  controlling solenoid brake  12 .  
         [0020]    Fixedly attached to output shaft  8  is the first pinion  20  of a reduction gearing comprising a gear  22  meshing with pinion  20 , to which gear  22  is keyed a second pinion  24  for driving output gear  26 , fixedly attached to, and thus driving, housing part  4 . While the above-described reduction gearing is clearly external to motor  6 , it is also possible to use a gear motor in which the reduction gearing is internal.  
         [0021]    Second pinion  24  is mounted in ball bearings  28  accommodated in bearing enclosure  30  (FIGS. 7 and 8). Fixedly attached to bearing enclosure  30  is stub axle  32 , mounting a ball bearing  34 . Housing part  4  is seated on the outer race of ball bearing  34 . Brake enclosure  14  acts as a counter-stub axle on the other side of motor  6 , carrying the inner race  36  of a needle bearing, the outer race  38  of which is press-fitted into housing part  2 .  
         [0022]    Also seen in FIG. 1 is tire  40 , seated on and retained by housing part  2 . The surface of tire  40  is provided with appropriate grooving to ensure traction. While tire  40  is shown as a solid tire, a slight modification of housing half  2  will permit the use of an inflatable tire.  
         [0023]    [0023]FIG. 2 shows housing part  2 , constituting both wheel disk  42  and wheel rim  44 , with the tire  40  ghosted in. Also shown is the shouldered seat  46  of the outer race  38  of the needle bearing (FIG. 1). Housing part  2  is reinforced by a number of ribs  48 . Peripheral threaded holes  50  and step  52  serve for the attachment of housing part  4 .  
         [0024]    Housing part  4  is illustrated in FIG. 3. Shown are neck portion  54 , fitting step  52  of housing part  2 ; peripheral, counter-sunk holes  56  registering with threaded holes  50  of housing part  2 ; a seat  58  for ball bearing  34  (FIG. 1), and threaded holes  60  for the attachment of gear  26 .  
         [0025]    Solenoid brake  12  is illustrated in FIGS. 4 and 5. Shown is ferromagnetic solenoid body  62  with its core  64 , and solenoid coil  66 , located in the annular space between them. The two ends  18  of coil  66  lead to the outside. Body  62  is fixedly attached to motor  6  by screws  68 . The ferromagnetic solenoid armature  70  is disposed above the coplanar faces of solenoid body  62  and core  64  and is biased by spring means (not shown) away from those faces, thus producing an air gap a of a few tenths of a millimeter.  
         [0026]    The above-mentioned spring means could be a number of helical compression springs inserted into peripheral holes in solenoid body  62  and in the free state, projecting above the face of solenoid body  62 . Clearly, this solenoid is of the normally open type.  
         [0027]    Further shown is a brake disk  72 , located between armature  70  and a counter-disk  74  firmly attached to solenoid body  62  by means of screws  75 , at a distance determined by three distance sleeves  76 . Brake disk  72  has a hexagonal central opening, into which the lower, hexagonal portion of end piece  78  fits. End piece  78  is fixedly connected to brake shaft  10  (FIG. 1) by means of two grub screws fitting threaded holes  80 .  
         [0028]    The braking position shown in FIG. 4 is attained by cutting off the current to normally open solenoid brake  12 . In a braking episode, this is done simultaneously with cutting the current supply to motor  6 . As a result, brake disk  70  becomes clamped between counter-disk  74  and armature  70  by the biasing force exerted on the armature by the above-mentioned spring means, and is then driven against the frictional force by the hexagonal portion of end piece  78  until the remaining kinetic energy of the conveyance is totally converted into heat. To release the brake, the solenoid is activated pulling down armature  70  against the biasing spring means and thereby unclamping brake disk  72 , allowing it and end piece  78 , and thus shaft  10 , to freely rotate.  
         [0029]    A front view of brake enclosure  14  is shown in FIG. 6. Seen are four countersunk holes  82  for screws, whereby brake enclosure  14  is attached to end plate  9  (FIG. 1); two threaded holes  84  for connection to a bracket  106  (FIG. 10), whereby the motor/wheel unit is attached, e.g., to the steering column of a conveyance; and one hole  86 , through which cable pairs  16  and  18  (FIG. 1) are led to the outside. In FIG. 1, hole  86  and hole  84  have been swung into a vertical plane for purposes of clarity.  
         [0030]    [0030]FIG. 7 represents a view of bearing enclosure  30 , seen from the side where it is attached to motor  6 , and FIG. 8 is a cross-sectional view along plane VIII-VIII of FIG. 7. Shown are flange  88  with peripheral holes  90  for connection to motor  6 , and two spaced-apart bores  92  for accommodating the ball bearings  28  that mount pinion  24 . Further provided are a cylindrical recess  94  and a bore  96  for accommodating stub axle  32 , as well as four countersunk holes  98  for the screws mounting the stub axle on the structure. Two threaded holes  100  serve to attach a retaining ring for the front ball bearing  28 .  
         [0031]    [0031]FIGS. 9 and 10 illustrate the way in which the hub motor according to the present invention is attached to a member of the conveyance, e.g., the forked ends  102 ,  104  of a tubular steering column. The hub motor is connected to ends  102 ,  104  by means of brackets  106 ,  108  welded to ends  102 ,  104 , respectively. Bracket  106  is attached to brake enclosure  14  by means of two screws  110  fitting threaded holes  84  (FIG. 6), and bracket  108  is mounted on the end face of stub axle  32  by means of another screw  110  fitting the internal thread of the stub axle end. Cables  16 ,  18  are led through tubular end  102 , as seen in FIG. 10.  
         [0032]    The block diagram of FIG. 11 comprises an operator&#39;s panel  112  for speed and direction control, an electronic drive and brake controller  114 , and a rechargeable battery  116 . Provision is also made for a free-wheeling switch that permits the release of solenoid brake  12  without activating motor  6 .  
         [0033]    It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.