Patent Application
20080078980
Further advantages of the invention are apparent by reference to the detailed description in conjunction with the figures, wherein elements are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:
The housings 22 and 24 are connected together by two tie rods 36a and 36b. Although two tie rods 36a and 36b are provided in the preferred embodiment, it will be understood that a single tie rod can be used instead. Further, it will be appreciated that when the tie rods 36a and 36b are removed, the housings 22 and 24 and the winch drum 16 are no longer connected and can be pulled apart freely, thereby simplifying maintenance. In other words, the winch drum 16 is effectively held in place and supported by the housings 22 and 24 when the latter are connected by means of the tie rods 36a and 36b.
The winch drum 16 is coupled to the drive shaft 12 via reduction gearing contained within the drive end housing 24 so that the drum 16 rotates in response to operation of the winch motor 14. In this manner, cable is released from the drum 16 as the winch motor 14 turns in a forward direction and is retrieved as the winch motor 14 turns in a reverse direction. Typical reduction gearing apparatuses and methods can be used to suitably couple the drive shaft 12 and winch drum 16, and to provide sufficient torque output to the winch drum 16.
In a preferred embodiment, the winch motor 14 is a low-speed, high-torque motor with 160 cc capacity. Suitable sources for such motors include White Hydraulics of Louisville, Ky. and the Dan Foss Company which is located in Wisconsin. The motor 14 may be driven by the host vehicle's hydraulic pressure supply. For example, the vehicle's power steering system may be utilized to provide hydraulic pressure for operation of the winch motor 14 as described in U.S. Pat. No. 5,842,684, the full disclosure of which is incorporated herein by reference. For a typical vehicle installation where the motor 14 is powered by a vehicle's power steering system, the vehicle's power steering pump will supply hydraulic fluid to the motor 14 at a pressure of about 2500 PSI with a flow rate of about eight GPM. This installation configuration produces a maximum torque of about 36,000 lb-in on the winch drum bottom wind and a nominal drum rotation rate of about 12 RPM during winch motor operation. However, it will be understood that the maximum torque and nominal drum rotation rate will vary depending on the particular installation configuration as well as the particular gear reduction ratio employed.
A preferred reduction gearing apparatus for coupling the drive shaft 12 to the winch drum 16 is illustrated in
The gear reduction plunger 44 mechanically couples the ring gear 42 to the drive end housing 24 by means of holes 46 along the outer surface of the ring gear 42. When the plunger 44 is retracted, and thereby removed from the holes 46, the ring gear 42 and planet gears 18a-c are drivingly decoupled from the winch drum 16. In other words, retracting the plunger 44 from the ring gear 42 effectively decouples the drive shaft 12 from the winch drum 16 so that the winch drum 16 free-spools. In this manner, a free-spooling capability is provided whereby cable may be unwound from the winch drum 16 without the assistance of the winch motor 14. This free-spooling capability is particularly useful for rapid removal of cable from the winch drum 16.
In a preferred embodiment, the gear reduction plunger 44 is urged toward the ring gear 42 by a spring 48. To disengage the plunger 44 from the ring gear 42, the plunger 44 is pulled in a axial direction away from the ring gear 42 by the rotation of a cam sleeve 50 to which the plunger 44 is attached. This condition is illustrated in
The winch drum may be driven in a high-speed, low-torque mode by coupling the rotation of the drive shaft 12 directly to the winch drum 16 with no gear reduction. A higher drum rotation speed is useful in retrieving long lengths of unspooled cable after load-moving operations are complete, or in taking up slack in the cable prior to moving a load. In the preferred embodiment of the invention, the coupling of the drive shaft 12 to the winch drum 16 is attained by a coupling plate 54 which is moveable between two axial positions: a low-speed position in which the winch drum 16 is decoupled from the drive shaft 12, and a high-speed position in which the winch drum is coupled to the drive shaft 12. For the exemplary vehicle installation described above (2500 PSI at eight GPM), the direct drive arrangement produces a nominal drum rotation rate of 38 rpm and a maximum torque of 2000 lb-in during winch motor operation.
As shown in
With reference to
It will be appreciated that high-speed operation of the winch 10 is achieved only when the gear reduction plunger 44 is retracted. In such a position, the plunger 44 does not engage any of the holes 46 in the ring gear 42, and the ring gear is free to rotate along with winch drum 16. If the plunger 44 is engaged in a hole 46 in the ring gear 42, no rotation of the ring gear 42 or the drive shaft 12 may occur. This is due to the meshing of the planet gears 18a-c with the ring gear 42 and the coupling of the drive shaft 12 to the planet gear shafts 20a-c by means of the coupling plate 54. In other words, when the plunger 44 is engaged with any of the holes 46 and the coupling plate 54 is engaged with the drive shaft 12, the winch drum 16 is in a locked position.
It will be appreciated that many mechanisms could be employed to move the coupling plate 54 in an axial direction to engage or disengage the drive shaft 12.
The plunger spring 60 allows for misalignment between the pinion gear 40 and the keyed hole 56 by holding the coupling plate 54 against the pinion gear 40 until proper alignment is achieved through rotation of the pinion gear 40 or otherwise. If misalignment between the keyed hole 56 and pinion gear 40 occurs, the plunger spring 60 will hold the coupling plate 54 against the pinion gear 40 until there is proper alignment. In this manner, the plunger spring 60 helps compensate and correct for initial misalignment.
To disengage the coupling plate 54 from the pinion gear 40, the plunger 64 is pulled away from the coupling plate 54 by the rotation of a cam sleeve 136 to which the plunger 64 is attached. This compresses the plunger spring 60, and the keyed hole 56 and pinion gear 40 disengage. This condition is illustrated in
A preferred embodiment of reduction gearing apparatus for coupling the motor 14 to the drive shaft 12 is depicted in
The pinion gear 72 meshes with three planet gears 76a-c that are preferably spaced at 120 degree increments about the axis of the pinion gear 72. The planet gears 76a-c are free to rotate about corresponding planet gear pins 78a-c, the ends of which are secured to a drive shaft plate 80 and a planet gear support 88. In the preferred embodiment of the invention, the drive shaft plate 80 is formed as an integral part of the drive shaft 12. However, it will be appreciated that the plate 80 may be attached to the shaft 12 by various means, such as by welding. The planet gears 76a-c mesh with a ring gear 82 which is secured to the motor end housing 22 by screws 84. A drum bearing 86 provides freedom of rotation between the drive shaft 12 and the drum 16. As shown in
In the preferred embodiment of the invention, the gear reduction ratio from the motor shaft 70 to the drive shaft 12 is six-to-one (6-to-1). This provides a torque which is twice that of the winch design described in U.S. Pat. No. 5,842,684.
In alternative embodiments of the invention, the motor shaft 70 may be coupled directly to the drive shaft 12, such as using a shaft coupler. In this embodiment, the drive shaft 12 rotates at the same speed as the motor shaft 70.
According to the preferred embodiment of the invention, the winch operator may select from four different modes of winch operation depending upon the positions of the gear reduction selector handle 52 and the direct drive selector handle 68. Low-speed winch operation is selected when the direct drive selector handle 68 is in the position shown in
In the preferred embodiment of the invention, the gear reduction plunger 44 and the direct drive plunger 64 are moved manually using the handles 52 and 68, respectively. However, one skilled in the art will appreciate that the plungers 44 and 64 may also be actuated by solenoids powered by the battery of the vehicle on which the winch 10 is mounted. An example of a circuit for controlling solenoids in this application is described in U.S. Pat. No. 5,842,684.
The foregoing description of preferred embodiments for this invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the invention and its practical application, and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
