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A variable speed drive includes a transmission in a housing with a rotatable control shaft for moving the transmission between neutral and drive positions. A rotary damper is engaged to an external control arm which rotates the control shaft. A return to neutral mechanism is engaged to the control s

A variable speed drive includes a transmission in a housing with a rotatable control shaft for moving the transmission between neutral and drive positions. A rotary damper is engaged to an external control arm which rotates the control shaft. A return to neutral mechanism is engaged to the control shaft to return the transmission to neutral. The external damper may be a viscous fluid damper having a plate, a rotor element with a first set of concentric projections, and a stator element with a second set of concentric projections that mesh with the first set of concentric projections. A method is provided for assembling a damper subassembly and a return arm subassembly, and connecting the damper subassembly to the housing, connecting the control arm to the control shaft and connecting the return arm subassembly to the control shaft for ease of assembly.

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1. A variable speed drive device, comprising: a hydraulic pump assembly disposed in a housing and comprising a cylinder block and a pump input shaft extending into the housing and engaged to the cylinder block, a rotatable swash plate for controlling the output of the cylinder block, and a control s

1. A variable speed drive device, comprising: a hydraulic pump assembly disposed in a housing and comprising a cylinder block and a pump input shaft extending into the housing and engaged to the cylinder block, a rotatable swash plate for controlling the output of the cylinder block, and a control shaft engaged to the swash plate for moving the swash plate between a neutral position and a plurality of non-neutral positions, wherein one end of the control shaft extends out of the housing;a control arm disposed external to the housing and engaged to the control shaft, wherein the control arm selectively rotates the control shaft;a rotary damper disposed external to the housing and engaged to the control shaft for dampening rotation of the control shaft; anda return to neutral mechanism engaged to the control shaft to rotate the control shaft from one of the plurality of non-neutral positions to the neutral position. 2. The variable speed drive device of claim 1, wherein the return to neutral mechanism comprises a neutral arm and a scissor return arm assembly rotatably disposed about an end of the control shaft, wherein the scissor return arm assembly cooperates with the neutral arm to rotate the control arm and move the control shaft into the neutral position. 3. The variable speed drive device of claim 2, wherein the rotary damper comprises: a plate having a first surface and second surface opposite the first surface, wherein at least a portion of the first surface is secured to an external surface of the housing so that the plate does not rotate with respect to the housing, wherein the control shaft extends through a first opening in the plate without engaging the plate;a stator fixed to the second surface of the plate in a non-rotatable manner, wherein the control shaft extends through a second opening in the stator without engaging the stator, the stator further comprising a first dampening mechanism formed thereon; anda rotor fixed to and rotatable with the control shaft, the rotor comprising a second dampening mechanism engaged to the first dampening mechanism. 4. The variable speed drive device of claim 1, wherein the rotary damper is a viscous fluid damper comprising a plate, a rotor element engaged to the control shaft and having a first set of concentric projections, a stator element having a plurality of anti-rotation projections that engage the plate and a second set of concentric projections that mesh with the first set of concentric projections. 5. The variable speed drive device of claim 4, wherein the rotor element is disposed in a damper cover and further comprises a face and a plurality of openings formed in the face to permit a viscous fluid to pass through the plurality of openings to occupy a space between the face and the damper cover. 6. The variable speed drive device of claim 5, wherein the rotor element further comprises a plurality of slots in the first set of concentric projections. 7. The variable speed drive device of claim 1, wherein the rotary damper comprises a plate secured directly to the housing. 8. The variable speed drive device of claim 7, further comprising a centering ring formed on the housing, the centering ring mating with a centering flange formed in the plate to assist in locating the plate on the housing. 9. A variable speed drive device, comprising: a transmission disposed in a housing and comprising a rotatable cylinder block, a swash plate for controlling the output of the rotatable cylinder block and a control shaft engaged to the swash plate and extending from the housing, wherein rotation of the control shaft moves the transmission between a neutral position and a plurality of drive positions;a control arm disposed external to the housing and engaged to the control shaft to move the transmission among the neutral position and the plurality of drive positions;a plate having a first surface and second surface opposite the first surface, wherein at least a portion of the first surface is secured to an external surface of the housing so that the plate does not rotate with respect to the housing, wherein the control shaft extends through an opening in the plate without engaging the plate;a stator fixed to the second surface of the plate in a non-rotatable manner, wherein the control shaft extends through an opening in the stator without engaging the stator, the stator further comprising a first plurality of frictional rings formed thereon;a rotor fixed to and rotatable with the control shaft, the rotor comprising a second plurality of frictional rings engaged to the first plurality of frictional rings; anda return to neutral mechanism engaged to the control shaft to provide a return force to return the control shaft to the neutral position when the control shaft is moved to one of the plurality of drive positions. 10. The variable speed drive device of claim 9, wherein the control shaft comprises a trunnion shaft engaged to the swash plate. 11. The variable speed drive device of claim 10, wherein the trunnion shaft is integrally formed as part of the swash plate. 12. The variable speed drive device of claim 9, wherein the return to neutral mechanism comprises a neutral arm integrally formed with the plate. 13. The variable speed drive device of claim 12, wherein the return to neutral mechanism further comprises a scissor return arm assembly rotatably disposed on the control shaft, and the scissor return arm assembly cooperates with the neutral arm to rotate the control arm and move the transmission into the neutral position. 14. A method of assembling a control assembly for a variable speed drive having a control shaft projecting from a drive housing, the method comprising: separately assembling a damper cover to a backing plate to form a damper subassembly, the damper subassembly further comprising a damper stator having a first rotatable damper element therein and a damper rotor having a second rotatable damper element therein;separately assembling a bi-directional scissor return subassembly comprising a pair of scissor return arms, each scissor return arm rotatable about a common point and having a separate contact surface, and a return spring connecting the pair of scissor return arms;connecting the damper subassembly to the drive housing;connecting a control arm to the control shaft adjacent the damper subassembly; andconnecting the bi-directional scissor return subassembly to the control shaft, whereby the control arm is disposed between the damper subassembly and the bi-directional scissor return subassembly. 15. The method of claim 14, wherein the damper subassembly further comprises a neutral arm disposed on the backing plate and having a first extension radially positioned about the control shaft, and the control arm comprises a second extension radially positioned about the control shaft. 16. The method of claim 15, further comprising the step of establishing a neutral position for the control assembly by rotating the control arm to cause the control shaft to move to a position corresponding to a neutral position for the variable speed drive, and rotating the damper subassembly to a point where the first extension and the second extension are in radial alignment, and securely locking the damper subassembly to the drive housing. 17. The method of claim 16, wherein the damper subassembly is securely locked to the drive housing by means of a neutral set screw extending through an opening formed in the backing plate. 18. The method of claim 14, wherein the step of fastening the damper subassembly to the drive housing comprises connecting the backing plate directly to the drive housing so that the backing plate does not rotate with respect to the drive housing. 19. The method of claim 14, wherein the damper rotor comprises a first set of concentric projections, and the damper stator further comprises a plurality of anti-rotation projections that engage the damper cover and a second set of concentric projections that mesh with the first set of concentric projections. 20. The method of claim 14, further comprising the step of providing a viscous PTFE-thickened damping grease in the damper subassembly.