Patent ID: 8789435
Filing Date: 2014-07-29
Classification: B62M,Y10T

Abstract:
1. A cam self-adaptive automatic speed shift hub, comprising: a left hub frame, a right hub frame, a case body, a power input device, a drive shaft, a wheel, arid a brake device; the left hub frame and the right hub frame are securely connected relative to the case body; a portion of the drive shaft extends out the case body to circumferentially cooperate with the wheel; the left hub frame and the right hub frame are respectively positioned on either side of the wheel; wherein the hub further including a low-gear drive shaft, a low-gear transmission mechanism provided on the low-gear drive shaft, and a cam self-adaptive speed shift assembly provided on the drive shaft; the low-gear drive shaft is positioned within the case body, rotatable with respect to the case body and in parallel with the drive shaft; the low-gear transmission mechanism includes as low-gear gear and a low-gear overrunning clutch in parallel sleeved on and circumferentially engaged with the low-gear drive shaft; the low-gear overrunning clutch is provided with a low-gear ring; the low-gear gear fits with the low-gear ring through the tow-gear overrunning clutch; the cam self-adaptive speed shift assembly includes the drive shaft, a clutch, a speed shift spring and a transmission gear positioned on the drive shaft; the clutch comprises a driving transmission part and a driven transmission part that can be engaged and disengaged; the transmission gear engages with the low-gear ring; and the driving transmission part of the clutch engages with the low-gear gear; at least one spirally expanded cam slot is provided on the periphery of the drive shaft, with a earn pin inserted into the cam slot; the clutch implements engaging/releasing based on the driving resistance, with the cooperation of the speed shift spring, the cam slot and the cam pin; when the clutch engages, the high-gear transmission is conducted; when the clutch is disengaged, the low-gear transmission is implemented through the low-gear gear, the low-gear overrunning clutch, and the low-gear ring in sequence; wherein the cam self-adaptive speed shift assembly is a clutch disc cam self-adaptive speed shift assembly; the clutch includes a driving clutch gear ring, at least one driving friction plate, a driven transmission sleeve, and a driven friction plate that forms a friction pair with the driving friction plate; the driving clutch gear ring circumferentially fit with the power input device; the transmission gear is sleeved on the drive shaft in clearance fit; the driving clutch gear ring engages with the low-gear gear; an equal number of radial pin holes (II) that match with the number of the spiral cam slots are evenly disturbed on the periphery of the driven transmission sleeve; driven transmission sleeve is sleeved on the outer periphery of the cam shaft in clearance fit; the cam pin inserts into the spiral cam slot of the cam shaft through the radial pin hole (II); the driving clutch gear ring is sleeved on the outer periphery of the driven transmission sleeve to have a rotation fit with the driven transmission sleeve; the driving clutch gear ring and the driven transmission sleeve each have their end face processed with an axial spline groove; the driving friction disc fits with the driving clutch gear ring via the spline groove on the outer periphery; the driven friction disc fits with the driven transmission sleeve via the spline groove on the inner periphery; the driving friction disc and the driven friction disc are alternatively installed spaced from each other, and tightly fit with each other under the effect of the speed shift spring; and an end of the transmission gear engages with an end of an axially extending annular member which has an outer conical face.