Stepping motor drive apparatus, gear pump, and stepping motor-driven gear pump system
First Claim
1. A stepping motor-driven system, comprising:
- a stepping motor including a rotor configured to rotate in response to driving of the stepping motor, the stepping motor defining at least one speed trap corresponding to a resonance condition, the stepping motor configured to drive the rotor according to a start/stop profile in order to avoid the at least one speed trap;
an output device including a drive shaft; and
a belt and pulley system operably coupling the rotor of the stepping motor with the drive shaft of the output device such that rotation of the rotor effects rotation of the drive shaft, the belt and pulley system including;
an input pinion engaged with the rotor of the stepping motor, the input pinion defining a plurality of spaced-apart, annularly arranged first teeth disposed on an outer surface of the input pinion, each tooth defining a first width;
an output pinion engaged with the drive shaft of the output device, the output pinion defining a plurality of spaced-apart, annularly arranged second teeth disposed on an outer surface of the output pinion, each second tooth defining a second width equal to the first width; and
a timing belt, disposed about the input pinion towards a first end of the timing belt and disposed about the output pinion towards a second end of the timing belt, the timing belt configured to inhibit elongation and defining a plurality of spaced-apart grooves on an inwardly-facing surface thereof, each groove defining a third width greater than each of the first and second widths,wherein the first and second teeth of the input and output pinions are disposed in meshed engagement within the grooves of the timing belt such that, as a result of the third width being greater than each of the first and second widths, a gap is defined within each groove, the gaps permitting backlash of the timing belt in response to changes in a rotational speed input to the belt and pulley system from the stepping motor,wherein, in accordance with the start/stop profile, the stepping motor is configured to switch from an accelerating mode to a constant-speed mode prior to reaching the resonance condition, thereby avoiding the at least one speed trap and inhibiting loss of control, wherein switching to the constant-speed mode enables backlash of the timing belt, thereby dissipating energy built up in the timing belt during operation of the stepping motor in the accelerating mode, andwherein, in accordance with the start/stop profile, the stepping motor is configured to switch back to the accelerating mode after dissipating the energy built up in the timing belt.
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Accused Products
Abstract
A stepping motor-driven system includes a stepping motor, an output device, and a belt and pulley system operably coupling the stepping motor with the output device to impart rotation therebetween. The belt and pulley system includes an input pinion engaged with the stepping motor, an output pinion engaged with the output device, and a timing belt. The timing belt is disposed about the input and output pinions, inhibits elongation, and defines a plurality of spaced-apart grooves on an inwardly-facing surface thereof that are wider than the teeth of the pinions and are configured to receive the teeth of the pinions in meshed engagement therewith. As a result, a gap is defined within each groove. The gaps permit backlash of the timing belt in response to changes in a rotational speed input to the belt and pulley system from the stepping motor, thereby inhibiting loss of control.
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Citations
12 Claims
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1. A stepping motor-driven system, comprising:
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a stepping motor including a rotor configured to rotate in response to driving of the stepping motor, the stepping motor defining at least one speed trap corresponding to a resonance condition, the stepping motor configured to drive the rotor according to a start/stop profile in order to avoid the at least one speed trap; an output device including a drive shaft; and a belt and pulley system operably coupling the rotor of the stepping motor with the drive shaft of the output device such that rotation of the rotor effects rotation of the drive shaft, the belt and pulley system including; an input pinion engaged with the rotor of the stepping motor, the input pinion defining a plurality of spaced-apart, annularly arranged first teeth disposed on an outer surface of the input pinion, each tooth defining a first width; an output pinion engaged with the drive shaft of the output device, the output pinion defining a plurality of spaced-apart, annularly arranged second teeth disposed on an outer surface of the output pinion, each second tooth defining a second width equal to the first width; and a timing belt, disposed about the input pinion towards a first end of the timing belt and disposed about the output pinion towards a second end of the timing belt, the timing belt configured to inhibit elongation and defining a plurality of spaced-apart grooves on an inwardly-facing surface thereof, each groove defining a third width greater than each of the first and second widths, wherein the first and second teeth of the input and output pinions are disposed in meshed engagement within the grooves of the timing belt such that, as a result of the third width being greater than each of the first and second widths, a gap is defined within each groove, the gaps permitting backlash of the timing belt in response to changes in a rotational speed input to the belt and pulley system from the stepping motor, wherein, in accordance with the start/stop profile, the stepping motor is configured to switch from an accelerating mode to a constant-speed mode prior to reaching the resonance condition, thereby avoiding the at least one speed trap and inhibiting loss of control, wherein switching to the constant-speed mode enables backlash of the timing belt, thereby dissipating energy built up in the timing belt during operation of the stepping motor in the accelerating mode, and wherein, in accordance with the start/stop profile, the stepping motor is configured to switch back to the accelerating mode after dissipating the energy built up in the timing belt. - View Dependent Claims (2, 3, 4, 6, 7, 8, 9, 10, 11, 12)
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5. The stepping motor-driven system, wherein the set of rollers inhibits transverse motion of the timing belt in response to the transverse waves and, as a result, energy is dissipated from the timing belt via the backlash of the timing belt.
Specification