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US-20260128701-A1 - LAWN AND GARDEN POWER TOOL INCLUDING ELECTRIC MOTOR WITH TWO SELECTABLE POWER OUTPUTS

US20260128701A1US 20260128701 A1US20260128701 A1US 20260128701A1US-20260128701-A1

Abstract

A lawn and garden power tool can include a battery, an electric motor, a shaft driven by the motor, an implement drive by the shaft, and a controller. The motor can include a rotor and two stator cores. A first coil can be wound on the first stator core and a second coil can be wound on the second stator core. The controller can be configured to selectively cause the motor to operate in a first output mode in which the battery pack is electrically connected to the first coil and the second coil based on a first predetermined condition, and the first coil is electrically connected in series with the second coil; and selectively cause the motor to operate in a second output mode in which the battery pack is electrically disconnected from the second coil and electrically connected to the first coil based on a second predetermined condition.

Inventors

  • Toshiyuki Hasegawa

Assignees

  • HONDA MOTOR CO., LTD.

Dates

Publication Date
20260507
Application Date
20241105

Claims (20)

  1. 1 . A lawn and garden power tool, comprising: a battery; an electric motor including: a housing; a rotor supported by the housing and rotatable relative to the housing about a rotational axis; a first stator core fixed to the housing and located about the rotor; a first coil wound on the first stator core; a second stator core fixed to the housing, located about the rotor, and stacked relative to the first stator core along the rotational axis; a second coil wound on the second stator core; a shaft connected to and driven by the rotor; an implement driven by the shaft; and a controller in electrical communication with the battery and configured to: if the controller receives a first operational request, cause the motor to operate in a first output mode in which the battery pack is electrically connected to the first coil and the second coil, and the first coil is electrically connected in series with the second coil; and if the controller receives a second operational request that is different from the first operational request, cause the motor to operate in a second output mode in which the battery pack is electrically disconnected from the second coil and electrically connected to the first coil.
  2. 2 . The lawn and garden power tool according to claim 1 , wherein the controller is configured to: cause the motor to operate in the first output mode if: the controller receives a third operational request that is different from the first operational request and the second operational request; and a temperature of the battery is less than or equal to a predetermined threshold; and cause the motor to operate in the second output mode if: the controller receives the third operational request; and the temperature of the battery is greater than the predetermined threshold.
  3. 3 . The lawn and garden power tool according to claim 2 , further comprising: a switch in electrical communication with each of the battery and the controller, wherein the controller is configured to: signal the switch to connect the battery, the first coil, and the second coil in series if the controller receives the first operational request; and signal the switch to disconnect the battery from the second coil and electrically connect the battery to the first coil if the controller receives the second operational request.
  4. 4 . The lawn and garden power tool according to claim 3 , wherein the controller is configured to: signal the switch to connect the battery, the first coil, and the second coil in series if: the controller receives the third operational request that is different from the first operational request and the second operational request; and the temperature of the battery is less than or equal to the predetermined threshold; signal the switch to disconnect the battery from the second coil and electrically connect the battery to the first coil if: the controller receives the third operational request; and the temperature is greater than the predetermined threshold.
  5. 5 . The lawn and garden power tool system according to claim 4 , wherein the switch includes a plurality of single-pole double-throw relays.
  6. 6 . The lawn and garden power tool according to claim 5 , further comprising: a motor driver in electrical communication with the controller and configured to receive a DC power input from the battery, convert the DC power to AC power, and output the AC power to the switch; and a relay driver in electrical communication with the controller and the switch, wherein the controller is configured to vary a relay signal based on the temperature and a received one of the first operational request, the second operational request, and the third operational request, and the relay driver is configured to cause the switch to selectively connect and disconnect electrical communication between the battery and the second coil based on the relay signal received from the controller.
  7. 7 . The lawn and garden power tool according to claim 2 , further comprising: a user input configured to permit a user of the power tool to select one of the first operational request, the second operational request, and the third operational request.
  8. 8 . The lawn and garden power tool according to claim 1 , wherein the implement is a cutting blade.
  9. 9 . The lawn and garden power tool according to claim 8 , further comprising: a mower deck including a cutting chamber; and a plurality of wheels mounted on the mower deck, wherein the cutting blade is mounted onto the shaft and rotatable inside the cutting chamber.
  10. 10 . The lawn and garden power tool according to claim 9 , further comprising: a handle connected to and extending away from the mower deck; and a user input mounted on the handle and configured to permit the user to select any one of the first operational request, the second operational request, and a third operational request that is different from the first operational request and the second operational request, wherein the controller is configured to: cause the motor to operate in the first output mode if: the controller receives the third operational request; and a temperature of the battery is less than or equal to a predetermined threshold; and cause the motor to operate in the second output mode if: the controller receives the third operational request; and the temperature of the battery is greater than the predetermined threshold.
  11. 11 . A lawn and garden power tool, comprising: a battery; an electric motor including: a housing; a rotor supported by the housing and rotatable relative to the housing about a rotational axis; a first stator core fixed to the housing and located about the rotor; a first coil wound on the first stator core; a second stator core fixed to the housing, located about the rotor, and stacked relative to the first stator core along the rotational axis; a second coil wound on the second stator core; a shaft connected to and driven by the rotor and configured to drive an implement; a user input configured to output a selected one of a first operational request, a second operational request, and a third operational request; and a controller in electrical communication with the battery and configured to: if the controller receives the first operational request, cause the electric motor to operate in a first output mode in which the battery pack is electrically connected in to the first coil and the second coil, and the first coil is electrically connected in series with the second coil; if the controller receives the second operational request that is different from the first operational request, cause the electric motor to operate in a second output mode in which the battery pack is electrically disconnected from the second coil and electrically connected to the first coil; and if the controller receives the third operational request that is different from the first operational request and the second operational request, cause the electric motor to: operate in the first output mode if a sensed variable has a first relationship to a predetermined threshold; and operate in the second output mode if the sensed variable has a second relationship to the predetermined threshold, the second relationship is different from the first relationship.
  12. 12 . The lawn and garden power tool according to claim 11 , further comprising: a motor driver electrically connected to the battery and the controller, and configured to convert a DC power input received from the battery into three-phase back electromotive force (Back EMF) or AC power; and a switch electrically connected to each of the controller, the motor driver, and the electric motor, and configured to receive the AC power from the motor driver and selectively distribute the AC power to the electric motor such that the electric motor operates in one of the first output mode and the second output mode, wherein the sensed variable is a temperature of the battery, the first relationship includes the temperature being less than or equal to the predetermined threshold, and the second relationship includes the temperature being greater than the predetermined threshold.
  13. 13 . The lawn and garden power tool according to claim 11 , wherein the electric motor is a three-phase AC electric or DC brushless motor, the first coil includes a plurality of first windings wired in a wye configuration, the second coil includes a plurality of second windings wired in a wye configuration, and the switch includes: a first relay configured to selectively connect a respective one of the first windings in series with a respective one of the second windings, a second relay configured to selectively connect a respective one of the first windings in series with a respective one of the second windings, and a third relay configured to selectively connect a respective one of the first windings in series with a respective one of the second windings.
  14. 14 . The lawn and garden power tool according to claim 11 , wherein the electric motor is a three-phase AC electric or DC brushless motor, the first coil includes a plurality of first windings wired in a delta configuration, the second coil includes a plurality of first windings wired in a delta configuration and the switch includes a first relay, a second relay, a third relay and a fourth relay, the first coil is connected in series with second coil if all of the first relay, the second relay, the third relay, and the fourth relay are energized, and the second coil is electrically disconnected from the first coil if all of the first relay, the second relay, the third relay, and the fourth relay are de-energized.
  15. 15 . The lawn and garden power tool system according to claim 14 , wherein each of the first relay and the second relay is a single-pole, double-throw relay, and each of the third relay and the fourth relay is a single-pole, single-throw relay.
  16. 16 . A lawn and garden power tool, comprising: a battery; an electric motor including: a housing; a rotor located adjacent the housing and rotatable relative to the housing about a rotational axis; a first stator core located about the rotor; a first coil wound on the first stator; a second stator core located about the rotor, and stacked relative to the first stator core along the rotational axis such that the first stator is located at a first position along the rotational axis and the second stator core is located at a second position different from the first position along with rotational axis; a second coil wound on the second stator core; a shaft connected to and driven by the rotor and configured to drive an implement; and a controller in electrical communication with the battery and configured to: if the controller is subject to a first operational request, cause the motor to operate in a high power mode in which the battery pack is electrically connected to the first coil and the second coil; and if the controller is subject to a second operational request that is different from the first operational request, cause the motor to operate in a low power mode in which the battery pack is electrically disconnected from the second coil and electrically connected to the first coil.
  17. 17 . The lawn and garden power tool according to claim 16 , wherein a power rating for the first coil is different than a power rating for the second coil.
  18. 18 . The lawn and garden power tool according to claim 16 , wherein the shaft is connected to the implement and the implement is configured as a lawn mowing blade.
  19. 19 . The lawn and garden power tool according to claim 16 , further comprising: a sensor, wherein the first operational request and second operational request are determined based on information received from the sensor.
  20. 20 . The lawn and garden power tool according to claim 19 , wherein the sensor is configured to determine one of: a temperature of the electric motor; an atmospheric temperature; a lawn dampness; and a lawn length.

Description

BACKGROUND The disclosed subject matter relates to an electrically powered lawn and garden power tool. More particularly, the disclosed subject matter relates to a battery-powered lawn and garden tool that includes an electric motor that has two selectable power outputs. Power equipment (also referred to as power tools) can be used to remove snow, generate electric power, pump water, or manicure vegetation of a landscaped area. The power equipment can be a handheld device, or supported by at least one wheel. When used to manicure the vegetation of a landscaped area, the power equipment can include a cutting implement such as a rotating spool of nylon string, a rotary blade, or a reciprocating blade. The cutting implement can be driven by an internal combustion engine or an electric motor. When used to remove snow, the power equipment can include an auger that is driven by the engine or electric motor. SUMMARY Some embodiments are directed to a lawn and garden power tool that can include a battery, an electric motor, a shaft, an implement and a controller. The electric motor can include a housing, a rotor, a first stator core, a first coil, a second stator core and a second coil. The rotor can be supported by the housing and rotatable relative to the housing about a rotational axis. The first stator core and the second stator core can be fixed to the housing and located about the rotor. The second stator core can be stacked relative to the first stator core along the rotational axis. The first coil can be wound on the first stator core and the second coil can be wound on the second stator core. The shaft can be connected to and driven by the rotor, and the implement can be driven by the shaft. The controller can be in electrical communication with the battery and configured to: if the controller receives a first operational request, cause the motor to operate in a first output mode in which the battery pack is electrically connected to the first coil and the second coil, and the first coil is electrically connected in series with the second coil; and if the controller receives a second operational request that is different from the first operational request, cause the motor to operate in a second output mode in which the battery pack is electrically disconnected from the second coil and electrically connected to the first coil. Some embodiments are directed to a lawn and garden power tool that can include a battery, an electric motor, a shaft, a user input and a controller. The electric motor can include a housing, a rotor, a first stator core, a first coil, a second stator core and a second coil. The rotor can be supported by the housing and rotatable relative to the housing about a rotational axis. The first stator core and the second stator core can be fixed to the housing and located about the rotor. The second stator core can be stacked relative to the first stator core along the rotational axis. The first coil can be wound on the first stator core and the second coil can be wound on the second stator core. The shaft can be connected to and driven by the rotor and configured to drive an implement. The user input can be configured to output a selected one of a first operational request, a second operational request, and a third operational request. The controller can be in electrical communication with the battery and configured to: if the controller receives the first operational request, cause the electric motor to operate in a first output mode in which the battery pack is electrically connected in to the first coil and the second coil, and the first coil is electrically connected in series with the second coil; if the controller receives the second operational request that is different from the first operational request, cause the electric motor to operate in a second output mode in which the battery pack is electrically disconnected from the second coil and electrically connected to the first coil; and if the controller receives the third operational request that is different from the first operational request and the second operational request, cause the electric motor to: operate in the first output mode if a sensed variable has a first relationship to a predetermined threshold; and operate in the second output mode if the sensed variable has a second relationship to the predetermined threshold, the second relationship is different from the first relationship. Some embodiments are directed to a lawn and garden power tool that can include a battery, an electric motor, a shaft and a controller. The electric motor can include a housing, a rotor, a first stator core, a first coil, a second stator core and a second coil. The rotor can be located adjacent the housing and rotatable relative to the housing about a rotational axis. The first stator core and the second stator core can be located about the rotor, and the second stator core can be stacked relative to the first stator core along the rotational