High-power cordless, hand-held power tool including a brushless direct current motor

Patent metadata

Field	Value
Publication number	US-11673248-B2
Application number	US-202217809467-A
Country	US
Kind code	B2
Filing date	Jun 28, 2022
Priority date	Nov 13, 2012
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

A cordless, hand-held power tool, such as a hammer drill/driver, an impact driver, an impact wrench, etc., that includes a brushless direct current (“BLDC”) motor. Each of the hand-held power tool includes a removable and rechargeable battery pack, electronics, and a BLDC motor that have been designed and balanced to produce high-performance-capable (e.g., high-power, high-current, high-torque) hand-held power tool. The hand-held power tool is capable of delivering high instantaneous (i.e., short duration) current to the BLDC motor for short-duration high power operation and high continuous (i.e., long duration) current to the BLDC motor for long duration high power operation. Additionally, the short and long duration power is capable of being provided in a smaller (in size) and lighter (in weight) power tool.

First claim

What is claimed is:

1. A power tool comprising:
a battery pack interface configured to receive a battery pack that is removably coupled to a housing of the power tool, the battery pack having a nominal voltage of 18 Volts to 36 Volts;
a brushless direct-current (“BLDC”) motor, the BLDC motor having an outer diameter of 50 millimeters to 80 millimeters and a weight of 336.5 grams to 720 grams;
a switching array including a plurality of switching field effect transistors (“FETs”) electrically connected between the BLDC motor and the battery pack interface, the plurality of switching FETs configured for controlling application of power to the BLDC motor, wherein the plurality of switching FETs have a drain-to-source resistance of below 3 milli-Ohms;
a controller configured to generate a control signal to selectively enable and disable the plurality of switching FETs in the switching array to drive the BLDC motor with power provided from the battery pack; and
an output shaft coupled to the BLDC motor to provide an output of the power tool, wherein when powered by the battery pack
the power tool is configured to produce a maximum short-duration power output of at least 600 Watts and an average long-duration power output, throughout a discharge cycle of the battery pack, of at least 400 Watts, and
a ratio of Ampere-hours (Ah) discharged by the battery pack for providing the average long-duration power output to length of run in seconds (s) of the average long-duration power output is at least 0.0072Ah:1 s.

2. The power tool of claim 1 , wherein a stator length of the BLDC motor is between 22 millimeters and 35 millimeters.

3. The power tool of claim 1 , wherein a stator weight of the BLDC motor is between 195 grams and 400 grams.

4. The power tool of claim 1 , wherein the maximum short-duration power output refers to a power output during a duration of between 20 seconds and 25 seconds.

5. The power tool of claim 1 , wherein a ratio of the maximum short-duration power output to the outer diameter of the BLDC motor is at least 10 Watts:1 millimeter.

6. The power tool of claim 1 , wherein a ratio of the average long-duration power output of the power tool to the outer diameter of the BLDC motor is at least 5 Watts:1 millimeter.

7. The power tool of claim 1 , wherein an energy consumed by the power tool for providing the average long duration power output is at least 30 Watt Hours.

8. The power tool of claim 1 , wherein a rotor weight of the BLDC motor is between 142 grams and 300 grams.

9. The power tool of claim 1 , wherein a rotor length of the BLDC motor is between 24 millimeters and 34 millimeters.

10. A power tool comprising:
a battery pack interface configured to receive a battery pack that is removably coupled to a housing of the power tool, the battery pack having a nominal voltage of 18 Volts to 36 Volts;
a brushless direct-current (“BLDC”) motor, the BLDC motor having an outer diameter of 50 millimeters to 80 millimeters and a weight of 336.5 grams to 720 grams;
a switching array including a plurality of switching field effect transistors (“FETs”) electrically connected between the BLDC motor and the battery pack interface, the plurality of switching FETs configured for controlling application of power to the BLDC motor, wherein the plurality of switching FETs have a drain-to-source resistance of below 3 milli-Ohms;
a controller configured to generate a control signal to selectively enable and disable the plurality of switching FETs in the switching array to drive the BLDC motor with power provided from the battery pack; and
an output shaft coupled to the BLDC motor to provide an output of the power tool, wherein when powered by the battery pack
the power tool is configured to produce a maximum short-duration power output of at least 600 Watts and an average long-duration power output, throughout a discharge cycle of the battery pack, of at least 400 Watts, and
an energy consumed by the power tool for providing the average long duration power output is at least 30 Watt Hours.

11. The power tool of claim 10 , wherein a stator length of the BLDC motor is between 22 millimeters and 35 millimeters.

12. The power tool of claim 10 , wherein a stator weight of the BLDC motor is between 195 grams and 400 grams.

13. The power tool of claim 10 , wherein the maximum short-duration power output refers to a power output during a duration of at least between 20 seconds and 25 seconds.

14. The power tool of claim 10 , wherein a ratio of the maximum short-duration power output to the outer diameter of the BLDC motor is at least 10 Watts:1.

15. The power tool of claim 10 , wherein a ratio of the average long-duration power output of the power tool to the outer diameter of the BLDC motor is at least 5 Watts:1.

16. The power tool of claim 10 , wherein a rotor weight of the BLDC motor is between 142 grams and 300 grams.

17. The power tool of claim 10 , wherein a rotor length of the BLDC motor is between 24 millimeters and 34 millimeters.

18. A power tool comprising:
a battery pack interface configured to receive a battery pack that is removably coupled to a housing of the power tool, the battery pack having a nominal voltage of 18 Volts to 36 Volts;
a brushless direct-current (“BLDC”) motor, the BLDC motor having an outer diameter of 50 millimeters to 80 millimeters and a weight of 336.5 grams to 720 grams;
a switching array including a plurality of switching field effect transistors (“FETs”) electrically connected between the BLDC motor and the battery pack interface, the plurality of switching FETs configured for controlling application of power to the BLDC motor, wherein the plurality of switching FETs have a drain-to-source resistance of below 3 milli-Ohms;
a controller configured to generate a control signal to selectively enable and disable the plurality of switching FETs in the switching array to drive the BLDC motor with power provided from the battery pack; and
an output shaft coupled to the BLDC motor to provide an output of the hand held power tool, wherein when powered by the battery pack the power tool is configured to produce a maximum short-duration power output of at least 600 Watts and an average long-duration power output, throughout a discharge cycle of the battery pack, of at least 400 Watts,
wherein a rotor weight of the BLDC motor is between 142 grams and 300 grams.

19. The power tool of claim 18 , wherein the maximum short-duration power output refers to a power output during a duration of between 20 seconds and 25 seconds.

20. The power tool of claim 18 , wherein a ratio of the maximum short-duration power output to the outer diameter of the BLDC motor is at least 10 Watts:1.

21. The power tool of claim 18 , wherein a ratio of the average long-duration power output of the power tool to the outer diameter of the BLDC motor is at least 5 Watts:1.

22. The power tool of claim 18 , wherein an energy consumed by the power tool for providing the average long duration power output is at least 30 Watt Hours.

23. The power tool of claim 18 , wherein a stator length of the BLDC motor is between 22 millimeters and 35 millimeters.

24. The power tool of claim 18 , wherein a stator weight of the BLDC motor is between 195 grams and 400 grams.

25. A power tool comprising:
a battery pack interface configured to receive a battery pack that is removably coupled to a housing of the power tool, the battery pack ha

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Verbrugge Brandon L
• Mergener Matthew J
• Wycklendt Matthew P
• Hessenberger Jeffrey C
• Grzybowski Dennis J

Classifications

• B25F5/02 Primary

  Construction of casings, bodies or handles {(B25F5/006, B25F5/008 take precedence)} · CPC title

• B25B21/02

  with means for imparting impact to screwdriver blade or nut socket · CPC title

• B25F5/00 Primary

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• B25F5/008

  Cooling means · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title