RING GEARS CONFIGURED TO ENCASE IN-LINE TORQUE TRANSDUCERS FOR POWER TOOLS

• US 20140011621A1
• Filed: 03/31/2011
• Published: 01/09/2014
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Ingersoll-Rand Industrial U.S., Inc. (Ingersoll Rand, Inc.)
• Original Assignee: Ingersoll-Rand Company (Trane Technologies plc)
• Inventors: Steckel, John Paul, Cooper, Timothy Richard, Becker, Daniel Jay, Albert, Gregory Paul
• Granted Patent: US 9,212,725 B2
• Time in Patent Office: Days
• US Class Current: 475/149
• CPC Class Codes: B25B 21/00 Portable power-driven screw or nut setting or loosening tools; details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00; for mounting or dismounting wheels B60B29/006; Attachments for drilling apparatus serving the same purpose machines B23P19/06
• CPC Class Codes: B25B 23/14 Arrangement of torque limiters or torque indicators in wrenches or screwdrivers couplings for transmitting rotation or clutches F16D; devices for measuring torque per se G01L
• CPC Class Codes: B25B 23/147 specially adapted for electrically operated wrenches or screwdrivers
• CPC Class Codes: B25F 5/001 Gearings, speed selectors, clutches or the like specially adapted for rotary tools
• CPC Class Codes: F16H 1/28 with gears having orbital motion

Abstract

Ring gears with a cylindrical ring gear body having a wall with a longitudinal length extending between opposing first and second ends, the wall having an outer surface and an inner surface. The inner surface has a first portion that extends a first sub-length of the ring gear body and a longitudinally spaced apart second portion that extends a second sub-length of the ring gear body. The first portion extends from the first end of the ring gear inward and the second portion extends from the second end of the ring gear inward. The inner surface of the first portion comprises a plurality of longitudinally extending splines and the inner surface of the second portion is devoid of the splines of the first portion.

Claims

1. A ring gear, comprising:

a cylindrical ring gear body having a wall with a longitudinal length extending between opposing first and second ends, the wall having an outer surface and an inner surface, wherein the inner surface has a first portion that extends a first sub-length of the ring gear body and a longitudinally spaced apart second portion that extends a second sub-length of the ring gear body, wherein the first portion extends from the first end of the ring gear inward and the second portion extends from the second end of the ring gear inward, wherein the inner surface of the first portion comprises a plurality of longitudinally extending splines and the inner surface of the second portion is devoid of the splines of the first portion.

2. The ring gear of claim 1, wherein the ring gear body inner surface further comprises a circumferentially extending rim between the first and second portions.

3. The ring gear of claim 1, wherein the inner surface of the second portion of the ring gear comprises at least one of:

(a) longitudinally extending slots;

(b) radially inward projecting, longitudinally extending rails;

or (c) at least one each of a longitudinally extending slot and a radially-inward projecting, longitudinally extending rail.

4. The ring gear of claim 1, wherein the second portion sub-length is less than the first portion sub-length.

5. The ring gear of claim 1, wherein the second portion has a smooth inner surface.

6. The ring gear of claim 1, wherein the second end of the wall has a thickness that is greater than the first end.

7. The ring gear of claim 1, wherein the second portion has a wall thickness that is greater than the first portion.

8. The ring gear of claim 7, wherein the wall has a substantially constant outer diameter.

9. The ring gear of claim 1, wherein the inner surface of the second portion of the ring gear comprises at least two circumferentially spaced apart longitudinally extending rails that project radially inward.

10. The ring gear of claim 1, wherein the inner surface includes a circumferentially extending rim positioned between the first and second portions, and wherein the second portion inner surface comprises two substantially diametrically opposed longitudinally extending rails that terminate proximate the rim.

11. The ring gear of claim 1, wherein the second portion is sized and configured to hold an outer wall of a disk shaped transducer to be flush or held just inward of the second end of the ring gear.

12. The ring gear of claim 1, wherein the first portion is sized and configured to surround first and second stage gears of a drive train for a power tool, and wherein the second portion is sized and configured to encase an outer wall of a disk shaped transducer.

13. The ring gear of claim 1, in combination with a disk-shaped torque transducer, wherein the disk-shaped torque transducer has a longitudinally extending outer wall with opposing first and second ends and a length therebetween, wherein the outer wall merges radially inward into a thin circular interior flat wall that surrounds a center hub defining an axially extending open channel, wherein the transducer outer wall length is the same or less than the sub-length of the second portion of the ring gear, and wherein the transducer outer wall resides encased in the second portion of the ring gear.

14. The ring gear and torque transducer of claim 13, wherein the ring gear second portion includes a plurality of longitudinally extending circumferentially spaced apart rails, wherein the transducer outer wall has a plurality of circumferentially spaced apart slots, and wherein the transducer slots matably engage the ring gear rails so that the transducer is held in a locked anti-rotational configuration with respect to the ring gear.

15. A power tool, comprising:

a motor having an outwardly extending rotor that defines a drive axis;

a drive train coupled to the rotor and configured to drive a tool output, the drive train comprising first and second stage gears and a ring gear with a wall having an inner surface with (i) a first segment having splines that engage the first and second stage gears and (ii) a spaced apart second segment that resides upstream of the first stage gears facing the motor; and

a disk-shaped torque transducer having an outer wall that radially merges into a thin flat interior wall having a center hub with an open channel that projects outward toward the motor with a hub center axis that is concentric with the drive axis, wherein the transducer outer wall resides encased inside the ring gear second segment in a locked anti-rotational configuration with respect to the ring gear.

16. The tool of claim 15, wherein the power tool is a cordless power tool, and wherein the transducer outer wall is held substantially flush with an end of the ring gear that faces the motor.

17. The tool of claim 15, wherein the ring gear comprises rails and the transducer outer wall comprises cooperating slots that slidably receive the rails to lock the transducer to the ring gear.

18. The tool of claim 15, wherein the ring gear inner surface further comprises a circumferentially extending rim positioned between the first and second segments so that the transducer abuts the rim when in position in the ring gear.

19. The tool of claim 15, further comprising a gearcase that surrounds the ring gear and a motor mount that holds the motor and attaches to the gearcase, wherein the ring gear is held inside the gearcase between the motor mount and a tapered end of the gearcase to have an axial float clearance on each end of the ring gear so that, during operation, the ring gear floats relative to the gearcase and motor mount.

20. The tool of claim 19, wherein the transducer center hub has external gear teeth that merges into a stepped wall portion proximate the thin flat center wall, wherein the motor mount comprises a transducer engaging segment with splines and a stepped segment, wherein the motor mount splines of the transducer engaging segment engage the hub external gear teeth and the stepped portion of the center hub matably engages the stepped segment of the motor mount to concentrically align the hub center axis with the drive axis, and wherein the motor rotor extends through a front portion of the center hub channel and attaches to a pinion that extends out of a rear portion of the center hub channel