GB2583796A - Motor terminals facing gear case in a power tool - Google Patents
Motor terminals facing gear case in a power tool Download PDFInfo
- Publication number
- GB2583796A GB2583796A GB1916565.3A GB201916565A GB2583796A GB 2583796 A GB2583796 A GB 2583796A GB 201916565 A GB201916565 A GB 201916565A GB 2583796 A GB2583796 A GB 2583796A
- Authority
- GB
- United Kingdom
- Prior art keywords
- motor
- terminals
- power tool
- gear case
- shows
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/22—Auxiliary parts of casings not covered by groups H02K5/06-H02K5/20, e.g. shaped to form connection boxes or terminal boxes
- H02K5/225—Terminal boxes or connection arrangements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B23/00—Portable grinding machines, e.g. hand-guided; Accessories therefor
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/46—Fastening of windings on the stator or rotor structure
- H02K3/52—Fastening salient pole windings or connections thereto
- H02K3/521—Fastening salient pole windings or connections thereto applicable to stators only
- H02K3/522—Fastening salient pole windings or connections thereto applicable to stators only for generally annular cores with salient poles
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/14—Structural association with mechanical loads, e.g. with hand-held machine tools or fans
- H02K7/145—Hand-held machine tool
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
- H02K7/116—Structural association with clutches, brakes, gears, pulleys or mechanical starters with gears
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Mechanical Engineering (AREA)
- Motor Or Generator Frames (AREA)
- Insulation, Fastening Of Motor, Generator Windings (AREA)
Abstract
A power tool which comprises an elongated handle including a motor housing and a handle portion, and a gear house disposed at a front end of the motor housing. A power module is provided within the elongated handle. An electric motor is provided within the motor housing, the motor including a plurality of terminals, the terminals being positioned proximate the gear case. The power tool may be an angle grinder. By placing the electrical connections adjacent the gearbox, they may be more shielded from external contamination drawn in with the motor cooling air, reducing metal contamination and abrasion and tracking or electrical shorting between the terminals. Having the terminals at the opposite end to the power module may allow for easier encapsulation of the terminals by means of dipping.
Description
Motor Terminals Facing Gear Case in a Power Tool The present invention relates to a power tool such as an angle grinder. Typically, in such power tools, a gear case is provided that includes the transmission gear, and an elongated handle is provided rearward of the gear case that includes a motor housing, a handle portion, and a power receptacle. A motor is disposed in a motor housing with motor terminals facing the handle portion. The handle portion in many designs includes power and/or control modules that regulate supply of electric power to the motor. A series of power lines are routed from the power module to the motor terminals.
Power tools such as small angle grinders (SAGs) are vulnerable to metal contamination abrasion and tracking (electrical shorting) due to their applications and environments. This contamination is "ingested" into the tool with the air flow required for cooling and creates reliability issues from abrasion and tracking due to its abrasiveness and conductivity. Brushless motors in such power tools are especially susceptible because they require wire routing along the end of the stator to connect the numerous coils and the have additional lead wires for addition phases vs a typical universal motor. Accordingly, all termination points & wire connections must be fully insulated/sealed to prevent contamination ingress & tracking against the exposed wires. In some designs, layers of shrink tube and/or epoxy are applied over all exposed metal. This is a very timely and costly process and has a high risk for exposed metal that could lead to failure.
Additionally, since the wire routing and termination points are on the upstream end of the motor, the contamination has a tendency to build up on the flat surfaces and restricted areas due to the large connections. These large connections also impede airflow in a critical area where we must maintain a small girth (gripping surface) and also house the rear bearing and sense system.
Accordingly, there is provided a power tool according to claim 1.
Two embodiments of the present invention will now be described with reference to the accompanying drawings of which: Figurel shows a side view of a known design of a power tool such as an angle grinder including a motor with terminals facing the handle portion; Figure 2 shows an axial view of the end of the motor of Figure 1 facing the handle portion; Figure 3 shows perspective view of a motor including shrink tubes around the terminals to prevent tracking to the stator lamination stack; Figure 4 shows a side view of a power tool with motor terminals placed in front of the motor proximate the gear case; Figure 5 shows an axial view of the front of the motor of Figure 4 facing the gear case; Figure 6 shows a perspective view of the motor including a motor terminal according to a first embodiment; Figure 7 shows a side view of the motor with the motor terminal of Figure 6; Figure 8 shows a perspective view of the motor including a motor terminal according to a second embodiment; Figure 9 shows a side view of the motor with the motor terminal of Figure 8; Figure 10 shows a perspective view of the motor including a motor terminal according to a third embodiment; Figure 11 shows a side view of the motor with the motor terminal of Figure 10; Figure 12 shows a perspective view of the power tool showing the rear of the motor housing; and Figure 13 shows a perspective view of the power tool showing the front of the motor housing.
These figures are described here in detail.
Figurel shows a side view of a known design of a power tool such as an angle grinder including a motor with terminals facing the handle portion. Figure 2 shows an axial view of the end of the motor of Figure 1 facing the handle portion.
Figure 3 shows perspective view of a motor including shrink tubes around the terminals to prevent tracking to the stator lamination stack. For the reasons discussed above, this arrangement encounters problems with airflow restriction, tracking risk, and difficulty in insulation protection.
Figure 4 shows a side view of a power tool with motor terminals placed in front of the motor proximate the gear case. Figure 5 shows an axial view of the front of the motor of Figure 4 facing the gear case. The mating area between the motor housing and the gear case in most angle grinders has a larger diameter to allow for disposition of the motor fan and/or baffle. This area has access clearance that is not needed for airflow and typically walled off with ribs. In an embodiment, to avoid the problems discussed above related to airflow restriction, tracking risk, and difficulty in insulation protection, the lead wires are terminated proximate the mating area between the motor housing and the gear case. In an embodiment, the stator terminals allow the lead wire to attach in a way that allows the existing lead wire to be routed past or along the stator lamination stack.
Figure 6 shows a perspective view of the motor including a motor terminal according to a first embodiment. Figure 7 shows a side view of the motor with the motor terminal of Figure 6. In this embodiment, the terminals are provided with radially-outward projecting portions that receive the ends of lead wires therein. Specifically, each terminal includes a planar portion that is received within a receiving pocket of the stator end insulator and a radially projecting portion that extends from the planar portion approximately perpendicularly. The lead wires exit the front of the stator facing the gear case, are routed along the outer surface of the stator lamination stack, and are connected to the power module within the handle portion. The end insulators of the stator may be provided with wire traps to route the lead wires.
Figure 8 shows a perspective view of the motor including a motor terminal according to a second embodiment. Figure 9 shows a side view of the motor with the motor terminal of Figure 8. In this embodiment, the terminals are axially arranged. Specifically, each terminal includes a planar portion that is received within a receiving pocket of the stator end insulator and a lead wire receiving portion that extends from the planar portion approximately axially. The wires are clamped within the wire reiving portion, run along the terminal, and are routed along the outer surface of the stator lamination stack.
Figure 10 shows a perspective view of the motor including a motor terminal according to a third embodiment. Figure 11 shows a side view of the motor with the motor terminal of Figure 10. In this embodiment, the motor terminal includes a main radially-oriented portion that is attached to the stator lamination stack, and a wire receiving portion that extends axially from the main portion to receive the end of the lead wire.
Having the exposed connections on the front of the stator without the lead wires reward allow for the stator to be dipped, covering all critical areas with tracking/abrasion protection in one application. The manufacturing method would significantly reduce steps & cost. Further, no terminals are provided in areas where contamination builds and is forced into openings. As shown in Figure 12, wire cross section is much smaller than the terminal tower, support structure and double layer of shrink tube, resulting in lower airflow restriction. Also, as shown in Figure 13, the front of the stator has extra space which could house additional ribbing to better protect/ close off the electrical connections.
Claims (1)
- Claims: 1. A power tool comprising: an elongated handle including a motor housing and a handle portion; a gear house disposed at a front end of the motor housing; an electric motor provided within the motor housing, the motor including a plurality of terminals; and a power module provided within the elongated handle, characterized in that the plurality of terminals are provided proximate the gear case.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1916565.3A GB2583796A (en) | 2019-11-15 | 2019-11-15 | Motor terminals facing gear case in a power tool |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1916565.3A GB2583796A (en) | 2019-11-15 | 2019-11-15 | Motor terminals facing gear case in a power tool |
Publications (2)
Publication Number | Publication Date |
---|---|
GB201916565D0 GB201916565D0 (en) | 2020-01-01 |
GB2583796A true GB2583796A (en) | 2020-11-11 |
Family
ID=69063266
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1916565.3A Withdrawn GB2583796A (en) | 2019-11-15 | 2019-11-15 | Motor terminals facing gear case in a power tool |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2583796A (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150364972A1 (en) * | 2013-04-04 | 2015-12-17 | Makita Corporation | Angle tool and electric tool |
WO2016192003A1 (en) * | 2015-06-01 | 2016-12-08 | Ac (Macao Commercial Offshore) Limited | Brushless can motor |
EP3187309A1 (en) * | 2014-08-29 | 2017-07-05 | Hitachi Koki Co., Ltd. | Electric working machine |
US20190280560A1 (en) * | 2015-02-04 | 2019-09-12 | Makita Corporation | Power tool |
-
2019
- 2019-11-15 GB GB1916565.3A patent/GB2583796A/en not_active Withdrawn
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150364972A1 (en) * | 2013-04-04 | 2015-12-17 | Makita Corporation | Angle tool and electric tool |
EP3187309A1 (en) * | 2014-08-29 | 2017-07-05 | Hitachi Koki Co., Ltd. | Electric working machine |
US20190280560A1 (en) * | 2015-02-04 | 2019-09-12 | Makita Corporation | Power tool |
WO2016192003A1 (en) * | 2015-06-01 | 2016-12-08 | Ac (Macao Commercial Offshore) Limited | Brushless can motor |
Also Published As
Publication number | Publication date |
---|---|
GB201916565D0 (en) | 2020-01-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
AU2022200281B2 (en) | Motor assembly for driving a pump or rotary device, having power plane with multi-layer power and control printed circuit board assembly | |
US6177740B1 (en) | Integrated motor and motor drive unit | |
DE112013000856B4 (en) | Mechanically and electrically integrated module | |
US8926360B2 (en) | Active cooling of electrical connectors | |
US9825509B2 (en) | Rotating electrical machine | |
US8299662B2 (en) | Motor connecting box and converter motor | |
US10468935B2 (en) | Motor | |
US20080018192A1 (en) | Permanent magnet motor | |
US8648507B2 (en) | Stator assembly including a terminal block for an electric machine | |
US9608492B2 (en) | Rotating electrical machine | |
US10530221B2 (en) | Cooling structure integrated with electric motor and controller | |
CN110858747B (en) | Electronic device for an electric motor of a motor vehicle | |
EP3223407B1 (en) | Ac generator for vehicles | |
US20140021833A1 (en) | Motor unit | |
GB2583796A (en) | Motor terminals facing gear case in a power tool | |
JP5420040B1 (en) | Rotating electric machine | |
US7880350B2 (en) | Multi phase generator arrangement | |
US20220247108A1 (en) | Assembled electrical cable, method for assembling an electrical cable, and electrical plug connection | |
US9431867B2 (en) | Rotating electrical machine | |
US10958140B2 (en) | Motor | |
JP2012196018A (en) | Wiring structure of three-phase motor | |
CN213959846U (en) | High temperature resistant three-phase asynchronous machine | |
US20240213848A1 (en) | Electric fan drive of a motor vehicle and fan module | |
DE102012001389A1 (en) | Transmission with a central housing part | |
CN111130273B (en) | Distributed coil motor, compressor with distributed coil motor and air conditioning system with distributed coil motor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |