GB2109489A - A power drive - Google Patents

A power drive Download PDF

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Publication number
GB2109489A
GB2109489A GB08230039A GB8230039A GB2109489A GB 2109489 A GB2109489 A GB 2109489A GB 08230039 A GB08230039 A GB 08230039A GB 8230039 A GB8230039 A GB 8230039A GB 2109489 A GB2109489 A GB 2109489A
Authority
GB
United Kingdom
Prior art keywords
motor
sun gear
gear
drive member
drive
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.)
Granted
Application number
GB08230039A
Other versions
GB2109489B (en
Inventor
Christopher John Dudden
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Air Compressors and Tools Ltd
Original Assignee
Desoutter Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Desoutter Ltd filed Critical Desoutter Ltd
Priority to GB08230039A priority Critical patent/GB2109489B/en
Publication of GB2109489A publication Critical patent/GB2109489A/en
Application granted granted Critical
Publication of GB2109489B publication Critical patent/GB2109489B/en
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
    • F16H3/02—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion
    • F16H3/08—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts
    • F16H3/10—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts with one or more one-way clutches as an essential feature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
    • F16H3/003—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion the gear-ratio being changed by inversion of torque direction
    • F16H3/005—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion the gear-ratio being changed by inversion of torque direction for gearings using gears having orbital motion

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Retarders (AREA)
  • Structure Of Transmissions (AREA)

Abstract

The power drive which is particularly for a power tool, comprises a reversible motor (10), an epicyclic gear box (13) and a drive member (19) rotatable by the motor through the gear box. The gear box comprises a sun gear (12), one or more planet gears (17) engaging with the sun gear and mounted on a planet carrier (15) which is fixed against rotation, and a ring gear (18) engaging with the planet gears. The sun gear is connected to the output shaft of the motor via a reduction gear box (14) and is connected to the drive member via a one-way clutch (22) so as to rotate the drive member in one direction at a first speed when the motor rotates in one direction. The ring gear is connected to the drive member via a one-way clutch (24) so as to rotate the drive member in said one direction at a lower speed when the motor rotates in an opposite direction. Hence, the speed of the drive member can be changed simply by reversing the direction of the motor. <IMAGE>

Description

SPECIFICATION A power drive This invention relates to a power drive and particularly but not exclusively to a power tool having such a power drive.
The invention, in one aspect, provides a power drive comprising a reversible motor, an epicyclic gear box and a drive member rotatable by the motor through the gear box, the gear box comprising a sun gear, one or more planet gears engaging with the sun gear and mounted on a planet carrier which is fixed against rotation, and a ring gear engaging with the planet gears, one of the sun gear and ring gear being connected to an output shaft of the motor and being connected to the drive member via a first one-way clutch so as to rotate the drive member in one direction at a first speed when the motor rotates in one direction, and the other of the sun gear and ring gear being connected to the drive member via a second one-way clutch so as to rotate the drive member in said one direction at a second speed when the motor rotates in an opposite direction.
Hence, the speed of the drive member can be changed simply by reversing the direction of the motor.
Advantageously, the sun gear is connected to the output shaft of the motor.
The motor may be a pneumatic hydraulic or electric motor.
A torque sensitive clutch may be provided to automatically reverse the direction of the motor.
The invention provides in another aspect, a power tool provided with a power drive according to the first aspect of the invention, the drive member being connected to or forming part of a tool holder of the power tool.
The invention will now be more particularly described with reference to the accompanying drawing, which is a sectional view of one embodiment of a power drive according to the invention.
Referring to the drawing, there is shown therein a power drive of a power tool, comprising a reversible electric, hydraulic or pneumatic motor 10 having an output shaft 1 The output shaft 11 is connected to a sun gear 12 of an epicyclic gear box 13 via a reduction gear box 1 4. A planet carrier 1 5 is fixed against rotation in housing 1 6 and carries three planet wheels 1 7 (only one shown) which are spaced angularly about the axis of the sun gear. The epicyclic gear box 14 also comprises a rotatable ring gear 1 8. An output drive member in the form of a work spindle 1 9 of the power tool is supported for rotation by bearings 20 and 21.One end of the work spindle 1 9 is provided with a screw-thread for receiving a tool holder (not shown) and the other end of the work spindle 1 9 has a blind bore which receives a ground parallel shaft portion at the end of the sun gear 12 remote from the motor 10. The ground parallel shaft portion of the sun gear engages with a first sprag clutch 22 which transmits rotation to the work spindle 19 directly from the sun gear 12 when the motor 10 rotates in one direction, the ratio of the gear box being 1:1 in this case.
The ring gear 1 8 is coupled to a sprag clutch carrier 23 which carries a second sprag clutch 24.
The clutch 24 transmits rotation of the ring gear 1 8 to the work spindle 1 9 when the motor rotates in an opposite direction. The gear ratio will be determined in this case by the number of teeth on the sun gear and the number of teeth on the ring gear and as the latter is greatsr than the former, the work spindle will rotate at a slower speed, but in the same direction as it does when the motor is rotating in said one direction due to the fact that the ring gear rotates in a direction opposite to that of the sun gear. Of course, when the motor rotates in said one direction the sprag clutch 24 releases its drive from the ring gear to the work spindle and when the motor rotates in said opposite direction the sprag clutch 22 releases its drive from the sun gear to the work spindle.
Hence, in order to change the speed of the work spindle, it is necessary only to reverse the direction of the motor 10.
Although, as described, the power drive is applied to a power tool, it can find other applications.
Moreover, the output shaft 11 of the motor 1 could be connected to the ring gear rather than the sun gear.
A torque sensitive clutch may be provided at the drive input to the sun gear in order to sense the torque and automatically reverse the direction of the motor at a predetermined level of torque.
This can be particularly useful for nut running power tools or the like. A torque sensitive clutch suitable for this purpose is described in our British Patent No. 1289056.
1. A power drive comprising a reversible motor, an epicyclic gear box and a drive member rotatable by the motor through the gear box, the gear box comprising a sun gear, one or more planet gears engaging with the sun gear and mounted on a planet carrier which is fixed against rotation, and a ring gear engaging with the planet gears, one of the sun gear and ring gear being connected to an output shaft of the motor and being connected to the drive member via a first one-way clutch so as to rotate the drive member in one direction at a first speed when the motor rotates in one direction, and the other of the sun gear and ring gear being connected to the drive member via a second one-way clutch so as to rotate the drive member in said one direction at a second speed when the motor rotates in an opposite direction.
2. A power drive as claimed in claim 1, wherein the sun gear is connected to the output shaft of the motor.
3. A power drive as claimed in claim 1 or claim 2, wherein the motor is a pneumatic motor.
4. A power drive as claimed in claim 1 or claim 2, wherein the motor is a hydraulic motor.
5. A power drive as claimed in claim 1 or 2,
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A power drive This invention relates to a power drive and particularly but not exclusively to a power tool having such a power drive. The invention, in one aspect, provides a power drive comprising a reversible motor, an epicyclic gear box and a drive member rotatable by the motor through the gear box, the gear box comprising a sun gear, one or more planet gears engaging with the sun gear and mounted on a planet carrier which is fixed against rotation, and a ring gear engaging with the planet gears, one of the sun gear and ring gear being connected to an output shaft of the motor and being connected to the drive member via a first one-way clutch so as to rotate the drive member in one direction at a first speed when the motor rotates in one direction, and the other of the sun gear and ring gear being connected to the drive member via a second one-way clutch so as to rotate the drive member in said one direction at a second speed when the motor rotates in an opposite direction. Hence, the speed of the drive member can be changed simply by reversing the direction of the motor. Advantageously, the sun gear is connected to the output shaft of the motor. The motor may be a pneumatic hydraulic or electric motor. A torque sensitive clutch may be provided to automatically reverse the direction of the motor. The invention provides in another aspect, a power tool provided with a power drive according to the first aspect of the invention, the drive member being connected to or forming part of a tool holder of the power tool. The invention will now be more particularly described with reference to the accompanying drawing, which is a sectional view of one embodiment of a power drive according to the invention. Referring to the drawing, there is shown therein a power drive of a power tool, comprising a reversible electric, hydraulic or pneumatic motor 10 having an output shaft 1 The output shaft 11 is connected to a sun gear 12 of an epicyclic gear box 13 via a reduction gear box 1 4. A planet carrier 1 5 is fixed against rotation in housing 1 6 and carries three planet wheels 1 7 (only one shown) which are spaced angularly about the axis of the sun gear. The epicyclic gear box 14 also comprises a rotatable ring gear 1 8. An output drive member in the form of a work spindle 1 9 of the power tool is supported for rotation by bearings 20 and 21.One end of the work spindle 1 9 is provided with a screw-thread for receiving a tool holder (not shown) and the other end of the work spindle 1 9 has a blind bore which receives a ground parallel shaft portion at the end of the sun gear 12 remote from the motor 10. The ground parallel shaft portion of the sun gear engages with a first sprag clutch 22 which transmits rotation to the work spindle 19 directly from the sun gear 12 when the motor 10 rotates in one direction, the ratio of the gear box being 1:1 in this case. The ring gear 1 8 is coupled to a sprag clutch carrier 23 which carries a second sprag clutch 24. The clutch 24 transmits rotation of the ring gear 1 8 to the work spindle 1 9 when the motor rotates in an opposite direction. The gear ratio will be determined in this case by the number of teeth on the sun gear and the number of teeth on the ring gear and as the latter is greatsr than the former, the work spindle will rotate at a slower speed, but in the same direction as it does when the motor is rotating in said one direction due to the fact that the ring gear rotates in a direction opposite to that of the sun gear. Of course, when the motor rotates in said one direction the sprag clutch 24 releases its drive from the ring gear to the work spindle and when the motor rotates in said opposite direction the sprag clutch 22 releases its drive from the sun gear to the work spindle. Hence, in order to change the speed of the work spindle, it is necessary only to reverse the direction of the motor 10. Although, as described, the power drive is applied to a power tool, it can find other applications. Moreover, the output shaft 11 of the motor 1 could be connected to the ring gear rather than the sun gear. A torque sensitive clutch may be provided at the drive input to the sun gear in order to sense the torque and automatically reverse the direction of the motor at a predetermined level of torque. This can be particularly useful for nut running power tools or the like. A torque sensitive clutch suitable for this purpose is described in our British Patent No. 1289056. CLAIMS
1. A power drive comprising a reversible motor, an epicyclic gear box and a drive member rotatable by the motor through the gear box, the gear box comprising a sun gear, one or more planet gears engaging with the sun gear and mounted on a planet carrier which is fixed against rotation, and a ring gear engaging with the planet gears, one of the sun gear and ring gear being connected to an output shaft of the motor and being connected to the drive member via a first one-way clutch so as to rotate the drive member in one direction at a first speed when the motor rotates in one direction, and the other of the sun gear and ring gear being connected to the drive member via a second one-way clutch so as to rotate the drive member in said one direction at a second speed when the motor rotates in an opposite direction.
2. A power drive as claimed in claim 1, wherein the sun gear is connected to the output shaft of the motor.
3. A power drive as claimed in claim 1 or claim 2, wherein the motor is a pneumatic motor.
4. A power drive as claimed in claim 1 or claim 2, wherein the motor is a hydraulic motor.
5. A power drive as claimed in claim 1 or 2, wherein the motor is an electric motor.
6. A power drive as claimed in any one of the preceding claims, wherein a torque sensitive clutch is provided to automatically reverse the direction of the motor.
7. A power drive, substantially as hereinbefore described with reference to and as shown in the accompanying drawing.
8. A power tool provided with a power drive according to any one of the preceding claims, the drive member being connected to or forming part of the tool holder of the tool.
GB08230039A 1981-10-22 1982-10-21 A power drive Expired GB2109489B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08230039A GB2109489B (en) 1981-10-22 1982-10-21 A power drive

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8131863 1981-10-22
GB08230039A GB2109489B (en) 1981-10-22 1982-10-21 A power drive

Publications (2)

Publication Number Publication Date
GB2109489A true GB2109489A (en) 1983-06-02
GB2109489B GB2109489B (en) 1985-02-06

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB08230039A Expired GB2109489B (en) 1981-10-22 1982-10-21 A power drive

Country Status (1)

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5531651A (en) * 1993-04-27 1996-07-02 Yang; Tai-Her Differential gear system using the change in input direction to control the output speed ratio
US5927691A (en) * 1994-06-07 1999-07-27 Harken, Inc. Four speed sailboat winch having separate second gear
CN1066251C (en) * 1998-10-19 2001-05-23 杨泰和 Differential gear system using input direction to control its gear ratio
DE102007033418A1 (en) * 2007-07-18 2009-01-22 Schaeffler Kg Planetary gear transmission, has drive unit, drive output units and free running units arranged such that drive torque is selectively transferred over one drive output unit depending upon drive rotation direction
US20100016121A1 (en) * 2007-01-16 2010-01-21 Tae-Jin Jung Transmission for motor and controlling device thereof
EP2685130A1 (en) * 2012-07-10 2014-01-15 Metabowerke GmbH Gearbox assembly
DE102014200720B3 (en) * 2014-01-16 2015-02-26 Schaeffler Technologies Gmbh & Co. Kg Planetary gear assembly
US20150276020A1 (en) * 2014-03-26 2015-10-01 Spg Co., Ltd. Two speed transmission
WO2020099178A1 (en) * 2018-11-12 2020-05-22 Atlas Copco Industrial Technique Ab Power tool and gear unit for such a power tool

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5531651A (en) * 1993-04-27 1996-07-02 Yang; Tai-Her Differential gear system using the change in input direction to control the output speed ratio
US5607369A (en) * 1993-04-27 1997-03-04 Yang; Tai-Her Differential motion gear system to control the speed ratio by means of the change of input direction
US5927691A (en) * 1994-06-07 1999-07-27 Harken, Inc. Four speed sailboat winch having separate second gear
CN1066251C (en) * 1998-10-19 2001-05-23 杨泰和 Differential gear system using input direction to control its gear ratio
US8449421B2 (en) * 2007-01-16 2013-05-28 Mbi Co. Ltd. Transmission for motor and controlling device thereof
US20100016121A1 (en) * 2007-01-16 2010-01-21 Tae-Jin Jung Transmission for motor and controlling device thereof
DE102007033418A1 (en) * 2007-07-18 2009-01-22 Schaeffler Kg Planetary gear transmission, has drive unit, drive output units and free running units arranged such that drive torque is selectively transferred over one drive output unit depending upon drive rotation direction
EP2685130A1 (en) * 2012-07-10 2014-01-15 Metabowerke GmbH Gearbox assembly
DE102014200720B3 (en) * 2014-01-16 2015-02-26 Schaeffler Technologies Gmbh & Co. Kg Planetary gear assembly
US20150276020A1 (en) * 2014-03-26 2015-10-01 Spg Co., Ltd. Two speed transmission
WO2020099178A1 (en) * 2018-11-12 2020-05-22 Atlas Copco Industrial Technique Ab Power tool and gear unit for such a power tool
CN113646560A (en) * 2018-11-12 2021-11-12 阿特拉斯·科普柯工业技术公司 Power tool and gear unit for the same
US20210402586A1 (en) * 2018-11-12 2021-12-30 Atlas Copco Industrial Technique Ab Power tool and gear unit for such a power tool

Also Published As

Publication number Publication date
GB2109489B (en) 1985-02-06

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19961021