WO2021111345A1 - A rotary damper of small size - Google Patents
A rotary damper of small size Download PDFInfo
- Publication number
- WO2021111345A1 WO2021111345A1 PCT/IB2020/061420 IB2020061420W WO2021111345A1 WO 2021111345 A1 WO2021111345 A1 WO 2021111345A1 IB 2020061420 W IB2020061420 W IB 2020061420W WO 2021111345 A1 WO2021111345 A1 WO 2021111345A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- housing
- annular rib
- wall
- rotor
- radially
- Prior art date
Links
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
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/10—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using liquid only; using a fluid of which the nature is immaterial
- F16F9/12—Devices with one or more rotary vanes turning in the fluid any throttling effect being immaterial, i.e. damping by viscous shear effect only
-
- 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
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F2226/00—Manufacturing; Treatments
- F16F2226/04—Assembly or fixing methods; methods to form or fashion parts
- F16F2226/044—Snapping
-
- 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
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F2230/00—Purpose; Design features
- F16F2230/30—Sealing arrangements
Definitions
- This invention relates to a rotary damper, of the type including:
- a housing comprising a radially inner wall, a radially outer wall, and an end wall which delimit a chamber containing a viscous braking fluid
- a rotor rotatably connected to said housing and mounted thereon on the opposite side relative to the end wall so as to close said chamber, said rotor comprising an annular band-shaped braking portion, which extends axially inside the chamber and is interposed between the radially inner wall and the radially outer wall of the housing.
- a device of this type is known, for example, from the German utility model DE 29604260 Ul, which describes a tilting handle provided with a handgrip hinged to a mounting wall of a vehicle.
- the handgrip is rotatable against the action of resilient means from a rest position, in abutment against the mounting wall, to an operating position.
- the handgrip is automati cally returned from the operating position to the rest position after release by the user.
- the movement of returning to the rest position is made softer by a braking device, of the type defined above, which acts on the axis of rotation of the handle.
- dampers for the application described above already have particularly compact dimensions, the need is felt to further reduce their dimensions in order to make them appli cable in other areas where the available spaces are even more limited, for example in the handles of suitcases.
- a specific problem related to this reduction in size is related to the fact that there may not be sufficient space to insert sealing gaskets.
- An object of this invention is therefore to provide a rotary damper of very small dimensions, in which acceptable braking performances are still obtainable.
- a rotary damper of the type defined at the outset wherein an outer annular rib and an inner annular rib are respectively formed on a radially outer surface and on a radially inner surface of the rotor, an outer annular groove and an inner annular groove are formed on the radially outer wall and on the radially inner wall, respectively, wherein the outer annular rib and the inner annular rib of the rotor are respectively snap-fitted into the outer annular groove and the inner annular groove of the housing to seal said chamber.
- the fluid is contained by means of the ribs of the rotor and the grooves of the housing which, in contact with each other, act as a “labyrinth” to prevent the fluid from escaping.
- the sealing gaskets There is therefore no need to use sealing gaskets and, consequently, the dimensions of the device may be reduced.
- Fig. 1 is an exploded view of a rotary damper according to the invention.
- Fig. 2 is a view in cross section of the damper in Fig. 1.
- the figures show a rotary damper of the barrel type, indicated collectively with 10.
- a damper may have very small dimensions, for example an external diameter of about 6 mm, a central through opening having a diameter of about 3.5 mm and a length of about 9 mm.
- the central through opening may therefore have a diameter of about, or slightly more than, half the outer diameter of the device.
- the device 10 comprises a housing 12 made of plastics material, on which a rotor 14 made of plastics material is mounted rotatable about an x axis.
- the housing 12 is substantially cylindrical and has a central through opening 15, which allows the device to be mounted on the axis of rotation of a mobile member, according to the arrangement described in the utility model DE 296 04 260 Ul.
- the central opening 15 may be absent, depending on how the damper 10 is installed.
- the housing 12 is an element made in one piece and defines a ring chamber 16 coaxial with the central opening 15, containing a high-viscosity viscous fluid, for example a grease.
- the ring chamber 16 is laterally delimited by a radially inner wall 17 and by a radially outer wall 18 and is closed at one end by an end wall 19.
- a tab 18c may be obtained configured to make the housing 12 integral in rotation with one of the elements of the torque, the relative rotary motion of which must be slowed down with the damper 10.
- the tab 18c there may be alternative arrangements having the same function.
- the end of the ring chamber 16 opposite the end wall 19 is open.
- An outer annular groove 18a and an inner annular groove 17a are arranged near this end, which are respectively formed on the radially outer wall 18 and on the radially inner wall 17.
- the outer annular groove 18a and the inner annular groove 17a are arranged at the same height relative to the x axis.
- the outer annular groove 18a and the inner annular groove 17a have a rounded profile; more specifically, the outer annular groove 18a and the inner annular groove 17a have a semicircular cross section.
- An outer annular rib 14a and an inner annular rib 14b are obtained on a radially outer surface and on a radially inner surface of the rotor 14, respectively.
- outer annular rib 14a and the inner annular rib 14b of the rotor 14 are snap-fitted into the outer annular groove 18a and the inner annular groove 17a of the housing 12 respectively to seal the chamber 16.
- the outer annular rib 14a and the inner annular rib 14b are arranged at the same height relative to the x axis.
- the outer annular rib 14a and the inner annular rib 14b have a rounded profile complementary to that of the ribs 17a and 18a; more specifically, the outer annular rib 14a and the inner annular rib 14b have a semicircular cross section.
- the housing 12 axially retains the rotor 14, so that this housing is able to close the ring chamber 16.
- the closure of the ring chamber 16 is sealed by the labyrinth formed by the surfaces of the ribs 14a and 14b and of the grooves 18a and 17a.
- Tabs 14b may be obtained on an axially outer surface of the rotor 14, configured to make the rotor 14 integral in rotation with the other of the elements of the torque, the relative rotary motion of which must be slowed down with the damper 10.
- tabs 14b alternative devices having the same function may be present.
- the alignment and centering of the rotor 14 relative to the chamber 16 of the housing 12 is ensured by the side walls 17 and 18 of the housing 12.
- the radially inner wall 17 of the housing 12 defines the rotation pin of the rotor 14.
- a through hole 25 is obtained in the rotor 14 and is intended to coaxially accommodate one of the members to which the device 10 is connected.
- This through hole 25 has a section 26 with an enlarged diameter, intended to receive the radially inner wall 17 of the housing 12 as a function of the rotation pin.
- the rotor 14 further comprises a first annular band- shaped braking portion 27, which extends axially inside the chamber 16 and is interposed between the radially inner wall 17 and the radially outer wall 18 of the housing 12.
- the braking portion 27 is obtained in a single piece with the rotor 14.
- respective interfaces are defined between the radially inner wall 17 and the braking portion 27, and between the braking portion 27 and the radially outer wall 18, which are bathed by the viscous fluid.
- a plurality of channels 33 extending axially along the braking portion 27 and arranged uni formly spaced in the circumferential direction is obtained on the braking portion 27 of the rotor 14, more precisely on the side thereof facing the radially outer wall 18 of the housing 12.
- a through opening 36 extending radially through the first braking portion 27 is obtained.
- the channels 33 and the opening 36 interrupt the otherwise circular profile of the first brak ing portion 27 and are therefore suitable to cause turbulence in the fluid inside the chamber 16. This prevents the formation of parallel fluid layers in the vicinity of the braking portion
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Fluid-Damping Devices (AREA)
Abstract
Rotary damper (10), including a housing (12) delimiting a chamber (16) containing a viscous braking fluid, and a rotor (14) comprising an annular band-shaped braking portion (27), which extends axially inside the chamber (16). An outer annular rib (14a) and an inner annular rib (14b) are respectively obtained on a radially outer surface and on a radially inner surface of the rotor (14). An outer annular groove (18a) and an inner annular groove (17a) are formed respectively on the radially outer wall (18) and on the radially inner wall (17) of the housing (12). The outer annular rib (14a) and the inner annular rib (14b) of the rotor (14) are respectively snap-fitted into the outer annular groove (18a) and the inner annular groove (17a) of the housing (12) to seal the chamber (16) of the housing (12).
Description
A rotary damper of small size
This invention relates to a rotary damper, of the type including:
- a housing comprising a radially inner wall, a radially outer wall, and an end wall which delimit a chamber containing a viscous braking fluid, and
- a rotor, rotatably connected to said housing and mounted thereon on the opposite side relative to the end wall so as to close said chamber, said rotor comprising an annular band-shaped braking portion, which extends axially inside the chamber and is interposed between the radially inner wall and the radially outer wall of the housing.
A device of this type is known, for example, from the German utility model DE 29604260 Ul, which describes a tilting handle provided with a handgrip hinged to a mounting wall of a vehicle. The handgrip is rotatable against the action of resilient means from a rest position, in abutment against the mounting wall, to an operating position. The handgrip is automati cally returned from the operating position to the rest position after release by the user. The movement of returning to the rest position is made softer by a braking device, of the type defined above, which acts on the axis of rotation of the handle.
Although the dampers for the application described above already have particularly compact dimensions, the need is felt to further reduce their dimensions in order to make them appli cable in other areas where the available spaces are even more limited, for example in the handles of suitcases. A specific problem related to this reduction in size is related to the fact that there may not be sufficient space to insert sealing gaskets.
An object of this invention is therefore to provide a rotary damper of very small dimensions, in which acceptable braking performances are still obtainable.
This object is achieved according to the invention by a rotary damper of the type defined at the outset, wherein an outer annular rib and an inner annular rib are respectively formed on a radially outer surface and on a radially inner surface of the rotor, an outer annular groove and an inner annular groove are formed on the radially outer
wall and on the radially inner wall, respectively, wherein the outer annular rib and the inner annular rib of the rotor are respectively snap-fitted into the outer annular groove and the inner annular groove of the housing to seal said chamber.
In such a device the fluid is contained by means of the ribs of the rotor and the grooves of the housing which, in contact with each other, act as a “labyrinth” to prevent the fluid from escaping. There is therefore no need to use sealing gaskets and, consequently, the dimensions of the device may be reduced.
Preferred embodiments of the invention are defined in the dependent claims.
Further features and advantages of the device according to the invention will become clearer from the following detailed description of an embodiment of the invention, made in refer ence to the accompanying drawings, provided purely for illustrative and non-limiting pur poses, wherein:
- Fig. 1 is an exploded view of a rotary damper according to the invention; and
- Fig. 2 is a view in cross section of the damper in Fig. 1.
The figures show a rotary damper of the barrel type, indicated collectively with 10. Such a damper may have very small dimensions, for example an external diameter of about 6 mm, a central through opening having a diameter of about 3.5 mm and a length of about 9 mm. In such a small damper, the central through opening may therefore have a diameter of about, or slightly more than, half the outer diameter of the device.
The device 10 comprises a housing 12 made of plastics material, on which a rotor 14 made of plastics material is mounted rotatable about an x axis. The housing 12 is substantially cylindrical and has a central through opening 15, which allows the device to be mounted on the axis of rotation of a mobile member, according to the arrangement described in the utility model DE 296 04 260 Ul. The central opening 15 may be absent, depending on how the damper 10 is installed.
The housing 12 is an element made in one piece and defines a ring chamber 16 coaxial with the central opening 15, containing a high-viscosity viscous fluid, for example a grease. The ring chamber 16 is laterally delimited by a radially inner wall 17 and by a radially outer wall 18 and is closed at one end by an end wall 19.
On a radially outer surface of the radially outer wall 18, a tab 18c may be obtained configured to make the housing 12 integral in rotation with one of the elements of the torque, the relative rotary motion of which must be slowed down with the damper 10. In place of the tab 18c there may be alternative arrangements having the same function.
The end of the ring chamber 16 opposite the end wall 19 is open. An outer annular groove 18a and an inner annular groove 17a are arranged near this end, which are respectively formed on the radially outer wall 18 and on the radially inner wall 17. According to the embodiment shown in the figures, the outer annular groove 18a and the inner annular groove 17a are arranged at the same height relative to the x axis. According to the embodiment shown in the figures, the outer annular groove 18a and the inner annular groove 17a have a rounded profile; more specifically, the outer annular groove 18a and the inner annular groove 17a have a semicircular cross section.
An outer annular rib 14a and an inner annular rib 14b are obtained on a radially outer surface and on a radially inner surface of the rotor 14, respectively.
The outer annular rib 14a and the inner annular rib 14b of the rotor 14 are snap-fitted into the outer annular groove 18a and the inner annular groove 17a of the housing 12 respectively to seal the chamber 16. In the embodiment illustrated in the figures, the outer annular rib 14a and the inner annular rib 14b are arranged at the same height relative to the x axis. In the illustrated embodiment, the outer annular rib 14a and the inner annular rib 14b have a rounded profile complementary to that of the ribs 17a and 18a; more specifically, the outer annular rib 14a and the inner annular rib 14b have a semicircular cross section.
With this arrangement, the housing 12 axially retains the rotor 14, so that this housing is able to close the ring chamber 16. The closure of the ring chamber 16 is sealed by the labyrinth
formed by the surfaces of the ribs 14a and 14b and of the grooves 18a and 17a.
Tabs 14b may be obtained on an axially outer surface of the rotor 14, configured to make the rotor 14 integral in rotation with the other of the elements of the torque, the relative rotary motion of which must be slowed down with the damper 10. Instead of tabs 14b, alternative devices having the same function may be present.
The alignment and centering of the rotor 14 relative to the chamber 16 of the housing 12 is ensured by the side walls 17 and 18 of the housing 12. In particular, the radially inner wall 17 of the housing 12 defines the rotation pin of the rotor 14. A through hole 25 is obtained in the rotor 14 and is intended to coaxially accommodate one of the members to which the device 10 is connected. This through hole 25 has a section 26 with an enlarged diameter, intended to receive the radially inner wall 17 of the housing 12 as a function of the rotation pin.
The rotor 14 further comprises a first annular band- shaped braking portion 27, which extends axially inside the chamber 16 and is interposed between the radially inner wall 17 and the radially outer wall 18 of the housing 12. The braking portion 27 is obtained in a single piece with the rotor 14.
Thus, respective interfaces are defined between the radially inner wall 17 and the braking portion 27, and between the braking portion 27 and the radially outer wall 18, which are bathed by the viscous fluid.
During the rotation of the rotor 14 relative to the housing 12, the viscous friction linked to the movement of the braking portion 27 of the rotor 14 in the chamber 16 causes the braking action provided by the damper 10.
A plurality of channels 33 extending axially along the braking portion 27 and arranged uni formly spaced in the circumferential direction is obtained on the braking portion 27 of the rotor 14, more precisely on the side thereof facing the radially outer wall 18 of the housing 12. At each of the channels 33 a through opening 36 extending radially through the first
braking portion 27 is obtained.
The channels 33 and the opening 36 interrupt the otherwise circular profile of the first brak ing portion 27 and are therefore suitable to cause turbulence in the fluid inside the chamber 16. This prevents the formation of parallel fluid layers in the vicinity of the braking portion
27, thus keeping the braking effectiveness of the device uniform over time.
Claims
1. Rotary damper (10), including :
- a housing (12) comprising a radially inner wall (17), a radially outer wall (18), and an end wall (19) that delimit a chamber (16) containing a viscous braking fluid, and
- a rotor (14) rotatably connected to said housing and mounted thereto on an opposite side with respect to the end wall (19) in such a way as to close said chamber (16), said rotor comprising an annular band-shaped braking portion (27) that extends axially within the chamber (16) and is interposed between the radially inner wall (17) and the radially outer wall (18) of the housing (12), characterized in that an outer annular rib (14a) and an inner annular rib (14b) are formed on a radially outer surface and on a radially inner surface of the rotor (14), respectively, an outer annular groove (18a) and an inner annular groove (17a) are formed on the radially outer wall (18) and on the radially inner wall (17) of the housing (12), respectively, wherein the outer annular rib (14a) and the inner annular rib (14b) of the rotor (14) are snap-fitted into the outer annular groove (18a) and into the inner annular groove (17a), respectively, of the housing (12) to seal said chamber (16).
2. Damper according to claim 1, wherein said outer annular rib (14a) and inner annular rib (14b) are arranged axially at the same level, and said outer annular groove (18a) and inner annular groove (17a) are arranged axially at the same level.
3. Damper according to claim 1 or 2, wherein said outer annular rib (14a) and inner annular rib (14b) have a round profile, and said outer annular groove (18a) and inner annular groove (17a) have a round profile complementary to that of the outer annular rib (14a) and inner annular rib (14b), respectively.
4. Damper according to claim 3, wherein said outer annular rib (14a) and inner annular rib (14b) have semicircular cross section, and said outer annular groove (18a) and inner an nular groove (17a) have semicircular cross section.
5. Damper according to any one of the preceding claims, wherein on the braking portion (27) there is formed a plurality of channels (33) extending axially along the braking portion (27) of the rotor (14).
6. A damper according to claim 5, wherein at each of said channels (33) there is formed at least one respective through-opening (36) extending radially through the braking portion (27).
7. Damper according to any of the preceding claims, wherein each of said housing and rotor is an element formed as one piece.
8. Damper according to any of the preceding claims, wherein said viscous braking fluid is a grease.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE112020005998.7T DE112020005998T5 (en) | 2019-12-05 | 2020-12-03 | Small size rotary damper |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT102019000023055 | 2019-12-05 | ||
IT102019000023055A IT201900023055A1 (en) | 2019-12-05 | 2019-12-05 | Rotary damper with reduced dimensions |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2021111345A1 true WO2021111345A1 (en) | 2021-06-10 |
Family
ID=70009245
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IB2020/061420 WO2021111345A1 (en) | 2019-12-05 | 2020-12-03 | A rotary damper of small size |
Country Status (3)
Country | Link |
---|---|
DE (1) | DE112020005998T5 (en) |
IT (1) | IT201900023055A1 (en) |
WO (1) | WO2021111345A1 (en) |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4869125A (en) * | 1987-10-08 | 1989-09-26 | Nifco Inc. | Rotary oil damper |
DE29604260U1 (en) * | 1996-03-08 | 1996-04-25 | ITW-Ateco GmbH, 97285 Röttingen | Folding handle |
EP1067308A2 (en) * | 1999-06-07 | 2001-01-10 | Enplas Corporation | Gear damper, rotating mechanism provided with gear damper and recorded information reproducing apparatus provided with rotating mechanism |
US7798297B1 (en) * | 2009-06-30 | 2010-09-21 | Nokia Corporation | Handheld apparatus and motion dampener for the same |
US20150034435A1 (en) * | 2012-03-08 | 2015-02-05 | Nifco Inc. | Rotary damper |
US20180023653A1 (en) * | 2015-02-20 | 2018-01-25 | Nifco Inc. | Damper and method for manufacturing damper |
-
2019
- 2019-12-05 IT IT102019000023055A patent/IT201900023055A1/en unknown
-
2020
- 2020-12-03 DE DE112020005998.7T patent/DE112020005998T5/en active Pending
- 2020-12-03 WO PCT/IB2020/061420 patent/WO2021111345A1/en active Application Filing
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4869125A (en) * | 1987-10-08 | 1989-09-26 | Nifco Inc. | Rotary oil damper |
DE29604260U1 (en) * | 1996-03-08 | 1996-04-25 | ITW-Ateco GmbH, 97285 Röttingen | Folding handle |
EP1067308A2 (en) * | 1999-06-07 | 2001-01-10 | Enplas Corporation | Gear damper, rotating mechanism provided with gear damper and recorded information reproducing apparatus provided with rotating mechanism |
US7798297B1 (en) * | 2009-06-30 | 2010-09-21 | Nokia Corporation | Handheld apparatus and motion dampener for the same |
US20150034435A1 (en) * | 2012-03-08 | 2015-02-05 | Nifco Inc. | Rotary damper |
US20180023653A1 (en) * | 2015-02-20 | 2018-01-25 | Nifco Inc. | Damper and method for manufacturing damper |
Also Published As
Publication number | Publication date |
---|---|
IT201900023055A1 (en) | 2021-06-05 |
DE112020005998T5 (en) | 2022-11-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5497863A (en) | Rotary damper | |
EP2003364B1 (en) | A rotary damper having a unidirectional clutch | |
JP4582512B2 (en) | Rotating damper | |
KR880012929A (en) | Seal assembly | |
JP2000329183A (en) | Hinge damper | |
EP0261051B1 (en) | Damper hinge construction having progressively increased dampening during closed position approach | |
WO2021111345A1 (en) | A rotary damper of small size | |
IT9067208A1 (en) | ELASTIC JOINT | |
KR100457198B1 (en) | Rotary damper and Assist grip device | |
US20100282553A1 (en) | Rotary damper having improved braking features | |
US6968929B2 (en) | Damper | |
US4687211A (en) | Sealing assembly particularly for railway axle bearings | |
KR0149119B1 (en) | Rotary damper | |
US3003796A (en) | Shaft seal | |
JP2002235856A (en) | Sealing device | |
WO2017217432A1 (en) | Damper | |
CN213478988U (en) | Rotary damper | |
US6575392B1 (en) | Fly fishing reel with a sealing member | |
WO2015115487A1 (en) | Damper device | |
EP2551566B1 (en) | Rotary valve and rotary valve seal | |
JP2010121743A (en) | Rotary damper | |
IT202000023791A1 (en) | SEAL FOR BEARING UNIT | |
JP4107744B2 (en) | Rotating damper | |
WO2018174024A1 (en) | Air damper | |
KR20070059745A (en) | Rotary oil-damper |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 20824344 Country of ref document: EP Kind code of ref document: A1 |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 20824344 Country of ref document: EP Kind code of ref document: A1 |