TORQUE-STABILIZING ROTARY DAMPER

Description

DESCRIPTION OF THE INDUSTRIAL INVENTION TITLE: "Torque-stabilizing rotary damper" By: CULTRARO AUTOMAZIONE ENGINEERING SRL, Italian nationality, Via Albenga, 94, 10098 Rivoli (Turin) Designated Inventors: Daniele STALLONE, Antonino CULTRARO Filed on: July 4, 2024 *** DESCRIPTION The present invention relates to a rotary damper, of the type including: - an enclosure comprising a side wall- and a terminal wall that delimit a room containing a viscous braking fluid, - a lid mounted on the casing from the side opposite to the end wall so as to close said room, and - a rotor, rotatably connected to said in- casing and mounted on it, said rotor having a portion of the control protruding outwards of the chamber through a hole made in the cover I'll. Devices of this type are commonly known type, in which the control portion of the rotor and the casing are configured for mating to respective parts whose mutual movement is to be slow down. It is generally observed that the resistive couple force applied by the rotary damper varies in significantly as a function of temperature and of the operating rotation speed of the device positive. This variability in performance is often undesirable. An object of the present invention is therefore that of making a rotary damper in able to operate in a more stable manner than to known rotary dampers. This purpose is achieved according to the invention by a rotary damper of the type defined at the beginning, where the rotor includes an axially fixed part on which is re- said control portion was extracted, and an axially floating part interposed between the axially fixed part of the rotor and the wall casing terminal and prismatic coupling- mind with the axially fixed part of the rotor, said axially floating part being able to translate axially with respect to the axial part fixed mind of the rotor and with respect to the casing. It has in fact been found that the presence of the floating part of the rotor allows to have a compensatory effect, as the conditions vary operating conditions (temperature, rotation speed) ne), which achieves the result of stabilizing al- less so the performance of the device. Preferred embodiments of the invention are defined in the claims employees. Additional features and benefits of the di- device according to the invention will become more clear re with the following detailed description of a embodiment of the invention, made with reference to the attached drawings, provided for information purposes only purely illustrative and not limiting, in which: - Figure 1 is a sectional view of one rotary damper according to the invention; - figure 2 is an exploded view of the damper of figure 1; and - figures 3 and 4 are seen on an enlarged scale fingers of a detail of figure 2, in two different operating positions. The figures show a rotary damper. tive, overall indicated with 10, of the type a barrel. This damper can have dimensions rather small, for example of the order of qual- that centimeter or even less. The attributes spatial terms used in the following, such as “axial” and “ra- diale”, are referred to the axis of rotation of the rod- rotary damper tor 10. The damper 10 comprises a casing 12 of plastic material, on which a rotor is mounted 14 made of plastic material, rotating around a x-axis. The casing 12 is substantially cylindrical and has one or more fixing appendages 15, which allow the device to be mounted on a support port (not illustrated). The shape of the appendages of fixing is not essential for the purposes of the invention, and it depends on the installation conditions of the di- device. Alternatively, the fixing appendices gio could be absent and replaced by others fastening means known to those skilled in the art. The casing 12 is an element made of a single piece and defines a chamber 16 containing a viscous fluid, such as silicone oil. room 16 is delimited laterally by a wall lateral 17, and at one end is closed by a pa- terminal network 19. The end of chamber 16 opposite the wall terminal 19 is open. At this point at the ends there is an annular groove 17a and a shoulder 17b, which are obtained on a su- radially internal surface of the lateral wall 17. On an axially internal surface of the a rotation pin is obtained on the end wall 19a, protruding into chamber 16. Coaxially with the rotation pin 19a, it is re- a protruding spacer formation 19b was dug out also towards the inside of room 16. The side wall 17 comprises a portion of internal surface 17c tapered towards the wall- terminal 19 of the casing 12. The portion of internal surface 17c is arranged coaxially with the rotation pin 19a. According to one form of less performing construction, the side wall 17 may be missing the su- portion internal surface 17c tapered towards the wall terminal 19 of the casing 12, and therefore have a radially internal long cylindrical surface the entire height extension of room 16. The damper 10 also comprises a cover chio 21 mounted on the casing 12 from the opposite side with respect to the terminal wall 19 so as to close to see the chamber 16. The lid 21 has a hole passerby 22. In the example illustrated, the edge of the cover snaps into place the annular groove 17a re- dug into the side wall 17. The arrangement of Mounting the lid is not essential for the purposes of the invention and may be different from that described above, provided that the same function is achieved closing action of chamber 16. The rotor 14 comprises an axially fixed 23 and an axially floating part 25 in- placed between the axially fixed part 23 of the tore 14 and the end wall 19 of the casing 12. Each of these parts 23 and 25 is made in a single piece, for example made of plastic material. The axially fixed part 23 of the rotor 14 comprises a main body 23a from which it extends a portion a radially outwards flange 23b, and from which it extends axially outwards a control portion 23c. The control portion 23c protrudes outside the chamber 16 through hole 22 made in the cover chio 21, and is configured to be coupled to a part (not illustrated) whose movement respect- to the support to which the casing is fixed 12 of the rotary damper 10 must be slowed down to. In the example illustrated, the portion of con- trollo 23c is configured to be paired pri- smatically to a gear wheel 24, which in its once it will be coupled with a further element toothed not illustrated. The type of coupling of the control portion 23c to the elements external to the rotary damper is not essential for the purposes of the invention and may be different from the one described above. In the main body 23a of the axial part- fixed part 23 of the rotor 14 a hole is made of 23d guide extending in the axial direction. The axially fixed part 23 of the rotor 14 is axially held between the cover 21 and the shoulder 17b obtained on the side wall 17 of the casing 12. In this way the retention of the axially fixed part 23 of the rotor 14 is made in a particularly simple way. Ta- the provision is not essential for the purposes of the invention, and may be replaced by a di- equivalent arrangement that still achieves the retaining of the axially fixed part 23 of the rotor 14. The axially floating part 25 of the rotor 14 features a cup-shaped body arranged at- I return to the main part 23a of the axial part fixed mind 23 of the rotor 14. The axial part floating 25 includes a portion of surface external 25a tapered towards one axial end of the axially floating part 25 facing the end wall 19 of the casing 12, in a manner ra approximately compliant with the portion of internal surface 17c of side wall 17 of the casing 12. According to one embodiment less performing part, the axially floating part many 25 may be missing the portion of tapered external surface 25a, and therefore have of a radially external cylindrical surface. The axially floating part 25 of the rotor 14 is coupled prismatically with the as- axially fixed 23 of the rotor 14. The axial part floating mind 25 is therefore able to translate axially with respect to the axially fixed part 23 of the rotor 14 and with respect to the casing 12. To this end, on the side of the axially floating part 25 of the rotor 14 facing the axial part fixed 23 a guide pin 25b is obtained coupling to prismatic with the 23d guide hole obtained- to in the axially fixed part 23 of the rotor 14. Although preferable for its simplicity of realization ization, this provision is not essential to purposes of the invention and may be replaced by a equivalent provision that you make the required prismatic coupling. For example, the pin-hole arrangement could be inverted ta compared to the one described, thus having the guide pin on the axially floating part and the guide hole on the axially fixed part of the rotor. The axially floating part 25 of the rotor 14 is rotationally coupled with the end wall 19 of the casing 12. To this end, on the side of the axially floating part 25 of the rotor 14 facing towards the end wall 19 a hole is made 25b guide coupled with the rotation pin 19a obtained on the end wall. Although prefer- Relevant for its compactness, this arrangement is not essential to the invention and may be be replaced by an equivalent provision that achieve the required coupling. For example, the pin-hole arrangement could be reversed compared to the one described, therefore having the pin of rotation on the axially floating part and the hole on the end wall. Figures 3 and 4 show the positions axially extreme positions achievable in exercise uncle from the axially floating part 25, respec- firmly against the end wall 19 of the casing 12 (more precisely, against the for- spacing mation 19b), and in batting against one end of the axially fixed part 23 of the rotor 14. The rest position of the as- floating 25 normally corresponds to the position of figure 3, while due to the effect of the operating conditions, such as a number of speed imposed on the damper or a high operating temperature, the axial part floating 25 tends to move towards the position of figure 4. In this way, a greater quantity of viscous fluid tends to flow into the area between the axially floating part 25 of the rotor 14 and the end wall 29 of the casing 12. Generally a few tenths of a millimeter of cor- knows between the two extreme positions to obtain an ef- compensatory effect, as the conditions of exercise (temperature, rotation speed), sufficient to stabilize appreciably the device's performance in terms of torque resistant. So that there is always a quantity sufficient viscous fluid in the area between the par- axially floating rotor 25 and the pa- terminal network 29 of the casing 12, the formation spacer 19b establishes a given distance d non-zero between a pair of axially arranged surfaces 19s, 25s respectively of the wall terminal 19 of the casing 12 and of the as- floating rotor 25. The formation spacer 19b can be arranged in a diff- inferring from what is described and represented above in the figures. Preferably, elastic means are interposed you are between the axially fixed part 23 and the part axially floating 25 of the rotor 14 for stress- tare the axially floating part 25 of the rotor 14 towards the end wall 19 of the casing 12. Such elastic means may comprise a spring 26, in particular a helical spring, di- moves coaxially with the axially fixed part 23 of the rotor 14. The elastic means are used to re- restore the rest position of the as- floating 25 when the conditions that have determined his removal from the pare- terminal 19 of the casing 12 are no longer present listen. According to an alternative embodiment- tive, less preferable, elastic means could to be absent. An annular gasket 27 is interposed between a radially external surface of the as- floating rotor 25 and the wall side 17 of the casing 12. This gasket ring 27 separates chamber 16 into a first region between the axially floating part 25 of the rotor 14 and the casing 12, where the viscous fluid is present so, and in a second region between the axial part floating part 25 and the axially fixed part 23 of rotor 14, where the viscous fluid is substantially absent mind.

Claims

1. Rotary damper (10), including: - a casing (12) comprising a side wall (17) and an end wall (19) delimiting a chamber (16) containing a viscous braking fluid, - a cover (21) mounted on the casing (12) on the opposite side to the end wall (19) so as to close said chamber (16), and - a rotor (14), rotatably connected to said casing (12) and mounted thereon, said rotor (14) having a control portion (23c) protruding outside the chamber (16) through a hole (22) formed in the cover (21), characterised in that said rotor comprises an axially fixed part (23) on which said control portion (23c) is formed, and an axially floating part (25) interposed between the axially fixed part (23) of the rotor (14) and the end wall (19) of the casing (12). and prismatically coupled with the axially fixed part (23) of the rotor (14),said axially floating part (25) being able to translate axially with respect to the axially fixed part (23) of the rotor (14) and with respect to the casing - 1 I0207651 (12)., 2. A damper according to claim 1, wherein said sidewall (17) comprises an internal surface portion (17c) tapering towards the endwall (19) of the casing (12), said internal surface portion (17c) surrounding the axially floating portion (25) of the rotor (14).

3. Damper according to claim 2, wherein elastic means (26) are interposed between the axially fixed part (23) and the axially floating part (25) of the rotor (14) to urge the axially floating part (25) of the rotor (14) towards the end wall (19) of the casing (12).

4. Damper according to claim 3, wherein said elastic means comprise a spring, in particular a helical spring.

5. Damper according to one of the preceding claims, wherein one of said end walls (19) of the casing (12) and axially floating part (25) of the rotor (14) is provided with a rotation pin (19a) coupled to a hole (25c) made in the other of said end walls (19) of the casing (12) and axially floating part (25) of the rotor (14), said rotation pin (19a) defining the rotation axis (x) of the rotor (14). - 2 I0207651 6. Damper according to claim 5, wherein a spacing formation (19b) is formed on at least one of said end wall (19) of the casing (12) and axially floating part (25) of the rotor (14) to establish a given non-zero distance (d) between a pair of axially opposed surfaces (19s, 25s) respectively of the end wall (19) of the casing (12) and of the axially floating part (25) of the rotor (14).

7. Damper according to one of the preceding claims, wherein one of said axially floating part (25) and axially fixed part (23) of the rotor (14) is provided with a guide pin (25b) prismatically coupled to a guide hole (23d) obtained in the other of said axially floating part (25) and axially fixed part (23) of the rotor (14).

8. Damper according to one of the preceding claims, wherein a gasket (27) is radially interposed between the axially floating part (25) of the rotor (14) and the side wall (17) of the casing (12).

9. Damper according to one of the preceding claims, wherein the axially fixed part (23) of the rotor (14) is held axially between the cover (21) and the side wall (17) of the casing (12).

10. Damper according to one of the preceding claims, wherein each of said casing (12), axially fixed part (23) of the rotor (14) and axially floating part (25) of the rotor (14) is an element obtained in a single piece.