ROTARY SHOCK ABSORBER.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- GLAENZER SPICER SA
- Filing Date
- 1990-06-25
- Publication Date
- 1991-12-27
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing rotary dampers lack effective means to vary damping laws based on angular displacement, limiting their performance and adaptability.
Incorporation of active members and axial displacement mechanisms outside the housing, utilizing threads and angular displacement conversion means to control axial movement, allowing for variable damping based on relative shaft and housing rotation.
Enables dynamic adjustment of damping characteristics in response to angular displacement, enhancing the damper's performance and adaptability.
Abstract
Description
i This application for a certificate of addition concerns a shock absorber rotary of the type described and illustrated in the main patent application No. O 90 03052 filed on March 9, 1990. This patent application relates to a rotary damper of the type comprising a sealed, hollow cylindrical housing in which are arranged discs that are alternately rotationally fixed to the housing or to a coaxial central shaft mounted for rotation within the housing, the internal chamber delimited by the housing being at least partially filled with a viscous fluid received between the opposing faces of the discs, and which includes means for varying the damping law of the damper as a function of the angular displacement relative of the central shaft in relation to the crankcase. The purpose of this application is to present, as an improvement, two embodiments of a rotary damper in which the means for varying the damping law are essentially made up of elements arranged outside the casing. To this end, the invention proposes a rotary damper according to claim 1 of the main patent application, characterized in that it comprises an active element arranged outside the housing, a portion of which extends axially inside the housing through an opening formed in a lateral flange of the housing in which it is received to slide axially, and an axial displacement element for the active element relative to the housing, the displacements of which are controlled by means for converting the relative angular displacement of the central shaft with respect to the housing into a axial displacement of the displacement element. According to other features of the invention, the displacement member is rotationally fixed to one of the two elements consisting of the housing and the central shaft and is capable of axial movement relative to one of these two elements, and it is connected to the other of the two elements by cooperation of forms provided respectively on the displacement member and on the other of the two elements and which convert the relative angular displacement into an axial displacement of the displacement member; the cooperating forms comprise a male thread and a complementary tapping formed on the displacement member or on the other of the two elements; the active member is a piston whose cylindrical rod is received in the orifice of the flange and whose head arranged outside the housing cooperates with the axial displacement member; the axial displacement member is a disc whose face facing the housing cooperates with the face opposite the head of the piston;elastic means for returning the piston in the direction corresponding to the exit of the rod from the crankcase are arranged between the head of the piston and the opposite face of the lateral flange of the crankcase; the active element is a rod received in the orifice; of the flange and whose free end is arranged at the exterior The inner part of the housing is fixed to the axial displacement member; the male thread is formed on the displacement member and the complementary tapping is formed in the housing; the male thread is formed on the central shaft and the complementary tapping is formed on the axial displacement member; and sealing means are arranged in the orifice wall to cooperate with the screw- surface vis-à-vis the active organ. Other features and advantages of J'inven- tion will appear upon reading the description detailed description which will follow for the understanding of which one will refer to the attached drawing in which: Figure 1 is a schematic half view in axial section of a first embodiment of a damper conforming to the teachings of the present invention; and Figure 2 is a view similar to that of Figure 1 of a variant embodiment of the rotary damper. In the description that follows, we will use the same reference figures as those appearing in the main patent application to designate compo- identical or equivalent. Figure 1 shows a rotary damper 10 comprising a hollow cylindrical housing 12 with axis XX, formed by an outer cylindrical ferrule 14 and two lateral flanges 16 and 18 which define a cylindrical internal chamber 20. The two disc-shaped side flanges 16 and 18 are pierced in their center to allow the passage of a central shaft 22 coaxial to the casing 12. The central shaft 22 is mounted freely for rotation in the housing 12 and the sealing of the chamber 20 is ensured by two O-rings 24 and 26 mounted in grooves formed in the cylindrical faces 28 and 30 which delimit the central bores of the flanges 16 and 18, the seals 24 and 26 cooperating with bearing surfaces corresponding cylindrical parts 32 and 34 of shaft 22. The housing 12 is axially immobilized relative to the shaft 22 in the direction XX due to the cooperation of the inner face 36 of the flange 18 with the shoulder 38 of the shaft 22 which defines the cylindrical bearing surface 34, against which it is held in contact by means of a spring ring 40 mounted in a groove 42 of the cylindrical bearing surface 34 against the face external 46 of the flange 18. The internal chamber 20 receives a plurality of disks 50 A and 50 B which are drilled in their center and substantially coaxial with the axis XX. The disks 50 A and 50 B are alternated and are alternately joined together. rotation of the housing 12 and the shaft 22 respectively- Thus, the discs 50 A are mounted to slide axially on axial keys 52 formed in the internal cylindrical wall of the ferrule 14, while the discs 50 B are mounted to slide axially on axial keys 54 formed on the portion 56 of the shaft 22 which extends between the cylindrical bearing surfaces 32 and 34. The means for varying the damping law of the damper 10 as a function of the relative angular displacement of the central shaft 22 with respect to the housing 12 are here constituted by a series of active components 80 whose axial displacements are controlled by a axial thrust or displacement component 58. Each of the active components 80 is a piston whose rod 82 is received in a sealed sliding motion within a orifice 84 of the side flange 16 of the housing 12 The seal- The seal between the orifice 84 and the rod 82 is ensured at using an O-ring 86. The free end 88 of the rod 82 moves inside the internal chamber 20 to cooperate with the opposite disc to vary the spacing between the discs 50A and 50B and to vary the internal volume of the chamber 20, which is at least partially filled with a viscous fluid. Each piston 80 has a head 90 whose free end face cooperates with the opposite face 92 of the displacement disk 58. A helical spring 94 arranged between the opposite face 17 of the flange 16 and the inner face of the piston head 80 elastically forces the latter in the direction corresponding to the extension of the rod 82 from the chamber 20, so that the head 90 is constantly pressed against the face 92 of the displacement member 58. The member 58 is made in the form of a thicker disc which is mounted to slide at its center on axial splines 96 of the shaft 22. The outer annular cylindrical edge of the disc 58 has a male thread 60 which is received in a complementary threaded hole 62 formed in the inner cylindrical wall of the portion 98 of the ferrule 14 which extends axially beyond the flange 16, to the right. considering figure 1. The rotary damper in Figure 1 operates by in the following way. If the central shaft 22 is driven in rotation relative to the housing 12, in a first direction of rotation, it drives the discs 50 B between the discs 50 A into rotation and produces a classic rolling effect of the viscous fluid which provides a braking effect of the rotation. This same rotation of the shaft 22 drives the axial displacement disc 58 into rotation by the splines 96 and therefore causes its axial displacement relative to the shaft 22 and the housing 12 due to the cooperation between the thread 60 and the tapping 62. Depending on the direction of the thread, the rotation in the first direction, for example clockwise, of the shaft 22, causes the axial displacement of the disc 58 in the direction corresponding to the compression of the discs 50 A and 50 B by the ends 88 of the rods 82 of the pistons, that is to say to the left considering figure 1.This axial displacement therefore has the effect of reducing the gap between the discs 50 A and 50 B and thus of varying the damping law resulting from the rolling of the viscous fluid as a function of the angular displacement in rotation of the shaft 22 with respect to the housing 12. The displacement of the rods 82 in the internal chamber also allows the pressure inside the internal chamber 20 to vary due to the reduction of the volume available for the viscous liquid contained in the latter. It is easily understood that the rotation of the shaft 22 with respect to the housing 12 in the opposite direction, by. for example, in the counter-clockwise direction, causes the displacement- the movement of disc 58 along the opposite axial direction, which corresponds to a "separation" of discs 50 A and 50 B, and which therefore provides a different damping law, the internal volume of chamber 20 increasing again due to the exit of rods 82 from chamber 20 under the action of the return springs 94. We will now describe the variant implementation represented in figure 2. The active parts 80 here consist of rods 82 whose ends 88 penetrate into orifices 84 of the lateral flange 16 in the same way as the rods 82 of the pistons 80 of the embodiment previous. The opposite free ends 89 of the rods 82 are fixed in corresponding bores 100 formed in the axial displacement disk 58. The axial and rotational immobilization of the rods 82 relative to the disc 58 ensures immobilization in rotation of the latter relative to the casing 12. The axial displacement disc 58 has a central hole in which a tapped hole 62 is formed which cooperates with a male thread 60 formed on the shaft 22. The rotary damper is shown in Figure 2. functions in a similar way to that of amortization- represented in Figure 1, the axial displacement of the organ 58 and the displacement of the rods 82 which in results in a pressure variation within inner part of the crankcase. The orifices 84 provided in the side flange 16 can be used for filling and draining the Internal chamber 20. In both embodiments, the orifices 84 are preferably distributed angularly in such a way regular on the same circle around the XX axis. The design of the alternative embodiments that are the subject of this certificate of addition is not limited to the two alternative embodiments that follow to be described, the means to convert the displacement- relative angular relationship between the shaft 22 and the housing 12 in an axial displacement of the displacement member 58 which can for example be achieved in the form of cooperation of cams and cam paths.
Claims
RRVENDICATIONS 1 Rotary damper (10) of the type comprising a sealed hollow cylindrical housing (12) in which are arranged discs (50 A, 50 B) which are alternately rotationally fixed to the housing (12) or to a coaxial central shaft (22) mounted for rotation in the housing, the internal chamber (20) delimited by the housing being at least partially filled with a viscous fluid received between the faces opposite the discs and which comprises means for varying the damping law of the damper as a function of the relative angular displacement of the central shaft with respect to the housing in accordance with claim 1 of the main patent application,characterized in that it comprises an active member (80) arranged outside the housing, a part (82) of which extends axially inside the housing through an orifice (84) formed in a lateral flange (16) of the housing into which it is received sliding axially, and a member (58) for axially displacing the active member (80) relative to the housing (12), the displacements of which are controlled by means (60, 62) for converting said relative angular displacement into, an axial displacement of the displacing element.
2. A rotary damper according to claim 1, characterized in that the displacement member (58) is rotationally fixed to one of the two elements constituted by the housing (12) and the central shaft (22) and is capable of axial movement relative to one of these two elements, and in that it is connected to the other of said two elements by cooperation of forms (60, 62) provided respectively on the displacement member (58) and on the other of the two elements and which convert said relative angular displacement into a axial displacement of the displacement element.
3. Shock absorber according to claim 2, characterized- defined in that said cooperating forms comprise a male thread (60) and a complementary tapped hole (62) formed on the moving member (58) or the other of said two elements (12, 22), 4 Rotary damper according to any one of the previous claims, characterized in that the active member (80) is a piston whose rod (82) is received in said orifice (84) and whose head (90) arranged outside the casing (12) cooperates with said axial displacement organ (58). Rotary damper according to claim 4, characterized in that said axial displacement member (58) is a disc whose face (92) facing the housing cooperates with the face opposite the head (90) of said piston (80). 6 Rotary damper according to one of the claims tions 4 or 5, characterized in that means (94) of elastic return of the piston in the corresponding direction The parts at the exit of the rod (82) from the housing (12) are arranged between the head of the piston (90) and the face in vis-à-vis (17) the lateral flange (16) of the housing. 7 Rotary damper according to any one of the claims 1 to 3, characterized in that the organ active (80) is a rod (82) received in said orifice (84) and whose free end (89) arranged at the exte- The inner part of the housing is fixed to the said moving part axial ( 58). 8 Rotary damper according to any one of the claims 4 to 6 taken in combination with the claim 3, characterized in that said male thread (60) is formed on the moving member (58) and in that the complementary tapping (62) is formed in the crankcase. 9 Rotary damper according to claim 7 taken in combination with claim 3, character- se in that said male thread (60) is formed on the central shaft (22) and in that the tapping completes- The mentary (62) is formed on the axial displacement member. 10 Damper according to any one of the previous claims, characterized in that sealing means (86) are arranged in the wall said orifice (84) to cooperate with the vis- surface vis-à-vis the active component (80) 11 Shock absorber according to any one of the previous claims, characterized in that the part (88) of the active organ (80) which extends to the inside of the casing cooperates with the disc in a vis-à-vis screw.