FR2869376A1 - POWER TRANSMISSION DEVICE - Google Patents

Abstract

This device includes a power cut-off mechanism which transmits power from the second drive side rotating body (50) to the driven side rotating body (60), by causing an engaging portion disposed in one of the second. drive-side rotation body (50) and the drive-side rotation body (60) to engage with each other of the second drive-side rotation body (50) and the drive-side rotation body (60), and disengages the engagement with the second drive side rotational body (50), causing said engagement portion to be broken by a circumferential shear force of the drive side rotational body (60), when a larger torque that a prescribed quantity is generated between the second drive side rotating body (50) and the drive side rotating body (60).

Description

2869376 1

  POWER TRANSMISSION DEVICE

  The present invention relates to a power transmission device which transmits power from a drive source of a vehicle to a compressor which is used, for example, in an air conditioning system for vehicles.

  As a power transmission device of this type, hitherto there has been known a power transmission device which comprises a pulley which rotates by the use of power from a power source, a transmission member which is rotated by the pulley, a hub which is connected to the transmission member via a torque limiter, a plurality of protuberances which are spaced in one of the pulley and the transmission member in the circumferential direction and axially extending, and a plurality of receiving portions which receive the protuberances, which are spaced apart in the other from the pulley and the transmission member in the circumferential direction, damping rubbers which are arranged between each protuberance and each receiving portion, respectively, and for transmitting the torque of the pulley to the transmission member via each of the damping rubbers.

  In the power transmission device described above, however, when a torque is applied to the pulley, the damping rubber between each protuberance and each receiving portion is elastically deformed in the compression direction to absorb shock and friction. torque is transmitted to the transmission member. For this reason, the damping rubber repeatedly receives the force in the compression direction and generates permanent forces. As a result, spacings are generated between each protrusion and each receiving portion and the damping rubber and harmful vibrations are generated between the pulley and the transmission member. Thus, the possibility that the damping effect decreases due to hardening of the damping rubber is high.

  In addition, since it is necessary to provide cushioning rubbers for each of the plurality of protuberances and multiple receiving portions, the number of parts and hours of labor for the installation increases and decreases. the manufacturing cost can rise.

  The object of the present invention is to provide a power transmission device which can perform power transmission consistently satisfactorily without reducing the damping effect of the damping rubbers.

  To achieve the above object, the invention provides a power transmission device, which includes a first drive-side rotating body which is rotated from outside power, a second drive-side rotating body. which is rotated by the first drive side rotating body, a damping rubber disposed between the first and second rotation bodies, a driven side rotating body to which a torque of the second driving side rotating body is transmitted, and a power interruption mechanism which interrupts the transmitted power of the second side rotating body would cause the driven side rotating body when a torque greater than a prescribed magnitude is generated between the second driven rotating body and the rotating body driven side, whereby the torque of the first driving side rotation body is transmitted to the second body drive-side rotation via damping rubber. In this power transmission device, the damping rubber is formed into an annular shape, multiple convexities which are circumferentially spaced apart from each other are each disposed on an outer circumferential surface and an inner circumferential surface of the rubber damping, multiple concavities which fit on each of the convexities on the side of the outer circumferential surface of the damping rubber are disposed on an inner circumferential surface of one of the first and second drive-side rotating bodies, and multiple concavities each fitting to each of the convexities on the side of the inner circumferential surface of the damping rubber are disposed on the outer circumferential surface of the other of the first and second drive side rotating bodies.

  Therefore, since the damping rubber is formed into an annular shape and because on the outer peripheral surface 2869376 3 and on the inner peripheral surface of the damping rubber, convexities which fit on the respective concavities respectively provided on the first and second drive-side rotating bodies are arranged, the convexities of the damping rubber are circumferentially compressed and elastically deformed in the shear direction. Accordingly, since during the power transmission the damping rubber can be elastically deformed in the compression direction and in the shear direction, it is possible to maintain the damping effect for a long period of time. reducing the occurrence of permanent forces due to elastic deformation only in the direction of compression as in a conventional damping rubber. In addition, the damping rubber is integrally formed in annular form, assembly work can be easily performed and an increase in productivity can be achieved.

  The above object and other objects, features and advantages of the invention will become apparent from the following descriptions and accompanying drawings.

  In the drawings: Fig. 1 is a side sectional view of a power transmission device in the first embodiment of the invention; FIG. 2 is an exploded perspective view of the power transmission device of the first embodiment; FIG. 3 is an exploded perspective view of the power transmission device of the first embodiment; FIG. 4 is a partial front sectional view; of the power transmission device of the first embodiment; FIG. 5 is a perspective view of a hub of the power transmission device of the first embodiment; FIG. 6 is a side sectional view of a torque plate, and of a hub which are integrally formed in the first embodiment Figure 7 is a partial side sectional view of the power transmission device of the first embodiment for which the power is interrupted; Fig. 8 is a perspective view of a buffer nut in another example; Fig. 9 is a perspective view of a buffer nut in another example; Fig. 10 is a partial front sectional view of the power transmission device of the first embodiment in another example; Fig. 11 is a side sectional view of a power transmission device in the second embodiment; of the invention; and Fig. 12 is a partial side sectional view of the power transmission device of the second embodiment for which power is interrupted.

  Figures 1 to 7 show the first embodiment of the invention.

  This power transmission device comprises a housing 20 which forms the main body of a compressor 10 as a rotary device, a pulley 30 as the first driving side rotating body to which a torque is transmitted from a power source, a damping rubber 40 which absorbs vibrations, shocks or changes in torque generated in the pulley 30, a torque plate 50 as a second driving side rotating body to which the torque of the pulley 30 is transmitted via the rubber 40, and a hub 60 as a driven side rotating body, which transmits the torque plate torque 50 to a rotary shaft 21 of the compressor 10.

  The housing 20 is formed of a cylindrical member, and a compression mechanism within the compressor 1C not shown in the drawing is rotated by the transmission of a torque to the rotating shaft 21 which protrudes from one end.

  The pulley 30 is disposed coaxially with the rotary shaft 21 and is rotatably supported by a bearing 22 provided in the housing 20. A torque from the power source is transmitted by winding a belt for power transmission (not shown ) on an outer peripheral portion of the pulley 30. On an inner circumferential surface of the pulley 30 on an axial end side, as shown in Figure 2, multiple concavities 31 which fit over the convexities 41 of the damping rubber 40 are circumferentially spaced from each other.

  The damping rubber 40 is formed of an elastic material, such as rubber, and formed as a torus which is of rectangular section, and on an outer circumferential surface of the damping rubber 40, as 2, multiple convexities 41 in the form of an axial section rectangle which fits into each of the concavities 31, which are arranged on the inner circumferential surface of the pulley 30, are circumferentially spaced apart from one another . Similarly, on the inner circumferential surface of the damping rubber 40, as shown in FIG. 3, there are a plurality of radially spaced radially spaced cross-sections 42, in the form of a rectangle in axial section, which fit into multiple concavities 51 provided on an outer circumferential surface of the torque plate 50, which will be described later. In addition, each of the convexities 41 on the rib d of the outer circumferential surface of the damping rubber 40 and each of the convexities 42 on the side of the inner circumferential surface thereof are arranged to be mutually circumferentially displaced.

  The torque plate 50 is made from a member which is obtained by forming a synthetic resin such as an annular thermosetting resin and, on an outer circumferential surface of the torque plate 50 on an axial end side. as shown in Fig. 3, multiple concavities 51 which fit over the convexities 42 of the damping rubber 40 are circumferentially spaced apart from each other.

  At this time, as shown in FIG. 4, the damping rubber 40 is formed in such a way that the zone 41 'between the convexities 41, 41 on the outer circumferential surface and the zone 42' between the convexities 42 , 42 on the inner circumferential surface, respectively come in mutual radial contact with the zone 31 'between the concavities 31, 31 of the pulley 30 and the zone 51': the concavities 51, 51 of the torque plate 50, in order to generate a circumferential resistance to friction.

  Displacements for expanding the damping rubber 40 are provided between the torque plate 50 and the pulley 30.

  The hub 60 is made from a member which is obtained by forming a metal material such as annular aluminum, and a coupling portion 61 of a spline structure which connects the rotary shaft 21. is formed in the middle of the radial direction of the hub 60 so that the hub 60 can be attached to the rotary shaft 21 by using a bolt 2. On an end face of the hub 60, in the axial direction, as 5, multiple coupling keys 62 are integrally disposed circumferentially spaced apart from each other as an engaging portion which extends in the axial direction of the hub 60.

  At this time, the torque plate 50 is fornied with a synthetic resin, the hub 60 being kept installed, and the torque plate 50 and the hub 60 are integrally formed. In this case, as shown in FIG. 6, the coupling key 62 of the hub 60 is covered with the synthetic resin and, as a result, the circumferential movement of the hub 60 relative to the torque plate 50 is restricted.

  In the power transmission device 000nstruit as described above, the torque plate 50 rotates solidly with the pulley 30 when power from the source power is transmitted to the pulley 30. On this occasion, the torque of the pulley 30 is transmitted to the torque plate 50 via the damping rubber 40, and the damping rubber 40 is elastically deformed between the concavities 31 of the pulley 30 and the concavities 51 of the torque plate 50, with the result Shocks from sudden changes in torque, etc., are absorbed. The torque of the torque plate 50 is transmitted to the hub 60 via the coupling key 62 and the rotary shaft 21 rotates with the hub 60.

  If an excessive rotational load is applied to the side of the pulley 30, for example, by the breakdown and adhesion of the compressor 10, as shown in Fig. 7, a base end 62a of the coupling key 62 disposed in the hub 60 is broken and, as a result, the torque transmission from the torque plate 50 to the hub 60 is interrupted. As a result, since a connection between the pulley 30 and the compressor 10 is broken and only the pulley 30 rotates, excessive rotational load is not applied to the power source. In addition, it is possible to arbitrarily set the magnitude of the torque for which the coupling keys 62 provided in the hub 60 are broken in accordance with the outside diameter of the coupling keys 62, at the radial distance from the center of the hub 60 or in the number of coupling keys 62.

  According to the power transmission device of the invention, the damping rubber 40 is formed in annular form, multiple convexities 41, 42 which are circumferentially spaced apart from each other are disposed on the outer peripheral surface and the surface internal periphery of the damping rubber 40, and concavities 31, 51 which fit over the convexities 41, 42 on the outer peripheral surface and the inner peripheral surface: damping rubber 40 are disposed on the inner circumferential surface of the pulley 30 and the outer peripheral surface of the torque plate 50. Therefore, during the power transmission, the damping rubber 40 can be elastically deformed in the compression direction and the shear direction, and it is possible to maintain the damping effect for a long time by reducing the permanent forces due to deformatio n elastic only in the compression direction as in a conventional damping rubber. In addition, because the damping rubber 40 is formed integrally in the form of a ring, the assembly work can be easily performed and an increase in productivity can be obtained.

  The damping rubber 40 is formed in such a way that the zone 41 'between the convexities 41, 41 on the outer circumferential surface and the zone 42' between the convexls 42, 42 on the inner circumferential surface respectively come into mutual radial contact with the zone 31 'between the concavities 31, 31 of the pulley 30 and the zone 51' between the concavities 51, 51 of the torque plate 50, so as to generate a circumferential friction resistance. Consequently, it is possible to prevent a circumferential movement between the zone 41 'between the convexities 41, 41 on the outer circumferential surface and the zone 42' between the convexities 42, 42 on the inner circumferential surface, on the one hand, and the zone 31 'between the concavities 31, 31 of the pulley 30 and the zone 51' between the concavities 51, 51 of the torque plate 50, on the other hand, and even when permanent forces are generated in the multiple convexities 41, 42 provided on the outer circumferential surface and the inner circumferential surface of the damping rubber 40, it is possible to prevent the generation of vibration and shock noises due to circumferential rattling between the convexities. 41, 42 of the damping rubber 40 and the concavities 31, 51 of the pulley 30 and the torque plate 50.

  Since each of the convexities 41 on the outer circumferential surface of the damping rubber 40 and each of the convexities 42 on the inner circumferential surface thereof are arranged to be mutually displaced circumferentially, it is possible to bring a force shearing to act positively on the damping rubber 40 and the permanent forces due to a compressive force can be positively inhibited.

  The torque plate 50 and the hub 60 are connected by the coupling key 62 and it is ensured that the coupling key 62 is capable of being broken to disengage the connection between the torque plate 50 and the compressor 10 when torque greater than a prescribed quantity is generated. As a result, it is possible to positively interrupt the transmission of a torque between the compressor 10 and the pulley 30 by using a simple structure and the manufacturing cost can be reduced.

  Because the coupling key 62 is formed to extend in the axial direction of the torque plate 50 and the hub 60, it is possible to positively engage the coupling key 62 to be broken by a prescribed shear force and a torque interruption of the power transmission can be easily fixed.

  Since the hub 60 is formed of a high fatigue limit metal material, fatigue fractures during ordinary torque transmission can be prevented and the reliability of the power interruption mechanism can be improved.

  As the torque plate 50 is formed of a synthetic resin, the realization is easy and the manufacturing cost can be reduced.

  Because the torque plate 50 is integrally formed with the hub 60 by molding the torque plate 50 from a synthetic resin, the coupling key 62 of the hub 60 is held in engagement with the hub plate 60. torque 50 and hub 60 can be handled as a single part, without assembly of torque plate 50 and hub 60 together in the assembly process and, as a result, assembly labor can be reduced .

  It should be noted that, in the embodiment described above, the description is given of the case in which the hub 60 consisting of metal is integrally formed with the torque plate 50 by the molding of a synthetic resin, with the torque plate 50 in position. However, by providing an engaging hole in the torque plate 50 and causing the engagement hole to engage the coupling key 62, the hub 60 can be attached to the torque plate 50 .

  Moreover, in the embodiment described above, the description is given of the case where the damping rubber 40 is formed such that the zone 41 ', between the convexities 41, z-1, on the surface outer circumferential circumferential circumferential zone 42 ', and the zone 42' between the convexities 42 42 on the inner circumferential surface respectively come into mutual radial contact with the zone 31 'between the concavities 31 31 of the pulley 30 and the zone 51' between the concavities 51, 51 of the torque plate 50, so as to generate a circumferential friction resistance. However, the damping rubber 40 may be formed such that the zone 41 ', between the convexities 41, 41, on the outer circumferential surface, and the zone 42', between the convexities 42, 42, on the circumferential surface internal, bring a portion of the zone 31 'between the concavities 31, 31 of the pulley 30 and the zone 51' between the concavities 51, 51 of the torque plate 50 in radial contact with each other, so to generate circumferential friction resistance. Or, alternatively, as shown in FIGS. 8 and 9, the zone 31 'between the concavities 31, 31 of the pulley 30 is brought into radial contact with at least some or both of the zone 41', between the convexities 41, 41, on the outer circumferential surface of the damping rubber 40, and the zone 42 ', between Ln convexities 42, 42, on the inner circumferential surface, to generate a circumferential frictional resistance and, at the same time, protuberances 43 or axially extending portions 44 which bring the area 51 'between the concavities 51, 51 of the torque plate 50 in radial contact, so as to generate a circumferential frictional resistance, are formed, whereby , as shown in FIG. 10, the protuberances 43 or the extension portions 44 can be brought into contact with the zone 31 'between the concavities 31, 31 of the pulley 30 and the zone 51' between the concavities 51, 5] . of the torque plate 50.

  Figures 11 and 12 show the second embodiment of the invention. In these figures, component parts equivalent to those of the first embodiment are indicated by identical reference characters.

  The compressor of this embodiment comprises a torque plate 70 as a second rotating body, drive side, to which a torque of a pulley 30 is transmitted to a damping rubber 40, a hub 80 as a rotating body, driven side which transmits the torque of the torque plate 70 to a rotary shaft 21 of the compressor 10, multiple balls 90, which transmit the torque of the torque plate 70 to the hub 80, and a ball drive ring 100, which depresses each of the balls 90 in the axial direction.

  As with the first embodiment, on the outer peripheral surface of the torque plate 70, concavities 71 which fit over convexities on the inner circumferential surface of the damping rubber 40 are circumferentially spaced apart from each other. A locking ring 72, which holds and locks each of the balls 90 radially from the outside, is installed on the inner circumferential surface of the torque plate 70. Multiple tapered surfaces 73, which form an angle prescribed by together with each other, are formed on the inner circumferential surface of the locking ring 72, and each of the balls 90 abuts against one of the tapered surfaces 73 which are adjacent to each other, so as to be positioned radially towards outside.

  The hub 80 is disk-shaped and disposed on the side of the inner circumferential surface of the torque plate 70. On one end face side of the hub 80, a coupling portion 81, which connects the rotary shaft 21, is provided, and the rotary shaft 21 is fixed to the hub 80 by a nut 82, which screws the rotary shaft 21 from the other end face of the hub 80. Multiple ball grooves 83 , which engage with each of the balls 90 to move them respectively radially, are circumferentially spaced from each other, and each of the balls 90 is circumferentially locked on the side of the inner surface of the ball grooves 83. In this case, a convexity 84 which protrudes axially is provided on the radial outside of each of the ball grooves 83, and the convexity 84 comes axially in abutment against the ball 90 positioned on the radial outside of the ball groove 83. In the middle radial axis of the other end face of the hub 80, an extension portion 85 which extends axially in cylindrical form is arranged to cover the nut 82.

  The ball drive ring 100 is axially movably engaged with the extension portion 85 of the hub 80 and an end side of the ball drive ring 100 abuts against each of the balls. 90. An inclined surface 101 which deaves axially progressively from the axial outside inwardly is disposed on an end face of the ball drive ring 90, and the ball 90 positioned on the radial outside of each ball grooves 83 abut against the radial outside of the inclined surface 101. A conical Belleville washer 102 which engages with the extension portion 85 of the hub 80 is disposed on the other side of the face of the hub. end of the ball drive ring 100, and the ball drive ring 100 is pushed toward the side of the ball 90 by the conical Belleville washer 102. The conical Belleville washer 102 is disposed in a compressed condition between a nut. ann 103, which is screwed onto the extension portion 85, and the driver ring 100, and it is possible to arbitrarily establish a driving force of the ball drive ring 100 by the conical Belleville washer 102 , by adjusting the fastening force of the nut 103.

  In the power transmission device constructed as described above, the torque plate 70 rotates integrally with the pulley 30, when the power from the power source is transmitted to the pulley 30. On this occasion, the torque of the pulley 30 is transmitted to the torque plate 70 via the damping rubber 40 and the convexities 41, 42 of the damping rubber 40 are elastically deformed between the concavities 31 of the pulley 30 and the concavities 71 of the torque plate 70 , with ef :: and that shocks from sudden changes in torque and so on. are absorbed. The torque of the torque plate 70 is transmitted to the hub 80 via the locking ring 72 and each of the balls 90, and the rotary shaft 21 rotates with the hub 80. On this occasion, each of the balls 90 is depressed towards the radial outside of each of the ball grooves 83 by the inclined surface 101 of the ball drive ring 100, and the torque plate torque 70 is transmitted to the hub 80 by circumferential engagement and locking of each of the 9D balls with the tapered surface 73 of the locking ring 72.

  If an excessive rotational load is applied to the side of the pulley 30, for example, by the breakdown and adhesion of the compressor 10, due to the depression of the tapered surface 73 of the locking ring 72, as shown on FIG. 12, each of the balls 90 moves radially inwardly of the ball groove 83 against the driving force of the ball driving ring 100. As a result, each of the balls 90 is held on the ball radial interior of the ball groove 83 by the convexity 84 of the ball groove 83 and the ball drive ring 100 and each of the balls is under stress in a position incapable of engagement and u: z Locking with the locking ring 72. As a result, the torque plate 70 becomes free with respect to the hub 80 and, as a result, the power transmission from the side of the pulley 30 to the rotary shaft 21 is interrupted. So according to the power transmission device of this mode of

  realization, the power of the torque plate 70 is transmitted to the hub 80, bringing the multiple balls 90 able fun radial movement to engage and lock the torque plate 70, and each of the balls 90 is moved in the direction radial hub 80 to disengage engagement with the torque plate 70, when a torque greater than a prescribed magnitude is generated between the torque plate 70 and the hub 80. Accordingly the power transmission can be positively interrupted by a prescribed torque and it is possible to arbitrarily set a torque used in the interruption and to interrupt the power with greater accuracy.

  The preferred embodiments described above are illustrative only and are not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims and all the examples of variants included in the claims of these

  Claims are included in the invention.

2869376 14

Claims (5)

  A power transmission device, comprising: a first drive side rotating body (30), which is rotated by power from outside, a second drive side rotating body (50), which is rotation by the first drive-side rotating body (30), a damping rubber (40) disposed between the first and second rotation bodies (30, 50), a driven-side rotating body (60), to which a torque second driving side rotation member x50) is transmitted, and a power interruption mechanism, which interrupts the transmitted power of the second drive side rotating body (50) to the driven side rotating body (60), when a torque greater than a prescribed quantity is generated between the second, drive side rotating body (50) and the driven side rotating body (60), whereby the torque of the first drive side rotating body (30) is transmitted s to the second drive side rotating body (50) via the damping rubber (40), wherein said damping rubber (1-0) is formed into an annular shape, a plurality of convexities (42), which are wax spaced apart from each other, each disposed on an outer circumferential surface and an inner circumferential surface of the damping rubber (40), a plurality of concavities (31) each fitting on each of the convexities (41). on the side of the outer circumferential surface of the damping rubber (40) are disposed on an inner circumferential surface of one of the first and second drive-side rotating bodies (30, 50), and a plurality of concavities (51) , which each adjusts to each of the convexities (42) on the side of the inner circumferential surface of the damping rubber (40), are disposed on an outer circumferential surface of the other first and second drive side rotating bodies (30, 50), characterized in that said power interruption mechanism is constructed such that the power interruption mechanism transmits the power of the second rotation body drive side (50) to the driven side rotating body (60), causing an engaging portion 2869376 disposed in one of the second drive side rotating body (50) and the driven side rotating body (60). ) engaging the other of the second drive side rotating body (50) and the driven side rotating body (60), and disengaging engagement with the second drive side rotating body (50), e: 1 causing said engaging portion to be broken by a circumferential shearing force of the driven side rotating body (60), when a torque greater than a prescribed magnitude is generated between e second drive side rotating body (50) and the driven side rotating body (60).   A power transmission device according to claim 1, wherein said engaging portion is formed to extend in the axial direction of the second drive side rotating body (50) and the driven side rotating body (50). 60).   A power transmission device according to claim 1 or 2, wherein said engaging portion is formed of a high fatigue limit metal material.   A power transmission device according to claim 1 or 2, wherein the second drive side rotating body (50) or the driven side rotating body (60) engaging with said engaging portion is formed of a synthetic resin.   A power transmission device according to claim 2, wherein the second drive-side rotating body (50) or the driven-side rotating body (60) which engages with said engaging portion is molded from of a synthetic resin in a condition of engagement with the engaging portion, and the drive-side rotating body (50) and the driven-side rotating body (60) are integrally formed with each other .