FR2885393A1 - Torque transmission device for engine, has rotating shaft extended outside water tight joint, rotating units facing each other to form covering in space between them, sealing device closing space leading towards exterior of clutch - Google Patents

Abstract

The device has rotating units (2, 4) connected to respective pinions (11) of a starter and an end of a rotating shaft (3), where the shaft is extended outside the engine by a water tight joint (19). The unit (2) has an impact absorber (7) installed between its periphery and a ring gear (8). The units face each other in a radial direction to form a covering in a space between them. A clutch (5) establishes a torque transmission from its inner part to outer parts. A sealing device (6) hermetically closes a space leading from the clutch towards the exterior of the clutch between the units.

Description

1 2885393

  ENGINE STARTER DESIGNED TO PRESENT SUSTAINABILITY

IMPROVED

  BACKGROUND OF THE INVENTION Technical Field of the Invention The present invention relates generally to a torque transmission device for use in transmitting a starting torque to an engine, and more particularly to such a torque transmission device equipped with a clutch which is designed to improve the longevity of the clutch.

  Background Art The first Japanese Patent Publication No. 10122107 discloses a starter device for an internal combustion engine which consists of an electric starter motor, a reduction gear element meshing with a pinion mounted on the starter motor, a starter drive gear meshing with a rotating gear element in unison with the reduction gear member, and a clutch disposed between the starter drive gear member, a rotatable shaft of the motor, and a cover connected to the motor housing.

  The clutch consists of an inner ring, an outer ring and clutch elements. The inner race is integrally formed with the starter drive gear member and held rotatable by the rotary shaft of the motor via a needle bearing. The outer ring is connected to the rotating shaft of the motor.

  In operation, when the reduction gear member is rotated by the starter motor, the starter drive gear member is driven through the rotary gear element to the starter motor. in unison with the reduction gear element, thereby transmitting the torque of the starter drive gear element to the rotary shaft of the motor through the clutch to start the engine.

  The starter device is also equipped with a drive gear member formed in the clutch outer race and a balancer meshing with the drive gear element. . The rotation of the balancing device will cause the engine oil to settle on the bottom of the cover to lubricate the clutch.

  Usually, the engine oil is contaminated with foreign particles such as wear debris during lubrication of the sliding parts of the engine. The intrusion of such foreign particles into the clutch will result in wear of the clutch torque transmission surfaces and in clutch malfunction.

  SUMMARY OF THE INVENTION It is therefore a principal object of the invention to avoid the disadvantages of the prior art.

  It is another object of the invention to provide an improved structure of a torque transmission device for use with an engine starter which is designed to provide improved longevity of a clutch.

  According to a present aspect of the invention, there is provided a torque transmission device for use with a starter for motors. The torque transmitting device operates to transmit torque output from the starter to a rotary shaft of the engine and comprises: (a) a first rotary member equipped with a ring gear to be selectively engaged with a starter gear (b) a second rotating member connected to one end of the rotating shaft extending out of the engine through a liquid-tight seal, the second rotating member being positioned to face the first rotating member in a direction axial axis of the first rotary member, (c) a bearing disposed between the first and second rotary members for holding the first and second rotatable members to rotate relative to one another, (d) a clutch including an inner portion provided on the first rotating member and an outer portion provided on the second rotating member, the outer portion being disposed outside the the inner portion in a radial direction of the first rotary member, the clutch acting to establish a torque transmission from the inner portion to the outer portion when the first rotating member is rotated by the starter, and (e) an element sealing acting to seal a spacing from the clutch outwardly of the clutch between the first and second rotating members.

  In particular, the sealing member serves to prevent the lubricating oil used in the clutch from escaping outside the torque transmission device. The rotating shaft extends outside the engine through the liquid-tight seal, thereby preventing oil leakage from the engine to the outside of the engine. This allows special lubricating oil to be used in the clutch, thus improving the longevity of the clutch.

  In the preferred embodiment of the invention, the bearing is disposed closer to the engine than the clutch in a torque transmission path. This allows special clutch lubrication oil to be used in the bearing as well to improve the longevity of the bearing.

  The first and second rotatable members partially face each other in a radial direction of the first and second rotatable members to form laps in the space between them which are located closer to the outside of the first and second rotating members second rotating elements than rolling. The covers serve as seals to prevent the intrusion of foreign objects from outside the torque transmission device to ensure clutch performance.

  The sealing member is disposed outside the clutch in the radial direction of the clutch. The bearing disposed within the clutch in the radial direction of the clutch. The clutch, the sealing member and the bearing are arranged to overlap in the radial direction. In particular, the clutch, the sealing element and the bearing are positioned coaxially with each other, thus allowing the size of the torque transmission device to be reduced in its axial direction.

  The torque transmission device also comprises an impact absorber installed in a torque transmission path through which the torque applied to the ring gear from the pinion is transmitted to the inner portion via the impact absorber.

  The impact absorber acts to absorb the excess torque applied to the crown input from the pinion to reduce mechanical noise from meshing the pinion with the crown. This allows the torque transmission device to have a silent structure.

  The impact absorber is positioned within the overlaps in the radial direction of the first and second rotating members. The overlaps serve to prevent the adherence of foreign particles to the impact absorber, which results in performance of the impact absorber during an extended period of time. The impact absorber may be made of rubber.

BRIEF DESCRIPTION OF THE DRAWINGS

  The present invention will be more fully understood from the detailed description given below and from the appended drawings of the preferred embodiments of the invention which, however, should not be construed as limiting the invention to the embodiments of the invention. but are intended for the purpose of explanation and comprehension only.

On the drawings.

  Fig. 1 is a cross-sectional view showing an internal structure of a torque transmission device for use in an engine starter according to the present invention, and Fig. 2 is a cross sectional view which represents the torque transmission device of Figure 1 which is connected to a rotating shaft of a motor.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS

  Referring to the drawings, where like reference numerals refer to like parts in the several views, in particular to FIG. 1, there is shown a torque transmission device 1 according to the invention. The torque transmission device 1 is used with a motor starter (not shown) that can be used when starting an automobile engine.

  The torque transmission device 1 consists essentially of a first rotary element 2 to be rotated by a torque output of the starter, a second rotary element 4 fixed to a rotary shaft 3 of the engine, a clutch 5 disposed between the first and second rotary members 2 and 4, and a seal 6 disposed on the opposite side to the clutch motor 5.

  The first rotary member 2 is as illustrated in Figure 2, consisting of an outer annular portion 2a, an inner annular portion 2b and arm 2c. The inner annular portion 2b is disposed within the outer annular portion 2a coaxially therewith. The arms 2c extend radially to connect between the outer and inner annular portions 2a and 2b. The arms 2c each have a smaller thickness than the outer and inner annular portions 2a and 2b in an axial direction of the torque transmission device 1 and are connected between front ends (i.e. the left ends, as seen in Figure 2) outer and inner annular portions 2a and 2b to define a recess or annular chamber between the inner periphery of the outer annular portion 2a and the outer periphery of the inner annular portion 2b within which the clutch 5 and the seal 6 are arranged.

  A ring 8 is fitted on the outer periphery of the outer annular portion 2a via an impact absorber 7. The impact absorber 7 consists of a rubber body, an inner metal ring 9 attached to the inner periphery of the rubber body and an outer metal ring 10 attached to the outer periphery of the rubber body and fitted tightly between the inner periphery of the ring gear 8 and the outer periphery of the outer annular portion 2a of the first rotary member 2.

  Referring again to FIG. 1, when the engine must be started, the ring gear 8 is brought into engagement with a pinion 11 of the starter, so that it is rotated by the torque transmitted from the pinion 11.

  The second rotary element 4, as clearly illustrated in FIG. 2, comprises a protuberance 4a protruding to the left, as seen in the drawing, and coupled with the first rotary element 2 in order to be able to turn relative to each other by through a bearing 12 adapted to the protuberance 4a. The second rotary member has an outer diameter substantially equal to that of the ring 8 and protuberances 4b formed on an outer peripheral portion of one of its opposite end walls. The protuberances 4b extend towards the ring 8 and are arranged all around the circumference of the second rotary element 4. The ring 8 comprises a ring 8b whose outer wall 8a faces the inside of the protuberances 8a. In particular, an outer peripheral portion of the ring 8 located outside the ring 8b has a smaller thickness and takes the form of a flange. In other words, an annular recess is formed in the outer periphery of the ring 8 to define the ring 8b. The ring 8b has the outer wall 8a which is close to the protuberances 4b of the second rotary element 4. In particular, the outer wall 8a partially overlaps the protuberances 4b in a radial direction of the ring 8 via spacing d such as labyrinth-like spacings acting as labyrinth-type joints.

  The bearing 12 is implemented by a ball bearing which consists of an inner ring 12a fitted on the outer periphery of the protuberance 4a, an outer ring 12b fitted on the inner periphery of the first rotary member 2 and balls. 12c disposed between the inner and outer rings 12a and 12b. Seals are disposed outside the balls 12c between the inner and outer rings 12a and 12b.

  The clutch 5 comprises a clutch mechanism 5a disposed between the inner annular portion 2b of the first rotary member 2 and an outer ring 13 adapted in the second rotary member 4.

  The outer ring 13 has a flange 13a formed integrally therewith. The flange 13a is connected to the second rotary element 4 by means of bolts 14. The outer ring 13 extends outside the end of the second rotary element 4 from which the protuberance 4a protrudes. The outer ring 13 enters an annular chamber formed in the first rotary member 2 and is outside the inner annular portion 2b of the first rotary member 2 coaxially therewith.

  The clutch mechanism 5a may consist for example of cams, rollers, or cylinders and acts as a unidirectional clutch together with the inner annular portion 2b of the first member. 2 and that the outer ring 13 of the second rotary member 4. In operation, when the first rotary member 2 can be rotated by the starter, the clutch mechanism 5a engages with the outer periphery of the inner annular portion. 2b and the inner periphery of the outer ring 13 to establish a torque transmission from the inner annular portion 2b to the outer ring 13. When after starting the engine, the second rotating member 4 is rotated by the motor and that the speed of the second rotary element 4 exceeds that of the first rotary element 2, this will cause the clutch mechanism 5a to disengage the inner annular portion 2b of the outer ring 13 to block the transmission of the torque of the outer ring 13 to the annular portion inside 2b.

  The seal 6 is an oil-tight seal with an inner lip and disposed outside the outer ring 13 in its radial direction within the annular chamber of the first rotary member 2. The seal 6 is fitted tightly at the inner periphery of the outer annular portion 2a of the first rotary member 2, with contact of the inner lip with the outer periphery of the outer ring 13 to seal a gap between the first rotary member 2 and the outer ring 13.

  The torque transmission device 1 of this embodiment is adapted to cause the first and second rotating members 2 and 4 to be disposed in proximity to each other in their axial direction and coupled via the bearing 12, the clutch 5 and the seal 6. The second rotary element 4 is connected at the level of the protuberance 4a to the rotary shaft 3 of the engine.

  The rotary shaft 3 is, as clearly illustrated in FIG. 1, rotatably retained in a mounting hole 16 formed in a side wall of a housing 15 (or engine block) of the engine and has an end s'. extending outside the housing 15 from the mounting hole 16.

  The end of the rotating shaft 3 has a flange 3a extending outside the mounting hole 16 in its radial direction and a small diameter portion 3b (i.e., a protuberance) formed on the edge 3a. The protuberance 4a of the second rotary element 4 is fitted on the outer periphery of the small-diameter portion 3b and firmly connected to the flange 3a by means of bolts 18.

  The casing 15 has an annular protuberance 15a formed around the mounting hole 16. The annular protuberance 15a is outside the rim 3a of the rotary shaft 3. A seal 16 is fitted tight to the inner periphery of the annular protuberance 15a. The seal 19 is implemented through an oil seal having a lip. The lip is placed in contact with the outer periphery of the rim 3a to sealingly close a gap between the housing 15 and the rim 3a tightly.

  During the operation of the torque transmission device 1, when the torque output from the starter is applied to the ring gear 8 via the pinion 11, this will cause the torque to be transmitted from the ring gear 8 to the first element 2 by means of an impact absorber 7 and to the second rotary element 4 from the first rotary element 2 via the clutch 5. The second rotary element 4 then rotates the rotary shaft 3 to start the engine.

  After starting the engine, when the second rotary element 4 is rotated by the torque supplied at the motor output and its speed exceeds that of the first rotary element 2, this will cause the clutch 5 to be disengaged in order to block the transmission. motor torque to the starter.

  Beneficial features exhibited by the torque transmission device 1 will be described below.

  The seal 6 is disposed on the side of the clutch 5 opposite the engine to establish a liquid-tight seal between the first rotating member 2 and the outer ring 13, thus avoiding leakage of lubricating oil used in the clutch 5 outside the outer ring 13. The seal 19 is also fitted tight on the inner periphery of the annular protrusion 15a of the housing 15, the lip being placed in contact with the outer periphery of the flange 3a of the rotary shaft 3 of the engine to establish a liquid-tight seal between the rim 3a and the housing 15, thereby preventing oil leakage from inside the engine. This avoids the intrusion of the engine oil into the clutch 5, thus allowing a special lubricating oil to be used in the clutch 5. In the case where the engine oil is used for the lubrication of the clutch 5, as described in the introductory part of this application, this will cause foreign particles such as wear debris contained in the engine oil to wear the torque transmission surface of the clutch 5, which results in a reduction in the performance of the clutch 5. The use of the special lubricating oil in the clutch 5 avoids this problem, thus ensuring an increased longevity of the clutch 5.

  The bearing 12 is located on the side of the clutch 5 near the melter, thus allowing a special lubricating oil to be used only for the bearing 12 in order to improve its longevity.

  In addition, the first rotary element 2 comprises the impact absorber 7 installed between its outer periphery and the ring 8. When subjected to excessive torque transmitted from the engine to the first rotary element 2, the absorber of impact 7 is elastically deformed in the circumferential direction of the first rotary member 3 to absorb the torque. The impact absorber 7 is positioned close to the ring gear 8 and thus acts to reduce the gearing noises coming from the engagement of the ring gear 8 with the pinion 11. In particular, the stop / start systems of the Automatic motors (usually called low-cost operating systems or idle shutdown systems) are required to start and stop the engine a large number of times, generating gear noises frequently. The impact absorber 7 is therefore very useful in such systems.

  The outer wall 8a of the ring 8 is, as described above, placed near the protuberances 4b of the second rotary element 4 in the radial direction of the ring 8 to form overlaps in the space between them, which create labyrinth-type spacings to prevent the intrusion of foreign objects from outside the torque transmission device 1, resulting in increased service life of the seal 6 and improved longevity of the clutch 5.

  The covers are located outside the impact absorber 7 of the first rotating element 2 in its radial direction, thus avoiding the adhesion of foreign objects on the impact absorber 7 to ensure the absorption operations. impact and noise reduction during an extended period of time.

  As clearly shown in Figure 2, the outer ring 13 extends into the annular chamber of the first rotary member 2 within which the clutch 5 is disposed within the outer ring 13, while the seal 6 is disposed outside the outer ring 13. The bearing 12 is interposed between the outer periphery of the protuberance 4a of the second rotary member 4 and the inner periphery of the inner annular portion 2b of the first rotary member 2. In particular, the bearing 12, the clutch 5 and the seal 6 are positioned at the same position, as observed from the radial direction of the first rotary element 2, which thus results in a reduction in the size of the torque transmission device 1 in its axial direction.

  The use of the torque transmission device 1 in the automatic engine start / stop systems can be obtained by placing the pinion 11 in constant engagement with the ring gear 8. The torque transmission device 1 can, however, be designed to make so that the crown 8 is selectively placed in engagement with the pinion 11 only when one must start the engine.

  While the present invention has been described in terms of the preferred embodiments so as to facilitate a better understanding thereof, it will be appreciated that the invention can be implemented in a variety of ways without departing from the principle of the invention. of the invention. Therefore, the invention should be understood to include all possible embodiments and modifications of the shown embodiments that can be implemented without departing from the principle of the invention as set forth in the claims. attached.

He 2885393

Claims (7)

  A torque transmission device (1) for transmitting torque output from a starter to a rotary shaft (3) of an engine comprising: a first rotary member (2) equipped with a crown (8) to be selectively engaged with a starter pinion (11), a second rotary member (4) connected to an end of the rotary shaft (3) extending out of the engine via a liquid-tight seal (19), said second rotatable member (4) being positioned to face said first rotatable member (2) in an axial direction of said first rotatable member (2), a bearing (12) disposed between said first and second rotary members (2, 4) for holding said first and second rotary members (2, 4) rotatable relative to each other, a clutch (5) having an inner portion provided on said first member rotating (2) and an outer part provided ur said second rotatable member (4), the outer portion being disposed outside the inner portion in a radial direction of said first rotatable member (2), said clutch (5) acting to establish torque transmission from the inner portion to the outer portion when said first rotary member (2) is rotated by the starter, and a sealing member (6) operative to seal a spacing from said clutch (5) outwardly of said clutch ( 5) between said first and second rotary members.   The torque transmission device (1) according to claim 1, wherein said bearing (12) is disposed closer to the engine than said clutch (5) in a torque transmission path.   A torque transmitting device (1) according to claim 1 or 2, wherein said first and second rotatable members (2, 4) are partially facing each other in a radial direction of said first and second rotating members (2, 4) for forming overlaps in the space between them which are located closer to the outside of said first and second rotating members (2, 4) than said bearing (12).   A torque transmitting device (1) according to any one of claims 1 to 3, wherein said sealing member (6) is disposed outside said clutch (5) in a radial direction of said clutch (5). ), and said bearing (12) is disposed within said clutch (5) in the radial direction of said clutch (5), and wherein said clutch (5), said sealing member (6) and said bearing (12) ) are arranged to overlap in the radial direction.   A torque transmitting device (1) according to any one of claims 1 to 4, further comprising an impact absorber (7) installed in a transmission channel of 1 torque through which the torque applied 0 input to the ring (8) from the pinion (11) is transmitted by the inner portion through said impact absorber (7).   The torque transmission device (1) according to claim 5, wherein said impact absorber (7) is located within the overlaps in the radial direction of said first and second rotating members (2, 4).   The torque transmission device (1) according to claim 5, wherein said impact absorber (7) is made of rubber.