JP2019510912A - Freewheel and starting device provided with this freewheel - Google Patents

Abstract

  The invention comprises an inner member (2), an outer race (3) and a locking member arranged displaceably within a limited range between the inner member (2) and the outer race (3). The invention relates to a freewheel (1) for a starter, characterized in that the locking member is a fastener (4) having a curved inner surface (6) and a curved outer surface (9).

Description

  The present invention relates to a freewheel. The invention further relates to a starting device provided with this freewheel.

  In the prior art, freewheels have long been known. DE 102005034039 describes a roller type freewheel and DE 2836114 describes a fastening body (sprag) type freewheel. Furthermore, DE 10 201 0052 921 discloses a variant of a freewheel in which the inner and outer races are provided with fastening profiles.

  The power density of the roller or bound freewheel is defined by the maximum use time of the contact between the fastening element and the track (hertz contact). In this case, the end of use time is often the material fatigue of the track or of the fastening element itself.

  In conventional roller-type and fastening-type freewheels, the radius of curvature is in most cases significantly different or even reversed between the fastening element and the track. This results in a substantially linear contact, which has to withstand high pressures.

  DE 10 201 0052 921 describes a variant in which the curvature of the track approximates the radius of the roller by means of recesses provided in the inner track and the outer track.

  The technical problem is therefore to overcome the drawbacks of the prior art and to achieve higher power densities. In this context, it is necessary to reduce the construction space and to transmit more torque with less material use.

  The above-mentioned problem is achieved according to the invention in particular by a free member for a starter comprising an inner member, an outer race and a locking member displaceably arranged within a limited range between the inner member and the outer race. A wheel, the locking member being solved by a freewheel characterized in that it is a fastener with a curved inner side and a curved outer side.

  By providing this fastener, a reduction in pressure between the fastening element and the track can be achieved.

  Preferably, the curvature represents a shape according to a curve, arc or circle. Preferably, at least one curve, arc or circle defines the curvature. Particularly preferably, the curvature represents a shape composed of at least two curves with different geometrical shapes and / or at least two arcs with different radii.

  In one embodiment according to the invention, the fasteners are formed to narrow in the area between the curved inner surface and the curved outer surface.

  By providing the constriction, the fastening can be easily performed.

  Preferably, the fastener has a biconcave shape. In this way, it is possible to easily switch over from freewheeling to torque transmission.

  The high capacity density of the freewheel enables a particularly slim form of construction. This results in the use of new manufacturing techniques, preferably the punching process of the outer race, which can result in lower production costs.

  In another embodiment according to the invention, the inner member has a curved inner track and the outer race has a curved outer track provided with arches or the inner member The arch has a curved inner track provided, and the outer race has a curved outer track.

  Preferably, the inner member or outer race is cylindrically shaped. Preferably, the inner member or outer race has a radius defining a cylindrical trajectory.

  By using a cylindrical inner track or a cylindrical outer track, fastening of the freewheel is possible without any slippage at any position.

  Preferably, the contours of the fastener and the outer track can be flexibly configured. This allows the design to be adjusted such that the fastening angle at the contact point increases when the "normal" torque is greatly exceeded. As the fastening angle increases, the freewheel slip tendency increases. This limits the transmittable torque to the maximum torque. At this time, the robust configuration of the outer race and the fastening piece prevents damage to the free wheel.

  In another embodiment according to the invention, the curvature of the inner trajectory is approximated to the curvature of the inner surface, and the curvature of the outer trajectory is approximated to the curvature of the outer surface.

  The curvature of the fastening tip is close to the curvature of the inner orbit and the curvature of the outer orbit. This creates an ideal, large contact surface at the point of contact when loaded. This reduces the pressure significantly.

  Preferably, the curvature of the inner track is less than the curvature of the inner surface. Preferably, the curvature of the outer track is less than the curvature of the outer surface.

  In another embodiment according to the invention, the curvature of the inner track corresponds to the curvature of the inner surface, and the curvature of the outer track corresponds to the curvature of the outer surface.

  This allows an alternative configuration of the freewheel.

  In another embodiment according to the invention, the inner surface forms a first contact surface with the inner track and the outer surface forms a second contact surface with the outer track to fasten the fastener. .

  Thereby, fastening can be performed easily.

  In another embodiment according to the invention, a spring is provided which generates a return force, the spring being arranged at the first end in the spring holder of the outer race and at the second end It is arranged at the fastening post.

  Preferably, the geometry and mass of the fastener, the position of the spring and the spring force are adjusted relative to one another such that lifting of the fastener from the inner track can be carried out from a predetermined number of rotations. The freewheel is thereby operable without loss during idle operation.

  Furthermore, the above problem is solved by a starting device for an internal combustion engine, in particular comprising a freewheel.

  This freewheel is suitable for use in starter drives of internal combustion engines, in particular in constant mesh starters. By using fasteners with different function areas, it is possible to limit the maximum transmittable torque. Thus, the freewheel is robust against unexpectedly high torque that may occur when, for example, the internal combustion engine fails to start.

  The invention is illustrated below in the drawings.

1 is a schematic view of a freewheel according to the present invention. It is a schematic plan view of the free wheel shown in FIG. It is the schematic of the fastening tip of a freewheel. It is the schematic of the freewheel in idling. It is the schematic of the free wheel in the state with which the fastening tip was fastened.

  FIG. 1 shows a schematic view of a freewheel 1 according to the invention, and FIG. 2 shows this freewheel 1 in a schematic plan view.

  The freewheel 1 is intended for starters for internal combustion engines. The freewheel 1 comprises a cylindrical inner member 2, an outer race 3, and three locking members arranged displaceably within a limited range between the inner member 2 and the outer race 3. The three locking elements are designed as fastening lugs 4. The fastening piece 4 has a curved inner side 6 and a curved outer side 9.

  The inner member 2 has a curved inner track 5. The outer race 3 has three arches 7 depending on the number of fasteners 4. The arch 7 forms a curved outer track 8 of the outer race 3. The inner member 2 has a cylindrical shape. By using the cylindrically formed inner member 2, an inner track 5 having a curvature according to the radius of the inner member 2 is obtained. In that case, the fastening of the freewheel takes place at all positions without a slippage distance. The curvature of the inner track 5 is approximated to the curvature of the inner surface 6. Furthermore, the curvature of the outer track 8 is approximated to the curvature of the outer surface 9.

  In order to fasten the fastener 4, the inner surface 6 forms a first contact surface with the inner track 5 and the outer surface 9 forms a second contact surface with the outer track 8.

  The freewheel 1 comprises three springs 11. The spring 11 is configured to generate a return force for the fastener 4. The three springs 11 are arranged at the first end in the spring holding part 10 of the outer race 3 and at the second end in the clamping shank 4.

  FIG. 3 shows a schematic view of the fastening block of the free wheel 1. As already mentioned above, the fastening insert 4 has a curved inner side 6 and a curved outer side 9. The cross section of the fastening tip 4 is formed so as to narrow in the region between the curved inner surface 6 and the curved outer surface 9. The fastener 4 has a biconcave shape.

  FIG. 4 shows a schematic view of the freewheel 1 during idling (see arrow 12), and FIG. 5 shows the torque (see arrow 13) when the fastener 4 is fastened.

  As the fastening angle increases, the slip tendency of the free wheel 1 rises. This limits the transmittable torque to the maximum torque. At this time, the robust configuration of the outer race 3 and the fastening piece 4 prevents the free wheel 1 from being damaged.

  The provision of this fastening piece makes it possible to limit the maximum transmittable torque. Thus, the freewheel is robust against unexpectedly high torque that may occur when, for example, the internal combustion engine fails to start.

DESCRIPTION OF SYMBOLS 1 free wheel 2 inner member 3 outer race 4 fastening top 5 inner track 6 inner side surface 7 arched portion 8 outer side track 9 outer side surface 10 spring holding portion 11 spring 12 arrow 13 arrow

Claims (8)

The inner member (2),
Outside race (3),
A locking member displaceably arranged within a limited range between the inner member (2) and the outer race (3);
A freewheel (1) for a starter, comprising
A freewheel (1), characterized in that the locking member is a fastener (4) having a curved inner surface (6) and a curved outer surface (9).   The freewheel (1) according to claim 1, wherein the fastening pin (4) is formed to narrow in the region between the curved inner surface (6) and the curved outer surface (9). ).   The inner member (2) has a curved inner track (5) and the outer race (3) has a curved outer track (8) provided with arched parts (7), Alternatively, the inner member (2) has a curved inner track (5) provided with arched parts (7) and the outer race (3) has a curved outer track (8) Freewheel (1) according to claim 1 or 2.   The curvature of the inner track (5) is approximated to the curvature of the inner surface (6) and the curvature of the outer track (8) is approximated to the curvature of the outer surface (9). Freewheel (1).   A free-running according to claim 3, wherein the curvature of the inner track (5) corresponds to the curvature of the inner surface (6) and the curvature of the outer track (8) corresponds to the curvature of the outer surface (9). The wheel (1).   In order to fasten the fastening pin (4), the inner surface (6) forms a first contact surface with the inner track (5), and the outer surface (9) is the outer track (8) 6. A freewheel (1) according to any one of claims 3 to 5, forming together with the second contact surface.   A spring (11) is provided which generates a return force, said spring (11) being arranged at the first end with the spring holding part (10) of said outer race (3), the second end 7. A freewheel (1) according to any one of the preceding claims, which is arranged in the fastening shank (4) in a part.   A starting device for an internal combustion engine, comprising a freewheel (1) according to any one of the preceding claims.

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