DE2624743A1 - PUSH DRIVE FOR A TURNING DEVICE OF COMBUSTION MACHINES - Google Patents

Description

R. 325S
25-5.1976 week / Sm

Attachment to

Patent and

Utility model auxiliary registration

ROBERT BOSCH GMBH, Stuttgart Thrust drive for a cranking device of internal combustion engines

The invention relates to a thrust drive for a cranking device of internal combustion engines, with a rotatable and displaceable relative to the drive shaft of the starting motor Starter pinion j which is attached to one end of a gear shaft protruding from a gear housing, which is in operative connection with the drive shaft via a releasable coupling and by one of a coaxially arranged one Engaging relay operated push member is movable.

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In the known cranking device for high performance, the thrust drive is electrically actuated in two stages. It will the starting pinion meshed in a first stage in the ring gear of the internal combustion engine before the second stage Main current contact is closed and the starting motor receives full current. To carry out the first stage, the known cranking device two different electrical power elements - engagement relay and control relay - required, which, however, are linked by switching and power tuning. The engagement relay exercises a on the thrust drive Toe-in force off, d. H. the starting pinion is moved axially towards the ring gear. The control relay causes the The starter motor rotates with a pre-stage torque that is matched to the toe-in force and thus a circumferential force on the thrust drive exercises so that the pre-engaged starting pinion on the ring gear is rotated to mesh with a tooth gap. Toe-in force and circumferential force must, however, have a very specific relationship to one another in order to ensure a reliable meshing process to ensure.

However, it has been found to be a disadvantage with this meshing system that mechanical and electrical tolerances and the different friction behavior of the bearings and brushes can cause the ratio of toe-in force to circumferential force to be so unfavorable that reliable meshing of the starting pinion cannot always take place. If the feed force is too high, the starter pinion pressed against the ring gear cannot be turned into the tooth gap position. The starting pinion cannot mesh. This switching process is referred to as dummy switching. If the circumferential force is too great, the face friction between the ring gear and the starter pinion is overcome. However, between the engaging starting pinion and the ring gear there is immediately such a high flank pressure that the starting

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The pinion is not fully in the ring gear the main power contact cannot be closed. It is coming only to a partial intervention. Flashing and partial intervention prevent the internal combustion engine from turning.

In addition, in the known thrust drive, the coupling between the drive shaft and the transmission shaft is designed as a multi-plate coupling. Slipping clutches, such as the multi-plate clutch, do have good damping properties and allow simple means of torque limitation, due to the inertia of the Lanicllenpaket and the path conditions inherent to the slip clutches, they are sufficient for the dynamic starting behavior of modern engines in certain cases not anymore.

The invention is therefore based on the object of creating a thrust drive in which the advantages of the known device like free-kicking starting pinion with a smaller number of teeth and thus a sufficient smaller starting motor as well Arrangement of the single-track gearbox protected against dirt and moisture with space-saving, coaxially arranged engagement relay together with the known mechanical starter pinion rotation and one with a damping device equipped coupling device, the quick change between torque transmission to the starting pinion and loosening of the starting pinion from the frictional connection with the drive shaft allows to be provided to a To create safe, space-saving, round and therefore installation-independent turning device that also meets the requirements suffice for more powerful internal combustion engines.

According to the invention the object is achieved in that a Tooth coupling between the gear shaft and the drive shaft

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is arranged, the driven coupling part on the transmission shaft is attached and the driving coupling part of which engages with a steep thread of a gear pot, which is non-rotatably connected to the drive shaft, but is arranged to be longitudinally displaceable with respect to it, a damping device has, on which a return spring rests, while a meshing spring between the driving clutch part and the gear box is housed, on which the Sehubglied rests.

To avoid excessive ratcheting of the tooth coupling when separating the tooth coupling parts is a further embodiment the invention has the advantage that the toothed clutch is provided with a centrifugal separator, the flyweights are arranged on the transmission shaft so as to be radially movable and have a conical surface which is attached to a conical annular shoulder of the driving clutch part can be pressed, and that the meshing spring is designed as a clutch spring.

Further advantageous embodiments of the invention emerge from the remaining subclaims and the description.

An embodiment of the thrust drive for turning devices is shown in the drawing. She shows in

1 shows the part of the starting device on the thrust drive side in longitudinal section,

2 shows the part of the cranking device on the engagement relay side in longitudinal section,

3 shows an electrical circuit diagram of the starting device.

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A starting motor 1 of the starting device has a motor housing 2 in which pole bodies 3, which carry the field winding 4, are fastened. A gear housing 6 (FIG. 1) and a collector bearing 7 (FIG. 2) are arranged on the end faces of the motor housing 2 and are firmly connected to the motor housing 2 by tie rods 8. The collector bearing 7 is cup-shaped. In a central bore 9 in the bottom 10 of the collector bearing 7, a sliding bearing 11 is inserted in which one end of a hollow drive shaft 12 is rotatably mounted. A collector 13 and an armature 14 of the starting motor 1 are arranged on the drive shaft 12. A brush holder 16 carrying positive pole brushes 15 and negative pole brushes is fastened in the collector bearing 7.

On the end of the drive shaft 12 protruding from the armature 14 a bell-shaped driver 17 is attached. The driver 17 is closed with a cover 18. The lid 18 is provided with an extension 19 which is rotatably received in a bearing 20 in a longitudinal bore 21 of the gear housing 6 is.

The drive shaft 12 has a longitudinal bore 22 with a bearing section 23 of larger diameter and with an enlarged end section adjoining the bearing section 23 The driver 17 is provided with internal straight teeth 25. A gear pot 26 has an external straight toothing 27, which meshes with the internal straight teeth 25. Gear pot 26 and driver 17 are through the straight teeth 27j 25 non-rotatably connected to one another, but against one another movable. The gear box 26 has an extension 28 with an inner bearing section 29 into which a bearing 30 is inserted and which extends into the enlarged end portion 24 of the drive shaft 12. The end of the appendix 28 is slidably received in the bearing section 23 of the drive shaft 12.

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The gear pot 26 is also with an internal partial thread 31 is provided, which engages with an external & partial thread 32 of a driving coupling part 33 of a spur tooth coupling stands. The coupling part 33 is sleeve-shaped and has saw teeth on its end face facing away from the armature 14 34 provided. They engage in corresponding teeth 35 on the face of a driven coupling part 36, which the transmission shaft 37 is formed.

A damping device is accommodated in an end section 38 of the gear box 26. It consists of a stop disk 39 ₃ a damping ring 40 made of elastic material, a damping bushing 41 and a retaining ring 42. First, the stop disk 39 is inserted into the end portion 38 so that it is on an annular shoulder 43 of the gear pot 26 and on an end face 44 of the the gear shaft 37 arranged driven coupling part 36 rests. The damping ring 40 is seated in the end section 38 on the damping bushing 4l and rests against its flange 45 and the stop disk 39. The damping bushing 4l is guided with its flange 45 in the end section 38 of the gear box 26. The retaining ring 42 is fastened in the end section 38 and limits the outward movement of the damping bush 4l. The gear shaft 37 protrudes through the base 46 of the damping bushing 41. A return spring 47 sits on the gear shaft 37 and rests with one end on the base 46 of the damping bushing 41, while its other end is supported on the cover 18 of the driver.

In addition to the bearing 20, a bearing 48 is inserted into the bore 21. The gear shaft is in the two bearings 48 and 30 rotated and slidably recorded. The transmission shaft 37 protrudes with one end through the bearing 48 and one in the outer end section inserted into the bore 21 of the gear housing 6

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Seal 49 out of gear housing 6. At the front this end of the transmission shaft opens into a blind hole 50, in the enlarged end portion 51 a shaft 52 of a Starter pinion 53 is used in a rotationally fixed manner. The blind bore 50 is provided with a threaded portion into which one Screw 54 is screwed with which the starter pinion 53 is attached the transmission shaft 37 is attached. The starting pinion 53 is for starting an internal combustion engine (not shown) can be engaged in their ring gear 55.

The tooth coupling 33, 36 is provided with a force separating device Mistake. In the transmission shaft 37 are arranged radially Guide pins 56 used. On each guide pin 56 is a ring segment as a flyweight 57 radially to Gear shaft 37 slidably attached. Any flyweight

57 has a conical surface 58. In the driving coupling part 33, a stop sleeve 59 is used, the one has conical edge 60 which is parallel to the conical surface

58 of the flyweights 57 is formed and almost touches the flyweights 57 when the tooth clutch 33, 36 is closed. One One-track spring 6l is inserted into the gearbox 26. It is supported on a connecting flange 62 of the gearbox 26 to the extension 28 and on the driving coupling part 33 a.b.

The mesh spring 6l serves as a clutch spring at the same time the tooth coupling 33, 36, which seeks to keep the teeth 34, 35 of the tooth coupling parts 33, 36 in engagement.

The end of the gear shaft 37 received in the bearing 30 protrudes into the extension 28 of the gear housing 26. The extension 28 has a bottom 63 · lies on the bottom 63; outside an end a push rod 64 which is slidably mounted in the bore 22 of the drive shaft 12.

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An engagement magnet 65 (FIG. 2) has a housing 66 ₃ which is fastened coaxially to the outside of the bottom 10 of the collector bearing 7. A coil 67 of the engagement magnet 65 is accommodated on a winding support 68 in the housing 66. It consists of a pull-in winding 69 and a hold-in winding 70. The winding support 58 is seated on a brass sleeve fl in which an armature is guided 72 of the engagement magnet 65th The anchor 72 is attached to an anchor rod 73. It extends through the brass sleeve 7.1 and a magnet core lh fastened to the housing 66 into the longitudinal bore 22 and rests against an end face 75 of the push rod 6h .

An end section 76 of the anchor rod 73 protrudes through the anchor 72. A compression spring 77 is located on the end section 76 arranged, which is at one end on a stop ring 78 of the end section 76 and rests with its other end on the bottom 79 of a switching sleeve 80. The shift sleeve 80 is also arranged on the end portion 76 and from the Compression spring 77 in the rest position shown in the drawing pressed against the bottom of a recess 8l of the armature 72. The switching sleeve 80 has a flange-like edge 82. In the recess 8l a cup-shaped switching element 83 is inserted movably. Its bottom is provided with an opening 84 through which the switching sleeve 80 and the end section 76 of the anchor rod 73 protrude. In addition, the switching member 83 has a flange-like Edge 85. In the rest position shown in the drawing, the switching element 83 is seated completely in the recess 81 of the armature 72. The edge 85 rests against an end face 86 of the armature 72.

A contact carrier sleeve 87 made of insulating material is movably arranged on the one contact bridge on the brass sleeve 71 88 is attached. At the end of a return yoke

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of the engagement magnet 65, two connection brackets 90 and 91 are fastened in an insulated manner. A contact 92 is formed on the connection bracket 90 and a contact 93 is formed on the connection bracket 91. The contacts 92 and 93 together with the contact bridge 88 form the main power switch. A return spring 9 ^ of the contact bridge 88 rests with one end insulated against the yoke 89 and is supported with the other end on a collar 95 of the contact carrier sleeve 87. In the rest position shown in FIG. 2, the return spring 9 ^ presses the contact carrier sleeve 87 against the edge of the switching element 83, which in turn rests against a cover cap 96 of the engagement magnet 65. The cap 96 sits sealingly on the collector bearing J and is attached to the connecting bolts 97 and 99 in a sealing and insulated manner.

The connecting bolt 97 is connected to the connecting bracket 90 in an electrically conductive and mechanical manner. A line 101 coming from the positive pole of a battery 100 serving as a direct current source (FIG. 3) is connected to it. The contact 92 of the main power switch is connected to the battery 100 via the line 101. The connecting bolt 98 is connected to a line 102 which is also connected to the positive pole of the battery 100 and into which a starter switch IO3 is connected. _{The pull-in winding 69 can be connected to the battery 100 parallel to the holding winding 70 3} to which the line 102 leads via a line 10 ^ branching off from the line 102. The connecting bolt 99 serves as an isolated return line. It is attached to a connection part 105, to which the negative-pole brush IO7 of the starting motor 1 via a line 106 and the holding winding 70 are connected to ground via a line 108. A busbar 109 is connected to the contact 93 of the main current switch via the connection bracket 91 and is connected to the field winding ^ of the starting motor 1.

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To start the internal combustion engine, the starter pinion 53 must first be meshed with the ring gear 55. This will be the starter switch 103 is closed, so that the pull-in winding 69 and the holding winding 70 connected in parallel to it Power from battery 100 via lines 102; lOif supplied will. The armature 72 is drawn into the coil 67. The anchor rod 73 presses on the end face 75 of the push rod 64, which oppose the single-track gear 33, 36, 37, 53 the force of the return spring 47 in a straight line on the ring gear 55 pushes. If the starter pinion 53 hits the tooth-on-gap position on the ring gear 55, then it can mesh immediately. In the straight toe-in movement, the Return spring 47 compressed while the meshing spring 61 maintains its original length, i.e. H. Gearbox 26 and gear shaft 37 do not perform any axial movement relative to one another.

When the armature 72 moves into the coil 67, the armature 72 releases a part of the switching element 83. The switching element 83 is still held in its rest position by the force of the return spring 9 ^. The switching sleeve 80 arranged on the end section 76 of the armature rod 73 is pushed with the end section 76 through the opening 84 in the bottom of the switching element 83. If the edge 82 of the switching sleeve 80 rests on the bottom of the switching element 83, the compression spring 77 is tensioned, the force of which is greater than that of the return spring 94. Shortly before the starting pinion 53 is fully engaged in the ring gear 55, the force of the tensioned compression spring is overcome 77 together with the pull-in force of the coil 67, which act on the bottom of the switching element 83, the force of the return spring $ k. The switching element 83 is held in its position in the armature 72 by the edge 82 of the switching sleeve 80 and is displaced together with the armature 72. With the edge 85, it presses the contact bridge 88 seated on the contact carrier sleeve 87 onto the contacts 92 and 93 the now

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closed main current contact. 92, 88, 93, the starting rotor 1 is connected to the power source 100. The starting pinion 53 meshed with the ring gear 55 is frictionally connected to the drive shaft 12 of the starting motor 1 _{via the gear shaft 37j, the toothed coupling 33 3} 36, the helical thread 31, 32, the straight teeth 25, 27 and the driver Y \. The starting motor 1 receives the full torque and rotates the internal combustion engine via the ring gear 55.

If the starting pinion 53 reaches the toothed ring 55 in a tooth-on-tooth position during straight pre-tracks, then starting pinion 53 and gear shaft 37 can no longer be moved axially. The armature 72 of the engagement magnet 65, however, continues its pull-in movement and thereby displaces the gearbox relative to the toothed clutch 33, 36 and the gear shaft 37 , which are rotated by a certain angle by the coarse thread 31, 32. The starter pinion 53 attached to the gear shaft 37 is rotated with ^ and moves into the next tooth-open-gap position to the ring gear 55.When the gear box 26 is moved in relation to the gear coupling 33, 36 and the gear shaft 37 in the direction of engagement, the engagement spring 6l between the gear pot 26, 62 and the driving tooth coupling part 33 compressed. When the starting pinion 53 reaches the next tooth-open-gap position, it is immediately meshed with the ring gear 55 by the force of the meshing spring 6i. The main current contact 92, 88, 93 is closed as described above and the starting motor 1 starts the internal combustion engine. If shocks occur from the starter pinion side when turning, they are absorbed and mitigated by the damping device 39 to ^ l. The closed tooth coupling 33> 36 can therefore not transmit any impacts that could endanger the starting motor 1.

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When the internal combustion engine has started, the ring gear 55 rotates the starting pinion 53 at a higher speed than the starting motor 1. The toothed coupling parts 33, 36 slide apart, the backs of the teeth 34, 35 ratcheting against one another for a short time. The centrifugal force occurring at the higher speed of the gear shaft 37, however, allows the centrifugal weights 57 to slide outward on the guide pins. The flyweights 57 press with the conical surfaces 58 against the conical edge 60 of the stop sleeve 59 and thus push the coupling part 33 against the force of the meshing spring 61 into the gear box 26. The teeth 34, 35 are kept disengaged and via the released tooth coupling 33j 36, dangerously high speeds cannot be transmitted to the armature 14 of the cranking motor 1. However, the starting pinion remains engaged in the ring gear 53 until the starter switch 103 is opened. When the starter switch 103 is opened, the coil 67 is de-energized. The return spring 94 opens the main current contact 92 88 93> by pushing the contact carrier sleeve 87 with the contact bridge 88 in its rest position shown in Figure 2. The contact carrier sleeve 87 presses the switching element 83 back onto the cover cap 36 . When the main current contact 92, 88, 93 opens, the starting motor 1 is de-energized. The return spring 47 pushes the gear shaft 37 together with the starter pinion 53j toothed coupling 33, 36 and gear pot 26 as well as push rod 64, armature rod 73 and armature 72 back into the rest position. Starting pinion 53 and gear shaft 37 run out immediately after being sensed, so that centrifugal weights 57 return to their rest position on gear shaft 37 and tooth coupling parts 33j 36 are meshed again when the starting device comes to a standstill.

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Claims (4)

¹¹ · ■ 3? ° » Where / Sm Expectations Thrust drove for a starting device of internal combustion engines, with a rotating and displaceable starting pinion opposite the drive shaft of the starting motor, which is attached to one end of a gear shaft protruding from a gear housing, which is operatively connected to the drive shaft via a releasable coupling and by one of a coaxially arranged engagement relay actuated thrust member is movable, characterized in that a tooth coupling (33j 36) is arranged between the gear shaft (37) and the drive shaft (12), the driven coupling part (36) of which is attached to the gear shaft (37) and the the driving coupling part (33) engages with a coarse thread (3I ₃ 32) of a gear box (26) which is non-rotatably connected to the drive shaft (12) but is arranged to be longitudinally displaceable with respect to it and has a damping device (39, 40, 4l), on which a return spring (47) rests, while a meshing spring (61) drift between the coupling part (33) and gear pot (26, 62) is accommodated, on which the thrust member (64) rests. . ./lh 7O98B0 / 02A5 -> if - R. 3 2 ⁵ 5 2. thrust drive according to claim 1, characterized in that the Tooth clutch (33j 36) with a centrifugal separator is provided, whose flywheels (57) on the gear shaft (37) are arranged to be radially movable and have a conical surface (58) which is attached to a conical annular shoulder (60) of the driving coupling part (33) can be pressed. 3. Thrust drive according to claim 1 or 2, characterized in that the meshing spring (61) as a clutch spring of the toothed clutch (33, 36) is formed. 4. Thrust drive according to claim 1 or 2, characterized in that the drive shaft (12) is connected to a driver (17) which is provided with an internal straight toothing (25), which is provided with a straight toothing section (27) of the gearbox (26) is engaged. 5- thrust drive according to claim 1, characterized in that the damping device has a damping ring (40), one end of which rests against a stop disk (39) and the other end of which rests against an axially movable damping member (4l), against which the damping ring ( 40) the return spring (47) is supported on the remote side. ¹ ^ 709850/0245