DE2505569A1 - PRESSURE MEDIUM CONTROL - Google Patents

Description

Cleveland, Ohio 44117 / V.St.A.

Our reference: T 1732

Pressure medium control

The invention relates generally to an improved pressure medium control and in particular to a pressure medium control which has a rotating input member, which is connected to a slide, so that a movement of the slide when the input member is rotated relative to this can be done. Steering controls, of the type to which the invention relates are used in hydrostatic power steering of a vehicle perform.

Pressure medium controls for hydrostatic steering of a vehicle are known. Such .Controls have a inner-axis rotary piston machine known as a gerotor with "fixed-point mounted inner rotor, this gerotor a pressure medium flow to a power steering cylinder and also a slide that the pressure medium to the Gerotor and leads to the steering cylinder. One of the driver's

509834/0262

■ "P« ·

The controlled input shaft is connected to the slide so that the slide can move when the slide is turned Input shaft can be made relative to this. After an initial rotation of the input shaft and movement of the From the initial position of the slide, a torsion clutch stores energy so that the slide can move into its Initial position can be returned. The torsion coupling is between the gerotor and the input shaft arranged. This known torsion coupling has a Tprsionsstab, which has a relatively large axial length and which is twisted about its central axis when the slide is moved. Since the torsion bar is dimensioned that it has the desired Pederkonstante, this rod has a limited outer surface, which for a derivation the heat is available, which is generated during the bending of the rod. Furthermore, the production the torsion bar and its connection points with the input shaft and the slide relatively expensive in the Manufacturing. Two known flow controls that incorporate torsional couplings are in the US patents 3,443,378 and 3,452,543.

The invention provides an improved pressure medium control, the at least one torsion blade has, which is elastic about its central axis upon rotation of an input member relative to a slide "is twisted. In a preferred embodiment of the In the invention, a pair of torsion blades are used to adjust the width and axial dimension of the blades and to achieve the desired spring rate. The opposite end portions of the torsion blades are arranged in mounting slots that are formed in the input member and in a component which is with connected to the gerotor.

In order to reduce the backlash to a minimum during an initial rotation of the input link

509834/0262

the torsion blades are preferably bent or curved ₃ so that they press firmly against the sides of the mounting slots. In order to avoid the introduction of relatively high mechanical stresses into the torsion blades next to the outer edges of the mounting slots, the blades are provided with projections or bumps which prevent the blades from resting against the edges of the slots when the blades are twisted.

The new and improved erfindungsgerea.Se pressure medium control has a simple torsional coupling that is inexpensive to manufacture and relatively free of stress concentrations and which further has an idle minimum. These advantages are due to the torsion blade construction created, which is elastic about its central axis upon movement of an input member relative to the Sliders are twisted. The slide can be moved out of an initial position in order to pressurize the gerotor feed and the elastically bendable torsion sheet structure is twisted around its central axis by the input force supplied to the input shaft will. This stores energy so that the slide can be moved back to its starting position when the Input force no longer acts.

The invention thus relates to an improved pressure medium control, which has a gerotor, which has a stator provided with internal teeth and one with external teeth provided rotor, which cooperate with one another to a metered flow of pressure medium produce. A slide sleeve is axially between a closed position in which the flow towards the gerotor and blocked away from the gerotor, and an open position movable, in which pressure medium is directed to the gerotor.

SQ9834 / 02S2

After an initial rotation of an input member, the slide sleeve is axially out of the closed position into the opening division moved. During the axial movement of the slide sleeve the input member elastically twists several torsion blades that extend between the input member and a wobble shaft which is connected to the rotor of the gerotor. When the rotation of the input link is stopped, the elastically twisted torsion blades are effective to rotate the slide sleeve relative to the input member so that the slide sleeve is back in its Closed position is moved. The torsion blades are connected to the input shaft and the wobble shaft in such a way that that the introduction of tensions at the joints between the blades and the two shafts is prevented.

In addition, the Torsionsbläcter work with both of them

Waves together in such a way that there is a gap at the joints between the leaves and the waves to a minimum is reduced. The sheets have major sides or major surfaces with a relatively large area so the dissipation of heat resulting from the bending of the leaves is facilitated.

Embodiments of the invention will be explained with reference to the figures of the drawing. Show it

Fig. 1 is an axial sectional view of an inventive trained pressure medium control,

Fig. 2 is a fragmentary view as seen from line 2-2 of Fig. 1,.

3 is an enlarged plan view of the torsion blades,

Figure 4 is a view taken from line 4-4 of the Figure showing the curved construction of the torsion blades is shown

509834/0262

Fig. 5 is an enlarged sectional view taken longitudinally the line 5-5 of Fig. 3 showing the formation of the inner end portions of the torsion blades is,

6 is an enlarged sectional view taken along its length the line 6-6 of Fig. 3 * in which the formation of the outer end portions of the torsion blades is shown,

Fig. 7 is an enlarged sectional view taken along line 7-7 of Fig. 3 showing the relationship between the inner end portions of the torsion blades when they are in an unloaded condition
and

Figure 8 is a sectional view of a portion of the controller shown in Figure 1 taken along the line 8-8.

The pressure medium control 10 designed according to the invention, which is shown in FIG. 1 has a gerotor 12. The gerotor 12 causes a metered flow of pressure medium is generated upon actuation of a control slide 14 in accordance with a rotation of an input shaft 16. the Pressure medium control 10 has an improved torsion coupling 18, which causes the slide 14 in its Initial or unactuated position is returned, as will be described.

The pressure medium control 10 has a generally cylindrical one Housing 22, which is connected via a line 24 to a pump or another pressure medium source is. The housing 22 is connected to a storage container via a second line 28. At an initial

509834/0262

rotation of the input shaft 16 cooperates a ball 24 with a generally helical groove 36, to move a slide sleeve 32 axially. This axial displacement of the slide sleeve 32 allows that under High pressure pressure medium flows from a pressure ring groove to the gerotor 12. Depending on whether the input shaft 16 is rotated in the direction of the clockwise direction of rotation or opposite to this direction, with a Shifting the slide sleeve 32 to the left or right takes place, a metered pressure medium flow from the Gerotor 12 via the slide either a line 44 which is connected to one side of a working cylinder, or via a line 46 which is connected to the opposite side of the working cylinder.

When the input shaft 16 is rotated in the clockwise direction, the ball 34 and the screw groove operate 36 together in such a way that the slide sleeve 32 to the left is moved. As a result, pressure medium is supplied to the gerotor 12 and conveyed from the gerotor 12 to the line 46. at a counterclockwise rotation of the input shaft 16, the slide sleeve 32 is displaced to the right. As a result, pressure medium is fed from a second pressure groove 48 to the gerotor 12 and from the gerotor 12 to the Line 44 promoted. The specific details of this control arrangement may vary and these details are generally known and are described in U.S. Patent 3,452 and the details are not described here should be.

The gerotor 12 has a stator 50 provided with internal teeth, and one with external teeth provided rotor 54 surrounds. The rotor 54 has a tooth less open than the stator 50 and works with the stator,

509834/0262

a spacer plate 56 and a bearing plate 58 together to form a plurality of pressure medium receiving chambers which generate a metered pressure medium output and that when the rotor rotates and revolves relative to the stator. A slider 62 cooperates with the gerotor 12, to direct the pressure medium into the working chambers and out from the working chambers formed between the stator 50 and the rotor 5 are formed ¹ J. The construction of gerotor 12 and the manner in which it cooperates with slides IU and 62 is the same as that described in US Pat. No. 3,452,543. In order to limit the scope of the description, the known relationships between these components will not be described further.

In accordance with the invention, the torsional coupling 18 has a pair Torsionsblätter 66 and 68 (FIG. ¹ to I). The torsion blades 66 and 68 extend between the input shaft 16 and a wobble shaft 7 which has an externally toothed head section 76 which meshes with an internal toothing of the rotor 50. When the input shaft 16 rotates, the torsion blades 66 and 66 are elastically twisted when the slide sleeve 32 is axially displaced into an operating position. The twisting of the torsion blades 66 and 68 stores a potential energy so that the slide 32 can be moved back to its initial or closed position after the rotation of the input shaft 16 is interrupted.

When the input shaft 16 rotates in the direction of the Clockwise, with the slide sleeve in the closed position shown in Fig. 1, the Torsion blades 66 and 68 elastically twisted in the clockwise direction about their longitudinal axes. If the Torsion blades 66 and 68 are twisted, the slide sleeve 32 is turned to the left by the cooperation between the ball 3 * 1 and the screw groove 36 moved. if once the slide sleeve 32 is in a working position

509834/0262

is pushed, a stop element (not shown) on the input shaft 16 rotates the slide sleeve 32 together with the input shaft. If the force acting on the input shaft 16 is removed, so is the potential energy stored in the elastically twisted torsion blades 66 and 68, sufficiently large to rotate the slide 32 counterclockwise and axially about it to move to the right in the position shown in Fig. 1 by the interaction between the ball 34 and the screw groove 36. This return the slide sleeve takes place through the torsion blades, which rotate the shaft 16 relative to the slide sleeve 32.

When the input shaft 16 is rotated in a counterclockwise direction, the torsion blades become 66 and 68 in a direction opposite to the clockwise rotation during the initial rotation of the input shaft 16 elastically twisted. When the torsion blades are twisted, the slide sleeve 32 is made from the one shown in FIG. position shown shifted to the right in order to supply pressure medium to the gerotor 12 and the steering cylinder. After this the force acting on the input shaft 16 is interrupted, the potential energy that is in the elastically twisted torsion leaves 66 and 68 is stored, effective to rotate the slide sleeve 32 and around this to the left by the action of the ball 34 and the screw groove 36 to move.

Blade 68 has two relatively large major sides 82 and 84 (FIGS. 3 and 4). the pressure medium within the Slide chamber 88 (Fig. 1) are exposed. When the pressure medium flows through the slide chamber 88, it flows along major side surfaces 82 and 84 of the sheet

509334/0262

Such a flow cools the sheet and conducts heat generated during the twisting of the blade. In addition to the main sides 82 and 84, the blade 68 two side surfaces 92 and "94, which are parallel extend to one another in such a way that the blade 68 has a substantially rectangular cross-section. Even though 3 only shows the configuration of the blade 68, it should be noted that the blade 66 is the same Configuration like sheet 68..

The blades 66 and 68 are with the input shaft 16 and the wobble shaft 74 by a tongue and groove connection 98 and 100 (Figs. 1 and 2) connected, which are relatively simple and inexpensive to manufacture. The connection 98 with the input shaft l6 has a slot 104 which extends diametrically across the inner end of the shaft 16 and which is dimensioned so that the -outer., · end sections 108 and 110 of the torsion blades 66 and 68 can accommodate. Around the torsion blades relative to the slot 104, a central fixing hole 112 is arranged in the end of the input shaft 16 and this takes axially protruding tongues 118 and 120 on the torsion blades 66 and 68 are formed.

The connection 100 to the shaft shaft 74 is generally similar to the connection 98 and has a slot 122 formed in an externally toothed head end 124 of the wobble shaft 74. The slot 122 extends diametrically across the wobble shaft Jh and receives inner end portions 126 and 28 of the torsion blades 66 and 68. The head end 124 of the wobble shaft 74, which is provided with external teeth, is in meshing engagement with axially extending internal teeth 132 which are formed on the slide sleeve 32. During the rotation

509834/0262

of the input shaft 16, the torsion blades 66 and 68 therefore transmit a torque to the slide sleeve 32 via the head end 12 ¹ I of the wobble shaft 74 a corresponding gear on the wobble shaft 74 work together. Since the connection 100 is formed in the head end 124 of the wobble shaft 74, the torsion blades 66 and 68 are rotated with the wobble shaft and the slide sleeve 32 when the wobble shaft is rotated about its central axis during the rotational movement of the rotor 54 relative to the stator 50. The rotor 54 and the wobble shaft 74 rotate about their central axes in the same direction as the input shaft 16.

During the operation of the gerotor 12, the rotor performs an orbital movement relative to the stator 50. The direction of orbital movement of the rotor is opposite to the direction in which the rotor rotates about its central axis. The orbital movement of the rotor 50 results in a pivoting movement of the head end 124 of the wobble shaft 74 relative to the teeth 132 of the slide sleeve and the torsion blades 66 and 68. To facilitate this pivoting movement of the head end 124 of the wobble shaft 74, the inner end sections 126 and 128 are cut to size that they are free from the diametrically extending bottom 136 of the slot 124. Blade 68 therefore has sloped end surfaces 138 and 140 (FIG. 3) spaced from the bottom 136 of slot 124. If the end portion 168 of the sheet 68 were cut straight or rectangular, that is, if it were cut along a line extending perpendicular to the flank sides 92 and 94 of the sheet, the end portion 128 of the sheet would be

503834/0262

- li - ■

against the bottom 136 of the slot 122 and would interfere with the movement of the wobble shaft 74. Although only the inner formation 128 of the blade 68 is shown in FIG It should be noted that the inner end portion 126 of the blade 66 has the same configuration.

When the torsion blades 66 and 68 are twisted, the major surfaces of the torsion blades are relative to the Sides of slots 104 and 122 are twisted. If the main sides of the torsion blades 66 and 68 are against the protruding Lay corner portions of slots 104 and 122 would result in severe local stresses formed in the torsion blades 66 and 68. Such severe local stress conditions would be for life the torsion blades very disadvantageous.

About the abutment of the major sides of the torsion blades 66 and 68 against the corner portions of the slots 104 and 122 To avoid this, the blades 66 and 68 are provided with rounded projections or bumps which the blades 66 and Keep 68 away from the corner portions of the slots. The outer end portion 110 of the blade 68 has a pair Projections or stools 144 and 146 (Figs. 3 and 6). These projections or bumps 144 and 146 lie against a flank 150 of the slot 104 (FIG. 2) at one point axially inward from the outer corner of the slot 104. The curvature of the projections 144 and 146 is sufficient so that the major side 82 of the sheet 68 is kept away from the corner portion of the slot 104 when the sheet 68 is twisted.

The inner end of the sheet 68 also has a pair of protrusions or stools 154 and 156 (Fig. 3) which against a flank 158 (Fig. 2) of the slot 122 abut to the major side surface 82 of sheet 68 from the corners

509834/0262

of the slot away while the blades 66 and 68 are twisted. The curvature configuration of protrusions or bumps 144, 146, 154 and 156, the formed in the blade 68 allow the projections 144, 146 to move freely relative to the input shaft 16 and pivot to the wobble shaft 74 and slide freely to this when the sheet is twisted or is bent.

Blade 66 is similarly formed with protrusions or bumps that correspond to those on blade 68. The outer end portion 108 of the blade 66 has a pair of projections or bumps 162 and 164 (FIG. 6) that have the same configuration as the projections 144 and 146 formed in the blade 68. Similarly, the inner end portion 126 of the blade 68 has a pair of projections or bumps 166 and 168 (FIG. 5) that have the same configuration as the projections or bumps 154 and 156 on the blade 68. The projections 162, 164, 166 and 168 abut the flanks of slots 104 and 122 which oppose the flanks against which the protrusions on blade 68 abut.

The interaction between axially projecting tabs 11θ and 120 on blades 68 and 66 and cylindrical bore 112 in input shaft 16 (FIG. 2) holds outer end portions 108 and 110 of the blades against radial movement toward slide sleeve 32. The inner end portions 126 and 128 of the blades 68 and 66 are also held against radial movement toward the slide sleeve 32. This is made possible by the teeth 132. The inner end portions of blades 66 and 68 are held in a centered position with respect to slide sleeve 32 by teeth 132 (Fig. 8). As the end portions 126 and 128 of the sheets

509834/0262

not relative to the teeth 132 of the slide sleeve itself rotate, teeth 132 hold blades 66 and 68 against a sideways movement firmly. Accordingly, both ends of the blades are restrained against radial movement and therefore do not interfere with the rotation of the slide sleeve 32.

Around the inner end portions 126 and 128 of the blades 66 and 68 restrained from axial movement relative to one another is a pair of oppositely projecting dimples or beads on the inner end portions 126 and 128 of each sheet 66 and 68 are formed. The sheet 68 has a recess or bead 172 which extends outwardly from the main face 82 of the sheet. A second bead or recess 174 extends from the opposite side 84 of sheet 68 out to the outside. These two wells 172 and 177 work together with a pair of wells 178 and 180, which are formed in the blade 66 in the manner as shown in FIG. 5 around the two blades 66 and 68 to hold against axial movement relative to each other.

To allow backlash motion between the torsion blades 66 and 68 and the input shaft 16 and the wobble shaft 74 An initial relative rotation between the input and the wobble shaft to a minimum, are the torsion blades designed in such a way that they are pressed tightly against the flanks of the slots 104 and 122, namely even if the manufacturing tolerances with which the Slots are formed such that they are not exactly the shape and size desired. About this density To ensure that the torsion blades 66 and 68 abut the flanks of the slots 104 and 122, the torsion blades exhibit a curvature extending in the longitudinal direction. The torsion sheet 68 is curved or bent such that the major side surface 82 has a convex curvature,

509834/0262

while. the main side surface 8 *} has a concave curvature (Fig. 4). The torsion sheet 66 has the same curved or domed configuration as the torsion sheet 68.

When the two torsion blades 66 and 68 are inserted into the pressure medium control 10, they are arranged with their concavely curved main sides next to one another in the manner shown in FIG. This results in an angular separation of the sheets at their end portions in the manner shown in Figures 2 and 4. When the blades are inserted into slots 104 and 122, the various protrusions or bumps on the end portions of the blades abut against the flanks of the slots and press the adjacent major sides against one another. The leaves work as feathers and have a tendency to return to their free state. If the slots 104 and 122 are too wide, due to manufacturing tolerances or other reasons, the oppositely curved or bowed leaves act as springs and resiliently urge the stools or protrusions on the end portions of the leaves against the flanks of the slot. An idle movement between the input shaft 16 and the wobble shaft 74 is thus reduced to a minimum.

The above description it can be seen that the pressure medium control 10 has a slide 14 which is actuated upon rotation of the input shaft 16 to actuate the gerotor 12 itself. When the input shaft 16 is initially rotated in the clockwise direction when the slide 14 is in the position shown in FIG is the position shown, the blades 66 and 68 are twisted. This twist is created by the Resistance of the rotor 54 to rotation. If this takes place, the input shaft 16 rotates relative to the wobble shaft 74. This rotation of the input shaft 16 relatively

50983 ^ / 0262

the torsion blades twist into a clockwise wobble shaft 66 and 68. When the torsion blades 66 and 68 are bent, the ball 34 cooperates with the helical groove 36 and slides the slider sleeve 32 axially to the left (when looking at Fig. 1). When the slide sleeve 32 is moved to the left, so slide the teeth 32 on the inside of the slide sleeve 32 relative to the external teeth on the head portion 144 of the wobble shaft

The movement of the slide sleeve 32 to the left leads to the fact that the slide 14 from its closed position into a Working position is brought in the pressure medium is conveyed from the pressure source to the gerotor 12. During the continued clockwise rotation of the input shaft 16 so the rotor 54 is clockwise rotated and thereby a pressure medium flow is returned in metered form to the slide and the steering cylinders fed through line 46. It should be noted that the other working cylinder line 44 is provided with a reservoir is connected via the slide 14.

When the rotation of the input shaft 16 is stopped, the slide sleeve 32 is in the left-hand position Is working position, energy is stored in the twisted torsion blades 66 and 68, and the torsion blades 66 and 68 exert a force that causes the inclination has to perform a relative rotation between the input shaft 16 and the slide sleeve 32. If this twist takes place, the slide sleeve 32 is displaced back into its original position by the interaction between the ball 34 and the groove 36. If this takes place, the twisted torsion blades 66 and 68 relax.

509834/0262

When the input shaft 16 rotates in the direction of the Clockwise rotation, the slide sleeve 32 is shifted to the right and the rotor 54 is opposite to the Turned clockwise, so that a measured Druckraittelströmung the working cylinder line 44 is supplied. When the slide sleeve 32 shifted to the right is, the torsion blades 66 and 68 are twisted or bent. During continued rotation of the input shaft 16 opposite to the clockwise direction of rotation and a rotation of the rotor 54 and the wobble shaft 74 about their central axes counterclockwise rotation, blades 66 and 68 are maintained in a twisted state. If the rotation of the input shaft 16 is interrupted in the opposite direction to the clockwise direction of rotation, the stored Energy in the torsion blades in the manner described above.

Although the torsion coupling 18 described here is formed by a pair of torsion blades 66 and 68 in the illustrated embodiment, it should be noted that either a greater or a smaller number of torsion blades can be used. It should be noted, however, that the use of multiple torsion leaves 66 and 68 enables the desired spring rate to be achieved with torsion leaves that have a relatively short axial length.

509834/0262

Claims (1)

Claims ) Pressure medium control with a housing which has a Having inlet port and a pair of outlet ports, and having an ignition device disposed in the housing is and is effective to achieve a metered pressure medium control, said metering device one having internally toothed component and an externally toothed component, which are arranged in meshing engagement with one another are and perform a relative orbital and rotary movement and further with a slide that is in the housing is arranged and is brought from an initial position into a working position in which this slide Pressure medium supplies the metering device and in which this slide pressure medium from the metering device is selected Outlet opening feeds and with a shaft having a first head end portion which is connected to the externally toothed component in such a way that this is rotates therewith and a second head end portion connected to the slide and further having a rotatable one Input shaft and a connection that enables the operation of the slide from the initial position to an operating position caused according to a rotation of the input shaft and stores the energy so that the slide from a Working position can be returned to the starting position, characterized in that this connection (34, 66, 68) has at least one elastically rotatable blade (66 or 68) which has a first end portion which connected to the input member (16) and a second end portion directly connected to the second head end portion (124) of the shaft (74) is connected, the blade (66 or 68) when the input member (16) rotates about its Longitudinal axis is twisted. 509834/0262 Pressure medium control according to claim 1, characterized in that a pair of elastically twistable blades (66 , 68) of equal length are provided, that the shaft (7 * 0 has a slot (122) which receives one end portion of the blades and the other end portion of the Sheets is arranged in a slot (110) in the input shaft (16), that the input shaft (16) further has a fixing bore (112) which receives axially projecting tongues 118, 120 of the sheets. Pressure medium control according to Claim 2, characterized in that each of the two blades (66, 68) is convex curved main side (82) and a concavely curved Kauptseite (84) that "the two sheets side by side Are arranged. That the concave curved main side one of the leaves points to the concave, curved main side of the other leaf. Pressure medium control according to Claim 2, characterized in that the sheets have projections or stools next to the corners (144, 146, 162, 164) which bear against the surfaces defining the slots in order to prevent the Sheet against the surface of the slot when the sheets are twisted. 509834/0262 Blank page