DE1908931A1 - Infinitely controllable piston pump - Google Patents

Description

190 * 833 T

(3104) DEERE & COMPANY

Infinitely controllable piston pump

The invention relates to a continuously controllable piston pump with a cylindrical eccentric _{r of} variable eccentricity which can be driven via a drive shaft.

In a known device of the above type, the eccentric is provided with a hole, which is angled to the drive shaft runs. To arrange the eccentric on the drive shaft, the latter is provided with a hub, the surface of which also runs at an angle to the drive shaft and the has a greater length than the width of the eccentric. Consequently so the eccentric can be moved on the hub, thereby changing its eccentricity. The postponement itself takes place as a function of the pressure prevailing on the pressure side (USA Patent 2,539,277). Such a one Construction is complex in its construction and above In addition, there are difficult tax problems for the Change in eccentricity.

The object to be solved with the subject matter of the invention is seen in a more advantageous design of the pump than before. This object has been achieved according to the invention in that the eccentric '. eccentrically mounted on a shaft connector connected eccentrically to the end face of the drive shaft and its eccentricity can be changed via adjustment means rotating with the drive shaft. In this way, the eccentric can be adjusted between two positions in which it assumes either an eccentric or a concentric position with respect to the drive shaft. In addition, the ■■ && - ■ firadungsgeiTväß 'pump can be easily and ^ iriiseT ^ tpjicn ¹ "manufac-tured.

According to a further feature of the invention, the adjustment means in a concentric to the drive shaft

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Housing provided and have a radially adjustable to the housing Control part on, the one with a center on the eccentric attacking stub shaft can be brought into engagement. Consequently can in that the adjusting part adjusts radially to the housing will that. Eccentric from its one end position to the other be adjusted, in which it either has the greatest eccentricity or is arranged concentrically to the drive shaft.

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According to the invention, the housing accommodating the adjustment means is non-rotatably connected to the shaft connector supporting the eccentric.

In detail, according to a further proposal of the invention, the actuating part can be displaced via a device into an end position in which the eccentric has the greatest eccentricity, and into the opposite end position. Advantageously, the device in its end position opposite the greatest eccentricity in; can be actuated depending on the pressure prevailing on the pressure side of the pump pressure on the pressure side of the pump -. "■" adjustable. This means that if the pressure rises above a specified limit, the eccentric is shifted to its concentric ψ end position, which prevents any further pressure increase in its end position which is opposite to the greatest eccentricity, a displaceable piston which can be acted upon by pressure and which is connected to the pressure side of the pump via lines.

However, so that the eccentric always has its greatest eccentricity when the pump is at a standstill, so as soon as the drive shaft is set in rotation, the pump can deliver pressure medium, which has the control part in its end position for largest eccentricity shifting device on a spring. This spring is adjustable.

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Advantageously, the control part is manual radially to the adjustment

medium-receiving housing adjustable. As for the construction concerned with setting the spring in detail, it takes place the engagement of the Wellenstumraels with the actuator via a Sleeve, its surface as well as the bore that receives it is arranged at an angle in the actuator with respect to the axis of rotation of the housing receiving the adjustment means. The sleeve according to the invention itself is mounted axially displaceably in the actuating part. An adjusting screw is provided for this purpose.

In the drawing there is a description below illustrated embodiment of the subject invention explained in more detail. It shows:

Fig. 1 the pump in longitudinal section ",

FIG. 2 shows a section along the line 2: 2 in FIG. 1,

3 shows the eccentric in cross section.

In Fig. 1 of the drawing is with. 2 denotes a pump with a pump housing 3 and a Declcel k. A pump chamber 5 provided in the pump housing is closed by the cover 4. A radially arranged cylinder 6 is incorporated into the pump housing 3 and is open towards the pump chamber 5. In the drawing, only a single cylinder is shown, although several cylinders are provided distributed around the circumference. The latter have suction and pressure valves (not shown). A piston 7 is guided in the cylinder 6 so as to be axially displaceable. A spring 8 rests against the outer closed end of the cylinder 6 and against the inner end of the piston 7. A drive shaft 9 is mounted in the pump housing via a bearing 10, the inner end of which is delimited by an annular flange 11 also provided in the pump housing 3. On the latter, a shaft connector 12 (FIG. 2) is arranged eccentrically with respect to the drive shaft 9. This extends from the annular flange 11 at the front as far as a bore I3, which in turn is incorporated in a housing 14. The housing 14 in turn has a

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Bearing shaft 15 ', which is in the pump cover 4 via a bearing 16 -; is mounted so that the housing can rotate with the drive shaft9.

An eccentric 17 is on the shaft connector 12 between the ■. The annular flange 11 and the housing 14 are arranged eccentrically and are provided with a bore 18 for this purpose (FIG. 3). The latter is eccentric with respect to the central axis of the eccentric: so that the eccentric, when it rotates around the shaft connector, from an end position which is concentric with respect to the drive shaft 9 into an end position which is eccentric with respect to the drive shaft End position can be pivoted. A shaft stub L9->'acting in the middle of the eccentric? extends forward as seen from the eccentric to the housing / 14. The eccentric is also provided with a bearing 20 and an outer race 21, against which the inner ends of the pistons 7 in turn rest. This reduces wear.

A bore 22 is also incorporated into the housing 14, ■■ _ which extends from the periphery through the central axis up to

a point near the opposite periphery / extends and a piston 23 slidably receives. This has an actuating part 24 engaging at its inner end

with a rectangular cross-section and an annular end portion. The latter is located at the end remote from the piston: see ρ and lies against the cylinder wall of the bore,

to guide the actuator in the back and forth movement. Of the / Piston 23 itself is via a spring 26 in the direction atif the closed end of the bore 22 pressed. The pen lies - one end against the ring-shaped end part 25, the other.

ends against a plug 27, which is the open end of the; ;: • Bore 22 closes. - "- ■ -" ·. /; - '^ vV

One not shown in the drawing for the sake of simplicity " te line connects the pressure side with a channel 28, tetz-- ". terer, is; incorporated in; pump cover 4 and opens into. Feinem small pressure space, 30, which through a 'corresponding hole in the'

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Pump cover 4 and in the bearing shaft 15 of the housing 14 was formed. The pressure space 30 is coaxial with the axis of rotation of the housing 14, a seal 29 preventing oil leakage. Another channel 31 in the housing 14 serves to connect the pressure chamber 30 to the closed one End of the bore 22. Thus, hydraulic fluid from the Reach the pressure side of the pump to the piston 23 and move the control part against the action of the spring 26.

The actuating part 24 itself has a bore 32, which with Angled with respect to the axis of rotation of the housing 14 and a sleeve 33 slidably receives, whose surface is similarly angled. The sleeve 33. is-m.iteiner Center bore 34 is provided, which runs parallel to the axis of rotation of the housing 14 and receives the stub shaft 19. This is, as already stated, provided on the eccentric and provided in the bore 22 Off ^ tion 35 performed. On the condition that the We11ensturnmel 19 is arranged in the sleeve 33, can via the axial movement of the actuating part 24 of the eccentric 17 around the shaft connector 12 in the area between its eccentric and its concentric end position can be adjusted. By: axial displacement the sleeve 33.in and out of the bore 32 can effective force of the spring 26 can be varied. The pen is can be clamped * or released without the ciaß cfcie position of the eccentric would have to be changed. . . .- · - ■■

As far as the construction for adjusting the Milse-33 is concerned, an adjusting knob 36 can be screwed into the fiimpengeJaäuse 3 and further through the printer kit a loteröing 37 loaning knife / s rgeftihrt that; ^ n © r ^ qkrattm <. "$ & with the ^ 2 f ertrfificiet: and ^ a S * IfA 3P four © hteb ^ atr iieg-fe denenelis against the Sf e ^ lsi ^ h ^ aMbe 36;

a; sejie ± b ^ ni ^ nlt # hen "inde" S9 / -an d-er Älsei: 3 ^ 3y: aaali © _gtj; ffln '^ # di re n-softly; g ^^ inr. ^^ Hacs ^^

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maintain contact with the sleeve, - if 'the;stell-; - ^Λ part 24 is axially displaced in the bore 22. · The '"Hül'Se-33 ^: ' is pressed out of the bore 32 against the end of the pin 38 via a plunger 40, which is supported in the longitudinal axis of the stub 19 and against the housing 33 is pressed over a 'spring latter is arranged in a recess provided in the eccentric 17 bore 42 and is located at one end against the plunger ¹ 40 and at the other against a tongue-receiving cap _4;.. to 3 now, if the adjusting screw 36 from the. If the cover 4 is unscrewed, the provided spring 41, together with the plunger 40, causes the sleeve 33 and the pin 38 to follow the adjusting screw 36. If the adjusting screw is screwed into the cover 4, the spring 41 is tensioned because the sleeve 33 pushes the - "- plunger 40 into the stub shaft 19. Since the adjusting screw is provided in the axis of rotation of the housing 14, the sleeve can be adjusted while the pump is working or before the pump is actuated. "·

When using the pump described above and provided that internal forces and friction are neglected, there are three essential torques that contribute to adjusting the eccentric 17 around the shaft connector 12; The first of these torques is a torque _f originating from the spring 26 which acts on the stub shaft 19 and contributes to increasing the eccentricity of the eccentric 17. This torque is inversely proportional to the value of the eccentricity of the eccentric 17Vand if the maximum eccentricity of the eccentric 1? is limited to a relatively large amount of time, this torque will be essentially linear to the value of the eccentric eccentricity »

Bas second torque tends DE® eccentric Ml 'if the stems to the shaft stub 12 * to vecdreaen ÄM _momeBtt% of the pressure of the ,, ^ derived from the "ΐ« 1 and on the TSeJ.lerastuiömel'"19 mfeiei ^ idem EÖ; 1-23 is transferred. This Jteehmoiäent-teaaäiexrt i

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maximum eccentricity of the eccentric 17 on a relative is limited to a small value, this torque will be essentially directly proportional to the pressure on the pressure side.

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The third torque depends on the load Pressure on the pressure side of the pump is determined and is behind outwardly directed movement of the piston 7 opposite. This Torque is directly proportional to the product of the pump pressure on the pressure side and. the value of the eccentricity of the Eccentric 17. If the pump now rotates counterclockwise, with reference to Fig. 2, rotates, carries this Torque contributes to the eccentricity of the eccentric 17 enlarge.

The usable torque, which tends to rotate the eccentric 17 around the shaft stub 12, is the algebraic one Sum of the torques that are dependent on the spring, the pressure and the load. If the spring force is chosen so, that when the amount of eccentricity of the eccentric changes, the torque from the spring increases or decreases in direct proportion to and to the same extent as the increase or decrease in torque of the load, and when the initial torque decreases The spring roughly corresponds to the torque of the pressure side, the usable torque which tends to move the eccentric 17 ' to rotate the stub shaft 12 will be approximately zero when the pump is operating at the intended pressure. Is working but the pump at a lower than the predetermined pressure, the usable torque tends to be the eccentricity of the eccentric 17 to enlarge. Is the pressure greater than the previously determined pump pressure, this is what causes it usable torque a reduction in the eccentricity of the Eccentric 17.

In order to be able to imagine the mode of action more simply, becomes the torque from the spring and the torque from the load combined into a single torque *, therefor

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tends to adjust the eccentric 17 in its end position, in which it has the greatest eccentricity. And if one assumes that this only torque comes from the force,. ^;

originates, which by the spring 26 on the shaft stub 19 is exercised, the operation of the pump described above can be summarized as follows: ". .. ■ -." .-

Before the pump is activated, the force of the \ "■ -spring 26 have moved the Stell.teil 24 into the position shown in the drawing, in which the eccentric is in its end position with the greatest eccentricity. " During use, the drive shaft 9 is now driven by a motor

fe or the like. driven. However, a rotation of the shaft / causes

at the same time a rotation of the housing 14 and the eccentric 17, so that the eccentric pushes the piston 7 radially outward. But as soon as the eccentric 17 is past the piston 7, ' the spring 8 moves the piston back inwards, d. H. into the pump housing 3 move. The resulting suction stroke of the Piston causes pressurized fluid through the suction valve is sucked into the cylinder. If the eccentric now continues to revolve, it again becomes a radially outward one Cause movement of the piston 7, and that in the cylinder 6 The pressure medium located is fed through the pressure valve into the Pressure line pressed; Thus, a pressure will build up on the pressure side of the pump, which is via the line

W or the channel that connects the pressure side with the channel 28, the channel 28, the pressure space 30 and the channel 31 will propagate to the closed end of the bore 22, where it will the piston 23 is applied. The pressure then acting on the piston 23 ″ moves it together with the actuating part 24 against the action of the spring 26, the latter being tensioned and the eccentric around the shaft connector 12 being adjusted into its end position, in which it is concentric is arranged to the drive shaft. If, however, the eccentric 17 is moved into its concentric end position, the stroke is reduced .. =. the piston 7, since the eccentric piston no longer moves so far radially, outward; can and the pistons no longer

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soy can enter the pump housing as far inwards as " it was possible with greater eccentricity. The shortened piston stroke in turn results in less fluid ■■ '■ "■ durchatζ on the pressure side. '■

As soon as the liquid pressure on the pressure side is a has reached a previously determined maximum value, the Pressure side prevailing pressure have adjusted the adjusting part 24 so far that the eccentric is in a with respect to the drive shaft 12 concentric position has been adjusted. Located The eccentric is now in its concentric end ■ position, the pistons 7 stand still and no additional ones More liquid can be pumped into the pressure line, not even if the eccentric continues to rotate .. / The pump will remain in this state until the pressure on the pressure side falls off again. · -.- ■■■■.

If the hydraulic system, which is supplied with pressure medium from the pump, also requires pressure! Fluid, the pressure on the pressure side will drop to a value below the previously determined value. At the same time, however, the fluid pressure which acts on the piston: 23: will also decrease. A 'lowering of this pressure in turn causes' that the spring 26 moves the control part, so that - the Ixzentep; now - the Wel- ^; lenstutzen 12 can be adjusted in its end position with the greatest eccentricity. The movement., Des; Position and the eccentricity of the; Pistons that ... will just be reined in by the eccentric depends on. the firoBe of the pressure drop ^ n on the pressure side, is now, but the eccentric ^{1 is} back in its * ¹ end position with the greatest eccentricity _y , the piston stroke becomes larger and more liquid gets into the pressure guide, wodujpch the liquid pressure on the previously determined; ^ maxim ^ iwert

Bear ¹ VoI 1 ständ; igfc; §irt hatlber must be pointed out; n _; daöi * Q3? steiende SchiildeaPUing d ^ 'Throwing.SKeise l ^ diglißh; Fewer eccentrics counteract the turn of the clock

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namely, with reference to FIG. 2, _: . is pivoted "but, when the pump rotates in the clockwise direction, again with reference to Figure 2," is the position of the eccentric 17 does not;.. _\; under the control of the torques, as it was stated above, since then the of The torque due to the load does not contribute to reducing the eccentricity of the eccentric ... ".... '"""'"'''·

If, on the other hand, it is desired: to change the previously determined maximum value for the liquid pressure on the pressure side, then it is only necessary to adjust the adjusting screw 3.6. The adjustment of the adjusting screw means that: ψ the effective force of the spring 26 is changed, via <u ± e the value of the pressure can be changed, which is high so that the piston 23 can move the eccentric to its concentric end position *

Claims (1)

Claims Infinitely controllable piston pump with a variable cylindrical eccentric that can be driven via a drive shaft Eccentricity, characterized in that the eccentric (17) on one with the end face of the drive shaft (9) eccentrically connected shaft connector (12) and its eccentricity over with the Adjusting means (23, 24 or 26) rotating around the drive shaft can be changed. 2. Piston pump according to claim 1, characterized in that the adjusting means (23 _f 24 or 26) are provided in a housing (14) arranged concentrically to the drive shaft (9) and have an adjusting part (24) which is adjustable radially to the housing and which is connected with a shaft stub (19) acting centrally on the eccentric (17) can be brought into engagement. 3. Piston pump according to claim 1 and 2, characterized in that the adjusting means (23, 24 or 26) receiving it The housing (14) is connected in a rotationally fixed manner to the shaft connector (12) which supports the eccentric (17). 4. Piston pump according to one or more of the preceding claims, characterized in that the set !! (24) each via a device (26 or 28, 30, 31, 23) into an end position in which the eccentric (17) has the greatest eccentricity and can be moved into the opposite end position. 5. Piston pump according to one or more of the preceding claims, characterized in that the actuating part (24) is in its end position opposite to the greatest eccentricity displacing device (28, 30, 31, 23) depending on the prevailing on the pressure side of the pump (2) Pressure can be actuated. '■; ■ - ■. ■' ■■■. ■■. ■■■■ - '- 12 - 909843/1099 .6. » Piston pump according to claim 5, characterized in that the device (28, 30, 31, 23) displacing the actuating part (24) into its end position opposite to the greatest eccentricity; which is connected to the pressure side of the pump (2) via lines (28, 30, 31). 7. Piston pump according to one or more of the preceding claims, characterized in that the adjusting part (24) shifting into its end position for greatest eccentricity Device has a spring (26). 8. Piston pump according to one or more of the preceding claims, characterized in that the spring (26) is adjustable. 9 .. piston pump according to one or more of the preceding claims, characterized in that the adjusting part (24) is manual radially to the adjusting means (23, 24 or 26) receiving housing (14) is adjustable. 10. Piston pump according to one or more of the preceding claims, characterized in that the engagement of the shaft stub (19) with the actuating part (24) via a Sleeve (33) takes place, the surface of which, like'die. she receiving bore (32) in the Steliteil (24). regarding _i; the axis of rotation of the housing (14) accommodating the adjustment means (23j 24 or 26) is angled, 11. Piston pump according to one or more of the preceding claims, characterized in that the sleeve (33) in the Adjusting part (24) is mounted so as to be axially displaceable. 12. Piston pump according to one-Odea * several. ^ Of the preceding claims, characterized in that the sleeve (33) is mounted axially displaceably in the adjusting part (24) via an adjusting screw (36). '. . 90 9 8-43 / 109 9- -