Device for transferring linear loads

Abstract

Device (10) for transferring a linear load through a component rotating at high speed, wherein the device comprises: a linear actuator (100) with an actuator cylinder (104) and a cylinder rod (102) which is axially movable in the actuator cylinder (104), a mounting adapter (110) which is secured against axial and rotational movement, wherein the mounting adapter (110) is rigidly attached to the actuator cylinder (104), an elongated guide sleeve (114) which is also attached to the mounting adapter (110), wherein the guide sleeve (114) has a linear groove (118) extending substantially axially along its length and the guide sleeve (114) is designed to allow passage of one end of the cylinder rod (102), an axially displaceable axial bearing (112) which is attached to one end of the cylindrical rod (102), wherein the bearing has a housing (116) and the housing (116) has an outer ring secured against rotation, a splined shaft (70) which is attached to an inner ring of the bearing for rotation and axial movement with it, and a guide pin (120) which extends radially through the groove (118) and is attached to the housing (116), wherein the guide pin (120) is designed for transverse movement along the linear groove (118) and interacts with the groove (118) to prevent rotation of both the housing (116) and the cylinder rod (102) while the cylinder rod (102) is extended and retracted in the actuator cylinder (104).

Description

Technical field

[0001] The present disclosure relates to linear actuators designed for transmitting linear loads through components rotating at high speed. In particular, the disclosure relates to a device for preventing unwanted rotation of an actuator cylinder rod in a compressor machine. background

[0002] Compaction machines, also sometimes called compaction machines, are frequently used to compact freshly laid asphalt, fill, gravel, and other compactable materials associated with road surfaces. One such compaction machine is a roller compactor, which has one or more rollers designed to compact a specific material over which the compactor is driven. To compact the material, the roller compactor has a roller assembly with a vibration mechanism that includes internal and external eccentric weights mounted on a rotating shaft located in a cavity of the internal eccentric weight. Both the vibration amplitude and frequency are typically controlled to achieve a desired degree of compaction.The amplitude is often controlled by a laterally movable linear actuator designed to exert axial pressure against an axially displaceable splined shaft, causing the splined shaft to rotate. The rotation of the splined shaft, in turn, alters the relative positions of the inner and outer eccentric weights to change the vibration amplitude generated by the roller. The vibration frequency is controlled by varying the speed of a drive motor located within the compressor roller.

[0003] To change the relative position of the inner and outer eccentric weights, the rotatable shaft typically engages with the weights through differently shaped outer surfaces of the shaft. For example, US Patent 4,350,460 A discloses the outer surface of a splined shaft having a specially shaped, i.e., polygonal, cross-section designed to engage with the inner eccentric weight, and another specially shaped cross-section designed to engage with the outer eccentric weight for the relative positioning of the eccentric weights to each other. Those skilled in the art will recognize that the eccentric weights are normally designed to rotate with each other at speeds approaching and / or exceeding 4,000 revolutions per minute. To ensure a level of vibration sufficient to achieve desired compaction results, some materials require higher vibration frequencies than others.Unfortunately, such vibrations in highly stressed structures can lead to undesirable relative movements of some parts of such machines to adjacent parts. In particular, cylindrical rods used to rotate the eccentric weights relative to each other can exhibit a tendency to rotate within their associated fixed cylinders, resulting in unwanted wear.

[0004] DE 10 2010 056 531 A1 describes a vibration system for a compressor.

[0005] Therefore, it would be advantageous to provide a system that minimizes wear on actuators and related components. By preventing and / or avoiding premature wear, such systems could, among other benefits, reduce the frequency of parts replacement. Summary

[0006] According to one aspect of the present disclosure, a device for transmitting a linear load by means of a high-speed rotating component for use in a compressor machine is disclosed. The device may include a linear actuator with an actuator cylinder configured to receive an axially movable cylinder rod. A thrust bearing may be attached to one end of the cylinder rod, and a splined shaft with a helical spline profile may be attached to the inner ring of the thrust bearing for rotating and axially moving the rod, the bearing, and the splined shaft components. The actuator cylinder may be rigidly attached to a fixed mounting adapter, and an elongated sleeve may also be attached to and extend from the adapter to prevent any axial or rotational movement of the sleeve.The sleeve can include an axially oriented elongated groove, and a guide pin can extend radially through the groove and be attached to the axially displaceable housing of the thrust bearing. The guide pin can be secured against rotation by the groove to prevent rotation of both the bearing housing and the cylindrical rod while the rod moves the splined shaft linearly between a retracted and extended position.

[0007] According to another aspect of the present disclosure, the device can be used in a compressor machine to move a concentrically positioned pair of eccentric weights between positions with minimum and maximum vibration amplitudes. For this purpose, the splined shaft of the device can comprise a helical splined profile at one end and an axial or straight splined profile at its opposite end. The axial splined profile can be configured to slide within one of the eccentric weights while the splined shaft is moved axially between the extended and retracted positions of the actuator cylinder rod.

[0008] According to another aspect of the present disclosure, a compressor machine may have a vibration mechanism comprising a) a splined shaft having a helical spline profile at one end and an axial or straight spline profile at its opposite end, and b) an outer eccentric weight having a helical bore (spiral bore) and an inner eccentric weight having an axial bore, wherein the splined shaft is positioned therein with its end having an axial spline profile and engages with the axial bore of the inner eccentric weight for linear relative movements therein, and with its opposite helical end engages with the helical bore of the outer eccentric weight to cause a relative rotation of the inner eccentric weight to the outer eccentric weight while the splined shaft is moved between the extended and retracted positions by the actuator cylinder rod.The vibration mechanism may further include a vibration motor designed to directly rotate the outer eccentric weight and thereby indirectly rotate the inner eccentric weight at the same speed. Brief description of the drawings Fig. Figure 1 is a schematic side view of a compaction machine, representing elements of the present disclosure. Fig. Figure 2 is an axial cross-sectional view along line 2-2 of the Fig. 1, the interior of a compaction roller having a vibration mechanism, which is located in the compaction machine of the Fig. 1 recorded shows, Fig. Figure 3 is an axial cross-sectional view of the vibration mechanism of the Fig. 2, which shows a splined shaft and the disclosed linear actuator components designed for axial displacement of the splined shaft, Fig. Figure 4 is a perspective view of the linear actuator components, showing a detailed interaction of the splined shaft with an axial bearing and a guide sleeve. Fig. 5 is a view of the guide sleeve and guide pin, with actuator cylinder rod and splined shaft in their fully extended positions shown, and Fig. Figure 6 is a view of the guide sleeve and guide pin, with actuator cylinder rod and splined shaft shown in their fully retracted positions. Detailed description

[0009] Initially referring to Fig. 1. A compaction machine 10 with twin vibratory rollers can be used to compact and / or increase the density of a compactable material or foundation 12, such as soil, gravel, and / or bituminous mixtures. The machine 10 can have a front compaction roller 14 and a rear compaction roller 16, both of which are rotatably mounted on a main frame 18. Although a twin-roller machine is shown here, the compactor 10 can alternatively use only a single vibratory roller without departing from the essence and scope of this disclosure. In the machine with a single vibratory roller, conventional wheels would be used instead of the second roller to allow for adequate mobility of the machine 10.

[0010] The main frame 18 can also support a motor 20 (shown with dashed lines) for providing drive power to the machine 10 as well as operating power for an electric generator 22 and / or a fluid pump such as a variable displacement fluid pump 24 (both shown with dashed lines). Since the front roller 14 and the rear roller 16 are structurally and functionally equivalent, the description of all associated components is given only with respect to the front roller 14. Thus, all aspects of the disclosure relating to the roller 14 are equally applicable to the rear roller 16.

[0011] With reference to Fig. 2 The front roller 14 can have first and second roller sections, i.e., a left section 26 and a right section 28 as shown, with the two sections separated by a gap 30 to define the twin-roll configuration (split-roll configuration). The twin-roll configuration allows for a speed difference between the rollers as the machine 10 rotates around a radius. Experts will recognize that the roller closest to the turning radius will typically rotate at a lower speed than the outer roller. These differential operations reduce the tendency for wear, tearing, or other damage to the surface being compacted.Both the first and the second roller section 26, 28 can be made from an outer shell 32 and have a first and second support wall 34 and 36 which are firmly secured to the inner diameters of the corresponding sections 26, 28 which form the respective outer shell 32.

[0012] A first and second drive motor 42, 44 are arranged between the main frame 18 and the first and second roll sections 26, 28, respectively. The drive motors 42, 44 can each be connected to a bearing plate (not shown) secured to the main frame 18. The output of the first and second drive motors 42, 44 can drive the first and second support walls 34 and 36, respectively, via an offset gear pair 46, which allows the drive motors 42 and 44 to be arranged with a slight offset from the roll axis 40. Alternatively, in another bearing configuration, the first and second drive motors 42, 44 can be directly connected to the support walls 34, 36, thus eliminating the need for the offset gear pair 46. Finally, the drive motors 42, 44 can be functionally connected to the power sources 22, 24 mentioned above, which can supply compressed fluid and / or electrical current to drive the motors to rotate the roller sections 26, 28.

[0013] A support assembly 50 rotatably connects the first roller section 26 to the second roller section 28 and also accommodates a vibration mechanism 60. The support assembly 50 is rotatably connected to the first and second support walls 34 and 36, respectively, so that the corresponding roller sections 26 and 28 can rotate relative to each other according to the differential aspect described above. Additionally, the support assembly 50 can have first and second support components 52 and 54, with the first component 52 rotatably arranged within the second component 54 for relative movement via a first bearing set 56, as shown. The support assembly 50, which shares its centerline with a roller axis 40, enables the differential rotation movements described above between the first roller section 26 via the first drive motor 42 and the second roller section 28 via the second drive motor 44.

[0014] With reference to Fig. 3. The vibration mechanism 60 is rotatably mounted about the roller axis 40 by a second bearing arrangement or a second bearing set 58. The vibration mechanism 60 can be driven via a drive shaft 64 by means of a vibration motor 62. The mechanism 60 can have a concentrically arranged inner and outer eccentric weight pair 66 and 68, respectively. A splined shaft 70 can be configured to engage with both weights 66 and 68 via a linear actuator 100, which is configured to move the splined shaft 70 in a manner described below.

[0015] The external eccentric weight 68 can be a driven or vibrating motor-side stub shaft 72 attached to the drive shaft 64, and a linear actuator-side stub shaft 74. The stub shafts 72 and 74 are arranged in the inner rings of the second bearing set 58 as shown. It will be recognized that the drive shaft 64 can be attached to the drive-side stub shaft 72 via a splined connection as shown, although other fastening mechanisms can also be used. The actuator-side stub shaft 74 has a helical bore 76 for the purpose described below.

[0016] While the assembly of parts of the eccentric weight 68 described above can form a hollow semi-cylindrical or curved housing that carries a greater weight on one radial side than the other, the inner eccentric 66 can be a single, albeit skewed, mass arranged within the hollow region of the outer eccentric weight 68. To allow rotational relative movement between the inner and outer eccentric weights 66, 68, the inner weight 66 can be supported within the weight 68 by a third bearing arrangement or set of bearings 78, positioned radially inside the left and right shaft stubs 72 and 74, as shown.

[0017] A bore 80, extending axially inward from the linear actuator end of the internal eccentric weight 66, is formed with an axially extending region 81 with an internal keyway profile for receiving the driven or left end 92 of the splined shaft 70. Correspondingly, the driven end of the splined shaft 70 can be formed with an external keyway profile that defines a region 82 with an axial keyway profile, designed to mesh with the keyway profile region 81 of the bore 80. In contrast, the actuator end or right end of the splined shaft 70 can have a region 84 with a helical keyway profile, designed to mesh with the helical bore 76 of the actuator-side shaft stub 74.

[0018] The splined shaft 70 can also define a smooth intermediate section 86 located between the axial splined section 82 and the helical splined section 84 at its respective left and right ends. The axial splined section 82 can engage in the bore 80 in a manner that ensures the inner eccentric weight 66 and the splined shaft 70 are rotationally fixed to each other, while allowing the splined shaft to slide axially within the bore 80. Conversely, the helical splined section 84 of the splined shaft 70 can be configured to engage with the helical splined section 76 of the shaft stub 74 in order to transmit axial motion of the splined shaft 70 into rotational motion of both the splined shaft 70 and the inner eccentric weight 66 relative to the outer eccentric weight 68, thus providing up to 180 degrees of relative rotational motion between the weight 66 and the weight 68.

[0019] As also from the Fig. As shown in Figure 3, the linear actuator 100 comprises an axially extending cylindrical rod 102, which can be configured to engage with the splined shaft 70 for axially transmissible movement with it. The cylindrical rod 102 extends from an actuator cylinder 104, which allows the cylindrical rod 102 to extend and retract linearly along the axis 40, thus extending and retracting the splined shaft 70.

[0020] With reference to the Fig. 4. An axial bearing 112 can be arranged between the otherwise abutting ends of the cylinder rod 102 and the section 84 with a helical spline profile of the splined shaft 70. The axial bearing 112 has a housing 116 that is secured to an adapter 110, which can be screwed to the offset gear 46. The inner ring of the axial bearing 112 is secured to the housing 116. The end of the section 84 with the helical spline profile of the splined shaft is secured to the rotatably movable inner ring of the axial bearing 112. Thus, when the cylinder rod 102 is pushed to the left, either manually by an operator or automatically via a computerized program, the splined shaft 70 is pushed to the left and thus set into rotation by the interaction of its section 84 with the helical spline profile in the bore 76 with the helical spline profile ( Fig. 3) brought about, since the shaft stub 74, which contains the bore, is rotationally fixed. The effect of the splined shaft rotation is a causing rotation of the inner eccentric weight 66 relative to the outer eccentric weight 68 via an interaction between the area 82 with axial splined profile of the splined shaft 70 and the area 81 with splined profile of the weight 66, since the splined profiles only allow axial movement.

[0021] It can now be seen that when the cylinder rod 102 is fully extended (as in Fig. 2 and Fig. 3 shown), the relative positions of the weights 66, 68 will be such that the weights are out of phase (arranged on opposite sides of the axis 40), and the vibration mechanism 80 will therefore operate with a minimum amplitude. Conversely, when the cylinder rod 102 is fully retracted ( Fig. 4) the weights are arranged in phase (each on the same side of the axis 40), and the vibration mechanism 80 is operated at its maximum amplitude. Naturally, stepless amplitude changes will be available between the minimum and maximum amplitude positions.

[0022] To avoid a natural tendency of the cylinder rod 102 to rotate under axial load in the comparatively strong vibration conditions of compressor machines, the disclosure provides for the use of a fixed guide sleeve 114, which is attached to an adapter 110 ( Fig. 4) is to be attached. The rotatable splined shaft 70, which is arranged concentrically in the guide sleeve, is attached to the inner ring of the thrust bearing as previously mentioned. Since the thrust bearing moves axially, the guide sleeve can be used to prevent the cylindrical rod 102 from rotating with the splined shaft. For this purpose, a guide sleeve groove 118 runs axially along the guide sleeve 114 together with a guide pin 120, which extends radially through the groove 118. The guide pin can be secured to the bearing housing 116 and designed to move laterally with the axial movement of the thrust bearing 112. When the pin is moved along the groove, the interaction between the guide pin 120 and the bearing housing 116 is such that the bearing housing is prevented from rotating.Accordingly, the cylinder rod, which is opposite the actuator end of the splined shaft, will not rotate even under conditions with strong vibrations and reciprocating motion.

[0023] With reference to the Fig. 5 and Fig. Figure 6 shows the linear actuator 100 in a fully extended and a fully retracted position. As mentioned previously, the extended position, in which the guide pin 120 is at the left end of the guide groove 118, as shown in Figure 6, represents the linear actuator 100 in a fully extended and a fully retracted position. Fig. Figure 5 shows a position with minimal vibration amplitude. Conversely, the retracted position, in which the guide pin 120 is located at the right end of the guide groove 118, as shown in Figure 5, represents a position with minimal vibration amplitude. Fig. Figure 6 shows a position with maximum vibration amplitude.

[0024] While the foregoing contains only brief descriptions of certain modifications and alternative constructions, this revelation is intended to encompass all modifications, alternative constructions and equivalents that fall within its nature and scope. Commercial applicability

[0025] In general, this disclosure relates to devices for preventing premature wear of linear cylinder rods and actuator parts used in a compressor machine. Such improved devices can be used in various industrial machines, for example, but not limited to, vibratory compactors, loaders, tracked tractors, or any other working machine used in construction, agricultural, and industrial environments.

[0026] In operation, the actuator can be used for the linear reciprocating motion of a splined shaft within the bore of an inner eccentric weight, which is arranged concentrically within an outer eccentric weight, without the undesirable effects of the relative rotation of linear actuator components. When a vibratory motor of an associated compaction machine rotates a pair of eccentric weights, the amplitude of the compaction can be controlled, as previously described, by bringing the inner eccentric weight in phase or out of phase with the outer eccentric weight. In particular, under conditions of significant vibration, the device of this disclosure can effectively minimize wear by preventing rotations of the described axial bearings and cylinder rod components that can occur during the extension and retraction cycles of the cylinder rod. Such rotations can be caused by the circular cyclic rotational movements of the splined shaft in a compaction machine.

[0027] The disclosed axial bearing and guide sleeve arrangement can effectively prevent cylinder rod rotation due to the guide pin being secured to the bearing housing by the guide sleeve groove. During the extension and retraction cycles of the cylinder rod and splined shaft, the rotation of the splined shaft, which is rotatably secured to the inner ring of the thrust bearing, will not cause any rotation of either the bearing or the cylinder rod due to the guide pin's securing position in the bearing housing. Although the guide pin is axially free to move along the guide sleeve groove during the extension and retraction of the splined shaft, it is prevented from rotating by the guide sleeve groove, and therefore rotation of the cylinder rod can be effectively prevented.

[0028] Finally, the described device offers a method for preventing actuator cylinder rod rotation by using a thrust bearing and a guide sleeve, wherein the guide sleeve includes a groove for receiving an axially displaceable guide pin that is attached to the thrust bearing housing. Thus, the method allows the splined shaft to rotate freely, while the cylinder rod can move linearly but is prevented from rotating.

Claims

[1] Device (10) for transferring a linear load through a component rotating at high speed, the device comprising: a linear actuator (100) with an actuator cylinder (104) and a cylinder rod (102) which is axially movable in the actuator cylinder (104), a mounting adapter (110) which is secured against axial and rotational movement, wherein the mounting adapter (110) is rigidly attached to the actuator cylinder (104), an elongated guide sleeve (114) which is also attached to the mounting adapter (110), wherein the guide sleeve (114) has a linear groove (118) extending substantially axially along its length and the guide sleeve (114) is designed to allow passage of one end of the cylinder rod (102), an axially displaceable axial bearing (112) which is attached to one end of the cylindrical rod (102), wherein the bearing has a housing (116) and the housing (116) has an outer ring secured against rotation, a splined shaft (70) which is attached to an inner ring of the bearing for rotation and axial movement with it, and a guide pin (120) which extends radially through the groove (118) and is attached to the housing (116), wherein the guide pin (120) is designed for transverse movement along the linear groove (118) and interacts with the groove (118) to prevent rotation of both the housing (116) and the cylinder rod (102) while the cylinder rod (102) is extended and retracted in the actuator cylinder (104). [2] Device (10) according to claim 1, further comprising a vibration mechanism (60) comprising an inner (66) and outer eccentric weight pair (66, 68), wherein the inner weight (66) is arranged concentrically in the outer weight (68), and wherein a linear movement of the splined shaft (70) causes the inner eccentric weight (66) to rotate relative to the outer eccentric weight (68) while the cylinder rod (102) is extended and retracted in the actuator cylinder (104). [3] Device (10) according to claim 2, wherein the inner eccentric weight (66) has a bore (80) with an axial wedge profile, and wherein the outer eccentric weight (68) has a bore (76) with a helical wedge profile, wherein the splined shaft (70) has a first end (92) with a region (82) with an axial wedge profile adapted to the bore (80) with an axial wedge profile, and wherein the splined shaft (70) has a second end with a region (84) with a helical wedge profile adapted to the bore (76) with a helical wedge profile. [4] Device (10) according to claim 3, wherein a linear movement of the cylinder rod (102) causes an axial movement of the splined shaft (70), wherein the axial movement of the splined shaft (70) leads to a rotational movement of the splined shaft (70), which in turn causes a relative rotational movement of the inner eccentric weight (66) to the outer eccentric weight (68). [5] Device (10) according to claim 2, wherein extending and retracting the cylinder rod (102) leads to moving the inner and outer eccentric weight (66, 68) between positions of the phase boundaries with maximum and minimum amplitude. [6] Device (10) according to claim 3, wherein when the area (82) with axial wedge profile of the splined shaft (70) is moved axially in the bore (80) with axial wedge profile of the inner eccentric weight (66), the area (84) with helical wedge profile of the splined shaft (70) interacts with the bore (76) with helical wedge profile to cause a rotation of the inner eccentric weight (66) relative to the outer eccentric weight (68). [7] Device (10) according to claim 1, wherein the component rotating at high speed further comprises a vibration motor (62) designed to rotate the vibration mechanism (60). [8] Device (10) according to claim 1, wherein the external eccentric weight (68) is arranged between a pair of stub shafts (72, 74) designed to rotate about an axis. [9] Device (10) according to claim 1, wherein the guide sleeve (114) and the actuator cylinder (104) are attached to opposite sides of the mounting adapter (110). [10] Device (10) according to claim 1, wherein the linear actuator (100) is driven by a pump (24). [11] Compressor machine (10) with a vibration mechanism (60) comprising an inner and outer eccentric weight pair (66, 68), wherein the inner weight (66) is arranged concentrically in the outer weight (68), the compressor machine (10) further comprising a device for rotating the weights relative to each other, wherein the device comprises: a linear actuator (100) with an actuator cylinder (104) and a cylinder rod (102) which is axially movable in the actuator cylinder (104), a mounting adapter (110) which is secured against axial and rotational movement, wherein the mounting adapter (110) is rigidly attached to the actuator cylinder (104), an elongated guide sleeve (114) which is also attached to the mounting adapter (110), wherein the guide sleeve (114) has a linear groove (118) extending substantially axially along its length and the guide sleeve (114) is designed to allow passage of one end of the cylinder rod (102), an axially displaceable axial bearing (112) which is attached to one end of the cylindrical rod (102), wherein the bearing has a housing (116) and the housing (116) has an outer ring secured against rotation, a splined shaft (70) which is attached to an inner ring of the bearing for rotation and axial movement with it, and a guide pin (120) which extends radially through the groove (118) and is attached to the housing (116), wherein the guide pin (120) is designed for transverse movement along the linear groove (118) and interacts with the groove (118) to prevent rotation of both the housing (116) and the cylinder rod (102) while the cylinder rod (102) is extended and retracted in the actuator cylinder (104). [12] Compressor machine (10) according to claim 11, wherein a linear movement of the splined shaft (70) leads to the relative rotation of the inner eccentric weight (66) to the outer eccentric weight (68), while the cylinder rod (102) is extended and retracted in the actuator cylinder (104). [13] Compressor machine (10) according to claim 12, wherein the inner eccentric weight (66) has a bore (80) with an axial wedge profile, and wherein the outer eccentric weight (68) has a bore (76) with a helical wedge profile, wherein the splined shaft (70) has a first end (92) with a region (82) with an axial wedge profile adapted to the bore (80) with axial wedge profile, and wherein the splined shaft (70) has a second end with a region (84) with a helical wedge profile adapted to the bore (76) with helical wedge profile. [14] Compressor machine (10) according to claim 13, wherein a linear movement of the cylinder rod (102) causes an axial movement of the splined shaft (70), wherein the axial movement of the splined shaft (70) leads to a rotational movement of the splined shaft (70), which in turn causes a relative rotational movement of the inner eccentric weight (66) to the outer eccentric weight (68). [15] Compressor machine (10) according to claim 12, wherein extending and retracting the cylinder rod (102) leads to moving the inner and outer eccentric weight (66, 68) between positions of the phase boundaries with maximum and minimum amplitude of the vibration mechanism.

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