For controlling gear motors in pumps and concrete mixers

Abstract

The utility model discloses a pump of a gear motor of a driving system for controlling the rotation of a drum of a concrete mixer truck. The pump is provided with a shaft, the shaft corresponds to a coupling interface of the pump, the pump comprises a removable flange and a chamber of the pump, the flange is provided with a central through hole for the shaft to pass through, the flange comprises an inner side oriented toward the chamber and an outer side oriented toward the outside of the pump, the inner side of the flange comprises an annular protrusion for inserting into the chamber, the flange is provided with a first seat, a first sealing ring is accommodated in the first seat, the flange is provided with a circular shoulder, the flange is also provided with a second seat, the second sealing ring is accommodated in the second seat between the outer side and the shoulder, and the second sealing ring protects the first sealing ring from pressurized water, dirt and corrosive environment. The double sealing system of the pump provides more effective protection against dirty and corrosive environments, obtains a longer service life of the pump, and a concrete mixer truck provided with the pump can reduce the vehicle operation cost.

Description

Technical Field

[0001] The utility model relates to a pump for controlling a gear motor. The gear motor is a gear motor of a driving system for rotating a drum of a concrete mixer truck. A double sealing element is arranged on a coupling interface of the pump.

[0002] The utility model also relates to a concrete mixer truck provided with the pump. Background Art

[0003] In the field of pumps, in particular, in the field of pumps for drive systems for the rotation of the drum of a concrete mixer truck, a combination of a pump and a drive system for rotating the drum of a concrete mixer truck is known, in which the concrete contained in the drum itself is continuously mixed. The rotation of the drum occurs in two directions, one direction is intended for mixing and one direction is intended for discharging the concrete contained in the drum. The drum must operate at a maximum rotation speed of 14 rpm-20 rpm and a maximum torque ranging from 30000 Nm to 60000 Nm and above, depending on the capacity of the mixing drum itself. The drum can be 3m to 4m long, for example but not limited to the application of the utility model, and the drum is fixed at its ends to the frame of a tractor with a road transport for concrete.

[0004] Existing solutions for pumps of drive systems for drum rotation of concrete mixer trucks have a seal for protection at the coupling interface of the pump to the universal joint for connection to the engine of the concrete mixer truck.

[0005] Problems with existing technology

[0006] The pumps of the drive system for the drum rotation of concrete mixer trucks are highly exposed to dust and deteriorating elements.

[0007] Prior art solutions that provide a seal for protection at the coupling interface of the pump to the universal joint suffer from different problems over time:

[0008] -Oil leakage problem;

[0009] -Problems associated with dirt penetrating into the gear motor.

[0010] These problems are caused by the fact that the application with respect to concrete mixer trucks is a particularly corrosive and / or dirty environment and the seals wear very quickly.

[0011] A further contribution to the premature degradation of the seals is due to the cleaning operations of the concrete mixer trucks which occur with high pressure washers.

[0012] The effect of this premature degradation is that the protection against dust penetration is lost and the protection of the oil seal in turn deteriorates with the dust penetration, so that the oil seal is damaged and oil leakage problems occur. Utility Model Content

[0013] The utility model aims to provide a pump for controlling a gear motor, wherein the gear motor is a gear motor of a driving system for rotating a drum of a concrete mixer truck, and the pump allows better protection of the seal on the coupling interface with a universal joint.

[0014] Wherein, the pump is provided with a double sealing system.

[0015] The solution according to the invention presents various advantages through a considerable inventive contribution, the effect of which constitutes an immediate and non-negligible technical advance.

[0016] The utility model provides a pump for controlling a gear motor, wherein the gear motor is a gear motor of a driving system for rotating a drum of a concrete mixer truck, wherein the pump is provided with a shaft extending according to a longitudinal axis of the pump, the shaft being positioned to correspond to a coupling interface of the pump, the pump comprising a removable flange corresponding to the coupling interface and a chamber of the pump closed by the flange, the flange being provided with a central through hole for the shaft to pass through, the flange comprising an inner side oriented toward the chamber and an outer side oriented toward the outside of the pump, the inner side of the flange comprising an annular protrusion for inserting into the chamber, the flange being provided with a first seat portion, the first seat portion being obtained on a protrusion corresponding to the inner side of the flange, a first sealing ring being accommodated in the first seat portion, the flange being provided with a circular shoulder portion, the circular shoulder being the end of the first seat portion, the flange being further provided with a second seat portion obtained on the outer side of the flange, the second sealing ring being accommodated in the second seat portion between the outer side and the shoulder portion, the second sealing ring protecting the first sealing ring from pressurized water, dirt and corrosive environment.

[0017] The utility model further provides a concrete mixer truck, comprising a mixing drum, wherein the concrete mixer truck comprises a gear motor for the drum, the gear motor is controlled by a pump, and is characterized in that the pump is according to the above-mentioned pump of the utility model.

[0018] The pump's double seal system provides protection against pressurized water that is used during the cleaning operations of the concrete mixer truck that occur with a high-pressure washer.

[0019] The double sealing system of the pump provides more effective protection against dirty and corrosive environments, resulting in a longer life of the pump, which in most cases covers the entire life cycle of the pump.

[0020] Maintenance is reduced, so that a concrete mixer truck equipped with the claimed pump can reduce vehicle operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In the following, implementations which are regarded as non-limiting examples of the invention will be described with reference to the included drawings, in which:

[0022] Figure 1 is a perspective and partially exploded view of a pump according to the present invention.

[0023] Figure 2 yes Figure 1 A cross-sectional view of a portion of a pump.

[0024] Figure 3 is Figure 2 Magnified view of the detail indicated by "A".

[0025] Figure 4 It is a cross-sectional perspective view of one of the seals of the pump according to the utility model.

[0026] Figure 5 A concrete mixer truck including a pump according to the utility model is schematically shown.

[0027] 1. Pump

[0028] 2. Shell

[0029] 3. Axis

[0030] 4. The first sealing ring

[0031] 5. Flange

[0032] 6. Second sealing ring

[0033] 7. Chamber

[0034] 8. Center through hole

[0035] 9. Protrusion

[0036] 10. O-ring

[0037] 11. First Space

[0038] 12. Second Space

[0039] 13. First Lip

[0040] 14. Second Lip

[0041] 15. Top

[0042] 16. First Subject

[0043] 17. Second Subject

[0044] 18. First Arm

[0045] 19. Second Arm

[0046] 20. Connection part

[0047] 21. First side

[0048] 22. Second side

[0049] 23. Concrete mixer truck

[0050] 24. Roller

[0051] 25.Support

[0052] 26. Framework

[0053] 27. Tractor

[0054] 28. Coupling interface

[0055] 29. Roller drive system

[0056] 30. Concave

[0057] 31. The First Seat

[0058] 32. Second seat

[0059] 33. Inside

[0060] 34. Outer side

[0061] 35. Coupling surface

[0062] 36. Inner surface

[0063] 37. Shoulders

[0064] 38. Longitudinal axis

[0065] 39. Contact interface

[0066] 40. Bump

[0067] 41. Gear motor

[0068] 42. Universal joint

[0069] 43. Engine

[0070] 44. Groove DETAILED DESCRIPTION

[0071] Reference Figure 5, the concrete mixer truck 23 comprises a tractor 27 operated by a corresponding engine 43. The concrete mixer truck 23 comprises a frame 26 connected to the tractor 27. On the frame 26, a rotating drum 24 is mounted to rest on a support 25. The rotation of the drum 24 occurs by means of a gear motor 41, which is coupled to the drum drive system 29 by means of a corresponding shaft of the gear motor 41 intended for coupling to the drum drive system 29. The gear motor 41 comprises a gear unit and an electric motor controlled by means of a pump 1. The electric motor is a hydraulic motor. The gear motor 41 rotates the drum 24 of the concrete mixer truck 23, in which continuous mixing of the concrete contained in the drum 24 itself occurs. The rotation occurs in two directions, one direction intended for mixing and one direction intended for discharging the concrete contained in the drum 24. The drum 24 is operated at a rotation speed generally but not limited to comprised in the range of about 14 rpm to 20 rpm, and at a maximum torque ranging from 30000 Nm to up to 60000 Nm.

[0072] The pump 1 supplies pressurized oil for controlling the hydraulic motor of the gear motor 41. According to a conventional solution immediately apparent to a person skilled in the art, the pump 1 comprises ( Figure 1 ) housing 2, in which the components of the pump 1 are housed. The pump 1 is connected to the engine 43 via a universal joint 42 ( Figure 5 ).

[0073] At the coupling interface 28 between the pump 1 and the universal joint 42 , there is a shaft 3 protruding from the housing 2 for coupling to the universal joint 42 to transmit the rotational force from the engine 43 .

[0074] A flange 5 is provided at the coupling interface 28 of the pump 1 ( Figure 1 , Figure 2 ), which flange can be removed from the housing 2 of the pump 1 to provide access to ( Figure 1 , Figure 2 ) chamber 7 of pump 1. Flange 5 is provided with a central through hole 8 for passage of shaft 3 of pump 1. Flange 5 comprises an inner side 33 oriented towards chamber 7 of pump 1, and flange 5 comprises an outer side 34 oriented towards the outside of pump 1, i.e. towards coupling interface 28. Inner side 33 of flange 5 comprises ( Figure 1 , Figure 2 ) is used to insert the annular protrusion 9 into the chamber 7, and the protrusion 9 is provided with a recess 30 for accommodating an O-ring 10, which is used for sealing ( Figure 2 ) A coupling surface 35 between the protrusion 9 of the flange 5 and the inner surface 36 of the chamber 7.

[0075] The first sealing ring 4 is accommodated inside the chamber 7. Therefore, the flange 5 is provided with ( Figure 2 , Figure 3) A first seat 31 is obtained on the inner side 33 of the flange 5, wherein the first seat 31 is open toward the central through hole 8 of the flange 5, so that the first seat 31 is communicated with the central through hole 8 of the flange 5. The first sealing ring 4 is accommodated in the first seat 31. The flange 5 is also provided with ( Figure 2 , Figure 3 ) A second seat 32 is obtained on the outer side 34 of the flange 5, wherein the second seat 32 is open toward the central through hole 8 of the flange 5 so that the second seat 32 is communicated with the central through hole 8 of the flange 5. The second sealing ring 6 is accommodated in the second seat 32.

[0076] Although the O-ring 10 between the protrusion 9 and the inner surface 36 of the chamber 7 is a sealing element between two elements fixed to each other, the first sealing ring 4 and the second sealing ring 6 are located between the flange 5 and the shaft 3, wherein the shaft 3 rotates relative to the flange 5 ( Figure 2 For this reason, the shape of the first sealing ring 4 and the shape of the second sealing ring 6 are such that the contact surface with the shaft 3 is minimized.

[0077] The first sealing ring 4 includes ( Figure 3 ) The first body 16 is a body with a "U" shape in cross section, and the first body 16 includes a first arm 18 and a second arm 19 connected to each other by a connecting portion 20 in such a manner that the first arm 18 and the second arm 19 are spaced apart from each other by a gap. The first sealing ring 4 is inserted into the first seat portion 31 in such a manner that the first arm 18 and the second arm 19 are parallel to the longitudinal axis 38 of the pump 1.

[0078] The second arm 19 is positioned so that ( Figure 3 ) corresponds to the hole 8 of the flange 5, i.e. in such a way that the second arm 19 is oriented towards the shaft 3. As explained previously, since the first seat 31 is open towards the central through hole 8 of the flange 5, the second arm 19 is an element of the first sealing ring 4 that corresponds to the inner side 33 of the flange 5, effectively sealing the hole 8 and the shaft 3. Due to the "U" shape of the first body 16 of the first sealing ring 4, the second arm 19 is flexible so as to ( Figure 3 ) adapts to the gap between the hole 8 and the shaft 3 and obtains a reliable seal. The flange 5 is provided with a circular shoulder 37, which is the end of the first seat 31. The first sealing ring 4 is held in place due to the interference between the outer peripheral radially outer surface of the first sealing ring 4 and the outer peripheral radially inner surface of the first seat 31. The second arm 19 includes ( Figure 3 ) The first lip 13 and the second lip 14 are spaced apart from each other in a direction parallel to the longitudinal axis 38, so that a first space 11 is defined between the first lip 13 and the second lip 14 corresponding to a first portion of the contact interface 39 between the shaft 3 and the flange 5. The first space 11 constitutes ( Figure 3) A first circular space is formed in the first circular space for containing a first amount of grease, which provides constant lubrication of the first sealing ring 4, avoids overheating in this area, and further reduces dynamic friction caused by the mutual rotation between the first sealing ring 4 of the shaft 3 and the flange 5. The first lip 13 and the second lip 14 minimize the contact between the first sealing ring 4 and the shaft 3, and also serve as a containing element for the first amount of grease in the first space 11.

[0079] As explained previously, the second sealing ring 6 is housed in a second seat 32 obtained on the outer side 34 of the flange 5, so that the second sealing ring 6 is accessible from the coupling interface 28 of the pump 1 without having to remove the flange 5. This solution offers great advantages since it allows an easy visual inspection of the second sealing ring 6 and, in the event of wear, the second sealing ring 6 can be easily replaced without having to remove the flange 5.

[0080] The second sealing ring 6 includes ( Figure 3 , Figure 4 ) a second body 17, the cross-sectional shape of the second body 17 corresponds to the cross-sectional shape of the second seat portion 32, so that when the second sealing ring 6 is inserted into the second seat portion 32, the second sealing ring 6 is held in place inside the second seat portion 32 due to interference and friction. The second sealing ring 6 includes ( Figure 3 , Figure 4 ) A groove 44 separating the first side 21 and the second side 22, which are mutually opposite sides of the second body 17 and are parallel to a direction parallel to the longitudinal axis 38 of the pump 1. The first side 21 is oriented towards the inner wall of the second seat 32 and is provided with a protrusion 40 to improve the interference and friction effect against the inner wall of the second seat 32 so as to keep the second sealing ring 6 in place inside the second seat 32. The second side 22 is positioned ( Figure 3 ) corresponds to the hole 8 of the flange 5, i.e. in such a way that the second side 22 is oriented towards the shaft 3. As explained previously, since the second seat 32 is open towards the central through hole 8 of the flange 5, the second side 22 is an element of the second sealing ring 6 which corresponds to the inner side 33 of the flange 5, effectively sealing the hole 8 and the shaft 3. The second side 22 of the second body 17 of the second sealing ring 6 is provided with a flexible tip 15 protruding from the second body 17 towards the hole 8, so as to ( Figure 3 ) adapts to the gap between the hole 8 and the shaft 3 and obtains a reliable seal. Due to the presence of the top 15, the second space 12 is defined between the top 15 and the shoulder 37 of the flange 5, corresponding to the second part of the contact interface 39 between the shaft 3 and the flange 5. The second space 12 constitutes ( Figure 3) A second circular space is formed in the second circular space for containing a second amount of grease, which provides constant lubrication of the second sealing ring 6, avoids overheating in this area, and further reduces the dynamic friction caused by the mutual rotation between the second sealing ring 6 of the shaft 3 and the flange 5. The top 15 minimizes the contact between the second sealing ring 6 and the shaft 3, and also acts as a containing element for the second amount of grease in the second space 12.

[0081] Due to the described construction comprising the first sealing ring 4 arranged corresponding to the inner side 33 of the flange 5 and the second sealing ring 6 arranged corresponding to the outer side 34 of the flange 5, the double lip 13, 14 sealing construction of the first sealing ring 4 is protected from pressurized water, dirt and corrosive environment by means of the second sealing ring 6, thereby obtaining a longer life of the pump 1, in most cases covering the entire service life of the device. This occurs due to the positioning of the second sealing ring 6 arranged corresponding to the outer side 34 of the flange 5.

[0082] Advantageously, the first sealing ring 4 and the second sealing ring 6 are mounted according to a spring-free configuration, which ensures low rotational friction and excellent resistance to corrosive agents, dirt and water. The grease contained in the first space 11 and the second space 12 ensures constant lubrication of the first sealing ring 4 and the second sealing ring 6, avoids overheating in this area, and further reduces dynamic friction. The grease also has an additional protective function, because any dirt that may enter the interior from the outside through the second sealing ring 6 will be blocked by the grease contained in the second space 12. Another improvement is given by reducing the gap between the flange 5 and the rotating shaft 3. In this way, the flange 5 further protects the first sealing ring 4 by creating a labyrinth seal formed by the top 15, the second space 12 and the shoulder 37.

[0083] Therefore, pump 1 is used for ( Figure 5 ) A pump 1 of a gear motor 41 of a drive system for rotating a drum 24 of a concrete mixer truck 23, wherein the pump 1 is provided with a shaft 3 extending according to a longitudinal axis 38 of the pump 1, the shaft 3 being positioned ( Figure 1 , Figure 2 ) corresponds to the coupling interface 28 of the pump 1, and the pump 1 includes ( Figure 1 ) A removable flange 5 corresponding to the coupling interface 28 and a chamber 7 of the pump 1 closed by the flange 5, the flange 5 being provided with a central through hole 8 for the shaft 3 of the pump 1 to pass through, the flange 5 comprising ( Figure 1 , Figure 2 , Figure 3 ) an inner side 33 oriented toward the chamber 7 and an outer side 34 oriented toward the outside of the pump 1, the inner side 33 of the flange 5 includes an annular protrusion 9 for insertion into the chamber 7, and the flange 5 is provided with ( Figure 2 , Figure 3) A first seat 31 is obtained on the protrusion 9 corresponding to the inner side 33 of the flange 5, and the first sealing ring 4 is accommodated in the first seat 31. The flange 5 is provided with a circular shoulder 37, which is the end of the first seat 31. The shoulder 37 of the flange 5 is in contact with the connecting portion 20 of the first sealing ring 4, and the first sealing ring 4 is held in place due to the interference between the outer peripheral radially outer side surface of the first sealing ring 4 and the outer peripheral radially inner side surface of the first seat 31. The flange 5 is also provided with ( Figure 2 , Figure 3 ) A second seat 32 is obtained on the outer side 34 of the flange 5, in which a second sealing ring 6 is housed between the outer side 34 and the shoulder 37, the second sealing ring 6 protecting the first sealing ring 4 from pressurized water, dirt and corrosive environment.

[0084] Therefore, the concrete mixer truck 23 includes ( Figure 5 ) a mixing drum 24, wherein the concrete mixer truck 23 comprises a gear motor 41 for the drum 24, wherein the gear motor 1 also comprises a gear unit and an electric motor, the gear motor 41 is controlled by a pump 1, the pump 1 is provided with a shaft 3 extending according to a longitudinal axis 38 of the pump 1, the shaft 3 is positioned corresponding to a coupling interface 28 of the pump 1, and the pump 1 is manufactured according to the aforementioned solution.

[0085] The present invention has been described with reference to the accompanying drawings in the preferred form of implementing the present invention, but it is obvious that many possible changes, modifications and variations will be immediately clear to those skilled in the art in view of the foregoing description. Therefore, it should be emphasized that the present invention is not limited to the foregoing description, but includes all changes, modifications and variations according to the attached claims.

Claims

1. A pump for controlling a gear motor, wherein the gear motor (41) is a gear motor of a drive system for rotating a drum (24) of a concrete mixer truck (23), wherein: The pump (1) is provided with a shaft (3) extending according to the longitudinal axis (38) of the pump (1), the shaft (3) being positioned to correspond to the coupling interface (28) of the pump (1), the pump (1) comprising a removable flange (5) corresponding to the coupling interface (28) and a chamber (7) of the pump (1) closed by the flange (5), the flange (5) being provided with a central through hole (8) for the shaft (3) to pass through, the flange (5) comprising an inner side (33) oriented towards the chamber (7) and a central through hole (8) oriented towards the chamber (7). An outer side (34) of the pump (1) directed outwardly, the inner side (33) of the flange (5) comprising an annular projection (9) for insertion into the chamber (7), the flange (5) being provided with a first seat (31) obtained on the projection (9) corresponding to the inner side (33) of the flange (5), the first sealing ring (4) being accommodated in the first seat (31), the flange (5) being provided with a circular shoulder (37) which is the end of the first seat (31), characterized in that The flange (5) is also provided with a second seat (32) obtained on the outer side (34) of the flange (5), a second sealing ring (6) being housed in the second seat (32) between the outer side (34) and the shoulder (37), the second sealing ring (6) protecting the first sealing ring (4) from pressurized water, dirt and corrosive environment.

2. The pump for controlling a gear motor according to claim 1, characterized in that: A second seat (32) is obtained on the outer side (34) of the flange (5) in such a way that the second sealing ring (6) is accessible from the coupling interface (28) of the gear motor (41) without having to remove the flange (5).

3. The pump for controlling a gear motor according to claim 1, characterized in that: The first seat portion (31) is open toward the central through hole (8) of the flange (5), so that the first seat portion (31) is communicated with the central through hole (8) of the flange (5).

4. The pump for controlling a gear motor according to claim 3, characterized in that: The first sealing ring (4) comprises a first body (16) having a U-shaped cross section, the first body (16) comprising a first arm (18) and a second arm (19) connected to each other by a connecting portion (20) in such a manner that the first arm (18) and the second arm (19) are spaced apart from each other by a gap, the first sealing ring (4) is inserted into the first seat (31) in such a manner that the first arm (18) and the second arm (19) are parallel to the longitudinal axis (38), the second arm (19) is positioned to correspond to the central through hole (8) of the flange (5), the second arm (19) is flexible so as to adapt to the gap between the central through hole (8) and the shaft (3), the shoulder (37) of the flange (5) contacts the connecting portion (20) of the first sealing ring (4), and the first sealing ring (4) is held in place due to interference between the peripheral radially outer surface of the first sealing ring (4) and the peripheral radially inner surface of the first seat (31).

5. The pump for controlling a gear motor according to claim 4, characterized in that: The second arm (19) comprises a first lip (13) and a second lip (14), wherein the first lip and the second lip are spaced apart from each other in a direction parallel to the longitudinal axis (38), so that a first space (11) is defined between the first lip (13) and the second lip (14) corresponding to a first portion of a contact interface (39) between the shaft (3) and the flange (5), wherein the first space (11) constitutes a first circular space for accommodating a first amount of grease.

6. The pump for controlling a gear motor according to claim 1, characterized in that: The second seat portion (32) is open toward the central through hole (8) of the flange (5), so that the second seat portion (32) is communicated with the central through hole (8) of the flange (5).

7. The pump for controlling a gear motor according to claim 6, characterized in that: The second sealing ring (6) comprises a second body (17), the cross-sectional shape of the second body corresponds to the cross-sectional shape of the second seat (32), so that when the second sealing ring (6) is in a state of being inserted into the interior of the second seat (32), the second sealing ring (6) is held in place in the second seat (32) due to interference and friction, the second sealing ring (6) comprises a first side (21) and a second side (22), the first side and the second side being mutually opposite sides of the second body (17) and parallel to a direction parallel to a longitudinal axis (38) of the gear motor (41), the second side (22) being positioned to correspond to the central through hole (8) of the flange (5) in such a manner that the second side (22) is oriented toward the shaft (3), and the second side (22) is provided with a flexible tip (15) protruding from the second body (17) toward the central through hole (8) to accommodate a gap between the central through hole (8) and the shaft (3).

8. The pump for controlling a gear motor according to claim 7, characterized in that: Corresponding to the second part of the contact interface (39) between the shaft (3) and the flange (5), a second space (12) is defined between the top end (15) and the shoulder (37) of the flange (5), and the second space (12) constitutes a second circular space for accommodating a second amount of grease.

9. The pump for controlling a gear motor according to claim 7, characterized in that: The first side (21) is oriented toward the inner wall of the second seat (32), and the first side (21) is provided with a protrusion (40) to improve the interference and friction effect against the inner wall of the second seat (32).

10. The pump for controlling a gear motor according to claim 1, characterized in that: The protrusion (9) is provided with a recess (30) for accommodating an O-ring (10) for sealing a coupling surface (35) between the protrusion (9) of the flange (5) and an inner surface (36) of the chamber (7).

11. A concrete mixer truck, comprising a mixing drum, wherein: The concrete mixer truck (23) comprises a gear motor (41) for the drum (24), the gear motor (41) being controlled by a pump (1), characterised in that the pump (1) is a pump according to any one of claims 1 to 10.

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