CN215186105U

CN215186105U - Gear motor device and screw conveyor

Info

Publication number: CN215186105U
Application number: CN202121079930.2U
Authority: CN
Inventors: 马尔凯西尼·魏纳
Original assignee: Wamgroup SpA
Current assignee: Wamgroup SpA
Priority date: 2020-05-20
Filing date: 2021-05-19
Publication date: 2021-12-14
Anticipated expiration: 2031-05-19
Also published as: BR202021009825U2; DE202021102773U1; TR2021008280U5

Abstract

A gear motor apparatus for rotating a rotatable element, such as an auger of a conveyor, and a screw conveyor, the gear motor apparatus comprising: a motor having a rotor and a stator, the rotor and the stator being housed in the housing, the motor further including a drive shaft extending along the axis; a gear unit including a first gear rotatable by the motor and a second gear disposed within the housing, the gear unit having an output shaft offset from the drive shaft and connectable to the rotatable element to rotate the rotatable element; a coupling flange for securing the gearmotor apparatus to a device comprising a rotatable element, the coupling flange being connected to the housing by a detachable non-permanent connection. The housing has a plurality of protrusions projecting transversely to the axis for receiving respective removable fixing elements adapted to removably connect the casing to the housing.

Description

Gear motor device and screw conveyor

Technical Field

The present invention relates to a gear motor arrangement adapted to rotate a rotatable element, such as an auger of a screw conveyor. The conveyor may comprise a tubular housing within which the auger is rotatably received. The auger allows for delivery of the flowable material in the forward direction. The flowable material may be a liquid in which solid portions may be dispersed, or a highly viscous fluid, or a solid material including chips, granules, or powder.

Background

In prior art screw conveyors, the auger is typically rotated by a gear motor arrangement comprising an electric motor and a gear unit. The electric motor is connected to the gear unit by means of a standard flange, that is to say a flange manufactured according to a specific international standard which determines many geometrical and dimensional parameters of the flange, such as the external diameter, the number of fixing holes allowing the flange of the electric motor to be fixed to the gear unit, the distance between the axes of the fixing holes, etc.

Although the prior art gear motor arrangement is robust and provides a reliable level of performance, it can be further improved, in particular in terms of its size, weight and cost.

SUMMERY OF THE UTILITY MODEL

The object of the present invention is to improve a gear motor device of the known type, in particular of the type used for rotating the auger of a tubular conveyor.

A further object is to provide a gearmotor arrangement having a limited size, in particular in the axial direction, so that the space required in the prior art conveyor to accommodate the gearmotor arrangement for driving the auger can be reduced.

Another object is to provide a gear motor arrangement with limited weight in order to simplify and lighten the supporting structure used for supporting the gear motor arrangement in prior art screw conveyors.

A further object is to reduce the cost of the gear motor arrangement.

According to the present invention, there is provided a gear motor arrangement for rotating a rotatable element, such as an auger of a conveyor, the gear motor arrangement comprising: a motor having a rotor and a stator housed in a housing, the motor further including a drive shaft extending along an axis; a gear unit including a first gear rotatable by the motor and a second gear disposed within the housing, the gear unit having an output shaft offset from the drive shaft and connectable to the rotatable element to rotate the rotatable element; and a coupling flange for fixing the gear motor arrangement to a device in which the rotatable element is included, the flange being connected to the housing by a detachable non-permanent connection, wherein the housing has a plurality of protrusions projecting transversely to the axis for receiving respective detachable fixing elements adapted to detachably connect the housing to the housing.

Compared with the gear motor device of the prior art, the gear motor device of the utility model has limited axial dimension.

Due to the protrusion made in the housing, the flange connecting the motor to the gear unit in the prior art can be eliminated. This allows a reduction in the weight of the gear motor arrangement, since the material used in the prior art for manufacturing the flange can be saved.

The axial dimension of the gear motor arrangement, i.e. the dimension of the gear motor arrangement parallel to the machine axis, is also reduced by an amount approximately corresponding to the thickness of the flange.

Furthermore, the provision of an output shaft that is not aligned with the drive shaft enables the axial dimensions of the gearmotor arrangement to be kept limited, since some components of the gearmotor arrangement may be arranged transversely with respect to the axis of the drive shaft, rather than being aligned with the drive shaft.

Further, the housing has a plurality of projections arranged to contact the projections of the housing, each of the detachable fixing elements being received in and received in the projections of the plurality of projections for detachably fixing the housing to the housing.

Further, a housing is coupled to the housing on the coupling plane, the housing having a cavity in which the stator and the rotor are housed, the cavity having an inner transverse dimension, measured on the coupling plane, greater than or equal to an outer transverse dimension of the stator, so as to allow the stator to be removed from the cavity after the gear unit is detached from the motor.

Further, the first gear is supported by and fixed relative to the drive shaft.

Further, still include: a first bearing for supporting the drive shaft at an end portion near the drive shaft, the first gear being fixed to the end portion; and a second bearing for supporting the drive shaft at the other end of the drive shaft opposite to the end portion.

Further, the inner diameter of the first bearing is larger than the outer diameter of the first gear.

Further, the first bearing is fixed in a seat made in the housing.

Further, the first gear is directly meshed with the second gear.

Further, the coupling flange has a seat for accommodating the sealing element on a face of the coupling flange furthest from the housing.

Further, a fan is also included, the fan being secured to the drive shaft on an opposite side of the drive shaft relative to the first gear.

Further, the housing projects laterally from the housing.

Further, the output shaft extends along another axis parallel to the axis.

Further, the second gear is keyed to the output shaft.

According to another embodiment of the present application, there is provided a screw conveyor comprising a tubular housing and an auger, the auger being at least partially received in the tubular housing, the screw conveyor gear motor means connected to the auger for rotating the auger about a respective longitudinal axis.

Further, screw conveyors are used to convey cement in powder form.

In one embodiment, the first gear is supported by the drive shaft in a fixed position relative to the drive shaft.

In this way, a particularly compact gear motor arrangement can be obtained. Further, a single pair of bearings may be used to support the drive shaft and the first gear.

In one embodiment, the housing of the motor is coupled to the housing of the gear unit along a coupling plane.

The housing has a cavity in which the stator and rotor are housed.

The cavity of the housing has an inner transverse dimension, e.g. an inner diameter measured on the coupling plane, which is greater than or equal to an outer transverse dimension, e.g. an outer diameter, of the stator.

Therefore, after the gear unit is detached from the motor, the stator can be taken out and replaced when a failure occurs.

This makes maintenance of the gear motor arrangement particularly easy and economical.

Indeed, in the event of a motor failure (in most cases associated with a stator failure), the motor can be repaired simply by replacing the damaged stator with a new one.

Thus, it is possible to avoid replacing the entire electric motor, which would be rather expensive, also due to the custom geometry of the electric motor, wherein the protrusions of the housing have replaced the standard flanges of conventional electric motors.

Drawings

The invention may be better understood and put into practice with reference to the accompanying drawings, which illustrate non-limiting exemplary embodiments of the invention and in which:

FIG. 1 is a perspective view of a gear motor apparatus for rotating a rotatable element (e.g., an auger of a conveyor);

FIG. 2 is a side view of the gear motor arrangement of FIG. 1;

FIG. 3 is a partial exploded view showing some of the components of the gear motor arrangement of FIG. 1;

fig. 4 is a section on the mid-plane of the gear motor arrangement of fig. 1.

Detailed Description

Fig. 1, 2, 3 and 4 show a gear motor arrangement 1 which can be used to rotate a rotatable element, in particular an auger of a screw conveyor.

The screw conveyor to which the gearmotor apparatus 1 is connectable may comprise a tubular housing at least partially housing an auger extending along a longitudinal axis. Screw conveyors may be used to convey liquid, or viscous fluids, or solid materials in the form of chips, granules or powders, which may contain dispersed solid portions, in an advancing direction. The gearmotor apparatus 1 may be connected to the augers to rotate the augers about respective longitudinal axes.

The gear motor arrangement 1 comprises an electric motor 2 for providing torque as an output. The motor 2 comprises a drive shaft 3, to which drive shaft 3 a rotor 4 is fixed. The stator 5 is arranged in a fixed position inside the motor 2, and in the example shown, the stator 5 surrounds the rotor 4. The stator 5 comprises a winding 6, in particular made of copper, which in the example shown has a prismatic geometry, with a hexagonal cross section.

The drive shaft 3 extends along an axis Z and is rotatable about the axis Z together with the rotor 4.

The motor 2 includes a housing 7, and the housing 7 accommodates the stator 5 and the rotor 4. The housing 7 is tubular and extends around the axis Z. The housing 7 has a plurality of fins 8 on its outer surface to facilitate cooling of the motor 2.

The drive shaft 3 is also at least partially accommodated in the housing 7.

The gear motor arrangement 1 further comprises a gear unit 9 for providing a desired speed value as an output from the gear motor arrangement 1 by reducing the rotational speed of the drive shaft 3.

The gear unit 9 comprises an output shaft 10, which output shaft 10 may be coupled to a rotatable element to be rotated by the gear motor arrangement 1. For example, the output shaft 10 may be coupled to an auger of a screw conveyor.

The output shaft 10 may be provided with a coupling element to allow the output shaft 10 to be coupled to a rotatable element to be rotated by the gear motor arrangement 1. The coupling element may comprise, for example, a spline profile 11 provided at the end of the output shaft 10.

The output shaft 10 extends along another axis Y.

The other axis Y is parallel to and offset with respect to the axis Z. Therefore, the output shaft 10 is not aligned with respect to the drive shaft 3, that is, is not aligned.

The gear unit 9 comprises a first gear wheel 12, which first gear wheel 12 can be driven by the drive shaft 3. The first gear 12 is fixed to the end of the drive shaft 3. More specifically, the first gear 12 may be interference fit on the drive shaft 3. In this way, the first gear wheel 12 is fixed relative to the drive shaft 3, that is to say the first gear wheel 12 and the drive shaft 3 act as a single body.

The gear unit 9 further comprises a second gear wheel 13, which second gear wheel 13 is fixed relative to the output shaft 10. In the example shown, the second gear 13 is directly in mesh with the first gear 12. In other words, no intermediate gear is interposed between the first gear 12 and the second gear 13. The gear unit 9 comprises only two gears.

In the example shown, the first gear 12 and the second gear 13 are cylindrical gears with helical teeth. However, this condition is not essential, and the first gear 12 and the second gear 13 may also be cylindrical gears having straight teeth.

The second gear 13 has a first primary diameter (primary diameter) which is larger than the primary diameter (primary diameter) of the first gear 12. Thus, the first gear 12 may be defined as a pinion gear and functions like a fast gear, while the second gear 13 functions like a slow gear. In other words, the output shaft 10 has a lower rotational speed than the drive shaft 3.

The gear unit 9 further comprises a housing 14, the housing 14 accommodating the first gear 12 and the second gear 13.

The casing 14 is fixed to the casing 7 by means of a plurality of removable fixing elements 15, which may in particular comprise threaded elements. The removable fixing element 15 allows to fix the gear unit 9 to the motor 2 and to repeatedly detach the gear unit 9 from the motor 2 any number of times.

The removable fixing elements 15 engage in corresponding fixing holes formed in corresponding projections 16 of the casing 7. The projection 16 projects from the body 17 of the housing 7 transversely to the axis Z, for example perpendicularly to the axis Z.

The projections 16 are distributed about the axis Z.

Furthermore, the casing 14 has a plurality of projections 18 adapted to abut against the projections 16 of the housing 7. Each projection 18 has a hole in which a removable fixing element 15 engages for removably connecting the housing 7 to the casing 14.

The projection 18 projects from the housing 14 transversely, in particular perpendicularly, to the axis Z of the drive shaft 3.

In a plane perpendicular to the axis Z, the projection 18 has a profile matching that of the projection 16.

The protrusion 16 and the projection 18 allow the motor 2 and the gear unit 9 to be detachably coupled without using a standard flange of the prior art.

More specifically, the projections 16 and the projections 18 make it possible to minimize the material between two consecutive projections 16 and between two consecutive projections 18, compared to the case where the motor 2 and the gear unit 9 have circular flanges for fastening to each other.

It is also possible to reduce the axial dimensions of the motor 2 and of the gear unit 9 by an amount approximately corresponding to the thickness of a conventional flange. In practice, the projection 16 and the projection 18 project laterally from the main body 17 of the casing 7 and from the casing 14, respectively.

The drive shaft 3 is supported by the pair of rolling bearings. More specifically, the drive shaft 3 is supported by a first bearing 19, which first bearing 19 may be of spherical type, located at the end of the drive shaft 3 where the first gear 12 is fixed. The drive shaft 3 is also supported by a second bearing 20, which may also be of spherical type, at the end of the drive shaft 3 opposite the end to which the first gear wheel 12 is fixed.

The second bearing 20 has an inner ring, in which the drive shaft 3 is inserted, and an outer ring, which is accommodated in an appendage 21 of the housing 7. The appendage 21 projects towards the inside of the casing 7.

The first bearing 19 has an inner ring through which the drive shaft 3 extends and an outer ring which is housed in a seat provided in the casing 14.

The outer diameter of the first gear 12 is smaller than the inner diameter of the first bearing 19. In this way, the first bearing 19 can be pulled out from the drive shaft 3 without interfering with the first gear 12. When the gear unit 9 is separated from the motor 2 together with the housing 14, the first bearing 19 is removed from the drive shaft 3. When this occurs, the first bearing 19 remains fixed to the housing 14 of the gear unit 9.

The housing 7 has a cavity 22, and the rotor 4 and the stator 5 are accommodated in the cavity 22. In the example shown, the cavity 22 has a substantially cylindrical shape.

The gear unit 9 is coupled to the motor 2 along a coupling plane P, the contour of which is shown in fig. 2 and 4. The coupling plane P is arranged transversely, in particular perpendicularly, to the axis Z.

The casing 14 abuts the housing 7 along a coupling area lying on the coupling plane P.

The cavity 22 of the casing 7 has an internal transverse dimension (for example, an internal diameter) measured on the coupling plane P, which is greater than or equal to an external transverse dimension of the stator 5. The outer transverse dimension of the stator 5 is measured perpendicular to the axis Z and may be, for example, the outer diameter of the stator 5.

This allows the stator 5 to be easily removed from the housing 7 to perform maintenance or repair operations, as described in more detail below.

In other words, the cavity 22 is open on the coupling plane P and the gear unit 9, or more precisely the housing 14 of the gear unit, acts as a cover of the cavity 22 in the assembled configuration of the gear motor device 1.

The gear unit 9 extends in an off-center position with respect to the motor 2.

More specifically, the gear unit 9 has a box-shaped body 23 which extends around the first gear 12 and the second gear 13, the box-shaped body 23 being laterally offset with respect to the housing 7. In other words, the box-shaped body 23 projects laterally from the casing 7, that is to say it projects from the casing 7 transversely to the axis Z.

The housing 14 also has a rib 24, the rib 24 protruding from the box-shaped body 23 and extending between the box-shaped body 23 and the case 7. The ribs 24 are provided on the opposite side of the box-shaped body 23 with respect to the portion of the box-shaped body 23 that projects laterally with respect to the housing 7.

The gear motor arrangement 1 further comprises a coupling flange 25, which coupling flange 25 is used to fix the gear motor arrangement 1 to a rotatable element to be rotated by the gear motor arrangement 1, for example to an auger of a screw conveyor. The coupling flange 25 is fixed to the housing 14 on the side opposite to the motor 2.

The coupling flange 25 is fixed to the casing 14 by means of a removable and non-permanent connection, for example by means of a plurality of threaded elements 26. This allows the coupling flange 25 to be detached from the housing 14 without damaging the components of the gear motor arrangement 1. In this way, the gear motor device 1 can be adapted to be fixed to different types of rotatable elements or augers simply by replacing the coupling flange 25.

The coupling flange 25 may be coaxial with the output shaft 10.

The coupling flange 25 has a central hole through which the output shaft 10 passes.

The output shaft 10 projects axially from the coupling flange 25.

The coupling flange 25 may have a seat 27 on its surface furthest from the housing 14, which seat 27 is intended to receive a sealing element, not shown, which allows the flange 25 to be sealingly coupled with a rotatable element to be rotated by the gear motor arrangement 1.

The gear motor arrangement 1 further comprises a fan 28 for cooling the electric motor 2. The fan 28 may be fixed at the end of the drive shaft 2 opposite to the end to which the first gear 12 is fixed. In this way, when drive shaft 3 rotates, fan 28 rotates about axis Z together with drive shaft 3.

The fan 28 may be housed in a compartment 29 formed between the concave body 30 and an end face 31 of the casing 7.

An electrical box 32 is further provided, the electrical box 32 housing a plurality of components for connecting and controlling the electric motor 2. The electric box 32 protrudes from one side of the housing 7.

During the over-operation of the gear motor arrangement 1, a malfunction of the electric motor 2 may occur. In this type of motor, the most frequently malfunctioning component is the stator 5. In case of a failure of the stator 5, the damaged stator 5 can be removed and replaced with a new stator 5 in a relatively easy manner.

For this purpose, the gearmotor arrangement 1 is removed from the apparatus connected thereto (for example from a screw conveyor).

At this point, the casing 14 is separated from the casing 7 by acting on the removable fixing element 15.

The second gear 13 and the first bearing 19 remain mounted on the housing 14. The coupling flange 25 also remains fixed to the housing 14.

The second gear 13 is disengaged from the first gear 12 which is fixed relative to the drive shaft 3.

The first bearing 19 is pulled out from the second gear 13.

At this time, the gear unit 9 is separated from the motor 2. The cavity 22 is accessible from the outside and a damaged stator 5 can be easily removed and replaced with a new stator 5.

The gear unit 9 can now be remounted to the electric motor 2 in the reverse operating sequence to that described above, after which the gearmotor apparatus 1 can continue to operate.

This avoids that in case of a failure of the stator 5 the entire gear motor arrangement 1 is thrown away and replaced with a new complete gear motor arrangement 1, resulting in significant cost savings.

The electric motor 2 may be designed in particular for the type of application in which the gear motor arrangement 1 is to be used.

For example, the gear motor arrangement 1 may be used in a screw conveyor designed to convey cement in powder form. This type of screw conveyor typically operates intermittently and its operation includes a period in which the auger is rotating, followed by a period in which the auger is stationary and therefore the motor 2 is not operating.

Furthermore, in screw conveyors intended to convey cement in powder form, the electric motor 2 is required to provide a relatively high initial torque in order to be able to move the cement which can be initially packaged. On the other hand, after starting, it is sufficient that the motor 2 provides a lower torque.

The electric motor 2 may be designed so as to operate in operating conditions close to overheating during the initial phase in which a relatively high starting torque is required. This has no negative effect on the duration or operation of the motor 2, since the motor 2 can cool in a satisfactory manner during periods of inactivity following the phase in which the motor 2 provides a lower torque.

Thus, the size of the motor can be optimized in such a way that sufficient power is installed to perform the transportation function and avoid installing a "commercial" oversized motor.

This optimization allows motor cost savings without adversely affecting operating efficiency.

Claims

1. A gear motor apparatus for rotating a rotatable element, such as an auger of a conveyor, comprising:

an electric motor (2) having a rotor (4) and a stator (5) housed in a casing (7), the electric motor (2) further comprising a drive shaft (3) extending along an axis (Z);

a gear unit (9) comprising a first gear (12) and a second gear (13), the first gear (12) being rotatable by the electric motor (2), the first gear (12) and the second gear (13) being arranged within a housing (14), the gear unit (9) having an output shaft (10) which is offset with respect to the drive shaft (3) and which is connectable to the rotatable element for rotating the rotatable element; and

a coupling flange (25) for fixing the gear motor arrangement (1) to a device comprising the rotatable element, the coupling flange (25) being connected to the housing (14) by a detachable non-permanent connection,

wherein the housing (7) has a plurality of projections (16) projecting transversely to the axis (Z) for receiving respective detachable fixing elements (15), the detachable fixing elements (15) being adapted to detachably connect the casing (14) to the housing (7).

2. Gear motor arrangement according to claim 1, characterised in that the housing (14) has a plurality of protrusions (18) arranged in contact with the protrusions (16) of the housing (7), each detachable fixing element (15) being received in a protrusion of the plurality of protrusions (16) and in a protrusion of the plurality of protrusions (18) for detachably fixing the housing (14) to the housing (7).

3. Gear motor device according to claim 1, characterised in that said casing (7) is coupled to said casing (14) on a coupling plane (P), said casing (7) having a cavity (22) in which said stator (5) and said rotor (4) are housed, said cavity (22) having an internal transverse dimension, measured on said coupling plane (P), greater than or equal to an external transverse dimension of said stator (5), so as to allow the stator (5) to be extracted from said cavity (22) after the gear unit (9) is detached from said electric motor (2).

4. Gear motor arrangement according to claim 1, characterised in that the first gear wheel (12) is supported by the drive shaft (3) and is fixed relative to the drive shaft (3).

5. The gear motor arrangement according to claim 4, further comprising: a first bearing (19) for supporting the drive shaft (3) at an end portion near the drive shaft (3), the first gear (12) being fixed to the end portion; and a second bearing for supporting the drive shaft (3) at the other end portion of the drive shaft (3) opposite to the end portion.

6. Gear motor arrangement according to claim 5, characterized in that the inner diameter of the first bearing (19) is larger than the outer diameter of the first gear wheel (12).

7. A gear motor arrangement according to claim 5, characterised in that the first bearing (19) is fixed in a seat made in the housing (14).

8. Gear motor arrangement according to claim 1, characterised in that the first gear wheel (12) is in direct mesh with the second gear wheel (13).

9. Gear motor arrangement according to claim 1, characterised in that the coupling flange (25) has a seat (27) for accommodating a sealing element on its face furthest from the housing (14).

10. Gear motor arrangement according to claim 1, characterised in that it further comprises a fan (28) fixed to the drive shaft (3) on the opposite side of the drive shaft (3) with respect to the first gear wheel (12).

11. Gear motor arrangement according to claim 1, characterised in that the housing (14) projects laterally from the housing (7).

12. Gear motor arrangement according to claim 1, characterised in that said output shaft (10) extends along a further axis (Y) parallel to said axis (Z).

13. Gear motor arrangement according to claim 1, characterised in that the second gear wheel (13) is keyed to the output shaft (10).

14. A screw conveyor, characterized by comprising a tubular casing and an auger at least partially housed in the tubular casing, the screw conveyor further comprising a gear motor device (1) according to claim 1, the gear motor device (1) being connected to the auger for rotating the auger about a respective longitudinal axis.

15. The screw conveyor according to claim 14, wherein the screw conveyor is for conveying cement in powder form.