GB2095727A - Refuse collecting apparatus - Google Patents

Abstract

In a self-propelled road sweeper 10 wherein a refuse tank 26 having a pick-up nozzle 24 is evacuated by suction apparatus 12, the apparatus 12 comprises a transverse internal combustion engine whose flywheel 70, Fig. 3, is coupled to the suction fan 32 by bolts 114 and a resilient coupling 80, the fan shaft having an additional bearing 78 supported from the fixed engine bell housing 72. This bearing arrangement is simple and compact while avoiding the application to the engine crankshaft of end thrust generated by the fan itself. <IMAGE>

Description

SPECIFICATION Refuse collecting apparatus This invention relates to refuse collecting apparatus and more particularly, but not exclusively, to suction operated refuse collecting apparatus in such forms as road sweeping apparatus, and apparatus for collecting refuse from bins, gullies and elsewhere through a positionable nozzle.

In this specification and in the claims, the expressions "road sweeping apparatus" and "road sweeper" are to be interpreted as covering also apparatus similar to road sweeping apparatus but which is intended for sweeping other large surfaces such as pavements or side walks, airport runways, and the like. Moreover, except where explicitly stated, the invention is not limited to the use of brushes in such sweeping apparatus since for certain applications brushes are not required, it being sufficient to apply suction through a suitable nozzle to the surface from which refuse is to be removed.

The present invention relates generally to the provision of an internal combustion engine to drive a fan to generate suction for the refuse collecting apparatus. A specific example of a machine to which the invention is applicable is a self-propelled road sweeper having a primary engine for traction purposes and a secondary or auxiliary engine to operate the road sweeping apparatus. The auxiliary engine is usually mounted in an engine compartment forming part of the road sweeping apparatus, and problems which have arisen in relation to such an engine are the complexity and inherent cost (as original equipment) and the considerable space requirements of the engine and fan assembly used for generating the suction required in such apparatus.

The auxiliary engine and fan assembly is usually mounted in front of the refuse tank of road sweepers, and therefore by virtue of the space it takes up it necessarily shortens and lowers the capacity of the refuse tank.

This space requirement and its consequences in relation to the refuse capacity are aggravated by the requirement for a transmission between the auxiliary engine and the fan, and in the case of one well known product this transmission takes the drive from one end of the transversely mounted engine through two right angled changes of direction to the fan which is mounted on the centre line of the vehicle for rotation about a horizontal fore/aft axis behind the engine. Other proposals use less complex drives to the fan, but in all cases known to the Applicants the drive transmission assembly for the fan introduces cost and space and payload and servicing penalties.

An object of the present invention is to provide suction operated refuse collecting apparatus having an internal combustion engine and a fan mounted for rotation by the engine, wherein an improved mounting and drive arrangement is provided for the fan.

According to the invention there is provided suction operated refuse collecting apparatus comprisingt an internal combustion engine; a fan mounted for rotation by the engine; a fan housing enclosing the fan and defining an air inlet and an air outlet; a refuse tank; a first air duct and a second air duct opening into the refuse tank, the first air duct being connectible to the air inlet of the fan housing; and a refuse collecting nozzle connected to said second air duct whereby refuse can be drawn into the refuse tank through the refuse collecting nozzle by suction generated by the fan; characterized in that said internal combustion engine comprises a crankshaft and crankshaft bearings supporting the crankshaft for rotation; and that said fan is supported for rotation on spaced bearings, one of said spaced bearings being an engine crankshaft bearing.

Preferably, no bearing and bearing support is provided on the side of the fan which is remote from the engine. The other bearing of said spaced bearings may be supported on a flange at the engine side of the fan. Said other bearing is preferably radially aligned with the fan, said flange having an axially-extending tubular portion on which said other bearing is mounted, said tubular portion extending into a complementary tubular mounting portion of said fan.

Preferably the fan is mounted on a shaft which is secured at its inner end to the engine crankshaft, or an extension thereof, such as the engine flywheel. The fan may be keyed to the other end of the fan-mounting shaft, in the region of said other bearing.

The inner end of the fan mounting shaft is preferably secured to the crankshaft through a resilient coupling. The resilient coupling may be annular in form with the fan-mounting shaft extending through the coupling and having a locating member at its inner end, the locating member engaging the crankshaft or an extension thereof.

The suction operated refuse collecting apparatus may be in the form of self-propelled road sweeping apparatus comprising a selfpropelled chassis having a primary internal combustion engine arranged to drive road wheels, the other internal combustion engine thus being an auxiliary engine, a driver's cab at the front end of the chassis with respect to the direction of operative forward motion of the road sweeping apparatus, and a refuse tank or hopper at the rear end of the chassis, the auxiliary engine being mounted between the driver's cab and the refuse tank. A compartment for the auxiliary engine may be provided at the forward end of the refuse tank.

The auxiliary engine is preferably mounted so that its crankshaft extends transverse to the direction of operative forward motion of the road sweeping apparatus.

An embodiment of the invention is described below. In this embodiment, the fan mounting arrangement avoids the application to the engine crankshaft of end thrust generated by the fan itself. Such end thrust is due to the air pressure differential on opposite sides of the fan. Also, the fan mounting arrangement permits the use of fan rotors having higher transverse moments of inertia than would have been possible with a fan supported solely on the engine crankshaft. Such higher transverse moments of inertia would have been expected to produce whirling problems due to the bending compliance of the engine crankshaft, in the case of a fully cantilevered fan rotor, which would have been free to oscillate in a transverse sense with respect to its axis of rotation.

The bearing arrangements in the embodiment disclosed below also serve to substantially reduce any out-of-balance loads generated by the fan which would have been applied directly to the crankshaft in a fully directly mounted fan.

Moreover, the wide separation of the fan mounting bearing and the nearest crankshaft bearing provides the fan mounting shaft with maximum resistance to transverse vibrations of the fan rotor, and the resilient coupling or mounting, in conjunction with this support system, provides a very compact mounting which nevertheless accommodates assembly alignment errors in an unlubricated environment.

Embodiments will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a side elevation view of a road sweeper; Figure 2 shows a transverse section through the auxiliary engine compartment of the road sweeper of Figure 1; Figure 3 shows a section through a coupling and mounting assembly provided between the engine crankshaft and fan seen in Figure 2; and Figure 4 shows, in a view similar to that of Figure 3, a section through a modified coupling and mounting assembly forming a further embodiment of the invention.

As shown in Figure 1, a self-propelled road sweeper 10 comprises suction-operated refuse collecting apparatus 12 mounted on a selfpropelled chassis 14 having a driver's cab 1 6 and ground wheels 18, 20.

Refuse collecting apparatus 12 comprises brush gear 22 and associated mounting and drive means therefor, a refuse collecting nozzle 24 and a refuse tank 26.

An internal combustion engine 28 (see Figure 2) is mounted in an engine compartment 30 at the front end of refuse tank 26, having regard to direction F of operative forward motion of the road sweeper. A fan 32 (see Figure 2) is mounted for rotation by engine 28 and is enclosed by a fan housing 34 which defines an air inlet 36 and an air outlet 38. A first air duct 40 connects air inlet 36 to refuse tank 26 whereby refuse can be drawn into the refuse tank through the nozzle by suction generated by fan 32.

Brush gear 22 comprises a narrow sweep brush 44 rotatable about an upwardly-extending axis, and a cylindrical wide sweep brush 46 rotatable about a generally horizontally extending axis. Brush 44 may be employed without brush 46.

Refuse tank 26 is formed integrally with engine compartment 30 and is mounted on chassis 14 so as to be pivotable relative thereto by means of hydraulic tipping gear (not shown) to a tipped discharge position. A rear door 50 is pivotally mounted at the open rear end of the tank for operation by a hydraulic door operating mechanism 52 during tank emptying operations.

Auxiliary engine 28 is a six cylinder in-line turbo charged diesel engine having a crankshaft 54 extending transverse to direction F, and crankshaft bearings 56 supporting the crankshaft for rotation about an axis 58 within the engine block/crank case assembly 60. Engine 28 is mounted within compartment 30 on rubber vibration dampers (not shown).

Fan 32 is a centrifugal or tangential flow fan comprising inner and outer mounting plates 62 and 64 having secured between them a series of curved fan blades 56 located at regular intervals around the periphery of the mounting plates whereby on rotation of the fan about axis 58 air is pumped outwards by the fan blades. Outer mounting plate 64 is formed with a central opening in which is secured an annular inlet duct 68 for rotation with the fan whereby during use, rotation of the fan about axis 58 causes air to be drawn in through duct 68 and discharged outwardly of the fan 32.

Crankshaft 54 has rigidly secured thereto a flywheel 70 which rotates with the crankshaft within a bell housing 72.

Details of the coupling and mounting assembly whereby fan 32 is mounted for rotation and coupled to crankshaft 54 are shown in Figure 3.

The corresponding portion of Figure 2 does not show these details and does not reflect exactly the structure shown in Figure 3. Therefore the details shown in this portion of Figure 2 are to be ignored and supplemented by the structure shown in Figure 3.

Referring now to Figure 3, fan 32 is secured to flywheel 70 (which is rigidly secured to crankshaft 54 so as to form an extension thereof), so as to be co-axial with the crankshaft, by means of a mounting and drive assembly 74 comprising a fan mounting shaft 76, a bearing 78 and a resilient coupling 80.

Fan mounting shaft 76 has a nose 82 which locates in a bush 84 provided in flywheel 70.

At its outer end, shaft 76 has fan 32 secured thereto by means of a hub 86 which carries fan plates 62, 64 and is drivably secured to shaft 76 by a key 88. Hub 86 is retained by a keeper plate 90 and associated bolts 92 which are locked by a wire retainer.

Bearing 78 is in the form of a ball race and is mounted on a tubular portion 94 of an annular mounting flange 96 extending inwardly from bell housing 72.

Resilient coupling 80 is secured to shaft 76 by a mounting nut 98 having an associated grub screw 100, which holds an outer hub portion 102 of the resilient coupling against an annular shoulder 104 provided on shaft 76. Hub portion 102 is drivably coupled to shaft 76 by a key 106.

Resilient coupling 80 has an inner hub and plate portion 108 which is received on the inner end of shaft 76 through a bush 110. An annular rubber ring 112 is bonded between hub and plate portions 102 and 108 of resilient coupling 80 in the conventional manner for drive transmission purposes. The inner hub portion 108 is drivably coupled to flywheel 70 by a pair of bolts 11 4.

It can now be seen that fan 32 is supported for rotation on spaced bearings, one cf said bearings being the outermost crankshaft bearing 56, and the other bearing being the ball race 78. No bearing is provided on the outer side of fan 32, remote from engine 28.

Fan 32 is drivably coupled to flywheel 70 through annular resilient coupling 80, while shaft 76 extends through the coupling and maintains axial alignment of the fan and the engine crankshaft.

In use, fan 32 rotates about axis 58 to draw air into housing 34 through duct 68 and the air is discharged outwardly of the fan causing a reduction of air pressure in the region of axis 58 whereby suction is applied through first air duct 40 to refuse tank 26 and hence through second air duct 42 to nozzle 24 whereby refuse swept by brush gear 22 is drawn into the tank 26.

The principal advantages of the embodiment described above have already been identified.

Among modifications which could be made in the above embodiment without departing from the scope of the invention are modifications to the location of the outer fan-supporting bearing and the structure provided to support that bearing, and modifications to the structure through which drive is transmitted to the fan mounting shaft whether by means of a resilient coupling or otherwise.

In the embodiment of Figure 3, the structure supporting the bearing 78 for fan-mounting shaft 76 is a fabrication.

The embodiment of Figure 4 is otherwise constructed substantially as described above in connection with Figure 3, but with the following modifications. The principal modification is the use of a support structure for bearing 78 in the form of a casting 130 secured by bolts 132 to bell housing 72.

The hub 134 of fan 32 is in the form of a casting having a profile complementary to that of bearing support casting 1 30.

This embodiment operates substantially as described above in connection with Figure 3.

Claims (Filed on 25 March 1982).

1. Suction operated refuse collecting apparatus comprising:- an internal combustion engine; a fan mounted for rotation by the engine; a fan housing enclosing the fan and defining an air inlet and an air outlet; a refuse tank; a first air duct and a second air duct opening into the refuse tank, the first air duct being connectible to the air inlet of the fan housing; and a refuse collecting nozzle connected to said second air duct whereby refuse can be drawn into the refuse tank through the refuse collecting nozzle by suction generated by the fan; characterized in that said internal combustion engine comprises a crankshaft and crankshaft bearings supporting the crankshaft for rotation; and that said fan is supported for rotation on spaced bearings, one of said spaced bearings being an engine crankshaft bearing.

2. Apparatus according to claim 1 characterized by no bearing and bearing support being provided on the side of the fan which is remote from the engine.

3. Apparatus according to claim 1 or claim 2 characterized in that said other bearing of said spaced bearings is carried by a bearing support member at the engine side of the fan.

4. Apparatus according to claim 3 characterized in that said other bearing is radially aligned with the fan, and said bearing support member has an axially-extending tubular portion on which said other bearing is mounted, said tubular portion extending into a complementary recess provided in said fan.

5. Apparatus according to any one of the preceding claims characterized in that the fan is mounted on a shaft which is secured at one end to the engine crankshaft or to an extension thereof such as the engine flywheel.

6. Apparatus according to claim 5 characterized in that said fan is drivably secured to the other end of the fan-mounting shaft in the region of the other of said spaced bearings.

7. Apparatus according to claim 5 or claim 6 characterized in that said one end of the fanmounting shaft is secured to the crankshaft through resilient coupling means.

8. Apparatus according to claim 7 characterized in that said resilient coupling is of annular form with said fan-mounting shaft extending through the coupling and having a locating member at said one end, the locating member engaging the engine crankshaft or an extension thereof.

9. Apparatus according to claim 1 wherein said fan is supported for rotation on spaced bearings substantially as described herein with reference to Figs. 1 to 3 of the accompanying drawings or Figs. 1 to 3 as modified by Fig. 4 thereof.

10. Self-propelled road sweeping apparatus comprising suction operated refuse collecting apparatus according to any one of the preceding

Claims (1)

1. claims.

   11. Road sweeping apparatus according to claim 10 comprising a self-propelled chassis having an additional internal combustion engine arranged to drive road wheels, a driver's cab at the front end of said chassis with respect to the direction of operative forward motion of the road sweeping apparatus, and a refuse tank or hopper at the rear end of the chassis, the auxiliary internal combustion engine connected to said fan being mounted between the driver's cab and the refuse tank.

   12. Road sweeping apparatus according to claim 11 characterized by a compartment for said auxiliary engine located at the forward end of the refuse tank.

   13. Road sweeping apparatus according to claim 12 characterized in that said crankshaft extends transverse to the direction of operative forward motion of the road sweeping apparatus.