GB2246720A

GB2246720A - Improved grinding machine

Info

Publication number: GB2246720A
Application number: GB9017030A
Authority: GB
Inventors: Chi-Shiang Chen
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-08-03
Filing date: 1990-08-03
Publication date: 1992-02-12
Also published as: GB9017030D0; FR2665648A1

Abstract

A grinding machine includes a horizontal drum 20 with an inner grinding member 25 and a grinding roller 30 disposed in the drum 20 with its peripheral grinding face to cooperate with the inner grinding member 25 of the drum. A drive unit 80 is provided to rotate the drum and the grinding roller. The drum is mounted rotatably on a base 11. The grinding roller 30 is mounted rotatably and adjustably by means of two hydraulically operated mounting units 70 which hold two ends of the shaft 31 of the grinding rollers 30. The grinding machine provides an increased effective grinding area and the selectivity for a desired particle size range. <IMAGE>

Description

IMPROVED GRINDING MACHINE This invention relates to a grinding machine, and particularly to a grinding machine which has a grinding roller rotatable about a horizontal axis and a arum surrounding said grinding roller and having an inner grinding face to cooperate with said grinding roller.

Various forms of grinding machines exist in the art. One of the grinding machine is shown in Figure 1 ana comprises a machine body A having a drive unit B to rotate a grinding member C and two upper truncated cone-shaped grinding members D to cooperate with the grinding member C. A material can be fed in from the directions shown by arrows F and the fine particles resulting from the grinding are swept out at the top of the machine body A by means of a stream of air. In such a grinding machine, the effective grinding area is small because the grinding face of the grinding member C is flat and forms a large angle # with the grinding member D as shown in Figure 1A.Moreover, during the grinding operation, the substance on the grinding member C is liable to migrate out to the peripheral portion of the grinding memoir C because of the centrifugal force induced Dy rotation of the grinding member C, thereby resulting in disuniform distribution of the contents between tne grinding members. Tne disuniform distributlon generally ass to the disuniform particle size of the end product as well as rapid wear of the grinding members.

An object of the invention is to provide a grinding machine which has an effective grinding area larger than those of conventional grinding machines.

Another object of the invention is to provide a grinding machine which outputs an end product of uniform particle size.

Further object of the invention is to provide a grinding machine with adjustable grinding members so that the selectivity for a desired particle size range is permitted.

According to the present invention, a grinding machine comprises: a drum having a horizontal axis, an inner first grinding face and two open ends; means for supporting the drum; a grinding roller provided in the drum, the grinding roller having an outer peripheral second grinaing face to cooperate with the first grinding face and a horizontal shaft which has two ends extending outwardly of the drum; means for holding the two ends of the shaft; means for covering the two open ends of the drum; means for rotating the shaft of the grinding roller; a feeding means provided in the covering means and extending into the drum; and a discharging means provided in the covering means.

In one aspect of the invention, the grining machine further comprises a means for returning coarse ground particles back to the region between the grinding faces of the drum and the grinding roller.

In another aspect of the invention, the drum is rotatably mounted on a base. The cover means includes two stationary cylindrical housings connected movably to two opposite open ends of the drum. The discharging means and the feeding means are disposed in the Stationary cylindrical housings and extend into the interior of the drum.

In further aspect of the invention, the holding means includes two frame members disposed across two Opposite ends of the shaft of the grinding roller and held by hydraulic lifts, and two clamping members which clamp the shaft against the frame members and are also held by another hydraulic lifts, whereby the shaft of the grinding roller can be raised or lowered slightly relative to the grinding face of the drum so as to adjust the space between the grinding faces of the drum and the grinding roller.

The exemplary preferred embodiment will be described in detail with reference to the accompanying drawings, in which: Figures 1 and 1A show a grinding machine in the art; Figure 2 is sectional view of a grinding machine according to the present invention; Figure 3 is a sectional view taken along line 3-3 of Figure 2; Figure 4 is a sectional view taken along line 4-4 of Figure 2; Figure 5 is a sectional view taken along line 5-5 of Figure 2; Figure 6 is a sectional view taken along line 6-6 of Figure 2; and Figure 7 shows an angle formed between the grinding faces of the drum and the grinding roller of Figure 2.

Referring the drawings, a grinding device according to the present invention includes a support base 10, a drum 20, a roller 30, two returning units 40, two cover units 50, two feeders 60, a mounting units 70 and a driving mechanism 80. As shown in Figures 2 and 3, two pairs of rollers 13 are respectively mounted on two shafts 14 each of which is supported by two pairs of legs 12. The legs 12 are mounted on a support base 11 and each has a roller 121 in rolling contact with the shaft 14.

The drum 20 has an annular grinding member 25 with inward flanges 26 at its two end. The grinding member 25 is covered by an outer shell 21 which is provided with spaced blades 22 extending radially and longitudinally from the periphery of the shell 21 to reinforce the drum as well as to dissipate heat. The outer shell 21 is rotatably supported by the roller 13. Around each end of the shell 21 is an annular guiae rail 23 and a transmission gear 24. The guide rails 23 are provided with rail grooves to engage with the rollers 13.

A grinding roller 30 is provided inside the drum 20. The roller 30 has a shaft 31 whose two ends are respectively connected to two gears 33. The outer periphery of the grinding roller 30 is lined with an abrasive grinaing member 34. The two ends of the grinding member 34 have rounded peripheral eages 3t which face the rounded corners formed by the inward flanges 26. The gaps formed between the peripheral edges 35 and the flanges 26 serve as outlet passages for the ground substance.

The returning units 40 are disposed at the two ends of the drum 20, respectively. Each returning unit 40 has a rotatable cylindrical housing 41 which is concentrically connected to the shell 21 and which confines an annular recess receiving shelf plates 42.

The shelf plates 42 are inclined with respect to radial lines substantially in the same directions. The cylindrical housings 41 receive ground particles coming from the outlet passages formea between the grinding roller 30 and drum 20. The shelf plates 42 lift the 9round particles curing the rotation of the cylindrical housing 41 ana discharge them onto conwarc inclining plates 44 provided on two sides of the drum 20. Each plate 44 is directed to a conveying conduit 45 which will be described below.

The covers 50 are connected to the first cylindrical housings 41 and each include a non-rotating second cylindrical housing 52 which has a shoulder portion 52a surrounding the first cylindrical housing 41. Sealing rings 53 are provided between the shoulder portion 52a and the first cylindrical housing 41.

Referring to Figure 6 in combination with Figure 2, each cover 50 further has a circular end cover 52b and two outward end flanges 521 which are mounted resiliently on two support stands 51. Each support stand has a vertical rail groove 511 to receive each outward end flange 521. Each groove 511 also has a spring 512 to support each end flange 521. A foursided concaved plate 552 is connected integrally to each circular end cover 52b to confine a narrow space therebetween. Both the end cover 52b and the concavea plate 552 are provided with holes 553 for the insertion of one of the restricted ends 31a of the shaft 31. The holes 553 are made larger than the cross-section of the restricted ends 31a of the shaft 31 so as to permit adjustment of the position of the shaft. Therefore, a sealing plate 551 is provided in the narrow space formed in the end cover 52b to seal the opening existing between the restricted portion of tne snaft 31 and the end cover 52b. The sealing plate 551 is sleeved on the restricted portion 31a of the shaft 31 and movably received in the narrow space of the end cover 52b so as to cover the holes 553 of the end cover 52b and the concaved plate 552.

Each feeding unit 60 has a inlet feed conduit 61 formed in each second cylindrical housing 52 and connected to a conveying conduit 62 which extends axially into the drum 20 from one of the housings 52. A screw rod 621 is provided in each conduit 62 for conveying feed material from the inlet conduit 61 to the interior of the drum 20 where the feed material falls between the grinding member 34 and the drum 20.

Like the conveying conduit 62, two conduits 45 of the returning units 40 are provided with screw roas 451 which sena coarse ground particles sliding down from the inclined plate 44 back to the interior of the arum 20. The inclined plates 44 are mounted on the housing 52.

Each second cylindrical housing 52 is further provided with an alr inlet port 57 and a sweeping Outlet port 58. An air conduit 59 (shown in Figure 3) is directed into the interior of the drum 20 from each second cylindrical housing 52 to suspend the fine particles resulting from grinaing. Other inlet ports (not shown) are provided to supply air to the conduits 59.

As shown in Figure 5, the driving mechanism 80 includes a driving shaft 85 driven by a motor (not shown) and mounted on two supports 84 at the two end the cover means 50. On the shaft 85 are mounted two first gears 81 which respectively engage the gears 24 of the drum 20 and two second gears 82 which engage the gears 33 of the shaft 31. The driving mechanism also includes transmission units ( not shown) to rotate the screw rods 621 of the conveying conduit 62 and the screw rods 451 of the conduit 45. These transmission units may be any suitable known transmission mechanism and therefore will not be detailed herein.

The mounting unit 70 has two opposite transverse frame members 73 mounted on two ends of the shaft 85 through bearing assemblies 72 and extending across the ends of the shaft 31. The other ends of the transverse frame members 73 are interconnected by a longitudinal frame member (not shown) and are respectively supported by two hydraulic units 74'. Two clamping arms 71 are also mounted on the bearing assemblies 72 of the shaft 85 and fastened to the frame members 73. A hydraulic unit 74 is mounted on the support base 11 and has a piston rod 741 holding each clamping arm 71 against each transverse frame member 73, thereDy clamping each end of the shaft 31 between each transverse frame member 73 and each clamping arm 71. The clamping arms 71 are also secured to the transverse frame members 73 by means of fasteners.The shaft 31 mounted thereby can be placea in a horizontal position and can be raisea or lowered slightly so that the space between the grinding roller 30 and the drum 20 can be adjusted as required according to a desired particle size range.

In operation, a feed material is fea into the conveying conduit 62 from the inlet port 61 and then sent to the interior of the drum 20. The material falls down between the grinding member of the arum 20 and the grinaing roller 30. Since the drum 20 and the grinding roller 30 are placed in a position as shown in Fig. 7, they provides a grinding area larger than those provided by conventional grinders. Moreover, an effective grinding pressure can be maintained by the hydraulic units 74, 74' and the weight of the grinding roller 30. The ground particles between the drum 20 and the grinding roller 30 are extruaea outward through the discharge passage formed at the flanges 26 of the drum 20.

The air conduits 59 blows the ground particles so that fine particles in the drum 20 are Swept out of the two ends of the drum 20. The air inlet ports 57 supply streams of air to blow out fine particles caught in the housings 52 through the outlet ports 58. The coarse particles discharged out from the discharge passages formed between the flange 26 of the drum 2v and the rounded edges of the grinding roller 30 are collected in the annular recesses of the cylindrical housings 41. During the rotation of the cylindrical housings 41, the coarse particles are liftea by the shelf plates 43 and then sent back to the interior of the drum 20 through the inclined plates 44 and the screw conveyer conduits 45.

It can be appreciated that the grinding machine of the present invention provides a increased grinding area since the inner grinding face of the arum is curved and forms with the grinding face of the cylindrical grinding roller an angle (Figure 7) smaller that shown in Figure 1A. In addition, the the hydraulically operated holding members which hold the ends of the shaft of the grinding roller permit the adjustment of the spacing of the grinding faces and firmly hold the grinding roller in position.

With the invention thus explained, it is apparent that various modifications and variations can be made without departing from the scope of the invention. It is therefore intended that the application be limited only as indicated in the appended claims.

Claims

CLAIMS:

1. A grinding machine comprising a drum having an inner first grinding face, feeding means for feeding a material to be ground into said drum, a grinding roller located within said drum, said grinding roller having an outer peripheral second grinding face to co-operate the said first grinding face and means for rotating said grinding roller.

2. A grinding machine as claimed in claim 1 further comprising means for supporting said drum.

3. A grinding machine as claimed in claim 1 or claim 2 in which the drum has two open ends and means are provided for covering said open ends.

4. A grinding machine as claimed in any one of the preceding claims in which the grinding roller is located on a horizontal shaft having two ends which extend outwardly of said drum and further comprising means for supporting said two ends of said shaft.

5. A grinding machine as claimed in any one of the preceding claims further comprising discharging means for discharging the ground material.

6. A grinding machine as claimed in any one of the preceding claims comprising means for returning coarse ground particles back to said drum.

7. A grinding machine as claimed in any one of the preceding claims comprising means for rotating said drum.

8. A grinding machine as claimed in claim 7 in which there are annular rail members and first transmission gears located around an outer periphery of said drum, said drum supporting means having supporting rollers each with a rail groove to engage one of said annular rail members, and said first transmission gears being connected to said drum rotating means.

9. A grinding machine as claimed in any one of the preceding claims in which said grinding roller lies adjacent a bottom part of said drum, said grinding roller having two ends at least one of which has a rounded peripheral edge, said drum having at least one inward annular end flange extending outwardly of said rounded peripheral edge, said inward annular end flange and said rounded peripheral edge defining a discharge passage for ground particles.

10. A grinding machine as claimed in claim 9 in which said particle returning means has at least one rotatable first cylindrical housing concentrically connected to one of said open ends of said drum, said first cylindrical housing having an annular recess adjacent said discharge passage, a plurality of shelf plates provided at intervals in said annular recess to convey ground particles from said discharge passage to a higher level, said shelf plates inclining with respect to radial lines of said first cylindrical housing, a fixed downward inclined plate provided below said higher level to receive and slide downward ground particles from said shelf plates, and a first conveying member provided below said downward inclined plate to resent the ground particles into said drum.

11. A grinding machine as claimed in claim 10, in which said covering means comprise two second cylindrical housings provided concentrically at said two open ends of said drum, each of said second cylindrical housings having a circular end cover plate.

12. A grinding machine as claimed in claim 11 in which said feeding means comprise at least one feed inlet port in one of said second cylindrical housings, and a second conveying member extending from said feed inlet port to the interior of said drum.

13. A grinding machine as claimed in claim 12 in which said second conveying member is a screw conveyor.

14. A grinding machine as claimed in any one of claims 4 to 13 in which said means for rotating said grinding roller comprise two gears mounted on said two ends of said shaft and a driving mechanism connected to drive said gears.

15. A grinding machine as claimed in any one of claims 4 to 14 further comprising two frame members extending transversely of said two ends, of said shaft, a first hydraulic lift means holding said frame members, two clamping arms respectively provided adjacent said frame members and clamping said two ends of said shaft against said frame members, a second hydraulic lift means holding said clamping arms in a clamping position relative to said frame members, and fasteners to fasten said clamping arms to said frame members, whereby the position of said shaft with respect to said drum can be adjusted by operating said first and second hydraulic lifts.

16. A grinding machine as claimed in any one of claims 11 to 15 in which said circular end cover plates of said second cylindrical housings are provided with shaft holes for said shafts, said shaft holes having a diameter larger than the cross-section of said shaft said circular end cover plates having sealing plates to seal said shaft holes and said shaft.

17. A grinding machine as claimed in any one of claims 11 to 16 in which said discharging means includes an air supply means provided in said second cylindrical housings and said drum so as to sweep out fine ground particles.

18. A grinding machine as substantially described hereinbefore with reference to figures 2 to 7 of the accompanying drawings.