A series of gear motors with orthogonal gear reducer

Abstract: Disclosed is a series and a series group of orthogonal gear reducers with motors. A motor cover (114) is disposed separately from a gear box (102). In each of sub-series (frame number) wherein the gear boxes have the same fitting dimensions (sizes) to be mounted to a mating machines, the following requirements are satisfied: 1 ○ The fitting dimension (I2) between the motor cover (114) and the gear box (2) is made constant; 2 ○ An axial shifted amount (e2) between a hypoid pinion (104) and a hypoid gear (105) is made constant; 3 ○ an outside diameter (D2) of the hypoid gear (105) is made almost constant; and 4 ○ a distance (B2) between the center (C) of the hypoid gear (105), and the mounting surface (116) for the motor cover (114) and the gear box (102) is made constant. Thus, it is possible to keep the required strength level of the hypoid gear set to be almost constant and to combine two kinds or more of the motors to one of the gear box by combining the hypoid pinion constituting the hypoid gear set having a low reduction ratio with a large capacity motor, and also combining the hypoid pinion (104) constituting the hypoid gear set having a high reduction ratio to a small capacity motor. With this construction, it is possible to increase the parts for common use as much as possible while securing various combinations of motor capacities and reduction ratios, and hence to meet the requirements of users with cost reduction.

Description: The present invention relates to a series of gear motors with an orthogonal gear reducer which permits a large number of combinations between required load capacities and reduction ratios thereby reducing the number of types of motors and gear boxes to be prepared. The present invention can be applied to physical distribution systems, particularly, conveyors or the like. In a physical distribution system constituted by a plurality of conveyors, it is efficient that only the required parts are operated. In this case, it is desirable to independently drive the conveyors. Also, in changing the arrangement of the individual conveyors, which is often carried out for modifying the conveying path, it is advantageous to independently drive the conveyors. Gear motors with orthogonal gear reducers generally have their maximum extent (longitudinal dimension) in the direction of the motor shaft. Accordingly, for enhancing the space performance the gear reducer is preferably mounted with its maximum extent (the direction of the motor shaft) in parallel to the conveyor while its output shaft for driving a shaft of the conveyor, is parallel to a shaft of the conveyor and thus orthogonal to the motor shaft. A gear motor with an orthogonal gear reducer is generally known from applicant's JP-A-1 126 468. Another gear motor of similar type is known in Figs. 14 and 15, which includes a hypoid gear set 20 as a first step, and a combination of parallel shaft gears 21 as a second or further steps. By changing the combination of the parallel shaft gears 21, the reduction ratio can be changed. In order to meet the various requirements of users, a plurality of "sub-series" (hereinafter, referred to as "frame number") are previously prepared. Namely, the fitting dimensions (mounting sizes) to the mating machine determined by the size of the output shafts and the gear boxes are classified into several types (from "small" to "large") to define several types of frame numbers, in accordance with the market requirement. Further, in the same frame number, several reduction ratios are previously systematized. Thus, by preparing a series constituted by the above frame numbers, it is possible to meet the various requirements of users. However, the known gear motor shown in Figs. 14 and 15 has the following inconvenience: one motor 1 is prepared in one frame number, and a special gear box 2 is prepared for each reduction ratio required in the same frame number. Accordingly, the number of parts for common use is very small in the whole "series". To increase the number of parts for common use there has been proposed a series of gear motors as shown in Figs. 16 to 19. Generally the gear reducer, reduces the rotation of the motor to the optimal rotational speed required for the mating driven machine. When the sizes of the output shaft and the gear box of the reducer are determined by the frame number, the limit of the mechanical strength (allowable output torque) is approximately determined. Consequently, even in the same frame number, the following combination is preferable for the strength balance between the output shaft and the reduction ratio: a large capacity motor is combined with a gear box of a low reduction ratio (the rotational ratio between the motor and the output shaft is small), while a small capacity motor is combined with a gear box of a high reduction ratio (the rotational ratio between the motor and the output shaft is small). Accordingly, for light weight and compactness, it is preferable to perform the serialization by combining motors having different capacities in one frame number. On the other hand, as shown in Figs. 14 and 15, if a hypoid gear set 20 is used for achieving the compactness as a whole, a hypoid pinion 4 is generally formed integrally with a motor shaft 3. In the hypoid gear set 20, an outside diameter d1 of the hypoid pinion 4 and an outside diameter D1 of a hypoid gear 5 are determined depending on the transmission amount and the reduction ratio. Further, based on the balance thereof, an axial shift e1 between the hypoid gear 5 and the hypoid pinion 4 is determined. As a result, depending on the strength balance between the hypoid gear 4 and the whole, a dimension (size) of a bearing 13 on the motor shaft load side and an axial interval Al between the bearing 13 and the center C of the hypoid gear 5 are determined. Under the above requirement, in the examples as shown in Figs. 16 and 19, the following serialization is achieved by combining two kinds or more of the motors in one frame number. Fig. 16 shows an example of combining a small capacity motor la with a high reduction ratio gear box 2a including a hypoid gear set 20a combined with two steps of parallel shaft gears 21a. Fig. 17 shows a development of the gear train thereof. Fig. 18 is an example of combining a large capacity motor 1b with a low reduction ratio gear box 2b including a hypoid gear set 20b combined with a one step of parallel shaft gear 21b. Fig. 19 is a development of the gear train thereof. Each example described above belongs to the same frame number. As shown in Fig. 17 (19), a wall surface 23a (23b) of the motor 1a (1b) on the gear box side is formed integrally with the gear box 2a (2b). A bearing 13a (13b) on the motor shaft load side is contained in a housing 24a (24b) provided on the wall surface 23a (23b). The hypoid gear sets 20a (20b) having the different sizes are prepared for respective capacities of the motors 1a (1b). The high reduction ratio gear reducer, which is smaller in motor capacity, is combined with the hypoid gear set 20a with a small size (see Figs. 16 and 17). On the other hand, the low reduction ratio gear reducer, which is larger in the motor capacity, is combined with the hypoid gear set 20b with a large size (see Figs. 18 and 19). Also, while being not shown, as for the motor shafts 3a (3b) integrally formed with the hypoid pinions 4a (4b), the motor shaft for a large capacity belonging to the frame number in the figure may be used for a high reduction ratio in the higher frame number. On the other hand, the motor shaft for a small capacity belonging to the frame number in the figure may be used for a low reduction ratio in the lower frame number. Thus, in the series, it is possible to reduce the types of the motor shafts 3a(3b). However, even in the series of the examples as shown in Figs. 16 to 19, in the same frame number, the gear boxes 2a and 2b differ in the axial shifts <ea> and <eb>, the bearings 13a and 13b on the motor shaft load side and in the axial intervals Aa and Ab of the hypoid gears 5a and 5b. As a result, there must be prepared one gear box 2a exclusively for the high reduction ratio (three-step type), and another gear box 2b exclusively for the low reduction ratio (two-step type). Accordingly, the parallel shaft gear trains 21a and 21b cannot be used in common. That is, even in the conventional series relating to the combination of the gear boxes and the motors as shown in Figs. 16 to 19, there has been significantly arisen the disadvantage of not sufficiently coping with the diversification and the cost reduction of the orthogonal gear reducers with motors generated by the rationalization of the recent production system. Concretely, in the physical distribution system frequently using the gear reducers, it is efficient that the required parts of the physical distribution system constituted by a plurality of conveyors are operated when required, and accordingly, the conveyors are intended to be independently driven. However, the gear motor used for a conveyor constitutes only a part of a mating machine (conveyor or the like), and further, the mating machine constitutes only a part of the whole physical distribution system. Accordingly, from the viewpoint of the whole physical distribution system, there are required various mounting (fitting) methods and reduction ratios, for containing the orthogonal gear motors and for obtaining the optimal output torque and the output rotational frequency. For example, the gear motors are required in the physical system to be used in the following various mounting methods, various combinations of the motor capacities and various reduction ratios. The above mounting methods involve: a) a foot mounting type of fitting the gear reducer to the mating machine at the floor surface parallel to the output shaft of the gear box; b) a flange mounting type of fitting the gear reducer to the mating machine at the surface right to the output shaft of the gear box; and c) a hollow-shaft type of making the output shaft of the gear box to be hollowed, and passing the gear box through the hollow portion, thereby directly connecting the gear reducer to the input shaft of the mating machine. However, in the series according to the conventional combination of gear box and the motor, there has been arisen a disadvantage of requiring the types of the gear boxes corresponding to those of the combination of the motor capacities in the same frame number. In general, the gear box occupies a large capacity in the whole orthogonal gear reducer and is large in weight, and further, requires a large number of the machining processes. Accordingly, increase in the number of types of gear boxes to be prepared as stock directly leads to cost rise. Also, in view of the whole physical distribution system, the gear motors are often required to be changed in the reduction ratio and the motor capacity. However, in the conventional series, the change in the motor capacity necessarily needs the change in the gear box, and consequently, the whole gear reducer must be exchanged. This results in the useless spending to users. Taking the above circumstances into consideration, the object of the present invention is to provide a series of gear motors with orthogonal gear reducers allowing to reduce the number of types of motors and gear boxes to be prepared. According to the present invention there is provided a series of gear motors according to claim 1. By using as many parts in common as possible diversification becomes possible to a large extent thereby reducing the costs of physical distribution systems. Moreover even if a gear motor assembled in the physical distribution system is required to be changed in the motor capacity and the reduction ratio, the need of exchanging the whole reducer can be eliminated, thereby improving the rationalization. Thus, according to the present invention, one gear box can correspond to the combination of the two kinds or more of the motors. Further, in this case, it is possible to keep the strength level of the hypoid gear set constant irrespective of the motor capacity. Also, since each hypoid gear set has a different reduction ratio, the gear train of the parallel shaft gear parts generally assembled with the hypoid gear set can be used in common, to thereby realize the cost reduction. That is, for example, if the gear box contains a reducing means besides the hypoid gear set, the reducing means is used in common and the hypoid gear set is changed in its reduction ratio to change the total reduction ratio of the gear box as a whole, then, it is possible to further promote the common use. Further, if there is provided a series group consisting of two or more series, each series has own gear boxes being mounted to mating machines by own mounting methods respectively, wherein the combinations of motors and gear boxes in each sub-series (frame number) of the series are unified, then in a combination of a motor and a gear box a gear box from an arbitrary series can be selected among the gear boxes of any series. Namely, by preparing the series for each gear box different in the mounting method, and unifying the combination of the motor and the gear box in each frame number, it is possible to use the motor in common even with gear boxes different in the mounting method, in the case of the same combination of the motor and the gear box. The above and further features and advantages of the present invention will be more apparent from the following description of the invention taken in conjunction with the accompanying drawings, wherein like reference characters designate the same or similar parts, and wherein: Fig. 1 is a diagram showing the gist of a series of gear motors with orthogonal gear reducers according to the present invention; Fig. 2 is a development of a gear motor showing an embodiment of applying the present invention to the flange mounting type gear box; Fig. 3 is an axial sectional view showing the arrangement of the gear train of Fig. 1; Fig. 4 is a development showing an embodiment, wherein the output direction of the output shaft in the flange-mounting type is situated on the side opposed to the case in Fig. 2; Fig. 5 is a development showing an embodiment, wherein a parallel shaft gear of a known reducer shown in Fig. 14 is left as it is, and a hypoid gear set is exchanged to that having a large capacity and low reduction ratio; Fig. 6 is a development of a gear train of an embodiment, wherein the present invention is applied to a gear box of a foot mounting type and a small capacity motor is combined with a large reduction ratio gear box; Fig. 7 is an axial sectional view showing the arrangement of the gear train of Fig. 6; Fig. 8 is a development of a gear train, wherein a large capacity motor is applied to the gear box of the foot mounting type of Fig. 6; Fig. 9 is an axial sectional view showing the arrangement of the gear train of Fig. 8; Fig. 10 is a development of a gear train of an embodiment, wherein the present invention is applied to a hollow-shaft type gear box, and a small capacity motor is combined with a large reduction ratio gear box; Fig. 11 is an axial sectional view showing the arrangement of the gear train of Fig. 10; Fig. 12 is a development showing an embodiment of a gear train, wherein a large capacity motor is applied to a hollow-shaft gear box; Fig. 13 is an axial sectional view showing the arrangement of the gear train of Fig. 12; Fig. 14 is a development of a gear train in an embodiment, wherein a small capacity motor is combined with a high reduction ratio gear box (the reducer itself is known); Fig. 15 is an axial sectional view showing the arrangement of the gear train of Fig. 14; Fig. 16 is a development of a gear train showing the conventional example, wherein a small capacity motor is combined with a high reduction ratio gear box; Fig. 17 is an axial sectional view showing the arrangement of the gear train of Fig. 16; Fig. 18 is a development of a gear train showing the conventional example, wherein a large capacity motor is combined with a low reduction ratio gear box; and Fig. 19 is an axial sectional view showing the arrangement of the gear train of Fig. 18. Hereinafter, embodiments of the present invention will be explained with reference to the accompanying drawings. The present invention is effectively embodied in the series that gear boxes are mounted to mating machines by various mounting methods (Claim 3); however, it can be embodied in the series that gear boxes are mounted by a single mounting method (Claims 1 and 2). This embodiment will be typically explained by way of the series having the flange mounting type gear boxes as shown in Figs. 2, 3, 14 and 15. As explained above, the orthogonal gear reducer itself with a motor as shown in Figs. 14 and 15 is already known. First, in the present invention, a series of the orthogonal gear reducers with motors is basically constituted of the collection of the sub series (frame numbers), wherein the gear reducers, being different in the reduction ratio from each other, have the same fitting dimensions (sizes) to be mounted to the mating machines. The gear motors as shown in Figs. 2 and 3, and in Figs. 14 and 15 belong to the same frame number, respectively. In the series of the present invention, the gear motor as shown in Figs. 14 and 15 corresponds to an embodiment having the combination of a small capacity motor with a high reduction ratio gear box. More specifically, in this embodiment, a small capacity motor 1 is combined with a three-step type high reduction ratio gear box 2 constituted of a hypoid gear 20 having a high reduction ratio of 10 and two steps of parallel shaft gear trains 21, to thereby realize the high reduction ratio with a small power. In addition, Fig. 15 is an axial sectional view of Fig. 14. In Figs. 14 and 15, a cover (motor cover) 14 of the motor 1 on the gear reducer side is constructed to be separated from a gear box 2. The motor cover 14 contains a bearing 13 on the motor shaft load side through a bearing housing 17, and prevents the leak of the lubricant from the gear box 2 by an oil seal 19. With this construction, the motor 1 is separable from the gear box 2. On the other hand, a motor shaft 3 of the motor 1 having the leading edge integrally formed with a hypoid pinion 4. The positioning between the motor 1 and the gear box 2 is performed by spigot-joining the motor 1 with the mounting surface 16 of the gear box 2, and is rigidly held by bolts 18. In this figure, numeral 6 is a second-step intermediate shaft; 7 is a second-step pinion; 8 is a second-step gear; 9 is a third-step intermediate shaft; 10 is a third-step pinion; 11 is a third-step gear; 12 is an output shaft; 15 is a spigot-joint portion. On the contrary, in the series of the present invention, the gear motor as shown in Figs. 2 and 3 corresponds to another embodiment, wherein a large capacity motor 101 is combined with a two-step type low reduction ratio gear box 102 constituted of a hypoid gear set 120 having a low reduction ratio of 5 and a one step of parallel shaft gear train 121, to thus realize the low reduction ratio with a large power. Fig. 3 is an axial sectional view showing an arrangement of the gear train of Fig. 2. In Figs. 2 and 3, the same or similar parts as in Figs. 14 and 15 are designated by the like reference characters in the two figures. The feature of the construction in the series according to the present invention will be explained by comparing the gear motor as shown in Figs. 2 and 3 with the gear motor as shown in Figs. 14 and 15 1 ○ The fitting dimensions (sizes) between the motor cover 14 (114 )and the gear box 2 (102), (for example, the diameter and depth of the spigot portion 15 (115), and the pitch of a bolt 18), constant, that is, the diameter of the spigot-portion I1 = I2 (see Figs. 2 and 14). 2 ○ An axial shift e1 (e2) between the hypoid pinion 4 (104) formed on the motor shaft 3 (103) and the hypoid gear 5 (105) is constant, that is, e1 = e2 (see Figs 3 and 15). 3 ○ An outside diameter D1 (D2) of the hypoid gear 5 (105) is almost constant (see Figs. 2 and 14). 4 ○ A distance B1 (B2) between the center C of the hypoid gear 5 (105), and the mounting surface 16 (116) for the motor cover 14 (114) and the gear box 2 (102) is constant, that is, B1 = B2 (see Figs. 3 and 15). Under the above requirements 1 ○ to 4 ○, the hypoid pinion 104, constituting the hypoid gear set 120 having a low reduction ratio of 5, can correspond to the large capacity motor 101. Further, the hypoid pinion 4, constituting the hypoid gear set 20 having a high reduction ratio of 10, can correspond to the small capacity motor 1. Further, under the above requirements 1 ○ to 4 ○, the pitch diameter of the hypoid pinion 104 formed integrally with a large capacity motor 101 is liable to be necessarily-made larger, and the pitch diameter of the hypoid pinion 4 formed integrally with a small capacity motor 1 is liable to be necessarily made smaller. Accordingly, preferably, the strength level (for example, contact stress of tooth) of each hypoid gear set can be almost equally secured. In addition, a large outside diameter d2 of the hypoid pinion 104 corresponds to the large capacity motor 101. Also, a small outside diameter dl of the hypoid pinion 4 corresponds to a small capacity motor 1. However, since the reduction ratio is liable to be low for the large capacity motor 101, and to be high for the small capacity motor 1, it is possible to make almost constant the outline D1 (D2) of the hypoid gear 5 (105). The distance A1 (A2) between the center C of the hypoid gear 5 (105) and the bearing 13 (113) on the motor load side is larger for the large capacity motor 101, and smaller for the small capacity motor 1. However, since the motor cover 14 (114) is formed separately from the gear box 2 (102), it is possible to make constant the distance B1 (B2) between the hypoid gear 5 (105) and the mounting surface 16 (116) by adjusting the size of the motor cover 14 (114). Thus, it is possible to combine various motors 1 and 101 different in dimension and capacity with one gear box 2 (102) (the gear boxes 2 and 102 are identical with each other) while keeping the required strength level. Further, it is possible to use in common the parallel shaft gear trains 21 (121) in its first step. The gear box 2 (102) has a housing for holding the bearing for a third-step intermediate shaft 109, to contain either two-step type or three-step type of the gear train including the hypoid gear set 20 (120). In using the two-step type gear train, the intermediate shaft 109 is not used. In addition, in this embodiment, for example, by taking the reduction ratio of the hypoid gear set 20 for a small capacity motor 1 as 10, and the reduction ratio of the hypoid gear set 120 for a large capacity motor 101 as 5, in the case of using such a parallel gear train as obtaining the total reduction ratio of 80, 100 and 120, it is possible to obtain the total reduction ratio of 40, 50 and 60 by the combination of the parallel gear train with the large capacity motor. Incidentally, in the present invention, there may be prepared another series of gear motors using the gear boxes different in the mounting methods (foot mounting type, flange mounting type, and hollow-shaft type and the like described above). Further, each series is constituted of the frame number group, and the combination of the motor and the reduction ratio for each frame number is unified irrespective of the mounting methods. With this arrangement, the present invention is made further effective. Another embodiment based on this thought will be shown in Fig. 4 to 13. Fig. 4 shows an example, wherein the embodiment of Fig. 2 is applied to another gear box 102b different in the output direction of the output shaft, and the hypoid gear with a large capacity and a low reduction ratio is used. Fig. 5 shows an example, wherein the parallel gear train 21 combined with the hypoid gear set 20 with a small capacity and a high reduction ratio is left as it is, and the hypoid gear set 20b is exchanged to that with a large capacity and a low reduction ratio, thereby changing the total reduction ratio and the output torque. Fig. 6 shows an example, wherein the present invention is applied to the gear box 102c of a foot mounting type and a small capacity motor I is combined with a large reduction ratio gear box 102c. Fig. 7 is an axial sectional view showing the arrangement of the gear train of Fig. 6. Fig. 8 is a development of an embodiment of combining a large capacity motor 101 with the gear box 102c of a foot mounting type. Fig. 9 is an axial sectional view showing an arrangement of the gear train of Fig. 8. Fig. 10 is a development of an embodiment of combining a small capacity motor 1 with the high reduction ratio gear train wherein the present invention is applied to the hollow shaft type gear box 102d. Fig. 11 is an axial sectional view showing an arrangement of the gear train of Fig. 10. Further, Fig. 12 is a development of the gear train wherein a large capacity motor 101 is applied to the gear box 102d of a hollow-shaft type as shown in Fig. 10. Fig. 13 is an axial sectional view showing an arrangement of the gear train of Fig. 12. Thus, even in the series of the reducers different in the mounting methods, it is preferable to unify the combination of the motors and the reduction ratios in each frame number of each series. With this construction, in the case of the same combination of the motor and the reduction ratio, the gear box of an arbitrary series (gear box of an arbitrary mounting method) can be selected among all types of the series. Thus, the effect of the present invention can be optimized to the maximum. In other words, it is possible to use in common the motors to be combined with the gear boxes different in the mounting method.

Claims: A series of gear motors with an orthogonal gear reducer, each gear motor comprising a motor (1, 101) with a motor-shaft (3, 103) and a gear box (2, 102, 102b, 102c, 102d) having an output shaft (12, 112) disposed to be orthogonal to said motor-shaft (3, 103), wherein said gear box at least contains a hypoid gear set including a hypoid pinion (4, 104) formed on the motor-shaft (3, 103), and a hypoid gear (5, 105) mounted on a shaft (6, 106) which is disposed by an axial shift (el, e2) eccentrically and orthogonal to said motor shaft (3, 103), wherein said series is constituted by a collection of sub-series (A, B, C...), in each of which the gear reducers have the same fitting dimensions required to be mounted on mating machines while being different in the reduction ratio extending from a low reduction ratio range to a high reduction ratio range, a motor cover (14, 114) is provided separately from said gear box on a mounting surface (16, 116) thereof to mount said motor (1, 101) separable from said gear box, the positioning between said separable motor cover (14, 114) and said gear box is achieved by spigot-joining said motor cover (14, 114) to said mounting surface (16, 116), the following requirements are satisfied in the same sub-series: (1) the fitting dimensions between said motor cover (14, 114) and said gear box while including the dimension of said spigot-joining portion are constant; (2) said axial shift (el, e2) between said hypoid gear (5, 105) and said hypoid pinion (4, 104) is constant; (3) an outside diameter (D1, D2) of said hypoid gear (5, 105) is substantially constant; and (4) a distance (B1, B2) between the center of said hypoid gear (5, 105) and said mounting surface (16, 116) is constant, and wherein a hypoid pinion (4, 104) of a gear reducer having a low reduction ratio is combined with a large capacity motor, and a hypoid pinion (4, 104) of a gear reducer having a high reduction ratio is combined with a small capacity motor, respectively, whereby making it possible to keep the required strength level of said hypoid gear set to be substantially constant and to combine all variants of said motors with one specific gear box. A series of gear motors, according to claim 1, wherein said gear box (2, 102, 102b, 102c, 102d) contains a reducing means besides said hypoid gear set, said reducing means is used in common, and the hypoid gear set is changed in the reduction ratio thereof to change the total reduction ratio of said gear box as a whole. A series of gear motors, according to Claim 1, which further comprises two kinds or more of series using gear boxes being mounted to mating machines by different mounting methods respectively, wherein the combinations of motors (1, 101) and gear boxes (2, 102, 102b, 102c, 102d) in each sub-series of two kinds or more of said series are unified, and in the same combination of a motor and a gear box, a gear box in an arbitrary series can be selected among gear boxes in two kinds or more of said series.

Inventors: ISOZAKI TETSUSHI, KOUNO ISAO, MINEGISHI KIYOJI, OGAMOTO MITSUO, TAKI KATSUMI, ISOZAKI, TETSUSHI, KOUNO, ISAO, MINEGISHI, KIYOJI, OGAMOTO, MITSUO, TAKI, KATSUMI
Applicants: SUMITOMO HEAVY INDUSTRIES, SUMITOMO HEAVY INDUSTRIES, LTD.
Application year: 1993
Main classification: F16H57
IPC codes: F16H3, F16H1, F16H57, H02K7