Electric trolling motor having planetary gear reduction

An electric trolling motor comprising an elongated and generally cylindrical lower unit for housing an electric motor, a gear reduction unit and a propeller, said unit comprising:

• a cylindrical motor housing having an electric motor therein and a motor drive shaft extending rearwardly therefrom and terminating in a rear driving end, said motor housing having an open rear end;
• a cylindrical gear housing located rearwardly of said motor housing and having a complementary shape therewith and abutting against said rear end of said motor housing, said gear housing including a bore and a transverse shoulder at the inner end of said bore, an internal gear ring mounted in said bore and abutting against said shoulder and means extending through said shoulder and threadably engaged in said ring for removably but rigidly securing said ring in said bore and against said shoulder, said gear housing also including a rearwardly extending hub, a rear sleeve thrust bearing mounted centrally in said hub, a propeller shaft rotatably journalled in said rear sleeve thrust bearing and extending through said hub and rearwardly thereof and terminating in a rear threaded end;
• a bearing support located within said bore of said gear housing and extending into said rear end of said motor housing, bolt means removably securing said bearing support in said motor housing, said bearing support having a central and axially extending aperture therethrough, an anti-friction ball bearing assembly mounted in said aperture, and an anti-friction needle bearing assembly mounted in said aperture and abutting against said ball bearing assembly;
• a sun and planetary gear assembly mounted within said gear housing and comprising, a planet gear rear carrier and a planet gear front carrier axially spaced apart and in coaxial alignment with one another, a plurality of planet gears rotatably mounted between said carriers and in circumferentially spaced relationship therearound, shaft means for each of said planetary gears and extending through said rear and front carriers, said gear assembly also including a centrally disposed sun gear in constant mesh with said planet gears, said plant gears also being in constant mesh with said internal gear ring, a front sleeve thrust bearing located in said front carrier and in which said motor shaft is journalled, said front sleeve thrust bearing abutting against said anti-friction needle bearing assembly, a propeller shaft having a detachable connection with said rear carrier and extending through said rear sleeve thrust bearing, a propeller hub detachably secured on the rear end of said propeller shaft, said sun gear and said rear end of said motor shaft forming an axial releasable driving connection therebetween, whereby said electric motor through its drive shaft acts to rotationally drive said gear assembly and consequently said propeller shaft and propeller hub, and the axial forward thrust of a propeller on said propeller hub is absorbed through said gear assembly, said front sleeve thrust bearing and said anti-friction bearing assembly in said bearing support.

An electric trolling motor comprising an elongated and generally cylindrical lower unit for housing an electric motor, a gear reduction unit and a propeller, said unit comprising:

• a cylindrical motor housing having an electric motor therein and a motor drive shaft extending rearwardly therefrom and terminating in a rear driving end, said motor housing having a front end and open rear end;
• a nose housing secured to said front end of said motor housing, a cylindrical gear housing located rearwardly of said motor housing and having a complementary shape therewith and abutting against said rear end of said motor housing, said gear housing including a bore and a transverse shoulder at the inner end of said bore, an internal gear ring mounted in said bore and abutting against said shoulder and means extending through said shoulder and threadably engaged in said ring for removably but rigidly securing said ring in said bore and against said shoulder, said gearing housing also including a rearwardly extending hub, a rear sleeve thrust bearing mounted centrally in said hub, a propeller shaft rotatably journalled in said rear sleeve thrust bearing and extending through said hub and rearwardly thereof and terminating in a rear threaded end;
• a bearing support located within said bore of said gear housing and extending into said rear end of said motor housing, said bearing support being axially separated from said gear ring, bolt means extending through said bearing support and said motor housing and threadably engaged in said nose housing for removably securing said bearing support, said motor housing and said nose housing together;
• second bolt means for removably securing said gear housing to said bearing support;
• said bearing support having a central and axially extending aperture therethrough, an anti-friction ball bearing assembly mounted in said aperture, and an anti-friction needle bearing assembly mounted in said aperture and abutting against said ball bearing assembly;
• a sun and planetary gear assembly mounted within said housing and comprising, a planet gear rear carrier and a planet gear front carrier axially spaced apart and in coaxial alignment with one another, a plurality of planet gears rotatably mounted between said carriers and in circumferentially spaced relationship therearound, a shaft for each of said planetary gears and extending through said rear and front carriers for supporting said planetary gears at each side thereof, each shaft having a removable snap ring to permit ready separation of said carriers, said gear assembly also including a centrally disposed sun gear in constant mesh with said planet gears, said planet gears also being in constant mesh with said internal gear ring, a front sleeve thrust bearing located in said front carrier and in which said motor shaft is journalled, said front sleeve thrust bearing abutting against said anti-friction needle bearing assembly, a propeller shaft having a detachable connection with said rear carrier and extending through said rear sleeve thrust bearing, a propeller hub detachably secured on the rear end of said propeller shaft, said sun gear and said rear end of said motor shaft forming an axial releasable driving connection therebetween, whereby said electric motor through its drive shaft acts to rotationally drive said gear assembly and consequently said propeller shaft and propeller hub, and the axial forward thrust of a propeller on said propeller hub is absorbed through said gear assembly, said front sleeve thrust bearing and said anti-friction bearing assembly in said bearing support.